Articoli di riviste: "Behaviour of mammals"

1

Short, R. V. "Sexual behaviour in mammals". Global Bioethics 9, n. 1-4 (gennaio 1996): 3–10. http://dx.doi.org/10.1080/11287462.1996.10800944.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Thinley, Jigme, Ugyen Dorji, Ugyen Tshering, Arjun Nepal, Lekey Chaida, Chaten Chaten, Kiran Rai et al. "Mineral Composition and Behaviour of Mammals at Natural Saltlicks in Jomotsangkha Wildlife Sanctuary, Bhutan". Bhutan Journal of Natural Resources and Development 7, n. 2 (31 dicembre 2020): 23–33. http://dx.doi.org/10.17102/cnr.2020.49.

Testo completo

Abstract (sommario):

Natural saltlicks are used by mammal species mainly to supplement mineral deficiency playing critical role in animal ecology. There is information gap on the use of natural saltlicks by mammals in Bhutan. Nine natural saltlicks from Jomotsangkha Wildlife Sanctuary were purposively selected to fill this gap of information. The study aimed to assess mineral composition and ecological behaviour of mammals at natural saltlicks. Nine composite soil samples were randomly collected and nine camera traps were set up at nine saltlicks for a duration of 56 days from 2 January to 28 February, 2019. Data management and analysis were carried out using camerabase and R software. Potassium, phosphorus and sodium elements were found in the saltlicks. Camera traps yielded 419 independent events of 12 species under 10 families. Herbivores were most common (n = 390) and non-herbivores the least (n = 12). Wild dog was also captured licking salts (n = 1) which is least reported across the world. Mineral composition (r = 0.70, p < .05) and anthropogenic activities (r = 0.60, p < .05) were key factors affecting the visitation rate and ecological behaviour of mammal species. Disturbed saltlicks from Samdrupcholing Range revealed fewer individuals of mammals (n = 71) with disturbed ecological behaviour while undisturbed saltlicks from Jomotsangkha Range revealed higher individuals of mammals (n = 340) with undisturbed ecological behaviour. Therefore, anthropogenic activities at disturbed saltlicks call for planned monitoring.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Larivière, Serge. "Behaviour and Ecology of Riparian Mammals". Journal of Mammalogy 81, n. 1 (febbraio 2000): 280–82. http://dx.doi.org/10.1644/1545-1542(2000)081<0280:r>2.0.co;2.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Murray, A. J., N. K. Waran e R. J. Young. "Environmental Enrichment for Australian Mammals". Animal Welfare 7, n. 4 (novembre 1998): 415–25. http://dx.doi.org/10.1017/s0962728600020959.

Testo completo

Abstract (sommario):

AbstractMany of Australia's nocturnal mammals are rare or endangered in the wild. The behavioural integrity of captive populations of endangered species can be maintained through the application of environmental enrichment techniques. This study investigated the effectiveness of feeding enrichment in promoting behavioural diversity, enclosure usage and species-typical behaviours in the ghost bat (Macroderma gigas) and the yellow-bellied glider (Petaurus australis). Animals were observed for 300 min day-1 over three consecutive time periods: baseline (12 non-consecutive days); enrichment: (12 consecutive days); and post-enrichment: (12 non-consecutive days). The use of a live insect dispenser decreased grooming and increased out-of-sight and social behaviour in the ghost bat. Artificial gum trees promoted species-typical behaviours in the yellow-bellied glider. Enrichment for nocturnal mammals had variable results and different welfare implications for these animals.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Williams, Amanda C. de C. "Persistence of pain in humans and other mammals". Philosophical Transactions of the Royal Society B: Biological Sciences 374, n. 1785 (23 settembre 2019): 20190276. http://dx.doi.org/10.1098/rstb.2019.0276.

Testo completo

Abstract (sommario):

Evolutionary models of chronic pain are relatively undeveloped, but mainly concern dysregulation of an efficient acute defence, or false alarm. Here, a third possibility, mismatch with the modern environment, is examined. In ancestral human and free-living animal environments, survival needs urge a return to activity during recovery, despite pain, but modern environments allow humans and domesticated animals prolonged inactivity after injury. This review uses the research literature to compare humans and other mammals, who share pain neurophysiology, on risk factors for pain persistence, behaviours associated with pain, and responses of conspecifics to behaviours. The mammal populations studied are mainly laboratory rodents in pain research, and farm and companion animals in veterinary research, with observations of captive and free-living primates. Beyond farm animals and rodent models, there is virtually no evidence of chronic pain in other mammals. Since evidence is sparse, it is hard to conclude that it does not occur, but its apparent absence is compatible with the mismatch hypothesis. This article is part of the Theo Murphy meeting issue ‘Evolution of mechanisms and behaviour important for pain’.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Shelley, Sarah L., Stephen L. Brusatte e Thomas E. Williamson. "Quantitative assessment of tarsal morphology illuminates locomotor behaviour in Palaeocene mammals following the end-Cretaceous mass extinction". Proceedings of the Royal Society B: Biological Sciences 288, n. 1950 (12 maggio 2021): 20210393. http://dx.doi.org/10.1098/rspb.2021.0393.

Testo completo

Abstract (sommario):

Mammals exhibit vast ecological diversity, including a panoply of locomotor behaviours. The foundations of this diversity were established in the Mesozoic, but it was only after the end-Cretaceous mass extinction that mammals began to increase in body size, diversify into many new species and establish the extant orders. Little is known about the palaeobiology of the mammals that diversified immediately after the extinction during the Palaeocene, which are often perceived as ‘archaic’ precursors to extant orders. Here, we investigate the locomotor ecology of Palaeocene mammals using multivariate and disparity analyses. We show that tarsal measurements can be used to infer locomotor mode in extant mammals, and then demonstrate that Palaeocene mammals occupy distinctive regions of tarsal morphospace relative to Cretaceous and extant therian mammals, that is distinguished by their morphological robustness. We find that many Palaeocene species exhibit tarsal morphologies most comparable with morphologies of extant ground-dwelling mammals. Disparity analyses indicate that Palaeocene mammals attained similar morphospace diversity to the extant sample. Our results show that mammals underwent a post-extinction adaptive radiation in tarsal morphology relating to locomotor behaviour by combining a basic eutherian bauplan with anatomical specializations to attain considerable ecomorphological diversity.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Delgado-Martínez, Carlos M., Fredy Alvarado, Melanie Kolb e Eduardo Mendoza. "Monitoring of small rock pools reveals differential effects of chronic anthropogenic disturbance on birds and mammals in the Calakmul region, southern Mexico". Journal of Tropical Ecology 38, n. 2 (17 dicembre 2021): 79–88. http://dx.doi.org/10.1017/s0266467421000547.

