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1
Bergen, R. D., K. S. Schwartzkopf-Genswein, T. A. McAllister, and A. D. Kennedy. "Effects of feeding time on behaviour, thermoregulation and growth of steers in winter." Canadian Journal of Animal Science 88, no. 3 (September 1, 2008): 369–79. http://dx.doi.org/10.4141/cjas07094.
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Two trials were conducted to determine whether the effects of morning (1000) vs. evening (2000) feed delivery on the frequency and duration of feedbunk visits, thermoregulatory physiology and growth performance of feedlot steers were modified by ambient winter temperatures. Night-time feeding behaviours were more pronounced for evening-fed than for morning-fed cattle during both the forage-based backgrounding and concentrate-based finishing periods. Evening feeding also led to increased core body temperatures during the coldest part of the day during the backgrounding period but had little effect during the finishing period. Although ambient temperatures were similar in both trials, evening feeding improved growth rate and efficiency during the coldest part of the backgrounding period in Trial 1 but not in Trial 2. Feeding time did not affect feedlot performance during the finishing period of either trial. Evening feeding successfully altered feeding behaviours and appeared to improve thermoregulatory status during the coldest part of the backgrounding period, but did not improve growth performance or efficiency. Key words: Beef cattle, thermoregulation, evening feeding, feeding behaviour
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Fourie, L. J., I. G. Horak, and M. R. Perrin. "Activity patterns and feeding behaviour of hyrax (Procavia capensis) in the Mountain Zebra National Park." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 6, no. 3 (March 17, 1987): 118–22. http://dx.doi.org/10.4102/satnt.v6i3.955.
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The activity patterns of marked hyrax in the Mountain Zebra National Park were quantified by direct observations. Extended periods are spent on basking during winter (6,8 h) and summer (5,3 h) respectively. At least 80 % of each day is spent in an inactive phase. The more extended time spent on movement and time spent within refuges during summer (0,4 and 2,7 h), compared to winter (0,2 and 0,9 h), can possibly be interpreted in terms of behavioural thermoregulation. Distinct differences between the feeding behaviour of juveniles (< 6 months) and older hyrax were observed. Foraging of juveniles was limited to a distance of 40 m or less from refuges and took place under the surveilance of adults. Foraging of older hyrax frequently occurred for extended distances (up to 500 m) from refuges. These hyrax frequently visited riparian thickets. Foraging excursions of individual hyrax lasted for 0,5 - 8 h. The reported early and late afternoon group feeding sessions for hyrax older than 5 months could not be confirmed.
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Deeming, D. C. "Effect of Winter Climatic Conditions on the Behaviour of Adult Ostriches (Struthio Camelus) on a British Farm." Animal Welfare 7, no. 3 (August 1998): 307–15. http://dx.doi.org/10.1017/s096272860002073x.
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AbstractOstrich welfare on farms of is great importance, particularly because little is known about appropriate husbandry conditions for these birds in a northern European environment. Rain has been shown to influence the pattern of behaviour during the spring months. This study examined the effects of four different climatic conditions (raining, dull but overcast, bright but overcast and sunny) on the behaviour of ostriches during the winter. Compared with dry conditions, there was a significantly higher rate of sitting during rainy periods — apparently at the expense of foraging (from pasture) and pacing (around the perimeter). The rate of sitting was much lower than that reported for the same birds during rain in the spring. During all climatic conditions, feeding (on concentrate feed provided) and foraging were the most dominant behaviours. Feeding was not significantly affected by rain but the frequency of foraging was reduced. Standing was a common behaviour. There were significant gender differences for standing (males > females) and foraging (females > males). These results show that winter conditions require ostriches to feed and forage at higher rates than during the spring or summer, presumably to consume more energy for thermoregulation. Gender differences in pacing and feeding behaviours previously observed in breeding birds were absent in non-breeding ostriches (presumably because males were not defending territories); although non-breeding males appeared to be more vigilant than females and needed to consume more food. Improvements in ostrich husbandry should take into account the need to provide both adequate shelter and more concentrate rations during the cold weather of winter. Energy requirements will be higher at this time, yet the ability of the birds to forage will be diminished. Without such considerations, ostrich welfare during the winter in northern Europe will be compromised.
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Siefert, Paul, Nastasya Buling, and Bernd Grünewald. "Honey bee behaviours within the hive: Insights from long-term video analysis." PLOS ONE 16, no. 3 (March 17, 2021): e0247323. http://dx.doi.org/10.1371/journal.pone.0247323.
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The combined behaviours of individuals within insect societies determine the survival and development of the colony. For the western honey bee (Apis mellifera), individual behaviours include nest building, foraging, storing and ripening food, nursing the brood, temperature regulation, hygiene and defence. However, the various behaviours inside the colony, especially within the cells, are hidden from sight, and until recently, were primarily described through texts and line drawings, which lack the dynamics of moving images. In this study, we provide a comprehensive source of online video material that offers a view of honey bee behaviour within comb cells, thereby providing a new mode of observation for the scientific community and the general public. We analysed long-term video recordings from longitudinally truncated cells, which allowed us to see sideways into the cells in the middle of a colony. Our qualitative study provides insight into worker behaviours, including the use of wax scales and existing nest material to remodel combs, storing pollen and nectar in cells, brood care and thermoregulation, and hygienic practices, such as cannibalism, grooming and surface cleaning. We reveal unique processes that have not been previously published, such as the rare mouth-to-mouth feeding by nurses to larvae as well as thermoregulation within cells containing the developing brood. With our unique video method, we are able to bring the processes of a fully functioning social insect colony into classrooms and homes, facilitating ecological awareness in modern times. We provide new details and images that will help scientists test their hypotheses on social behaviours. In addition, we encourage the non-commercial use of our material to educate beekeepers, the media and the public and, in turn, call attention to the general decline of insect biomass and diversity.
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Björnsson, Björn. "Thermoregulatory behaviour in cod: Is the thermal preference in free-ranging adult Atlantic cod affected by food abundance?" Canadian Journal of Fisheries and Aquatic Sciences 76, no. 9 (September 2019): 1515–27. http://dx.doi.org/10.1139/cjfas-2018-0305.
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This study supports the hypothesis that well-fed cod (Gadus morhua) seek higher temperatures to increase growth rate, and poorly fed cod select lower temperatures to save metabolic energy. Depth and temperature of free-ranging adult cod (44–79 cm) were studied with data storage tags as part of a ranching project in an Icelandic fjord. Forage fish were regularly provided at four feeding stations where cod formed distinct “herds” (herd cod) that did not mingle much with the rest of the unconditioned cod in the fjord (wild cod). Several parameters (stomach fullness, liver index (fat reserves), condition factor, and growth rate) indicated that food intake was much greater in herd cod than in wild cod. In August, when the thermocline was well established, the herd cod remained in shallow (15–35 m) and warm water (8–10 °C), whereas the wild cod stayed in deep (80–90 m) and cold water (3–4 °C), but occasionally both groups explored depths and temperatures outside their preferred range. After vertical mixing in autumn when thermoregulation was not possible, the depth difference between the two groups decreased significantly.
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Eliason, Chad M., and Julia A. Clarke. "Metabolic physiology explains macroevolutionary trends in the melanic colour system across amniotes." Proceedings of the Royal Society B: Biological Sciences 285, no. 1893 (December 12, 2018): 20182014. http://dx.doi.org/10.1098/rspb.2018.2014.
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Metabolism links organisms to their environment through its effects on thermoregulation, feeding behaviour and energetics. Genes involved in metabolic processes have known pleiotropic effects on some melanic colour traits. Understanding links between physiology and melanic colour is critical for understanding the role of, and potential constraints on, colour production. Despite considerable variation in metabolic rates and presumed ancestral melanic coloration in vertebrates, few studies have looked at a potential relationship between these two systems in a comparative framework. Here, we test the hypothesis that changes in melanosome shape in integumentary structures track metabolic rate variation across amniotes. Using multivariate comparative analyses and incorporating both extant and fossil taxa, we find significantly faster rates of melanosome shape evolution in taxa with high metabolic rates, as well as both colour- and clade-specific differences in the relationship between metabolic rate and melanosome shape. Phylogenetic tests recover an expansion in melanosome morphospace in maniraptoran dinosaurs, as well as rate shifts within birds (in songbirds) and mammals. These findings indicate another core phenotype influenced by metabolic changes in vertebrates. They also provide a framework for testing clade-specific gene expression patterns in the melanocortin system and may improve colour reconstructions in extinct taxa.
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Adelman, James S., Amanda W. Carter, William A. Hopkins, and Dana M. Hawley. "Deposition of pathogenic Mycoplasma gallisepticum onto bird feeders: host pathology is more important than temperature-driven increases in food intake." Biology Letters 9, no. 5 (October 23, 2013): 20130594. http://dx.doi.org/10.1098/rsbl.2013.0594.
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Although ambient temperature has diverse effects on disease dynamics, few studies have examined how temperature alters pathogen transmission by changing host physiology or behaviour. Here, we test whether reducing ambient temperature alters host foraging, pathology and the potential for fomite transmission of the bacterial pathogen Mycoplasma gallisepticum (MG), which causes seasonal outbreaks of severe conjunctivitis in house finches ( Haemorhous mexicanus ). We housed finches at temperatures within or below the thermoneutral zone to manipulate food intake by altering energetic requirements of thermoregulation. We predicted that pathogen deposition on bird feeders would increase with temperature-driven increases in food intake and with conjunctival pathology. As expected, housing birds below the thermoneutral zone increased food consumption. Despite this difference, pathogen deposition on feeders did not vary across temperature treatments. However, pathogen deposition increased with conjunctival pathology, independently of temperature and pathogen load, suggesting that MG could enhance its transmission by increasing virulence. Our results suggest that in this system, host physiological responses are more important for transmission potential than temperature-dependent alterations in feeding. Understanding such behavioural and physiological contributions to disease transmission is critical to linking individual responses to climate with population-level disease dynamics.