Testo completo

Abstract (sommario):

AbstractGreat attention has been drawn to the impacts of habitat deforestation and fragmentation on wildlife species richness. In contrast, much less attention has been paid to assessing the impacts of chronic anthropogenic disturbance on wildlife species composition and behaviour. We focused on natural small rock pools (sartenejas), which concentrate vertebrate activity due to habitat’s water limitation, to assess the impact of chronic anthropogenic disturbance on the species richness, diversity, composition, and behaviour of medium and large-sized birds and mammals in the highly biodiverse forests of Calakmul, southern Mexico. Camera trapping records of fauna using sartenejas within and outside the Calakmul Biosphere Reserve (CBR) showed that there were no effects on species richness, but contrasts emerged when comparing species diversity, composition, and behaviour. These effects differed between birds and mammals and between species: (1) bird diversity was greater outside the CBR, but mammal diversity was greater within and (2) the daily activity patterns of birds differed slightly within and outside the CBR but strongly contrasted in mammals. Our study highlights that even in areas supporting extensive forest cover, small-scale chronic anthropogenic disturbances can have pervasive negative effects on wildlife and that these effects contrast between animal groups.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Miller, Lance J., Moby Solangi e Stan A. Kuczaj. "Immediate response of Atlantic bottlenose dolphins to high-speed personal watercraft in the Mississippi Sound". Journal of the Marine Biological Association of the United Kingdom 88, n. 6 (17 marzo 2008): 1139–43. http://dx.doi.org/10.1017/s0025315408000908.

Testo completo

Abstract (sommario):

Measuring the impact of anthropogenic factors on marine mammals is critical to the conservation of these species. Recently, the effect of personal watercraft on marine mammal behaviour and well-being has become a topic of increasing concern. The purpose of this study was to examine the immediate effects of high-speed personal watercraft on Atlantic bottlenose dolphin (Tursiops truncatus) behaviour. Opportunistic surveys were conducted from a research vessel in the Mississippi Sound (30º13′22.6″N 89º01′36.5″W) from September 2003 through to August 2005. The passing of a high-speed personal watercraft significantly increased dolphin dive duration, dolphin group cohesion and dolphin breathing synchrony. Additionally, in 47% of the encounters a dolphin group's behaviour changed within one minute of the presence of a high-speed personal watercraft. The most notable changes were an increase in dolphin travelling behaviour and a decrease in feeding behaviour following the boat's presence. The results demonstrated an immediate, short-term change in dolphin behaviour, suggesting that an increase in the frequency of high-speed personal watercraft in this area could produce long-term detrimental effects. Research on the long-term effects of boat traffic on marine mammals is clearly needed to assess and hopefully mediate any potential long-term effects.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Stewart, F. E. C., e A. G. McAdam. "Wild Peromyscus adjust maternal nest-building behaviour in response to ambient temperature". Canadian Journal of Zoology 95, n. 6 (giugno 2017): 411–15. http://dx.doi.org/10.1139/cjz-2016-0236.

Testo completo

Abstract (sommario):

The heat dissipation limit (HDL) hypothesis suggests that energy output during lactation in mammals might be constrained by their ability to dissipate heat. This hypothesis predicts that wild mammals ought to adjust nest insulation in response to heat load, but these predictions have rarely been tested in wild mammals. Here we developed a simple score of nest-building for wild deer mice (Peromyscus maniculatus (Wagner, 1845)) on an ordinal scale from 0 to 4, based on three qualitative and easy to observe aspects of nest-building behaviour: bedding quality, nest shape, and mouse visibility. We used this measure to track 472 nest-building observations across 14 wild P. maniculatus that were brought into captivity and housed under pseudoambient temperatures across one reproductive event. Our observations of nest-building behaviour of the genus Peromyscus Gloger, 1841 provide varying support for the HDL hypothesis; there is a negative effect of ambient temperature on nest-building behaviour and lactating females became more sensitive to temperature as days post partum increased. However, females generally build more elaborate nests in lactation than other reproductive states and there are no effects of litter size, total pup mass, or days post partum on nest scores during lactation. Our observations have broad implications for quantifying behaviours in nest-building species and metabolic relationships in wild mammals.

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Poindron, Pascal. "Mechanisms of activation of maternal behaviour in mammals". Reproduction Nutrition Development 45, n. 3 (maggio 2005): 341–51. http://dx.doi.org/10.1051/rnd:2005025.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Manger, Paul. "Why study brains and behaviour of different mammals?" IBRO Reports 7 (dicembre 2019): 53. http://dx.doi.org/10.1016/j.ibror.2019.09.005.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Logan, Darren W. "The complexity of pheromone-mediated behaviour in mammals". Current Opinion in Behavioral Sciences 2 (aprile 2015): 96–101. http://dx.doi.org/10.1016/j.cobeha.2014.10.011.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Clout, Mick N., e James C. Russell. "The invasion ecology of mammals: a global perspective". Wildlife Research 35, n. 3 (2008): 180. http://dx.doi.org/10.1071/wr07091.

Testo completo

Abstract (sommario):

Of the extant species of land mammals, 124 (2.6%) can be classed as ‘successful invaders’, whereas 1038 (21.6%) are classed as threatened, according to the 2006 IUCN Red List. Relatively high proportions of successful invaders are found among Artiodactyla, Carnivora, Lagomorpha and Perissodactyla. Compared with other organisms, mammals seem relatively likely to become established when introduced outside their natural range. Studies of determinants of invasion success indicate that the number of individuals released, the size of the natural range of the introduced species, and the temperateness of climate in the new range can all increase the probability of establishment of introduced mammals. Negative impacts of invasive mammals on native biodiversity include direct effects such as predation, browsing and competition, but can extend to disruption of patterns of nutrient flow, and trophic cascades. Eradication of several species of invasive mammals from increasingly large areas is now possible. In this context, it is important to better understand ecological interactions between such mammals (and between them and other species) to avoid unwanted consequences such as mesopredator or competitor release, after the removal of particular species. Finally, it is increasingly apparent that research is needed on the behaviour of dispersing and invading individuals, to improve the early detection of new mammal invasions or reinvasions.

Gli stili APA, Harvard, Vancouver, ISO e altri

14

French, Jeffrey A., Aaryn C. Mustoe, Jon Cavanaugh e Andrew K. Birnie. "The influence of androgenic steroid hormones on female aggression in ‘atypical’ mammals". Philosophical Transactions of the Royal Society B: Biological Sciences 368, n. 1631 (5 dicembre 2013): 20130084. http://dx.doi.org/10.1098/rstb.2013.0084.

Testo completo

Abstract (sommario):

Dimorphism on dominance and agonistic behaviour in mammals tends to be strongly biased toward males. In this review, we focus on a select few species of mammals in which females are as or more aggressive than males, and/or are dominant to males, and explore the role of androgenic hormones in mediating this important difference. While the data are not as clear-cut as those published on traditional laboratory mammals, our review highlights important endocrine substrates for both organizational and activational influences of steroids on female aggressive behaviour. We highlight areas in which further observations and experiments are crucial, especially the potential facilitative effects of androgens on female aggression. Finally, new and innovative techniques, including molecular genetics and receptor pharmacology, portend important insights into the ways in which androgenic hormones regulate aggressive behaviour in ‘atypical’ female mammals.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Montes de Oca, Daniela Paula, Martín Neyen Lammel e Regino Cavia. "Small-mammal assemblages in piggeries in a developing country: relationships with management practices and habitat complexity". Wildlife Research 47, n. 6 (2020): 485. http://dx.doi.org/10.1071/wr19199.

Testo completo

Abstract (sommario):

Abstract ContextPig production is increasing in developing countries and is increasing the coexistence of different production systems regarding management practices. Small mammals can cause major economic and sanitary problems on pig farms. The interactions among small mammals, production practices and habitat complexity have been sparsely studied. AimsThe aim was to compare small-mammal assemblages on extensive and intensive pig-production systems, and to analyse the relationship with environmental characteristics and management practices. MethodsSeasonal live-trapping of small mammals within 18 farms (under intensive or extensive management) was performed in central Argentina, simultaneously with a survey of environmental and management practices. Multiple regression analyses were performed to assess the relation between infestation levels and environmental characteristics. Key results In total, 472 small mammals were captured, including the exotic murids Rattus norvegicus, R. rattus and Mus musculus, three native sigmodontines, namely, Akodon azarae, Oligoryzomys flavescens and Oxymycterus rufus, and two native marsupials, namely, Didelphis albiventris and Lutreolina crassicaudata. The location of waste deposits, the density of cats, the frequency of rodent control and the way pig food was stored influenced wild small-mammal abundance; exotic rodent species were lower when the density of cats increased. Rattus norvegicus was more abundant where rodent control was not frequent or null, contrary to M. musculus. Both species were more abundant in food and pig sheds, whereas native species were associated with vegetated areas outside of sheds. Also, A. azarae was associated with the density of pigs. Didelphis albiventris was more abundant on extensive farms, whereas L. crassicaudata was captured on intensive farms. Conclusions Small-mammal abundance did not respond to the type of production system per se, but exotic species abundance was influenced by management decisions. The most important human behaviours related to exotic rodent infestation were the possession of cats, the frequency of rodent control and the way waste and pig feed were managed. Implications Our findings highlighted the need for integrated studies on factors influencing the dynamics of rodent populations in commercial piggery systems, for the development of effective pest management. Management recommendations need to assess environmental complexity and human behaviour as important moderators of the population dynamics of small mammal species in and around piggeries.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Schumann, Nicole, Nick J. Gales, Robert G. Harcourt e John P. Y. Arnould. "Impacts of climate change on Australian marine mammals". Australian Journal of Zoology 61, n. 2 (2013): 146. http://dx.doi.org/10.1071/zo12131.

Testo completo

Abstract (sommario):

Increasing evidence suggests that climate change is negatively affecting marine ecosystems and biota. However, little is known of how climate change will impact marine mammals. This review aims to identify the effects of climatic variations on Australian marine mammals and determine their potential responses to climate change. Shifts in distributions and reproductive success have been associated with climatic factors, while stranding events, drowning of seal pups, exposure to altered water conditions and disease in several marine mammal species have followed extreme weather events. Climate change may produce distributional shifts as the ranges of warm-water species expand or shift southwards, and those of cold-water species contract. Reductions in the extent of key habitats, changes in breeding success, a greater incidence of strandings in dugongs and cetaceans, and increased exposure of coastal species to pollutants and pathogens are likely. The capacity of Australian marine mammals to adapt to climate change is poorly understood, though there is evidence that several species may be able to modify their physiology or behaviour in response to warming temperatures. To increase the resilience of marine mammals, it is necessary to address non-climatic threats, such as ensuring that key habitats are protected in Australia.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Connor, Richard C. "Social Behaviour in Mammals. Tertiary Level Biology.Trevor B. Poole". Quarterly Review of Biology 61, n. 2 (giugno 1986): 289. http://dx.doi.org/10.1086/414997.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Caro, T. M. "Demography and behaviour of African mammals subject to exploitation". Biological Conservation 91, n. 1 (novembre 1999): 91–97. http://dx.doi.org/10.1016/s0006-3207(99)00033-6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Hooker, S. K., A. Fahlman, M. J. Moore, N. Aguilar de Soto, Y. Bernaldo de Quirós, A. O. Brubakk, D. P. Costa et al. "Deadly diving? Physiological and behavioural management of decompression stress in diving mammals". Proceedings of the Royal Society B: Biological Sciences 279, n. 1731 (21 dicembre 2011): 1041–50. http://dx.doi.org/10.1098/rspb.2011.2088.

Testo completo

Abstract (sommario):

Decompression sickness (DCS; ‘the bends’) is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N 2 ) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N 2 tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N 2 loading to management of the N 2 load . This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years.

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Schakner, Zachary A., Michael G. Buhnerkempe, Mathew J. Tennis, Robert J. Stansell, Bjorn K. van der Leeuw, James O. Lloyd-Smith e Daniel T. Blumstein. "Epidemiological models to control the spread of information in marine mammals". Proceedings of the Royal Society B: Biological Sciences 283, n. 1844 (14 dicembre 2016): 20162037. http://dx.doi.org/10.1098/rspb.2016.2037.

Testo completo

Abstract (sommario):

Socially transmitted wildlife behaviours that create human–wildlife conflict are an emerging problem for conservation efforts, but also provide a unique opportunity to apply principles of infectious disease control to wildlife management. As an example, California sea lions ( Zalophus californianus ) have learned to exploit concentrations of migratory adult salmonids below the fish ladders at Bonneville Dam, impeding endangered salmonid recovery. Proliferation of this foraging behaviour in the sea lion population has resulted in a controversial culling programme of individual sea lions at the dam, but the impact of such culling remains unclear. To evaluate the effectiveness of current and alternative culling strategies, we used network-based diffusion analysis on a long-term dataset to demonstrate that social transmission is implicated in the increase in dam-foraging behaviour and then studied different culling strategies within an epidemiological model of the behavioural transmission data. We show that current levels of lethal control have substantially reduced the rate of social transmission, but failed to effectively reduce overall sea lion recruitment. Earlier implementation of culling could have substantially reduced the extent of behavioural transmission and, ultimately, resulted in fewer animals being culled. Epidemiological analyses offer a promising tool to understand and control socially transmissible behaviours.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Hume, Georgina, Elizabeth Brunton e Scott Burnett. "Eastern Grey Kangaroo (Macropus giganteus) Vigilance Behaviour Varies between Human-Modified and Natural Environments". Animals 9, n. 8 (27 luglio 2019): 494. http://dx.doi.org/10.3390/ani9080494.