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Kukal, Olga. "Winter mortality and the function of larval hibernacula during the 14-year life cycle of an arctic moth, Gynaephora groenlandica." Canadian Journal of Zoology 73, no. 4 (April 1, 1995): 657–62. http://dx.doi.org/10.1139/z95-077.
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Larvae of the arctic moth Gynaephora groenlandica stop feeding and spin silk hibernacula before the peak of summer season in the Canadian High Arctic Archipelago. This study examines the function of these hibernacula in relation to the biotic and abiotic mortality factors of parasitism and temperature. Winter mortality of 10% among larvae in cages on the tundra was compared with previous results on parasitism (56% mortality). Prior to winter, the cages were used to record larval behaviour and the location of hibernacula. The majority of the larvae (81%) spun hibernacula, most of which were concealed between the stems of arctic heather, Cassiope tetragona. Fewer hibernacula were found on the primary host plant, arctic willow, Salix arctica, than on C. tetragona or Dryas integrifolia, which formed the dominant plant cover. Nearly one-half of all the larvae that spun hibernacula made joint hibernacula with other larvae. Frequency of larvae sharing hibernacula declined with increasing numbers of larvae per cage. At low population density about half of the larvae occupied communal hibernacula, whereas only one-quarter of the larvae at high density shared hibernacula. In most cases only 2 larvae spun a common hibernaculum, 3 larvae shared hibernacula less frequently, and greater numbers of larvae were rarely found in a single hibernaculum. Unlike the high excess body temperatures usually achieved through thermoregulation by feeding larvae and pupae, temperatures within hibernacula were nearly identical with those of the surrounding substrate over 18 h and rose < 5 °C during the afternoon. This study suggests that larval hibernacula lower summer and winter mortality of G. groenlandica larvae. Hibernacula are an effective barrier to parasitism, which is the primary mortality factor. Furthermore, the behavioural shift from feeding to spinning hibernacula may prevent energy depletion by inducing metabolic depression during mid to late summer, which may be essential for winter survival.
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Briggs, Allan. "Roosting and breeding behaviour of Tawny Frogmouths Podargus strigoides in central-coastal Queensland." Australian Field Ornithology 40 (2023): 70–76. http://dx.doi.org/10.20938/afo40070076.
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The roosting and breeding behaviour of a pair of Tawny Frogmouths Podargus strigoides was observed on the central Queensland coast over a period of 4 years (2018–2021). The study was conducted in a subtropical climate near Rockhampton, and provides data from a different geographical and climatic area compared with previous studies that were conducted in temperate southern Australia (New England Tablelands, Moree, and Sydney, New South Wales, and the Australian Capital Territory). Breeding data matched other studies: breeding in November–December, incubation of 28–30 days, fledging at 27–31 days, care of fledglings from 1–3 months, nests located in a horizontal fork of a tree on the edge of a clearing. Breeding success was high at 80% (8 of 10 nestlings survived). Roost sites were generally in tree species with a fibrous dark bark that provided camouflage, and were mostly within the leafy canopy (average height 9.11 m above ground), which provided protection from high daytime temperatures in both winter and summer. Only early in the morning on very cool days in winter did Frogmouths seek lower perches where sun exposure was greatest. These findings are consistent with other studies identifying thermoregulation and camouflage as important determinants of roost selection, although the need for greater sun exposure in winter was much lower in this study, reflecting the generally warm winter days. Fidelity to roost trees was high (90% of roosts were in four trees) and Frogmouths nested in a different tree each year. Both roosts and nests were confined to a home range of 1.6 ha. The frequency of feeding increased with nestling age, and was higher during the early part of the night. Overall, these findings advance understanding of the breeding biology of the Tawny Frogmouth in subtropical Australia.
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di Virgilio, Agustina, Juan M. Morales, Sergio A. Lambertucci, Emily L. C. Shepard, and Rory P. Wilson. "Multi-dimensional Precision Livestock Farming: a potential toolbox for sustainable rangeland management." PeerJ 6 (May 30, 2018): e4867. http://dx.doi.org/10.7717/peerj.4867.
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Background Precision Livestock Farming (PLF) is a promising approach to minimize the conflicts between socio-economic activities and landscape conservation. However, its application on extensive systems of livestock production can be challenging. The main difficulties arise because animals graze on large natural pastures where they are exposed to competition with wild herbivores for heterogeneous and scarce resources, predation risk, adverse weather, and complex topography. Considering that the 91% of the world’s surface devoted to livestock production is composed of extensive systems (i.e., rangelands), our general aim was to develop a PLF methodology that quantifies: (i) detailed behavioural patterns, (ii) feeding rate, and (iii) costs associated with different behaviours and landscape traits. Methods For this, we used Merino sheep in Patagonian rangelands as a case study. We combined data from an animal-attached multi-sensor tag (tri-axial acceleration, tri-axial magnetometry, temperature sensor and Global Positioning System) with landscape layers from a Geographical Information System to acquire data. Then, we used high accuracy decision trees, dead reckoning methods and spatial data processing techniques to show how this combination of tools could be used to assess energy balance, predation risk and competition experienced by livestock through time and space. Results The combination of methods proposed here are a useful tool to assess livestock behaviour and the different factors that influence extensive livestock production, such as topography, environmental temperature, predation risk and competition for heterogeneous resources. We were able to quantify feeding rate continuously through time and space with high accuracy and show how it could be used to estimate animal production and the intensity of grazing on the landscape. We also assessed the effects of resource heterogeneity (inferred through search times), and the potential costs associated with predation risk, competition, thermoregulation and movement on complex topography. Discussion The quantification of feeding rate and behavioural costs provided by our approach could be used to estimate energy balance and to predict individual growth, survival and reproduction. Finally, we discussed how the information provided by this combination of methods can be used to develop wildlife-friendly strategies that also maximize animal welfare, quality and environmental sustainability.
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Lactin, Derek J., and Dan L. Johnson. "ENVIRONMENTAL, PHYSICAL, AND BEHAVIOURAL DETERMINANTS OF BODY TEMPERATURE IN GRASSHOPPER NYMPHS (ORTHOPTERA: ACRIDIDAE)." Canadian Entomologist 130, no. 5 (October 1998): 551–77. http://dx.doi.org/10.4039/ent130551-5.
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AbstractWe describe a model which estimates grasshopper body temperature (Tb) by linking energy-flow equations with empirical descriptions of aboveground gradients of air temperature (Ta) and wind speed. The model was tested using restrained grasshopper nymphs; estimated and observed Tb agreed well (r2 > 0.81). At a rangeland site near Lethbridge, Alberta, Canada (49 °42′N, 112 °48′W), we observed 315 free-living grasshoppers. We recorded the shadow each cast on a horizontal surface, then reconstructed their orientation to the sun by geometric analysis. We used the model to estimate their Tb and the range and frequency of possible Tb within their environment. Modelled Tb exceeded Ta, and was generally lower than the modelled maximum possible Tb, but was well correlated with Tb of insects on top of the dense layer of vegetation which pervaded the site. This observation suggests that behaviours which elevate Tb are constrained by environmental barriers. Tb exceeded the value expected if insects were located and oriented randomly within their environment (mean difference = 3.95 °C, SE = 0.115); this is unequivocal evidence for behavioural thermoregulation. Heuristic simulations using temperature-dependent developmental- and feeding-rate equations for Melanoplus sanguinipes (Fabricius) suggest that thermoregulatory behaviour increased these rates by 30–40% compared with those for insects located and oriented randomly within their environment. During this study, population processes were never inhibited by excess heat; therefore any climatic warming at the experimental site will probably accelerate the phenology of these grasshopper species. Effects at other sites may differ; the model can be applied to test this possibility.
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Faulkner, Patricia C., David Hala, Jessica Shimskie, Rachel Johnson, Anna Schneider, Taylor Cubbage, Nicolette Lozano, and Lene H. Petersen. "Juvenile American Alligators (Alligator mississippiensis) Use Behavioral Thermoregulation to Cope with Dehydration and Salt-Loading when Chronically Exposed to 12 ‰ Saltwater." Animal Behavior and Cognition 10, no. 1 (February 1, 2023): 1–13. http://dx.doi.org/10.26451/abc.10.01.01.2023.
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American alligators (Alligator mississippiensis) are native to freshwater habitats in the Southeastern United States. These areas are susceptible to salinity increases due to extreme weather events (e.g., hurricanes) and climate change. The goal of this study was to investigate behaviors in juvenile alligators exposed to 12‰ saltwater for five weeks. Sixteen alligators were maintained in an experimental tank with 90 L of water and a heat lamp overhanging a basking plate. Observations were conducted in freshwater (prior to exposure to saltwater) and over the course of 5 weeks in 12‰ saltwater. This allowed for comparison of behaviors in freshwater and in saltwater in the same group of animals. Behaviors related to thermoregulation (basking and staying in the water) and feeding were recorded via instantaneous sampling, in which sampling intervals of 1 min occurred throughout a 20 min observation period. Saltwater-exposed alligators reduced foraging and feeding within the first week of saltwater exposure and spent significantly less time basking compared with freshwater observations. Furthermore, significantly fewer animals chose to bask over the course of 5 weeks in saltwater. A novel behavior, never seen in freshwater, was the closing of the outer eyelids when alligators were in the saltwater. Collectively, the present study demonstrates that chronic saltwater exposure has significant impact on the thermoregulatory behavior in juvenile alligators concomitantly exposed to dehydration and salt-loading without access to freshwater. As alligator hatchlings emerge during peak hurricane season, the survivability of hatchlings may be compromised if access to freshwater is unattainable.