Testo completo

Abstract (sommario):

Rapid increases in urban land use extent across the globe are creating challenges for many wildlife species. Urban landscapes present a novel environment for many species, yet our understanding of wildlife behavioural adaptations to urban environments is still poor. This study compared the vigilance behaviour of a large mammal in response to urbanisation at a landscape level. Here, we investigate urban (n = 12) and non-urban (n = 12) populations of kangaroos in two regions of Australia, and the relationship between kangaroo vigilance and urbanisation. We used a linear modelling approach to determine whether anti-predator vigilance and the number of vigilant acts performed were influenced by land use type (i.e., urban or non-urban), human population densities, kangaroo demographics, and environmental factors. Kangaroo behaviour differed between the two study regions; kangaroo vigilance was higher in urban than non-urban sites in the southern region, which also had the highest human population densities, however no effect of land use was found in the northern region. Season and sex influenced the vigilance levels across both regions, with higher levels seen in winter and female kangaroos. This study is the first to compare urban and non-urban vigilance of large mammals at a landscape level and provide novel insights into behavioural adaptations of large mammals to urban environments.

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Middleton, Owen S., Jörn P. W. Scharlemann e Christopher J. Sandom. "Homogenization of carnivorous mammal ensembles caused by global range reductions of large-bodied hypercarnivores during the late Quaternary". Proceedings of the Royal Society B: Biological Sciences 287, n. 1929 (24 giugno 2020): 20200804. http://dx.doi.org/10.1098/rspb.2020.0804.

Testo completo

Abstract (sommario):

Carnivorous mammals play crucial roles in ecosystems by influencing prey densities and behaviour, and recycling carrion. Yet, the influence of carnivores on global ecosystems has been affected by extinctions and range contractions throughout the Late Pleistocene and Holocene (approx. 130 000 years ago to the current). Large-bodied mammals were particularly affected, but how dietary strategies influenced species' susceptibility to geographical range reductions remains unknown. We investigated (i) the importance of dietary strategies in explaining range reductions of carnivorous mammals (greater than or equal to 5% vertebrate meat consumption) and (ii) differences in functional diversity of continental carnivore ensembles by comparing current, known ranges to current, expected ranges under a present-natural counterfactual scenario. The present-natural counterfactual estimates current mammal ranges had modern humans not expanded out of Africa during the Late Pleistocene and were not a main driver of extinctions and range contractions, alongside changing climates. Ranges of large-bodied hypercarnivorous mammals are currently smaller than expected, compared to smaller-bodied carnivorous mammals that consume less vertebrate meat. This resulted in consistent differences in continental functional diversity, whereby current ensembles of carnivorous mammals have undergone homogenization through structural shifts towards smaller-bodied insectivorous and herbivorous species. The magnitude of ensemble structural shifts varied among continents, with Australia experiencing the greatest difference. Weighting functional diversity by species’ geographical range sizes caused a threefold greater shift in ensemble centroids than when using presence–absence alone. Conservation efforts should acknowledge current reductions in the potential geographical ranges of large-bodied hypercarnivores and aim to restore functional roles in carnivore ensembles, where possible, across continents.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Bell, Catherine, Peter Shaughnessy, Margie Morrice e Bob Stanley. "Marine mammals and Japanese long-line fishing vessels in Australian waters: operational interactions and sightings". Pacific Conservation Biology 12, n. 1 (2006): 31. http://dx.doi.org/10.1071/pc060031.

Testo completo

Abstract (sommario):

Observers from the Australian Fisheries Management Authority worked on randomly chosen Japanese long-line vessels in the Australian Fishing Zone (AFZ) between 1980 and 1997. Observer reports (n = 451) were inspected for interactions or sightings of marine mammals. An operational interaction was defined as an activity or behaviour that involved direct contact between a marine mammal and fishing gear, bait, target fish or bycatch, or indications that the marine mammal was feeding. A sighting was defined as the recording of marine mammals that passed the vessel without changing course and/or did not appear to interact with the vessel or its gear. Observers witnessed 23 interactions and made another 44 sightings of marine mammals. A further 24 interactions and sightings were relayed by crew members. Killer whales were reported most frequently: most incidences of fish being damaged, taken or frightened away were attributed to them. Eleven marine mammals were caught: two died, seven were released, and the fate of two others was not recorded. Between 1991 and 1996, when observer coverage was 11.5% overall in the AFZ, the incidence of interactions was 1.71 per million hooks set. The estimated number of interactions in that seven-year period was 157 in the AFZ. Since 1997, the long-line fishery has been conducted by Australian vessels, primarily off the east coast of mainland Australia in warm-temperate waters. A higher proportion of interactions can be expected with killer whales and short-finned pilot whales in these waters, and fewer with seals.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Bubela, T. M., C. R. Dickman e A. E. Newsome. "Diet and Winter Foraging Behaviour of The Red Fox (Vulpes vulpes) In Alpine and Subalpine New South Wales." Australian Mammalogy 20, n. 3 (1998): 321. http://dx.doi.org/10.1071/am98321.

Testo completo

Abstract (sommario):

Foxes were studied from January 1991 to January 1993 in 167 square kilometres of the alpine and subalpine areas of Kosciusko National Park, New South Wales, Australia (36 24' S, 148 26' E, 1260-2238 m altitude). The study area encompassed two ski resorts. This study confirmed the varied nature of the diet of the red fox. Foxes are mainly insectivorous during snow-free months, but also prey upon three small mammal species, Antechinus swainsonii, Mastacomys fuscus and Rattus fuscipes. Direct observations indicate that human refuse from ski resorts is food for foxes in winter. It is probable that this supplementary food source sup- ports a higher density fox population than would occur in its absence. The management implications for populations of native small mammals of predation and supplementary food for foxes are discussed. We recommend that the impact of red fox predation on small mammals, particularly M. fuscus be assessed and that action be taken to limit the availability of human refuse to foxes in winter.

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Piggins, Hugh D., e Clare Guilding. "The neural circadian system of mammals". Essays in Biochemistry 49 (30 giugno 2011): 1–17. http://dx.doi.org/10.1042/bse0490001.

Testo completo

Abstract (sommario):

Humans and other mammals exhibit a remarkable array of cyclical changes in physiology and behaviour. These are often synchronized to the changing environmental light–dark cycle and persist in constant conditions. Such circadian rhythms are controlled by an endogenous clock, located in the suprachiasmatic nuclei of the hypothalamus. This structure and its cells have unique properties, and some of these are reviewed to highlight how this central clock controls and sculpts our daily activities.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Queiroz, Marina, e Robert Young. "The Different Physical and Behavioural Characteristics of Zoo Mammals That Influence Their Response to Visitors". Animals 8, n. 8 (14 agosto 2018): 139. http://dx.doi.org/10.3390/ani8080139.