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Mekonnen, Addisu, Peter J. Fashing, Vivek V. Venkataraman, Colin A. Chapman, Nils Chr Stenseth, and R. Adriana Hernandez-Aguilar. "Sleeping Site and Tree Selection by Bale Monkeys (Chlorocebus djamdjamensis) at Kokosa Forest Fragment in Southern Ethiopia." International Journal of Primatology 42, no. 6 (November 4, 2021): 915–32. http://dx.doi.org/10.1007/s10764-021-00251-1.
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AbstractAlthough selecting advantageous sleeping sites is crucial for nonhuman primates, the extent to which different factors contribute to their selection remains largely unknown for many species. We investigated hypotheses relating to predator avoidance, food access, and thermoregulation to explain the sleeping behavior of Bale monkeys (Chlorocebus djamdjamensis) occupying a degraded fragmented forest, Kokosa, in the southern Ethiopian Highlands. We found that the study group reused 11 out of 20 sleeping sites used during the 42 study days over a 6-month period. Sleeping sites were usually close to the last feeding trees of the day (mean distance =15.2 m) and/or the first feeding trees of the next morning (mean distance = 13.5 m). This may reflect an attempt to maximize feeding efficiency and reduce travel costs. Compared to the mean trees in the study area, sleeping trees were significantly shorter. Bale monkeys selected sleeping places in trees with high foliage density above and below them, lending support to the hypothesis that they select sleeping places that can conceal them from predators and at the same time offer shelter from cold weather. The monkeys also frequently huddled at night. Our results suggest that predator avoidance, access to food resources, and thermoregulation all likely influence the selection of sleeping sites by Bale monkeys.
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Yakimova, Krassimira S., Rumen P. Nikolov, Ivan G. Todorov, and Milen H. Hristov. "Leptin and Gaba Interactions on Thermoregulation of Rats." Journal of Biomedical and Clinical Research 7, no. 1 (November 1, 2014): 20–24. http://dx.doi.org/10.1515/jbcr-2015-0120.
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Abstract Leptin inhibits feeding, reduces body weight and increases thermogenesis. Experimental data suggest involvement of GABAergic mechanisms in the regulation of feeding behavior and energy balance. The present study was set to determine the effect of combinations from leptin, GABAB-agonist baclofen and GABAB-antagonist CGP35348 on thermoregulation of male Wistar rats, using in vivo and in vitro experiments. The substances used for in vivo experiments were administered intraperitoneally (i.p.). The measurement of the body temperature was done via thermistor probes (TX8) and monitored on multichannel recorder Iso-Thermex16. In vitro experiments were conducted on rat PO/AH neurons, recorded extracellulary by conventional electrophysiological equipment, using brain slice preparations. The separate intraperitoneal injection of leptin as well as GABAB-antagonist CGP35348 produced significant hyperthermia in rats while the GABAB-agonist baclofen caused a decrease in the core body temperature. The probable synergy between the hyperthermic effects of leptin and GABAB-antagonist did not occur. On the contrary, the effect of this combination was lower as compared to the result of the separate administration of GABAB-antagonist. When leptin was applied just prior to GABAB-agonist baclofen, neither of their separate effects appeared. In vivo effects determined correlated with in vitro changes of firing rate observed in PO/AH neurons. The data from this study provide a new point of view concerning the interactions of leptin and GABA on the level of thermoregulation. These results represent a step forward in understanding the complicated mechanisms involved in thermoregulation.
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KUKAL, OLGA, BERND HEINRICH, and JOHN G. DUMAN. "Behavioural Thermoregulation in the Freeze-Tolerant Arctic Caterpillar, Gynaephora Groenlandica." Journal of Experimental Biology 138, no. 1 (September 1, 1988): 181–93. http://dx.doi.org/10.1242/jeb.138.1.181.
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Larvae of the high arctic caterpillar, Gynaephora groenlandica (Wöcke) (Lepidoptera: Lymantriidae) spent most (60 %) of their time orienting towards the sun (i.e. basking) and only 20% feeding, primarily near midday. Larvae usually basked after feeding, then either fed again or moved to a new feeding site. Basking larvae reached their highest body temperatures (Tb) of ≊30°C (≊20°C in excess of the ambient temperature) when surrounded by snow on a calm day in the midday sun. Setae significantly decreased larval cooling rates. Maximal metabolic rates were attained in basking larvae, but at body temperatures below 10°C oxygen uptake was greatly reduced. Our studies indicate that G. groenlandica larvae are behaviourally adapted to utilize available solar radiation for growth and development.
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Werth, Alexander J. "Adaptations of the cetacean hyolingual apparatus for aquatic feeding and thermoregulation." Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology 290, no. 6 (2007): 546–68. http://dx.doi.org/10.1002/ar.20538.
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Iigaya, Kamon, Yoshino Minoura, Hiroshi Onimaru, Sayumi Kotani, and Masahiko Izumizaki. "Effects of Feeding-Related Peptides on Neuronal Oscillation in the Ventromedial Hypothalamus." Journal of Clinical Medicine 8, no. 3 (March 1, 2019): 292. http://dx.doi.org/10.3390/jcm8030292.
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The ventromedial hypothalamus (VMH) plays an important role in feeding behavior, obesity, and thermoregulation. The VMH contains glucose-sensing neurons, the firing of which depends on the level of extracellular glucose and which are involved in maintaining the blood glucose level via the sympathetic nervous system. The VMH also expresses various receptors of the peptides related to feeding. However, it is not well-understood whether the action of feeding-related peptides mediates the activity of glucose-sensing neurons in the VMH. In the present study, we examined the effects of feeding-related peptides on the burst-generating property of the VMH. Superfusion with insulin, pituitary adenylate cyclase-activating polypeptide, corticotropin-releasing factor, and orexin increased the frequency of the VMH oscillation. In contrast, superfusion with leptin, cholecystokinin, cocaine- and amphetamine-regulated transcript, galanin, ghrelin, and neuropeptide Y decreased the frequency of the oscillation. Our findings indicated that the frequency changes of VMH oscillation in response to the application of feeding-related peptides showed a tendency similar to changes of sympathetic nerve activity in response to the application of these substances to the brain.
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Rollo, C. D., M. Lai, K. Whitehead, M. L. Perreault, J. Lemon, and A. M. Chaudhry. "Thermoregulation of transgenic growth hormone mice." Canadian Journal of Zoology 82, no. 6 (June 1, 2004): 934–49. http://dx.doi.org/10.1139/z04-052.
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Transgenic growth hormone (TG) mice (Mus musculus L., 1758) obtain enhanced growth via compensatory feeding at intermediate sizes and via higher growth efficiency. The latter involves diverting resources from other functions such as locomotion and wakefulness. Thermogenesis is a major expense for small mammals, so we explored whether TG mice express a trade-off between growth and thermoregulation. TG mice are hypothermic and cannot maintain their body temperature under cold stress. TG mice showed initial enlargement of brown adipose tissue and subsequent age-related decreases not seen in controls. Some TG mice became torpid after fasting durations not known to affect other mice. On a high-calorie diet, TG mice had higher body temperatures even though controls did not. Our background strain developed obesity on a high-protein and high-fat diet, and on a diet supplemented with carbohydrates, whereas TG mice never developed obesity. White adipose tissue deposits of TG females were relatively larger, but those of TG males were relatively smaller, than those of controls fed standard food. We also found significant effects of the three experimental diets, as well as gender, age, body mass, ambient temperature, and behavioural activity, on rectal temperatures of TG mice and controls in a large breeding colony. Thermogenesis of TG mice fed standard food appears energetically constrained, likely contributing to enhanced growth efficiency.
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Lactin, Derek J., N. J. Holliday, and L. L. Lamari. "FEEDING BY COLORADO POTATO BEETLE LARVAE (COLEOPTERA: CHRYSOMELIDAE) IN FIELD CAGES: MEASUREMENTS AND A MODEL." Canadian Entomologist 127, no. 4 (August 1995): 479–92. http://dx.doi.org/10.4039/ent127479-4.
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AbstractFeeding rates of Colorado potato beetle larvae were measured in 24-h trials in small field cases on potato leaflets that remained attached to the plants. Four models were constructed to explain the results; these differed by including or excluding the effect of insolative heating on larval body temperature, and by including or excluding thermoregulatory behavior, in all combinations. In all instars, observed feeding was independent of mean body temperature during the trial as estimated by each model, and less than the amount predicted using this mean to drive constant-temperature feeding rate functions.The four models were assessed by regressing model predictions on observed feeding rates. For first and second instars, there was no relationship between observed feeding and the amount predicted by any of the models, probably because the feeding rate was small relative to the precision of the measurements. For third and fourth instars, predictions from the model that included both insolative heating and behavioral thermoregulation did not differ significantly from observations. Simulations using this model suggested that daily mean body temperature fails to predict foliage consumption because this mean cannot account for the effects of transient occurrences of suboptimal temperatures.
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Hori, Tetsuro, Toshikazu Kiyohara, Toshihiro Nakashima, Masaaki Shibata, and Hisao Koga. "Multimodal responses of preoptic and anterior hypothalamic neurons to thermal and nonthermal homeostatic parameters." Canadian Journal of Physiology and Pharmacology 65, no. 6 (June 1, 1987): 1290–98. http://dx.doi.org/10.1139/y87-205.
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The hypothesis that thermosensitive neurons in the preoptic anterior hypothalamic nuclei (POAH) have a principal role in central thermoregulation is based on numerous findings, suggesting correlations between the activity of thermosensitive neurons and thermoregulatory responses. Such relationships have been observed during thermal (local and peripheral) and pharmacological stimulation, during modulation of neural inputs from extra-POAH brain regions, and during actual thermoregulatory responses. Recent studies using in vitro slice preparations and conscious animals have revealed that 40–70% of POAH thermosensitive neurons respond to nonthermal homeostatic parameters such as local osmolality, blood pressure, and nonthermal emotional stimuli. About two-thirds of the POAH thermosensitive neurons, which responded in monkeys during bar press thermoregulatory tasks, changed their activity during bar press feeding behavior. A high degree of convergence of thermal and nonthermal homeostatic signals on the POAH neurons, together with abundant neural connections between the POAH and divergent areas of the brain, suggests that POAH thermosensitive neurons may be involved in the coordination of thermoregulation and nonthermal autonomic and behavioral responses controlled from the hypothalamus.
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Nobre, Ismael De Sousa, Gherman Garcia Leal de Araújo, Edson Mauro Santos, Gleidson Giordano Pinto de Carvalho, Bonifácio Benicio de Souza, Ossival Lolato Ribeiro, Silvia Helena Nogueira Turco, Anderson Barbosa Cavalcante, and Italo Reneu Rosas de Albuquerque. "Ingestive behavior and thermoregulation in sheep fed forage cactus silage undergoing intermittent water supply." Semina: Ciências Agrárias 39, no. 4 (August 2, 2018): 1683. http://dx.doi.org/10.5433/1679-0359.2018v39n4p1683.
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This study aimed to assess the effect of using forage cactus silage in the diet of sheep under intermittent water supply on its ingestive behavior and thermoregulation. We used in the experiment thirty-six intact male sheep of undefined genotype with an initial average weight of 19.8 ± 2.1 kg and age of approximately six months. The experimental design was a randomized block design in a 3 × 3 factorial scheme composed of three levels of forage cactus silage in the diet (0, 21, and 42%), three water supply periods (0, 24, and 48 hours), and four replications. For the ingestive behavior, observations were carried out every 5 minutes for 2 periods of 24 hours. Thermoregulatory responses were taken at 7:00 and 15:00 h on days other than those intended for ingestive behavior tests. Intermittent water supply did not affect any of the studied variables (P > 0.05). The use of forage cactus silage significantly influenced the ingestive behavior of animals (P < 0.05). Sheep fed forage cactus silage in the diet presented an average feeding efficiency of 255.77 g DM h?1 and an average rumination efficiency of 102.16 g DM h?1, while animals fed control diet showed values of 198.63 and 78.45 g DM h?1, respectively. Urinary frequency increased according to the levels of forage cactus silage in the diet, with 23.60 urination per day in animals fed diets with 42% of forage cactus silage and 10.83 urination per day in animals fed control diet. However, the search for water reduced, with averages of 2.73 and 0.54 per day for animals fed 0 and 42% forage cactus silage, respectively. The use of forage cactus silage also increased thermoregulatory responses of sheep, with an average respiratory rate of 103.35 mov. min?1 and heart rate of 140.08 mov. min?1 in the warmest period of the day (in the afternoon). Thus, sheep fed forage cactus silage increases its feeding and rumination efficiencies, decreases its search for water, and increases its thermoregulatory responses. The intermittent water supply within 48 hours does not influence the ingestive behavior and thermoregulation of confined sheep.
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Westbury, Becky. "Baby hats at birth: help or hindrance?" Practising midwife 25, no. 10 (November 1, 2022): 32–34. http://dx.doi.org/10.55975/fhev5889.
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Hats are placed on many babies during initial skin-to-skin contact. Thermoregulation of the newborn is an important consideration of midwifery care, however skin-to-skin contact is arguably the most important element of this, and hats for term babies in skin-to-skin don’t aid temperature maintenance. Skin-to-skin also reduces postpartum haemorrhages and increases oxytocin. Whilst hats are beneficial for preterm babies, they may impede instinctive feeding and bonding behaviours for term babies and prevent parents from smelling and kissing their baby’s head. Therefore, individualised consideration and discussion with parents may be preferable to routine use of hats at birth for healthy term babies.
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Chessman, Bruce C. "Behavioural thermoregulation by Australian freshwater turtles: interspecific differences and implications for responses to climate change." Australian Journal of Zoology 67, no. 2 (2019): 94. http://dx.doi.org/10.1071/zo20004.
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The abilities of freshwater turtles to control their body temperatures by behavioural means have implications for activity, food ingestion and digestion, growth, reproduction and potential responses to climate change. I compared various forms of basking in nature, and responses to aquatic and aerial photothermal gradients in the laboratory, among three species of Australian chelid turtles: Chelodina expansa, C. longicollis and Emydura macquarii. Proclivity for behavioural thermoregulation varied substantially among these species, being highest in C. longicollis and lowest in C. expansa. However, C. expansa had a thermophilic response to feeding. For C. longicollis and E. macquarii, behavioural thermoregulation may enhance colonisation of more southerly latitudes or higher elevations as climatic warming proceeds. However, increasing air temperatures may pose a hazard to turtles dispersing or sheltering terrestrially (for example, when water bodies dry during drought). C. longicollis appears the best placed of the three species to avoid this hazard through its abilities to thermoregulate behaviourally and to aestivate in terrestrial microenvironments that are buffered against temperature extremes.
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Telliez, Frédéric, Véronique Bach, André Leke, Karen Chardon, and Jean-Pierre Libert. "Feeding behavior in neonates whose diet contained medium-chain triacylglycerols: short-term effects on thermoregulation and sleep." American Journal of Clinical Nutrition 76, no. 5 (November 1, 2002): 1091–95. http://dx.doi.org/10.1093/ajcn/76.5.1091.
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Jensen, Paul G., Peter J. Pekins, and James B. Holter. "Compensatory effect of the heat increment of feeding on thermoregulation costs of white-tailed deer fawns in winter." Canadian Journal of Zoology 77, no. 9 (November 15, 1999): 1474–85. http://dx.doi.org/10.1139/z99-111.
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For northern white-tailed deer (Odocoileus virginianus) fawns, the energetic cost of thermoregulation (HcE) during severe winters can result in substantial catabolism of body-tissue reserves. The heat increment of feeding (HiE) has the potential to offset thermoregulatory energy expenditure that would otherwise require the catabolism of these reserves. During winters 1996 and 1997, we conducted 18 fasting and 18 on-feed heat-production trials using indirect respiration calorimetry in a metabolic chamber. Nonlinear regression analysis was used to estimate the lower critical temperatures (Tlc) and determine the fasting metabolic rate (FMR) and resting metabolic rate (RMR). Resulting models were used to calculate HiE, HcE, and percent substitution of HiE for HcE. For fawns fed a natural browse diet, estimated FMR and RMR were 352 and 490 kJ·kg body mass (BM)-0.75·d-1, respectively; this 40% increase in thermoneutral heat production reduced Tlc from -0.8 to -11.2°C between the fasted and fed states, respectively, and reduced HcE by 59% for fed fawns. For fawns fed a concentrate diet, estimated FMR and RMR were 377 and 573 kJ·kg BM-0.75·d-1, respectively. Level of browse intake had a significant effect on RMR andTlc. RMR was 12% higher for fawns on a high versus a low level of intake, and estimated Tlc was -15.6 and -5.8°C, respectively. Our data indicate that the energetic cost of thermoregulation is probably a minor portion of the energy budget of a healthy fawn consuming natural forage.
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Schekkerman, Hans, G. Henk Visser, and C. Blem. "Prefledging Energy Requirements in Shorebirds: Energetic Implications of Self-Feeding Precocial Development." Auk 118, no. 4 (October 1, 2001): 944–57. http://dx.doi.org/10.1093/auk/118.4.944.
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Abstract Understanding ecological consequences of avian developmental modes requires knowledge of energy requirements of chicks of different positions in the precocial–altricial spectrum, but those have rarely been measured in birds with self-feeding precocial young. We studied prefledging energy budgets in chicks of Black-tailed Godwit (Limosa limosa) and Northern Lapwing (Vanellus vanellus) in the field and in the laboratory. Lapwings show slower growth than godwits, reaching a 29% lower fledging mass (142 vs. 201 g) in a 32% longer period (33 vs. 25 days). Daily energy expenditure (DEE), measured by the doubly labelled water (DLW) technique, and daily metabolized energy (DEE plus energy deposited into tissue) increased proportionally to body mass at similar levels in both species. Total metabolized energy (TME) over the fledging period was 8,331 kJ in godwits and 6,982 kJ in lapwings, 39 and 29% higher than an allometric prediction (Weathers 1992). That suggests that self-feeding precocial chicks have high energy requirements compared with parent-fed species, due to costs of activity and thermoregulation associated with foraging. Those components made up 50–53% of TME in the shorebirds, more than twice as much as in seven parent-fed species for which DLW-based energy budgets are available. In captive lapwings and godwits growing up under favorable thermal conditions with food readily accessible, thermoregulation and activity costs were 53–58% lower and TME was 26–31% lower than in free-living chicks. The proportion of TME allocated to tissue formation (13–15% deposited as tissue plus 10–12% synthesis costs) was low in the shorebirds, and reductions in food intake may therefore sooner lead to stagnation of growth than in parent-fed chicks. Furthermore, the need to forage limits potential for saving energy by reducing activity in periods of food scarcity, because that will further decrease food intake. Self-feeding precocial chicks thus seem to operate within fairly narrow energetic margins. At the same time, self-feeding may allow birds to use food types that could not be profitably harvested if they had to be transported to the young.