Testo completo

Abstract (sommario):

The factors underlying the ‘zoo visit effect’ (changes in animal behaviour/physiology in response to visitor presence) are still poorly understood, despite it being widely investigated. The present study examined the effect of zoo visitors on the behaviour of 17 different species of mammals at the Belo Horizonte Zoo, Minas Gerais, Brazil. The behaviour of the animals was recorded using scan (focal in one case) sampling with instantaneous recording of behaviour, during 12 continuous months. Data were analysed using a comparative method examining five different factors: diet, body weight, stratum occupied, activity cycle, and habitat, as well as three different visitor categories: small and quiet audience, medium size audience and medium noise, and large size and loud audience. Significant changes in the behaviour for each factor, especially increases in locomotor and resting behaviour, were observed in response to different visitor categories. The factors that most explained responses to visitor categories were habitat and activity cycle. Species from closed habitats compared to open habitats were significantly more impacted (more behaviour affected), probably, because they are, evolutionarily, less accustomed to visual contact with people. Diurnal species showed more behavioural changes than nocturnal ones, possibly, because they were being observed during their normal activity cycle. These results may help zoos identify which mammal species are most susceptible to the zoo visitor effect, and consequently, be more pro-active in the use of mitigating strategies.

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Tripovich, Joy S., Tracey L. Rogers e Geoff Dutton. "Faecal testosterone concentrations and the acoustic behaviour of two captive male Australian fur seals". Australian Mammalogy 31, n. 2 (2009): 117. http://dx.doi.org/10.1071/am09009.

Testo completo

Abstract (sommario):

Seasonal changes in reproductive and acoustic behaviour are potentially affected by hormonal fluctuations; however, as it is difficult to routinely sample marine mammals, these associations are mostly inferred. Australian fur seals are vocal marine mammals that have a highly synchronous breeding season. The present study collected information on the testosterone concentration in faeces, vocalisations and behaviour of two captive male Australian fur seals to determine whether there are any associations between these variables. Positive associations were evident between the non-interactive agonistic behaviours (Head sway, Lay down and Head up) and an increase in calling rate of the bark calls in males. Barks were highest during August through to October, corresponding to the breeding period, while faecal testosterone levels peaked in September, coinciding with the high frequency in the calling rates of barks. Guttural threat calls were rarely heard throughout the year, but peaked in August. This call was not frequently heard but was associated with specific behaviours that were produced during more intense fighting interactions. This study presents preliminary information on the vocalisations, behaviour and hormone profiles for two captive Australian fur seals. Future studies with increased sample sizes from both wild and captive animals would clarify the intricate association between these factors.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Banks, Peter B., Alexandra J. R. Carthey e Jenna P. Bytheway. "Australian native mammals recognize and respond to alien predators: a meta-analysis". Proceedings of the Royal Society B: Biological Sciences 285, n. 1885 (22 agosto 2018): 20180857. http://dx.doi.org/10.1098/rspb.2018.0857.

Testo completo

Abstract (sommario):

Prey naiveté is a failure to recognize novel predators and thought to cause exaggerated impacts of alien predators on native wildlife. Yet there is equivocal evidence in the literature for native prey naiveté towards aliens. To address this, we conducted a meta-analysis of Australian mammal responses to native and alien predators. Australia has the world's worst record of extinction and declines of native mammals, largely owing to two alien predators introduced more than 150 years ago: the feral cat, Felis catus , and European red fox, Vulpes vulpes . Analysis of 94 responses to predator cues shows that Australian mammals consistently recognize alien foxes as a predation threat, possibly because of thousands of years of experience with another canid predator, the dingo, Canis lupus dingo . We also found recognition responses towards cats; however, in four of the seven studies available, these responses were of risk-taking behaviour rather than antipredator behaviour. Our results suggest that a simple failure to recognize alien predators is not behind the ongoing exaggerated impacts of alien predators in Australia. Instead, our results highlight an urgent need to better understand the appropriateness of antipredator responses in prey towards alien predators in order to understand native prey vulnerability.

Gli stili APA, Harvard, Vancouver, ISO e altri

29

MØLLER, A. P., e T. R. BIRKHEAD. "Copulation behaviour in mammals: evidence that sperm competition is widespread". Biological Journal of the Linnean Society 38, n. 2 (ottobre 1989): 119–31. http://dx.doi.org/10.1111/j.1095-8312.1989.tb01569.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Rosen, David A. S., Arliss J. Winship e Lisa A. Hoopes. "Thermal and digestive constraints to foraging behaviour in marine mammals". Philosophical Transactions of the Royal Society B: Biological Sciences 362, n. 1487 (maggio 2007): 2151–68. http://dx.doi.org/10.1098/rstb.2007.2108.

Testo completo

Abstract (sommario):

While foraging models of terrestrial mammals are concerned primarily with optimizing time/energy budgets, models of foraging behaviour in marine mammals have been primarily concerned with physiological constraints. This has historically centred on calculations of aerobic dive limits. However, other physiological limits are key to forming foraging behaviour, including digestive limitations to food intake and thermoregulation. The ability of an animal to consume sufficient prey to meet its energy requirements is partly determined by its ability to acquire prey (limited by available foraging time, diving capabilities and thermoregulatory costs) and process that prey (limited by maximum digestion capacity and the time devoted to digestion). Failure to consume sufficient prey will have feedback effects on foraging, thermoregulation and digestive capacity through several interacting avenues. Energy deficits will be met through catabolism of tissues, principally the hypodermal lipid layer. Depletion of this blubber layer can affect both buoyancy and gait, increasing the costs and decreasing the efficiency of subsequent foraging attempts. Depletion of the insulative blubber layer may also increase thermoregulatory costs, which will decrease the foraging abilities through higher metabolic overheads. Thus, an energy deficit may lead to a downward spiral of increased tissue catabolism to pay for increased energy costs. Conversely, the heat generated through digestion and foraging activity may help to offset thermoregulatory costs. Finally, the circulatory demands of diving, thermoregulation and digestion may be mutually incompatible. This may force animals to alter time budgets to balance these exclusive demands. Analysis of these interacting processes will lead to a greater understanding of the physiological constraints within which the foraging behaviour must operate.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Hollén, Linda I., e Andrew N. Radford. "The development of alarm call behaviour in mammals and birds". Animal Behaviour 78, n. 4 (ottobre 2009): 791–800. http://dx.doi.org/10.1016/j.anbehav.2009.07.021.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Cowan, P. E., e C. H. Tyndale-Biscoe. "Australian and New Zealand mammal species considered to be pests or problems". Reproduction, Fertility and Development 9, n. 1 (1997): 27. http://dx.doi.org/10.1071/r96058.