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Wildhaber, Mark L., and Larry B. Crowder. "Testing a Bioenergetics-Based Habitat Choice Model: Bluegill (Lepomis macrochirus) Responses to Food Availability and Temperature." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 9 (September 1, 1990): 1664–71. http://dx.doi.org/10.1139/f90-190.
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Using an automated shuttlebox system, we conducted patch choice experiments with 32, 8–12 g bluegill sunfish (Lepomis macrochirus) to test a behavioral energetics hypothesis of habitat choice. When patch temperature and food levels were held constant within patches but different between patches, we expected bluegill to choose patches that maximized growth based on the bioenergetic integration of food and temperature as predicted by a bioenergetics model. Alternative hypotheses were that bluegill may choose patches based only on food (optimal foraging) or temperature (behavioral thermoregulation). The behavioral energetics hypothesis was not a good predictor of short-term (from minutes to weeks) patch choice by bluegill; the behavioral thermoregulation hypothesis was the best predictor. In the short-term, food and temperature appeared to affect patch choice hierarchically; temperature was more important, although food can alter temperature preference during feeding periods. Over a 19-d experiment, mean temperatures occupied by fish offered low rations did decline as predicted by the behavioral energetics hypothesis, but the decline was less than 1.0 °C as opposed to a possible 5 °C decline. A short-term, bioenergetic response to food and temperature may be precluded by physiological costs of acclimation not considered explicitly in the behavioral energetics hypothesis.
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Jenssen, Bjørn Munro, Morten Ekker, and Claus Bech. "Thermoregulation in winter-acclimatized common eiders (Somateria mollissima) in air and water." Canadian Journal of Zoology 67, no. 3 (March 1, 1989): 669–73. http://dx.doi.org/10.1139/z89-096.
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Metabolic heat production, body temperature, and skin temperatures of the back and breast were measured and the thermal conductance, and thus insulation, estimated in winter-acclimatized common eiders (Somateria mollissima) exposed to air and water. When exposed to low air temperatures, the plumage was responsible for most of the insulation. When exposed to water, the insulation in the plumage was reduced. This decrease was, however, compensated through increased peripheral vasoconstriction. A low total thermal conductance lowers the energetic costs of existence in cold environments. This reduces the nutritional demands, and may be an adaptation to living in polar and subpolar regions where temperatures are low and where the short day length during winter may reduce the time available for feeding.
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Welch,, Kenneth C., and Raul K. Suarez. "Altitude and temperature effects on the energetic cost of hover-feeding in migratory rufous hummingbirds, Selasphorus rufus." Canadian Journal of Zoology 86, no. 3 (March 2008): 161–69. http://dx.doi.org/10.1139/z07-127.
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During migratory stopovers, rufous hummingbirds ( Selasphorus rufus (Gmelin, 1788)) can achieve high daily rates of net energy intake and mass gain while foraging at a range of elevations and ambient temperatures, despite the high energetic costs of hovering flight and thermoregulation. To gain insights into the factors affecting the energetic costs incurred during foraging, we captured migratory hummingbirds and measured their oxygen consumption rates during hover-feeding. Measurements were performed in situ where rufous hummingbirds forage as they migrate at several locations along a gradient in elevation and over the range of ambient temperatures normally experienced. Oxygen consumption rates during hover-feeding varied between the sexes and between juveniles and adults. These differences appeared to reflect differences in the power requirements for hovering flight in relation to variation in wing morphology. Decreasing ambient temperature and increasing elevation both significantly increased oxygen consumption rate during hover-feeding. The effects of these two environmental variables were additive, suggesting that hummingbird thermoregulatory requirements were not met by the additional heat produced by the higher metabolic rate necessary to support hovering flight at higher elevation. These results provide insight into the ways different foraging strategies may allow hummingbirds to maximize net energy intake.
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Gregory, Patrick T., Lisa H. Crampton, and Kristina M. Skebo. "Conflicts and interactions among reproduction, thermoregulation and feeding in viviparous reptiles: are gravid snakes anorexic?" Journal of Zoology 248, no. 2 (June 1999): 231–41. http://dx.doi.org/10.1111/j.1469-7998.1999.tb01199.x.
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Hawkins, P., P. Butler, A. Woakes, and G. Gabrielsen. "Heat increment of feeding in Brunnich's guillemot." Journal of Experimental Biology 200, no. 12 (January 1, 1997): 1757–63. http://dx.doi.org/10.1242/jeb.200.12.1757.
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The rate of oxygen consumption (O2), respiratory quotient (RQ) and deep body temperature (TB) were recorded during a single, voluntary ingestion of Arctic cod Boreogadus saida (mean mass 18.9+/-1.1 g, s.e.m., N=13) by five postabsorptive Brunnich's guillemots (thick-billed murre, Uria lomvia). The birds were resting in air within their thermoneutral zone, and the fish were refrigerated to 0-2 degreesC. The rate of oxygen consumption increased by a factor of 1.4 during the first few minutes after ingestion, but there was no significant change in TB. Mean rate of oxygen consumption returned to preingestive levels 85 min after the birds ate the fish. The telemetered temperature of one fish reached TB within 20 min. This suggests that the persistent elevation in O2 over the next hour corresponded to the obligatory component of the heat increment of feeding (HIF) and was not related to heating the fish. Abdominal temperature increases after diving bouts in free-ranging common guillemots (common murre, Uria aalge) are possibly achieved through the HIF, since meals are processed at sea. Of the increase in O2 measured in the laboratory, it is calculated that 30 % is required to heat the fish, while 70 % is due to the HIF. In free-ranging birds, the excess heat provided by the HIF could contribute 6 % of the daily energy expenditure. This suggests that the HIF augments heat production in Uria spp. and thus reduces the energetic cost of thermoregulation.
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Gregory, Patrick T. "Feeding, Thermoregulation, and Offspring Viability in Gravid Garter Snakes (Thamnophis sirtalis): What Makes Laboratory Results Believable?" Copeia 2001, no. 2 (May 2001): 365–71. http://dx.doi.org/10.1643/0045-8511(2001)001[0365:ftaovi]2.0.co;2.
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Moosa, M. Y. H., and F. Y. Jeenah. "Orexin - does it have a role in mental illness?" South African Journal of Psychiatry 14, no. 2 (June 1, 2008): 2. http://dx.doi.org/10.4102/sajpsychiatry.v14i2.159.
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Orexin-A and Orexin-B (also known as hypocretin 1 and 2) are, respectively, 33- and 28-amino acid residue peptides that activate a G-protein-coupled ‘orphan’ receptor, i.e. which has no known ligand. Immuno-cytochemical studies show that orexin-positive neurons are located in the lateral hypothalamic area and arcuate and perifornical nuclei. They are also found in various sites beyond the hypothalamus such as the thalamic paraventricular and reuniens nuclei, locus coeruleus, nucleus of the solitary tract, raphe and septal nuclei. The hypothalamus has a major role in regulating various behaviours that contribute to homeostasis (such as arousal, feeding, and thermoregulation) by integrating external and internal stimuli. It is involved in the regulation of nutritional status via the co-ordination of many neurotransmitter systems implicated in food intake and energy expenditure. The hypothalamic orexin system directly and strongly innervates and potently excites noradrenergic, dopaminergic, serotonergic, histaminergic and cholinergic neurons. Orexin also has a major role in modulating the release of glutamate and other amino acid transmitters. This widespread distribution and effect of orexin on multiple neurotransmitters suggests that it may be implicated in functions other than feeding, viz. other vegetative and neuroendocrine regulations or those related to general arousal states.
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Benoit, Joshua B., Giancarlo Lopez-Martinez, Michael A. Elnitsky, Richard E. Lee, and David L. Denlinger. "Short Note: Increase in feeding by the tick, Ixodes uriae, on Adélie penguins during a prolonged summer." Antarctic Science 21, no. 2 (November 19, 2008): 151–52. http://dx.doi.org/10.1017/s0954102008001685.
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Ixodes uriae White is the only tick species found in Antarctica, and in our research area at Palmer Station it feeds predominantly on Adélie penguins. At the beginning of the summer the ticks leave their off-host aggregation sites, feed on penguins, then subsequently return to their off-host habitats, where they remain until the next summer (Benoit et al. 2007). These ticks have been implicated as a competent vector for Borrelia spirochetes (Olsen et al. 1993) and tick-borne viruses (Nuttall 1984), and are thought to impact development, cause anaemia, alter the thermoregulation, and even lead to the death of penguins (Gauthier-Clerc et al. 1998, Mangin et al. 2003). In this report, we note a striking increase in the number of fed ticks found near Adélie penguin rookeries in 2007 compared to 2006, suggesting that the longer and warmer summer of 2007 may have permitted more ticks to find their hosts. High levels of parasitism could be detrimental to the already declining Adélie penguin populations near Palmer Station (Fraser & Patterson 1997).