Testo completo

Abstract (sommario):

In New Zealand and Australia, 25 and 16 introduced mammals are viewed as pests, respectively, as well as a further 17 native mammals in Australia. Most introductions were deliberate and the deleterious effects became apparent later. These pests affect primary production, act as a sylvatic reservoir of disease, cause degradation of natural ecosystems, or threaten rare or endangered native animals and plants. Many species have multiple impacts. In Australia, some native mammals, particularly kangaroos and wallabies, are also controlled because of their adverse impacts on primary production. In both countries, current control depends largely on the use of poisons, shooting, the spread of disease (in the case of rabbits), trapping, habitat alteration, and commercial or recreational hunting. Methods of control by interfering with fertility (immunocontraception) are currently being investigated for rabbits, house mice, foxes, and kangaroos in Australia, and for the brushtail possum in New Zealand. If these methods prove effective, they may be applied to other mammal pests, but the need to tailor the particular approach to the ecology and behaviour of the species means that there will be a necessarily long lead time

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Hocking, David P., Felix G. Marx, Travis Park, Erich M. G. Fitzgerald e Alistair R. Evans. "A behavioural framework for the evolution of feeding in predatory aquatic mammals". Proceedings of the Royal Society B: Biological Sciences 284, n. 1850 (marzo 2017): 20162750. http://dx.doi.org/10.1098/rspb.2016.2750.

Testo completo

Abstract (sommario):

Extant aquatic mammals are a key component of aquatic ecosystems. Their morphology, ecological role and behaviour are, to a large extent, shaped by their feeding ecology. Nevertheless, the nature of this crucial aspect of their biology is often oversimplified and, consequently, misinterpreted. Here, we introduce a new framework that categorizes the feeding cycle of predatory aquatic mammals into four distinct functional stages (prey capture, manipulation and processing, water removal and swallowing), and details the feeding behaviours that can be employed at each stage. Based on this comprehensive scheme, we propose that the feeding strategies of living aquatic mammals form an evolutionary sequence that recalls the land-to-water transition of their ancestors. Our new conception helps to explain and predict the origin of particular feeding styles, such as baleen-assisted filter feeding in whales and raptorial ‘pierce’ feeding in pinnipeds, and informs the structure of present and past ecosystems.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Warnock-Juteau, Kendra, Valérie Bolduc, Daniella LoScerbo, Michelle Anderson, Caroline Daguet e Jochen A. G. Jaeger. "Co-use of existing crossing structures along roads by wildlife and humans: Wishful thinking?" Nature Conservation 47 (25 marzo 2022): 235–70. http://dx.doi.org/10.3897/natureconservation.47.73060.

Testo completo

Abstract (sommario):

This study assesses existing human-purpose underpasses below an unfenced high-traffic 4-lane highway in the Appalachian region of Quebec, Canada, as potential crossing structures for native mammal species. Eight underpasses of three types (five water culverts with minimum height and width of 1.8 m, one low-use gravel road byway, and two railroad underpasses) were continuously monitored by motion-detection infrared camera traps for time periods spanning up to 778 days (September 2016 to November 2018). We asked how the ratios of successful crossings through the structures (termed full crossings) and aversions to the structures (termed aversions) differed between species and we explored the influence of human activity levels on the use of these structures by wildlife. All monitored crossing structures had low human observations (with averages of less than 35 human activities per day). Our results provide evidence that 21 species of mammals in the study area successfully crossed through at least one of the eight observed underpasses on a minimum of one occasion. Some species were observed crossing through some of the underpasses on a regular basis, namely raccoon, red fox, and white-tailed deer. We propose a classification of mammal species into five human co-use classes (no or low co-use to very high co-use) to explore the relationship between mammal use of the structures and human presence. We found that humans and mammals were observed sharing passages for the four mammal species identified as tolerant of human co-use (high and very high co-use classes), but co-use was observed to be limited or not occurring for most other species. The strengths of this study include the length of time during which monitoring took place, as well as the placement of four cameras at each structure (two facing inward and two facing outward) to determine whether individuals successfully crossed through the structures or displayed avoidance behaviour. The results suggest select species of mammals show some co-use with humans at existing underpasses. The activity patterns of mammals documented over the two-year study can assist with future estimates of highway permeability. Further, measurements of human and mammal co-use have species-specific implications for retrofitting existing structures and constructing wildlife fences and purpose-built wildlife passages.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Dickman, Christopher R., Sarah M. Legge e John C. Z. Woinarski. "Assessing Risks to Wildlife from Free-Roaming Hybrid Cats: The Proposed Introduction of Pet Savannah Cats to Australia as a Case Study". Animals 9, n. 10 (14 ottobre 2019): 795. http://dx.doi.org/10.3390/ani9100795.

Testo completo

Abstract (sommario):

Hybrid cats—created by crossing different species within the family Felidae—are popular pets, but they could potentially threaten native species if they escape and establish free-roaming populations. To forestall this possibility, the Australian government imposed a specific ban on importation of the savannah cat, a hybrid created by crossing the domestic cat Felis catus and serval Leptailurus serval, in 2008. We develop a decision–framework that identifies those species of non-volant native mammals in Australia that would likely have been susceptible to predation by savannah cats if importation and establishment had occurred. We assumed that savannah cats would hunt ecologically similar prey to those that are depredated by both the domestic cat and the serval, and categorised native mammals as having different levels of susceptibility to predation by savannah cats based on their size, habitat range, and behaviour. Using this framework, we assessed savannah cats as likely to add at least 28 extant native mammal species to the 168 that are known already to be susceptible to predation by the domestic cat, posing a risk to 91% of Australia’s extant non-volant terrestrial mammal species (n = 216) and to 93% of threatened mammal species. The framework could be generalised to assess risks from any other hybrid taxa.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Pineda-Munoz, Silvia, e John Alroy. "Dietary characterization of terrestrial mammals". Proceedings of the Royal Society B: Biological Sciences 281, n. 1789 (22 agosto 2014): 20141173. http://dx.doi.org/10.1098/rspb.2014.1173.

Testo completo

Abstract (sommario):

Understanding the feeding behaviour of the species that make up any ecosystem is essential for designing further research. Mammals have been studied intensively, but the criteria used for classifying their diets are far from being standardized. We built a database summarizing the dietary preferences of terrestrial mammals using published data regarding their stomach contents. We performed multivariate analyses in order to set up a standardized classification scheme. Ideally, food consumption percentages should be used instead of qualitative classifications. However, when highly detailed information is not available we propose classifying animals based on their main feeding resources. They should be classified as generalists when none of the feeding resources constitute over 50% of the diet. The term ‘omnivore’ should be avoided because it does not communicate all the complexity inherent to food choice. Moreover, the so-called omnivore diets actually involve several distinctive adaptations. Our dataset shows that terrestrial mammals are generally highly specialized and that some degree of food mixing may even be required for most species.

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Vernes, Karl, e Peter Jarman. "Long-nosed potoroo (Potorous tridactylus) behaviour and handling times when foraging for buried truffles". Australian Mammalogy 36, n. 1 (2014): 128. http://dx.doi.org/10.1071/am13037.

Testo completo

Abstract (sommario):

Truffles represent an important food resource for many small mammals, but because most mycophagous mammals are difficult to observe in the wild, behavioural observations of mammals handling and consuming truffles are almost non-existent. Using camera traps, we observed the behaviour of long-nosed potoroos (Potorous tridactylus) foraging for buried truffles, and recorded the rate at which truffles were excavated and consumed. Potoroos excavated buried truffles rapidly (2.4 ± 0.2 s) with synchronous drawing strokes of their forepaws, then gathered the excavated truffles with forepaws and/or mouth and cleaned away adherent debris before consuming the truffle. When potoroos were unsuccessful at recovering a truffle, they spent significantly more time digging (4.8 ± 0.6 s) before giving up. Potoroos were successful at recovering a truffle in 76% of digging attempts, and once they had located a cache of buried truffles, achieved a rate of recovery of ~2.4 truffles per minute.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

Briscoe, Natalie J., Kathrine A. Handasyde, Stephen R. Griffiths, Warren P. Porter, Andrew Krockenberger e Michael R. Kearney. "Tree-hugging koalas demonstrate a novel thermoregulatory mechanism for arboreal mammals". Biology Letters 10, n. 6 (giugno 2014): 20140235. http://dx.doi.org/10.1098/rsbl.2014.0235.

Testo completo

Abstract (sommario):

How climate impacts organisms depends not only on their physiology, but also whether they can buffer themselves against climate variability via their behaviour. One of the way species can withstand hot temperatures is by seeking out cool microclimates, but only if their habitat provides such refugia. Here, we describe a novel thermoregulatory strategy in an arboreal mammal, the koala Phascolarctos cinereus. During hot weather, koalas enhanced conductive heat loss by seeking out and resting against tree trunks that were substantially cooler than ambient air temperature. Using a biophysical model of heat exchange, we show that this behaviour greatly reduces the amount of heat that must be lost via evaporative cooling, potentially increasing koala survival during extreme heat events. While it has long been known that internal temperatures of trees differ from ambient air temperatures, the relevance of this for arboreal and semi-arboreal mammals has not previously been explored. Our results highlight the important role of tree trunks as aboveground ‘heat sinks’, providing cool local microenvironments not only for koalas, but also for all tree-dwelling species.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Dulac, Catherine, e A. Thomas Torello. "Molecular detection of pheromone signals in mammals: from genes to behaviour". Nature Reviews Neuroscience 4, n. 7 (luglio 2003): 551–62. http://dx.doi.org/10.1038/nrn1140.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

40

HALSEY, L. G., T. M. BLACKBURN e P. J. BUTLER. "A comparative analysis of the diving behaviour of birds and mammals". Functional Ecology 20, n. 5 (ottobre 2006): 889–99. http://dx.doi.org/10.1111/j.1365-2435.2006.01170.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Kobayashi, Hisato, Katsutaka Oishi, Shuji Hanai e Norio Ishida. "Effect of feeding on peripheral circadian rhythms and behaviour in mammals". Genes to Cells 9, n. 9 (settembre 2004): 857–64. http://dx.doi.org/10.1111/j.1365-2443.2004.00769.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Donkor, Noble T. "Behaviour and Ecology of Riparian Mammals. Nigel Dunstone , Martyn L. Gorman". Quarterly Review of Biology 75, n. 2 (giugno 2000): 195. http://dx.doi.org/10.1086/393433.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

43

NOWACEK, DOUGLAS P., e PETER L. TYACK. "ASSESSING EFFECTS OF ANTHROPOGENIC NOISE ON THE BEHAVIOUR OF MARINE MAMMALS". Bioacoustics 17, n. 1-3 (gennaio 2008): 338–41. http://dx.doi.org/10.1080/09524622.2008.9753869.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Costa, Daniel P., Carey E. Kuhn, Michael J. Weise, Scott A. Shaffer e John P. Y. Arnould. "When does physiology limit the foraging behaviour of freely diving mammals?" International Congress Series 1275 (dicembre 2004): 359–66. http://dx.doi.org/10.1016/j.ics.2004.08.058.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Kortmulder, Koenraad, e Jacob Dubbeldam. ""Teder" behaviour (tenderness) – an exploration into the neural pathways of mild touch perception in mammals and birds". Animal Biology 59, n. 1 (2009): 55–65. http://dx.doi.org/10.1163/157075609x417099.

Testo completo

Abstract (sommario):

AbstractA category of teder interaction is proposed as the main source of (mutual) mild touch stimuli in higher vertebrates. The somatosensory circuits for the perception of these stimuli in mammals and birds are discussed using data from the literature. In addition to the usual somatosensory areas of the brain, in mammals mild touch signals are also conducted to the insula, which is closely connected to the limbic system. This separate processing of mild touch stimuli lends more substance to the category of teder behaviour. The comparable neuroanatomy in birds is more difficult to interpret. There are some intriguing parallels between the relevant circuits of mammals and birds, though in the telencephalic parts in particular, conclusions are limited by uncertainties as to the homologies of the mammalian and avian brains.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Fitzpatrick, Leah Lucy Joscelyne, Vincent Nijman, Rodrigo Ligabue-Braun e K. Anne-Isola Nekaris. "The Fast and the Furriest: Investigating the Rate of Selection on Mammalian Toxins". Toxins 14, n. 12 (1 dicembre 2022): 842. http://dx.doi.org/10.3390/toxins14120842.

Testo completo

Abstract (sommario):

The evolution of venom and the selection pressures that act on toxins have been increasingly researched within toxinology in the last two decades, in part due to the exceptionally high rates of diversifying selection observed in animal toxins. In 2015, Sungar and Moran proposed the ‘two-speed’ model of toxin evolution linking evolutionary age of a group to the rates of selection acting on toxins but due to a lack of data, mammals were not included as less than 30 species of venomous mammal have been recorded, represented by elusive species which produce small amounts of venom. Due to advances in genomics and transcriptomics, the availability of toxin sequences from venomous mammals has been increasing. Using branch- and site-specific selection models, we present the rates of both episodic and pervasive selection acting upon venomous mammal toxins as a group for the first time. We identified seven toxin groups present within venomous mammals, representing Chiroptera, Eulipotyphla and Monotremata: KLK1, Plasminogen Activator, Desmallipins, PACAP, CRiSP, Kunitz Domain One and Kunitz Domain Two. All but one group (KLK1) was identified by our results to be evolving under both episodic and pervasive diversifying selection with four toxin groups having sites that were implicated in the fitness of the animal by TreeSAAP (Selection on Amino Acid Properties). Our results suggest that venomous mammal ecology, behaviour or genomic evolution are the main drivers of selection, although evolutionary age may still be a factor. Our conclusion from these results indicates that mammalian toxins are following the two-speed model of selection, evolving predominately under diversifying selection, fitting in with other younger venomous taxa like snakes and cone snails—with high amounts of accumulating mutations, leading to more novel adaptions in their toxins.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Amrein, Irmgard, e Hans-Peter Lipp. "Adult hippocampal neurogenesis of mammals: evolution and life history". Biology Letters 5, n. 1 (28 ottobre 2008): 141–44. http://dx.doi.org/10.1098/rsbl.2008.0511.