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Podhorna, Jana, Cindy Aubernon, Marie Borkovcova, Julien Boulay, Valery Hedouin, and Damien Charabidze. "To eat or get heat: Behavioral trade-offs between thermoregulation and feeding in gregarious necrophagous larvae." Insect Science 25, no. 5 (July 17, 2017): 883–93. http://dx.doi.org/10.1111/1744-7917.12465.
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Mikitová, Barbora, Martina Šemeláková, and Ľubomir Panigaj. "Wing morphology and eyespot pattern of Erebia medusa (Lepidoptera, Nymphalidae) vary along an elevation gradient in the Carpathian Mountains." Nota Lepidopterologica 45 (July 5, 2022): 233–50. http://dx.doi.org/10.3897/nl.45.68624.
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Butterfly wings play a crucial role during flight, but also in thermoregulation, intraspecific signalling and interaction with predators, all of which vary across different habitat types and may be reflected in wing morphology or colour pattern. We focused on the morphological variability of Erebia medusa in order to examine patterns and variations in the colouration and morphology of wings from areas representing different habitat types with different environmental characteristics. The barrier (larger fragments of forest) between populations of Erebia medusa along the elevation gradient of Kojšovská hoľa might be the aspect that hinders the movement of the population. The wing characteristics (shape, size, spotting) of males representing populations of Carpathian mountain habitats (Volovské vrchy, Ondavská vrchovina) located at different elevations were measured. The forewing shape analysis, using geometric morphometry based on 16 landmarks, showed significant differences between populations from different elevation levels. The pattern of the forewings also varied between populations. Morphological changes among individuals of Erebia medusa populations along the elevation gradient in the Carpathian Mountains showed that in the cold, highland habitats we observed smaller, narrower and elongated forewings with a reduced number of spots, while males from warmer habitats at low elevations had rounder, larger and more spotted forewings. Introduction The ecological role of individual butterfly species is largely reflected in the wings, whose shape, size and colour pattern often have adaptive value and provide information about important differences, even at the population level (Altizer and Davis 2010; Mega 2014). The variability of butterfly wing shape or size, which reflects flight performance (Cespedes et al. 2015; Le Roy et al. 2019a, b), can even provide insight into the suitability of the habitat (Pellegroms et al. 2009; Chazot et al. 2016) and the dispersal rate (Wells et al. 2018; Taylor-Cox et al. 2020). The final wing shape and size of adults depends on conditions of larval development, which can be affected by aggregation behaviour (Allen 2010; Montejo‐Kovacevich et al. 2019; Palmer et al. 2019) but also by environmental conditions (Karl and Fischer 2008; Gibbs et al. 2011; Van Dyck et al. 2016; Palmer et al. 2019). Phenotypic clines along environmental gradients can sometimes be explained by ecological rules, whose use on insects can be debatable (Blanckenhorn and Demont 2004). Bergmann’s rule is the classic ecogeographic principle that relates the body size of endotherms with environmental temperature (or latitude) (Shelomi 2012). The converse of Bergmann’s rule (Park 1949; Mousseau 1997), based on the season length effect, predicts a decrease of body size with elevation. Various clines in body size can also be explained by a combination of several other theories or hypotheses, such as the north-south cline theory (Nylin and Svärd 1991) or the “temperature – size rule” (Angilletta and Dunham 2003). The wing eyespot pattern, which may serve different functions, can also play an irreplaceable role. While the pattern on the dorsal side is usually used for intraspecific communication (Oliver et al. 2009; Westerman et al. 2012; Tokita et al. 2013), the eyespots on the ventral side are rather used to deceive predators by intimidation or deflection by distracting predators from the vital, vulnerable body parts (Lyytinen et al. 2003; Stevens 2005; Stevens et al. 2007; Kodandaramaiah 2011; Prudic et al. 2015; Ho et al. 2016). Moreover, in several butterfly species, wing colour modifications are related to thermoregulation (Dennis and Shreeve 1989; Taylor-Cox et al. 2020). Previous studies (Nice et al. 2005; Jugovic et al. 2018) have demonstrated that populations separated by time, space or geographical barrier may undergo changes in the shape, size and colouration of external traits (Tatarinov and Kulakova 2013). Restrictions of the movement and migration of butterfly species have an impact on the intensity and direction of gene flow between populations (Andrews 2010; Slatkin and Excoffier 2012). Characterisation of the morphological traits of E. medusa, a species inhabiting a wide range of environments, can provide insight into the selection pressures that affect adaptive responses (Cespedes et al. 2015; Taylor-Cox et al. 2020). For the sedentary butterfly Erebia medusa, high intraspecific variability (numerous subspecies) and mosaic distribution throughout most of its Euro-Siberian region is characteristic (Warren 1936; Schmitt et al. 2000; Polic et al. 2014). Our study focused especially on the influence of elevation differences in the Carpathian region on intraspecific variation. For this species, large fragments of forests (Schmitt et al. 2000) may be a serious obstacle for movement. According to the study by Kleckova and Klecka (2016), E. medusa prefers a warm environment, so the adaptations to high elevation habitats needed for the activity of this species can be expected. Lower activity due to low temperature can cause a decrease of chances of escape; therefore, selection will act against some individuals (large sized or with large eyespots) (Dennis et al. 1986). A higher number of eyespots, which are important especially in escape mechanisms, may reflect increased rates of predation with rising temperature (Hillebrand et al. 2009; Vucic-Pestic et al. 2011) but also by sexual selection (Tokita et al. 2013). Based on morphological features (wing size, shape, colour pattern) examined by traditional and geometric morphometry, we focused on the morphological differences between populations from habitats differing in elevation and separated by forest areas. We predicted that the morphological diversity between E. medusa populations would show changes that correlate with the average annual temperature, which varies within the elevation gradient. Our study is based on the hypothesis that i) morphological traits of males (size, shape and pattern of forewings) vary in response to various environmental conditions within an elevation gradient. We also focused on examining whether ii) the forewing size of individuals from higher elevations is smaller than the forewing size of individuals from lower and warmer regions, which induce longer feeding periods during larval development (Juhász et al. 2016). Further, iii) males from higher elevation habitats with lower temperatures were expected to have aerodynamically (narrower, angular) shaped wings that reduce energy costs (Dudley 2002; Lentink et al. 2007; Kovac et al. 2012). Finally, iv) a reduction in the eyespot number with elevation, involving various selection pressures, was expected (Slabý 1950; Tatarinov and Kulakova 2013).
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Davis, R. W., T. M. Williams, J. A. Thomas, R. A. Kastelein, and L. H. Cornell. "The effects of oil contamination and cleaning on sea otters (Enhydra lutris). II. Metabolism, thermoregulation, and behavior." Canadian Journal of Zoology 66, no. 12 (December 1, 1988): 2782–90. http://dx.doi.org/10.1139/z88-406.
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The purpose of this study was to develop a method to clean and rehabilitate sea otters (Enhydra lutris) that might become contaminated during an oil spill and to determine which physiological and behavioral factors were important in restoring the insulation provided by the fur. Tests were conducted on 12 sea otters captured in Alaska and brought to the Sea World Research Institute in San Diego. Measurements of average metabolic rate, core body temperature, behavior, and squalene (the major lipid of sebum) concentration on the fur were made under three conditions: (i) before oiling (base line), (ii) 1–3 days after 20% of the body surface area was covered with fresh crude oil, and (iii) after cleaning. Under base-line conditions in water at 13 °C, average metabolic rate was 8.0 W/kg, core body temperature was 38.9 °C, and whole body thermal conductance was 10.7 W/(m2∙ °C). Otters spent 35% of their time grooming, 45% resting, 10% swimming, and 10% feeding. The squalene concentration on the fur averaged 3.7 mg/g fur. Oiling increased thermal conductance 1.8 times. To compensate for the loss of insulation and maintain a normal core body temperature (39 °C), the otters increased average metabolic rate (1.9 times) through voluntary activity and shivering; the time spent grooming and swimming increased 1.7 times. Using Dawn detergent, we were able to clean the oiled fur during 40 min of washing and rinsing. Grooming activity by the otters was essential for restoring the water-repellent quality of the fur. Core body temperature, average metabolic rate, and thermal conductance returned to base-line levels 3–6 days after cleaning. Squalene was removed by cleaning and did not return to normal levels in the oiled area after 7 days. Veterinary care was important to keep the otters healthy. At least 1–2 weeks should be allowed for otters to restore the insulation of their fur and for recovery from the stress of oiling and cleaning.
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Kaseloo, Paul A., and James R. Lovvorn. "Effects of surface activity patterns and dive depth on thermal substitution in fasted and fed lesser scaup (Aythya affinis) ducks." Canadian Journal of Zoology 83, no. 2 (February 1, 2005): 301–11. http://dx.doi.org/10.1139/z05-012.
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High thermoregulation costs incurred by aquatic endotherms can be reduced if heat from digestion and exercising muscles can substitute for thermogenesis. Costs (VO2) of surface activities and diving were measured in lesser scaup (Aythya affinis (Eyton, 1838)) ducks while fasted and when feeding on mixed grain at depths of 1.2 and 2 m at thermoneutral (23 °C) and sub-thermoneutral (8 °C) water temperatures. Substitution occurred if the heat increment of feeding (HIF) or costs of activities above resting metabolic rate (RMR) were lower at 8 °C than at 23 °C, indicating that the thermoregulatory part of RMR at 8 °C had been reduced. Changes in body core temperature were not significant, and there was no substitution of HIF. At the surface at 8 °C, fasted birds that were active (nonresting) >75% of the time had lower RMR, and lower cost of activities above RMR, than less active birds. Dive recovery cost after dive bouts (DRC) constituted 33%–35% of total dive costs at 23 °C and 48%–55% at 8 °C. Dive costs above RMR (including DRC) were lower at 8 °C than at 23 °C by 14% at 1.2 m and 25% at 2 m, suggesting appreciable substitution that increased with longer, deeper dives; however, results varied widely and were not statistically significant. Our experiments indicate that thermal substitution varies in importance depending on levels of activity and heat loss.
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Shimatani, Hiroyuki, Yuichi Inoue, Yota Maekawa, Takahito Miyake, Yoshiaki Yamaguchi, and Masao Doi. "Thermographic imaging of mouse across circadian time reveals body surface temperature elevation associated with non-locomotor body movements." PLOS ONE 16, no. 5 (May 28, 2021): e0252447. http://dx.doi.org/10.1371/journal.pone.0252447.
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Circadian clocks orchestrate multiple different physiological rhythms in a well-synchronized manner. However, how these separate rhythms are interconnected is not exactly understood. Here, we developed a method that allows for the real-time simultaneous measurement of locomotor activity and body temperature of mice using infrared video camera imaging. As expected from the literature, temporal profiles of body temperature and locomotor activity were positively correlated with each other. Basically, body temperatures were high when animals were in locomotion. However, interestingly, increases in body temperature were not always associated with the appearance of locomotor activity. Video imaging revealed that mice exhibit non-locomotor activities such as grooming and postural adjustments, which alone induce considerable elevation of body temperature. Noticeably, non-locomotor movements always preceded the initiation of locomotor activity. Nevertheless, non-locomotor movements were not always accompanied by locomotor movements, suggesting that non-locomotor movements provide a mechanism of thermoregulation independent of locomotor activity. In addition, in the current study, we also report the development of a machine learning-based recording method for the detection of circadian feeding and drinking behaviors of mice. Our data illustrate the potential utility of thermal video imaging in the investigation of different physiological rhythms.
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Babcock, Alex M., and Chris Barton. "Bombesin-Induced Hypothermia in the Insulin-Treated Rat: Effect on Tail-Skin Temperature." Perceptual and Motor Skills 69, no. 3_suppl (December 1989): 1339–45. http://dx.doi.org/10.2466/pms.1989.69.3f.1339.
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Bombesin-like peptides are widely distributed in the mammalian central nervous system and appear to participate in the regulation of a variety of autonomic functions. Bombesin has been shown to alter feeding behavior, locomotor activity, and thermoregulation. Microinfusion of bombesin into the preoptic area of the hypothalamus produces a reduction in core body temperature, but only if the rat has been cold-exposed, food-deprived, or pretreated with insulin. The mechanism for bombesin-induced hypothermia under the latter two conditions is unknown. The present study evaluated the possible contribution of peripheral heat loss mechanisms in bombesin-induced hypothermia. Rats were administered insulin (10U/kg, Regular Iletin I i.m.) or saline followed by an intrahypothalamic injection of bombesin (.05 μg/.25 μl) or peptide vehicle. Rectal and tail-skin temperatures were measured continuously for 120 min. Changes in temperature were evaluated at 30, 60, 90, and 120 min., using analysis of variance. As previously demonstrated, bombesin produced hypothermia in rats pretreated with insulin. This reduction in core temperature was not associated with any significant alteration in tail-skin temperature. Results suggest that bombesin-induced hypothermia in rats pretreated with insulin may not be mediated by an increase in peripheral heat loss.
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Babcock, Alex M., and Chris Barton. "Bombesin-Induced Hypothermia in the Insulin-Treated Rat: Effect on Tail-Skin Temperature." Perceptual and Motor Skills 69, no. 3-2 (December 1989): 1339–45. http://dx.doi.org/10.1177/00315125890693-251.
Full textAbstract:
Bombesin-like peptides are widely distributed in the mammalian central nervous system and appear to participate in the regulation of a variety of autonomic functions. Bombesin has been shown to alter feeding behavior, locomotor activity, and thermoregulation. Microinfusion of bombesin into the preoptic area of the hypothalamus produces a reduction in core body temperature, but only if the rat has been cold-exposed, food-deprived, or pretreated with insulin. The mechanism for bombesin-induced hypothermia under the latter two conditions is unknown. The present study evaluated the possible contribution of peripheral heat loss mechanisms in bombesin-induced hypothermia. Rats were administered insulin (10U/kg, Regular Iletin I i.m.) or saline followed by an intrahypothalamic injection of bombesin (.05 μg/ .25 μl) or peptide vehicle. Rectal and tail-skin temperatures were measured continuously for 120 min. Changes in temperature were evaluated at 30, 60, 90, and 120 min., using analysis of variance. As previously demonstrated, bombesin produced hypothermia in rats pretreated with insulin. This reduction in core temperature was not associated with any significant alteration in tail-skin temperature. Results suggest that bombesin-induced hypothermia in rats pretreated with insulin may not be mediated by an increase in peripheral heat loss.
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Ross, S., R. Kamnitzer, B. Munkhtsog, and S. Harris. "Den-site selection is critical for Pallas’s cats (Otocolobus manul)." Canadian Journal of Zoology 88, no. 9 (September 2010): 905–13. http://dx.doi.org/10.1139/z10-056.
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We evaluated the habitat selection of 101 den sites used by 21 individual Pallas’s cats ( Otocolobus manul (Pallas, 1776) = Felis manul Pallas, 1776) in summer, winter, and the maternal period in central Mongolia using generalized linear mixed models. Pallas’s cats used rock crevices and marmot burrows as dens for giving birth, raising young, thermoregulation, feeding, mating, and as important cover from predators. Den sites were selected with higher proportions of rocky and ravine habitats in the surroundings, and in winter Pallas’s cats avoided the presence of humans. Habitat and structural features suggested that dens were selected to minimize predation risk. Selection of dens in shade in summer and the use of insulated dens of Siberian marmots ( Marmota sibirica (Radde, 1862)) in winter indicated that thermal properties may also be important. We contend that dens are a critical habitat for Pallas’s cats and the availability of suitable den sites is critical for the conservation of the species. Repeated use of maternal dens suggested they may be a limiting resource. Although marmot dens are unlikely to be limiting at present, over hunting of marmots is likely to reduce burrow availability in the future.
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Gyalus, Adrienn, Péter Lovászi, Zsolt Végvári, and Tibor Csörgő. "Effects of climate variables on the White Stork (Ciconia ciconia L.) productivity in a long term study." Ornis Hungarica 30, no. 2 (November 25, 2022): 61–74. http://dx.doi.org/10.2478/orhu-2022-0020.
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Abstract We analysed the effects of weather and climatic patterns on the productivity of the White Stork in Hungary between 1958 and 2017, using i) linear mixed effect models (LMM), ii) LMM-s extended by a single random effect variable or a nested combination; iii) LMM-s extended by a single fixed effect variable and iv) using an additive model of the selected variables. As a preselection, the following climatic variables were identified with substantial support: March mean temperature, March precipitation, April mean temperature, June mean temperature, June precipitation (negative), July mean temperature. The slight increase of the mean number of fledged chicks over 59 years could be the result of the increasing mean temperature, but in itself it might not be strong enough to prove that climate change will overall benefit White Stork productivity. Higher temperature and precipitation values are favourable, probably because of the higher biomass, providing more prey, but high precipitation is unfavourable until the thermoregulation of chicks is not developed. Decreasing amounts of precipitation may cause loss of wetlands as suitable feeding sites. Extreme weather is important to complement the picture given by climate change.
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HILLSTRÖM, Lars, and Juan Moreno. "Variation in Time and Energy Budgets of Breeding Wheatears." Behaviour 120, no. 1-2 (1992): 11–39. http://dx.doi.org/10.1163/156853992x00183.
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AbstractWe examined the sources of variation in time allocation of males and females of the wheatear (Oenanthe oenanthe) on the island of Öland, South Sweden, throughout the breeding season. We quantified rates of prey capture attempts and specified foraging methods used. From respirometric measurements of basal metabolic rate and temperature-dependent metabolism on captive wheatears, and after having made certain assumptions abour the costs of different activities, we estimated the energy budgets of both sexes during the different reproductive phases. Males and females differed in their time allocation and foraging rates during prelaying, laying, and incubation, but not while feeding grown nestlings. During prelaying and laying, females foraged at higher rates than males; they also perched less often, gleaned more on the ground, and flew less. Although incubation was the least costly phase for females because of their low activity, high foraging rates yet indicated that this phase may represent an energetic bottleneck as a result of restrictions on foraging time. After incubation, females switched from foraging mostly on the ground during early breeding phases to hunting from elevated perches during later breeding phases. The shift in foraging behavior corresponds to the drastic changes in time allocation. Relatively high daily energy expenditures (DEE) by brooding females coupled with low foraging rates may explain the observed posthatching body mass losses. In both sexes, high required energy acquisition rates when feeding large nestlings indicate that parent wheatears then may encounter another energetic bottleneck. Postfledging was the least costly phase because, compared with the period of feeding nestlings, there were reduced thermostatic costs and a marked drop in flight time. Males and females had similar DEEs during prelaying, laying and nestling feeding, but females had lower needs during incubation. The elective components of energy budgets during nestling feeding, as well as the estimated sum of the elective components throughout the season, were 12% higher for males than for females. The elective components of the energy budgets varied more than the obligatory components (basal + thermoregulation), especially in females, and were more important in determining the variation of DEE throughout the breeding season. A validation study with doubly labeled water indicated that the energy budget model used was accurate enough for comparisons between sexes or breeding phases, but not for measuring individual variation.
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Martinez, Quentin, Julien Clavel, Jacob A. Esselstyn, Anang S. Achmadi, Camille Grohé, Nelly Pirot, and Pierre-Henri Fabre. "Convergent evolution of olfactory and thermoregulatory capacities in small amphibious mammals." Proceedings of the National Academy of Sciences 117, no. 16 (April 6, 2020): 8958–65. http://dx.doi.org/10.1073/pnas.1917836117.
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Olfaction and thermoregulation are key functions for mammals. The former is critical to feeding, mating, and predator avoidance behaviors, while the latter is essential for homeothermy. Aquatic and amphibious mammals face olfactory and thermoregulatory challenges not generally encountered by terrestrial species. In mammals, the nasal cavity houses a bony system supporting soft tissues and sensory organs implicated in either olfactory or thermoregulatory functions. It is hypothesized that to cope with aquatic environments, amphibious mammals have expanded their thermoregulatory capacity at the expense of their olfactory system. We investigated the evolutionary history of this potential trade-off using a comparative dataset of three-dimensional (3D) CT scans of 189 skulls, capturing 17 independent transitions from a strictly terrestrial to an amphibious lifestyle across small mammals (Afrosoricida, Eulipotyphla, and Rodentia). We identified rapid and repeated loss of olfactory capacities synchronously associated with gains in thermoregulatory capacity in amphibious taxa sampled from across mammalian phylogenetic diversity. Evolutionary models further reveal that these convergences result from faster rates of turbinal bone evolution and release of selective constraints on the thermoregulatory-olfaction trade-off in amphibious species. Lastly, we demonstrated that traits related to vital functions evolved faster to the optimum compared to traits that are not related to vital functions.
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da Silva, Charlene, Sven E. Kerwath, Henning Winker, Stephen J. Lamberth, Colin G. Attwood, Chris G. Wilke, and Tor F. Næsje. "Testing the waters to find the 'goldilocks' zone: fine-scale movement of Mustelus mustelus in relation to environmental cues." Marine and Freshwater Research 73, no. 1 (2022): 110. http://dx.doi.org/10.1071/mf20369.
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The fine-scale movement of Mustelus mustelus in relation to environmental conditions was investigated at various temporal scales with acoustic telemetry and temperature–depth transmitters inside a coastal marine protected area in South Africa. Twenty-four sharks were equipped with acoustic tags and logged by an array of 28 acoustic receivers from November 2006 to November 2008. Generalised additive and generalised additive mixed models (GAMMs) were used to explain patterns of movement in terms of the environmental conditions related to temperature, the rate of change of temperature, tidal flow, diel cycle and moon phase. The most important environmental parameters affecting movement and direction of movement were related to absolute temperature and changes in temperature at the position of the shark. The movement of M. mustelus was not affected by tide and only minimally affected by the diel cycle, suggesting behavioural thermoregulation as the ultimate cause of the movements. M. mustelus preferred temperatures from 18 to 22°C, as determined by GAMMs for environmental conditions experienced in summer. The combination of the thermal environment, rich feeding grounds and protective effect of the Langebaan Marine Protected Area may explain the high abundance and regular occurrence of M. mustelus within this marine protected area.
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Vitt, Laurie J., Peter A. Zani, and A. Claudia Marinho Lima. "Heliotherms in tropical rain forest: the ecology of Kentropyx calcarata (Teiidae) and Mabuya nigropunctata (Scincidae) in the Curuá-Una of Brazil." Journal of Tropical Ecology 13, no. 2 (March 1997): 199–220. http://dx.doi.org/10.1017/s0266467400010415.
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ABSTRACTKentropyx calcarata (Teiidae) and Mabuya nigropunctata (Scincidae) occur together in lowland tropical forest of the Amazon near the Rio Curuá-Una of Brazil. During the wet season of 1995 these lizards were common at forest edge along narrow roads that transect forest, in treefalls and along streams where sun reaches the ground. Both species are heliothermic, basking to gain heat. Their association with open patches results from high activity temperature requirements in an environment where sun availability is low. Null temperature distributions from forest and treefalls showed that forest does not offer opportunities for heat gain similar to treefalls. Moreover, the large proportion of time spent basking by both species indicates the importance of these patches for thermoregulation. K. calcarata is slightly larger in body length and heavier at a given body length than M. nigropunctata. Both species are active foragers that seek out prey while moving through the habitat, feeding on orthopterans, roaches and spiders. M. nigropunctata also eat significant numbers of insects that occur on vegetation, such as hemipterans. Prey size is larger in K. calcarata and associated with lizard body size. Prey size does not vary with body size in M. nigropunctata and prey are typically relatively small.Many of the ecological differences between these two lowland forest species appear to be historical: the ecology of K. calcarata is very similar to that of other species of Kentropyx and teiids in general and the ecology of M. nigropunctata is most similar to that of other studied species of south American Mabuya.
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OKITA, MINORU, AKIO INUI, MASAKI MIURA, YOSHIAKI HIROSUE, MASAHARU NAKAJIMA, and SHIGEAKI BABA. "Central Actions of Neuropeptide Y and Its Related Peptides in the Dog, with Special Reference to Their Effects on the Hypothalamic-Pituitary-Adrenal Axis, Feeding Behavior, and Thermoregulation." Annals of the New York Academy of Sciences 611, no. 1 Central and P (November 1990): 483–85. http://dx.doi.org/10.1111/j.1749-6632.1990.tb48993.x.
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Corcoran, Andrea E., George B. Richerson, and Michael B. Harris. "Functional link between the hypocretin and serotonin systems in the neural control of breathing and central chemosensitivity." Journal of Neurophysiology 114, no. 1 (July 2015): 381–89. http://dx.doi.org/10.1152/jn.00870.2013.
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Serotonin (5-HT)-synthesizing neurons of the medullary raphe are putative central chemoreceptors, proposed to be one of potentially multiple brain stem chemosensitive cell types and loci interacting to produce the respiratory chemoreflex. Hypocretin-synthesizing neurons of the lateral hypothalamus are important contributors to arousal state, thermoregulation, and feeding behavior and are also reportedly involved in the hypercapnic ventilatory response. Recently, a functional interaction was found between the hypocretin system and 5-HT neurons of the dorsal raphe. The validity and potential significance of hypocretin modulation of medullary raphe 5-HT neurons, however, is unknown. As such, the purpose of this study was to explore functional interactions between the hypocretin system and 5-HT system of the medullary raphe on baseline respiratory output and central chemosensitivity. To explore such interactions, we used the neonatal in vitro medullary slice preparation derived from wild-type (WT) mice (normal 5-HT function) and a knockout strain lacking all central 5-HT neurons ( Lmx1b f/f/p mice). We examined effects of acidosis, hypocretin-1, a hypocretin receptor antagonist (SB-408124), and the effect of the antagonist on the response to acidosis. We confirmed the critical role of 5-HT neurons in central chemosensitivity given that the increased hypoglossal burst frequency with acidosis, characteristic of WT mice, was absent in preparations derived from Lmx1b f/f/p mice. We also found that hypocretin facilitated baseline neural ventilatory output in part through 5-HT neurons. Although the impact of hypocretin on 5-HT neuronal sensitivity to acidosis is still unclear, hypocretins did appear to mediate the burst duration response to acidosis via serotonergic mechanisms.
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HARRISON, JON M. "Temperature Effects on Haemolymph Acid-Base Status In Vivo and In Vitro in the Two-Striped Grasshopper Melanoplus Bivittatus." Journal of Experimental Biology 140, no. 1 (November 1, 1988): 421–35. http://dx.doi.org/10.1242/jeb.140.1.421.
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In this study, I examine the effect of temperature on haemolymph acid-base status in vivo and in vitro in the two-striped grasshopper Melanoplus bivittatus. Melanoplus bivittatus experience wide (up to 40 °C) diurnal body temperature fluctuations in the field, but maintain body temperature relatively constant during sunny days by behavioural thermoregulation. Haemolymph pH was statistically constant (7.12) between 10 and 25°C, but decreased by −0.017 units °C− from 25 to 40°C. Relative alkalinity and fractional protein dissociation were conserved only at body temperatures at which feeding and locomotory activity occur, above 20°C. Haemolymph total CO2 (Ctot) increased from 10 to 20°C and decreased from 20 to 40°C. Haemolymph Pco2 increased from 10 to 20°C and was statistically constant between 20 and 40°C. Carbonic acid pKapp in haemolymph was 6.122 at 35°C, and decreased with temperature by −0.0081 units°C−1. Haemolymph buffer value averaged −35mequivl−1pHunit−1. Haemolymph pH changes with temperature were small (less than −0.004 units°C−1) in vitro at constant Pco2. Therefore, passive physicochemical effects cannot account for the pattern of acid-base regulation in vivo. The temperature shift from 10 to 20°C was accompanied by a net addition of 4.2-6.2 mmoll−1 of bicarbonate equivalents to the haemolymph. The temperature shift from 20 to 40°C was accompanied by a net removal of 10–14 mmoll−1 of bicarbonate equivalents from the haemolymph. Haemolymph acid-base regulation in vivo during temperature changes is dominated by active variation of bicarbonate equivalents rather than by changes in Pco2 as observed for most other air-breathers.