Testo completo

Abstract (sommario):

Substantial production of new neurons in the adult mammalian brain is restricted to the olfactory system and the hippocampal formation. Its physiological and behavioural role is still debated. By comparing adult hippocampal neurogenesis (AHN) across many mammalian species, one might recognize a common function. AHN is most prominent in rodents, but shows considerable variability across species, being lowest or missing in primates and bats. The latter finding argues against a critical role of AHN in spatial learning and memory. The common functional denominator across all species investigated thus far is a strong decline of AHN from infancy to midlife. As predicted by Altman and colleagues in 1973, this implies a role in transforming juvenile unpredictable to predictable behaviour, typically characterizing mammalian behaviour once reproductive competence has been attained. However, as only a fraction of mammalian species has been investigated, further comparative studies are necessary in order to recognize whether AHN has a common unique function, or whether it mediates species-specific hippocampal functions.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Reggente, Melissa A. L. V., Elena Papale, Niall McGinty, Lavinia Eddy, Giuseppe Andrea de Lucia e Chiara Giulia Bertulli. "Social relationships and death-related behaviour in aquatic mammals: a systematic review". Philosophical Transactions of the Royal Society B: Biological Sciences 373, n. 1754 (16 luglio 2018): 20170260. http://dx.doi.org/10.1098/rstb.2017.0260.

Testo completo

Abstract (sommario):

Some aquatic mammals appear to care for their dead, whereas others abandon their live offspring when conditions are unfavourable. This incredible variety in behaviours suggests the importance of comparing and contrasting mechanisms driving death-related behaviours among these species. We reviewed 106 cases of aquatic mammals (81 cetaceans and 25 non-cetaceans) reacting to a death event, and extrapolated ‘participant’ ( age class , sex , relationship and decomposition ) and ‘social’ characteristics ( escorting , calf dependence , alloparental care , herding and dispersal patterns ) from published and unpublished literature. A multiple correspondence analysis (MCA) was performed to explore the relationships between these characteristics and death-related behaviours, with species clustered based on MCA scores. Results showed that both cetaceans and non-cetaceans react to death but in different ways. Non-cetaceans, characterized by a short maternal investment, were observed to protect the dead (defending it from external attacks), while cetaceans spent much longer with their offspring and display carrying (hauling, spinning, mouthing with the carcass and diving with it) and breathing-related (lifting and sinking the carcass) activities with the dead generally in association with other conspecifics. Our work emphasizes the need of increased documentation of death-related cases around the world to improve our understanding of aquatic mammals and their responses to death. This article is part of the theme issue ‘Evolutionary thanatology: impacts of the dead on the living in humans and other animals’.

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Baars, B. J. "There are no Known Differences in Brain Mechanisms of Consciousness Between Humans and Other Mammals". Animal Welfare 10, S1 (febbraio 2001): S31—S40. http://dx.doi.org/10.1017/s0962728600023496.

Testo completo

Abstract (sommario):

AbstractRecent scientific findings indicate that consciousness is a fundamental biological adaptation. The known brain correlates of consciousness appear to be phylogenetically ancient, going back at least to early mammals. In all mammals, alertness and sensory consciousness are required for the goal-directed behaviours that make species survival and reproduction possible. In all mammals, the anatomy, neurochemistry and electrical activity of the brain in alert states show striking similarities.After more than seven decades of cumulative discoveries about waking and sensory consciousness, we have not yet found any fundamental differences between humans and other mammals. Species differences such as the size of neocortex seem to be irrelevant to the existence of alertness and sensory consciousness, though different mammals obviously specialize in different kinds of sensory, cognitive and motor abilities.Sceptics sometimes claim that objective evidence for consciousness tells us little about subjective experience, such as the experience of conscious pain. Scientifically, however, plausible inferences are routinely based on reliable and consistent patterns of evidence. In other humans, we invariably infer subjective experiences from objective behavioural and brain evidence - if someone yells ‘Ouch!’ after striking a finger with a hammer, we infer that they feel pain. The brain and behavioural evidence for subjective consciousness is essentially identical in humans and other mammals. On the weight of the objective evidence, therefore, subjective experience would seem to be equally plausible in all species with human-like brains and behaviour. Either we deny this experience to other humans (which is rarely done) or, to be consistent, we must also attribute it to other species that meet the same objective standards. It seems that the burden of proof for the absence of subjectivity in mammals should be placed on the sceptics.

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Pardue, M. T., J. G. Sivak e K. M. Kovacs. "Corneal anatomy of marine mammals". Canadian Journal of Zoology 71, n. 11 (1 novembre 1993): 2282–90. http://dx.doi.org/10.1139/z93-320.

Testo completo

Abstract (sommario):

The corneal anatomy of fin whales (Balaenoptera physalus), minke whales (Balaenoptera acutorostrata), harp seals (Phoca groenlandica), ringed seals (Phoca hispida), and bearded seals (Eriganthus barbatus) was examined to determine if marine mammals have evolved specialized corneas for life in a marine habitat. One to seven eyes of each species were analyzed: paraffin sections stained with haematoxylin and eosin for light microscopy; and ultrathin sections for transmission electron microscopy. All corneas contain the five typical mammalian layers: epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The corneas of these marine mammals are thicker than human corneas because of a thicker stromal layer. The other layers are thinner than those found in humans, except for the epithelial layer in the bearded seal and the cetaceans where it may provide extra protection for the eye during feeding behaviour. The epithelial cells in all corneas studied have an abundance of tonofilaments, which may strengthen the cells and distribute force across the corneal surface. No special organization of collagen fibrils was found in the stroma that would offer protection from ultraviolet radiation or glare for pinnipeds when on ice. The thickness of the sclera in the cetaceans may serve to hold the inner globe of the eye in an elliptical shape, while the thinning of the sclera in the equatorial region in pinnipeds may flatten the eye in air to reduce aerial myopia.

Gli stili APA, Harvard, Vancouver, ISO e altri

Articoli di riviste sul tema "Behaviour of mammals"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili