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1
Bowman, Timothy Dale. "Ecology of male black ducks molting in Labrador /". Orono, Me, 1987. http://www.arlis.org/docs/vol1/A/17591492.pdf.
Testo completo
2
Somerville, Alison Joan. "Advantages to late breeding in Ruddy ducks". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25045.
Testo completoAbstract (sommario):
Ruddy Ducks in the Chilcotin parklands of British Columbia nest in late June, July and early August, later than most other waterfowl species breeding in southwestern British Columbia, Canada. This thesis considers factors that may affect the timing of breeding in Ruddy Ducks by comparing Ruddy Ducks to Barrow's Goldeneye and Bufflehead (species that breed early but do not renest) and to American Coot (a species that breeds early and is able to renest). These factors include predation, flooding and desertion of nests, feeding behavior of ducklings, abundance of food, availability of green vegetation and fluctuations in temperature.
Possible advantages of late breeding include reduced nest predation and higher ambient temperature during incubation. Longer dive durations and more frequent feeding and resting by Ruddy ducklings may enable ducklings to maximize energy for growth. Reduced nest flooding late in the season, dependence on green vegetation for nesting and greater abundance of food for young in summer were not demonstrated by this study. Therefore, these factors apparently do not explain the timing of breeding in Ruddy Ducks in southwestern British Columbia.
Despite insufficient time to renest and shorter time for ducklings to mature before ponds freeze, the average number of 2B age class young produced per pair of Ruddy Ducks was similar to that of American Coots. Forty percent of nesting Ruddy females did not hatch any young, whereas almost all nesting Coot females successfully hatched young; however, survival of Ruddy ducklings to 2B age class (four weeks old) was higher than that of American Coots, Barrow's Goldeneye and Bufflehead.Science, Faculty of
Zoology, Department of
Graduate
3
Davis, Jonas Ian. "Mallard nesting ecology in the Great Lakes". CONNECT TO THIS TITLE ONLINE, 2008. http://etd.lib.umt.edu/theses/available/etd-05272008-112947/.
Testo completo
4
Gagnon, Christine. "Pathological consequences of infection by Cyathocotyle bushiensis Khan, 1962 and Sphaeridiotrema globulus (Rudolphi, 1814) in two species of dabbling ducks". Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59282.
Testo completoAbstract (sommario):
Cyathocotyle bushiensis (Digenea) and Sphaeridiotrema globulus (Digenea) are gastrointestinal pathogens of waterfowl, and are known to co-occur in salvaged ducks. The intensity and time-dependent pathogenesis induced by single infections of the two digeneans, and concurrent infections were studied in two species of dabbling ducks. Gross tissue pathology by single C. bushiensis infection was found to be a function of both the intensity and the duration of infection. Infection with single species infections of C. bushiensis and S. globulus was associated with decreased weight gain, tendencies for increased body temperatures and increased hematological parameters in Pekin ducklings. The hematological parameters in blue winged teal infected with C. bushiensis were found to decrease. Infection with S. globulus did not induce any significant systemic changes in the blue winged teal. A preliminary study of the effects of concurrent infection on the duck hosts suggests that in general, concurrent infection enhances the detrimental aspects of single infection, decreasing weight gain, increasing body temperatures, and decreasing hematological parameters in both species.
5
Hoeve, John. "Recurrent, late-summer mortality of dabbling ducks in Southern Quebec induced by the digeneans, Sphaeridiotrema globulus (Rudolphi, 1814) and Cyathocotyle bushiensis Khan, 1962". Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66131.
Testo completo
6
Pockley, Simon Charles Nepean. "The flight of ducks research report". [Melbourne] : S. Pockley, 1998. http://purl.nla.gov.au/nla/pandora/FOD.
Testo completoAbstract (sommario):
"Submitted by Simon Charles Nepean Pockley ... as a partial requirement for Degree of Doctor of Philosophy by Project 18th July, 1998". "WARNING culturally sensitive material". Available [on line] http://www.cinemedia.net/FOD/FOD0043.html Archived at ANL http://purl.nla.gov.au/nla/pandora/FOD http Text, graphics, sound and animation The Flight of ducks is a multi-purpose on-line work built around a collection of archival material from a camel expedition into the central Australian frontier in 1933. This journey was revisited in 1976 and retraced in 1996."- leaf 1.
7
Warnock, Jeffrey P. "Ducks, cups, bushes, planters, and statues". The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1382711430.
Testo completo
8
Benlashehr, Imad. "Fumonisin toxicity in ducks and turkeys". Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0070/document.
Testo completoAbstract (sommario):
Les fumonisines (FBs) sont les principales mycotoxines produites par Fusarium verticillioides et Fusarium proliferatum, qui se retrouvent partout dans le monde dans le maïs et ses produits dérivés. Les doses toxiques et les signes cliniques de toxicité provoqués par les FBs varient dune espèce à lautre. La toxicité des FBs est généralement liée à leur capacité à bloquer le métabolisme des sphingolipides chez les espèces animales, y compris chez les espèces aviaires. De précédentes études ont démontré que les canards présentent une plus grande sensibilité à la toxicité des FBs que les dindes, alors que laccumulation de sphinganine (Sa) dans les tissues est plus importante chez les dindes que chez les canards. Lobjectif de nos travaux était de comprendre les différences de toxicité entre les dindes et les canards los dune exposition aux FBs. Les trois hypothèses suivantes ont été explorées : i) La toxicocinétique de la fumonisine B2 chez les dindes et les canards. ii) La capacité des cellules aviaires à se protéger de limportante accumulation de sphingolipides libres en augmentant leur catabolisme (phosphorylation). iii) Des mécanismes de toxicité des FBs autre que leur altération via le métabolisme des sphingolipides (stress oxydatif et les réponses inflammatoires). Lanalyse des paramètres de toxicocinétique de la fumonisine B2 na pas mis en évidence de différence significative entre les dindes et les canards. Les mesures de la toxicité simultanée de plusieurs FBs chez les dindes et les canards ont confirmé la forte sensibilité des canards. Laccumulation de shingasine-1-phosphate (Sa1P) dans le foie a également été corrélée avec la quantité de Sa mais pas avec les paramètres hépatiques de toxicité. De plus cette étude a mis en évidence que la quantité de Sa dans le foie était fortement dépendante de la teneur en FBs. Cependant les FBs nont eu aucun effet sur les paramètres de stress oxydatif pour les deux espèces. De manière intéressante, les FBs ont eu une légère réponse inflammatoire chez les canards mais pas chez les dindes. Des investigations plus poussées sur les effets des FBs sur le métabolisme des céramides et sur les processus inflammatoires seraient nécessaires pour comprendre les différences de toxicité entre les dindes et les canards exposés aux FBsFumonisins (FBs) are the major mycotoxins produced by Fusarium verticillioides and Fusarium proliferatum, which are found worldwide in maize and maize products. FBs toxic dose and clinical signs of toxicity vary from one species to another. FBs toxicity is commonly linked to their ability on blocking sphingolipids metabolism in all animal species, including avian species. Previous studies have demonstrated that ducks exhibit higher sensitivity to FBs toxicity than turkeys, whereas, the accumulation of sphinganine (Sa) in tissues is more pronounced in turkeys than in ducks. The objectives of our works were to investigate the causes which lead to different toxicity between ducks and turkeys to FBs exposure. The following three hypotheses were investigated: i) Toxicokinetics of fumonisin B2 in ducks and turkeys. ii) Ability of bird cells to protect themselves against high accumulation of free sphingolipids by increasing their catabolism (phosphorylation). iii) Other toxicity mechanisms of FBs rather than their alteration of sphingolipids metabolism (oxidative stress damage and inflammatory responses). The analysis of toxicokinetic parameters of fumonisin B2 did not provide a significant difference between ducks and turkeys. The measurement of simultaneous toxicity of FBs in ducks and turkeys confirmed higher sensibility of ducks. Also the accumulation of Sphingasine-1-Phosphate (Sa1P) in the liver correlated with the amount of Sa but not parameters of hepatic toxicity. Moreover, this study revealed that the amount of Sa in the liver was strongly dependent on the amount of FBs. On the other hand, FBs had no effect on oxidative damages parameters in both species. Interestingly, FBs had mild inflammatory response effect in ducks but not in turkeys. Further investigation on the effects of FBs on ceramide metabolism and inflammatory processes would be necessary to understand the different toxicity between ducks and turkeys to FBs exposure
9
Smith, Cyndi. "Survival and recruitment of juvenile Harlequin Ducks". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0023/MQ51472.pdf.
Testo completo
10
Farhat, Antoine G. "Nutritional evaluation of industrial food wastes in ducks diets". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0006/MQ29689.pdf.
Testo completo
11
Furilla, Robert Alan. "Control of heart rate during diving in ducks". Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27077.
Testo completoAbstract (sommario):
Forced submergence of redhead ducks (Aythya americana)
caused heart rate to fall from 100 ± 3 beats⋅min⁻ ¹ (mean ±
s.e.m., N = 12) to a stable rate of 35 ± 4 beats⋅min⁻ ¹ (N =
12) within 5 seconds after submergence. Bradycardia was
unaffected by breathing oxygen before the dive or by
denervation of the baroreceptors, but was virtually eliminated
by local anaesthesia of the narial region. When freely diving
on a man-made pond, heart rate of redhead ducks and lesser
scaup (A. affinis) two seconds after submergence was
positively correlated with the pre-dive rate (r² = 0.71). Breathing oxygen before the dive and denervation of baroreceptors had little effect on this relationship. Chasing to induce submergence caused a slight enhancement of bradycardia, heart rate during the dive being about 10% lower than after a voluntary dive. Local anaesthesia of the narial region inhibited voluntary diving, but heart rates in chase-induced dives after nasal blockade were significantly higher (10-30%) than those obtained from untreated ducks in chase-induced dives.
Dive heart rate, at 2-5 seconds submergence, was linearly related to the logarithm of the pre-dive rate for all voluntary and forced dives as well as dabbles. Even the heart rate which occurred 2-5 seconds after being trapped under water as a function of the rate immediately before trapping fitted this relationship. The function was described by the equation Y = -451 + 246 LOG X, where Y = dive (or trapped) and
X = pre-dive (or pre-trap) heart rate (r² = 0.98). The relationship was unaltered by β-blockade with propranolol. Data from stimulation of the cut distal ends of vagal and cardiac sympathetic nerves suggest that a similar increase in vagal activity occurs on submergence in all of these dives. The first cardiac interval in voluntary dives represents a lower heart rate, indicating a higher level of vagal activity.
When dabbling ducks (Anas platyrhynchos) dabble, heart rate at two seconds submergence is little changed from the pre-dabble rate. When these birds dive, however, heart rate at two seconds submergence is about 250 beats⋅min⁻ ¹, regardless of the pre-dive rate. Bilateral denervation of arterial baroreceptors significantly altered the dive:pre-dive relationship .
These results have shown that nasal receptors are responsible for bradycardia in diving ducks when forcibly submerged, but that nasal receptors contribute little to the change in heart rate when ducks dive voluntarily. The results also suggest that there is a psychogenic modulation of the heart rate in voluntary dives which influences the pre-dive rather than the dive heart rate. Finally, dabbling ducks differ from diving ducks in their response to forced and voluntary diving. Chemoreceptors are responsible for the majority of the response in forced dives, and baroreceptors provide primary control in voluntary dives.Science, Faculty of
Zoology, Department of
Graduate
12
Reichart, Letitia Marie. "Conspecific brood parasitism in ruddy ducks (Oxyura jamaicensis)". Online access for everyone, 2008. http://www.dissertations.wsu.edu/Dissertations/Summer2008/L_Reichart_072408.pdf.
Testo completo
13
Martinho, Antone. "Ducks and decussation : information in the avian brain". Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:342aeaab-726a-4410-b417-2d2d8115675a.
Testo completoAbstract (sommario):
A vertebrate brain must acquire, store, and process vast amounts of information. For birds, the majority of the incoming sensory information is visual, and like all vertebrates - except eutherian mammals - their visual system is bifurcated, with each eye feeding incoming information to the contralateral brain hemisphere. As a result, the bird must integrate these two banks of information to produce unified responses. This arrangement raises several questions about how a bird acquires, manages, and represents incoming visual information, and this thesis explores three of these questions. First, two studies investigate information integration across the two brain hemispheres in a long-term and short-term assay of birds trained monocularly with one eye and then tested with the other. The first finds that over a long term learning task in pigeons, some interhemispheric transfer of learned information occurs, but that complete integration does not occur. The second, using imprinting in ducklings, shows that the eye occluded during training has no demonstrable access to the learned information for at least three hours. A third study demonstrates that New Caledonian crows hold tools laterally in order to prioritize visual contact with the tool by their dominant eye during foraging, offering a potential underlying cause of this previously unexplained behavioural laterality. The fourth study explores the nature of information itself in the avian brain, showing that the maternal imprint formed by a newly hatched duckling can include abstract concepts defining the maternal stimulus, rather than just memory for visual images. This extends relational concept learning to a new species and suggests a much broader phylogenetic distribution of this ability. Combined, the studies suggest that the avian brain coordinates action managing two somewhat independent banks of information, biasing body positions in monocular tasks to allow control by a preferred eye, and has hitherto unsuspected capacity for abstract concept formation.
14
Silverman, Emily Davies. "Ducks in the muck : models of waterfowl aggregation /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/6376.
Testo completo
15
Shimizu, Manabu. "Acid-base balance in arterial plasma of white Pekin duck (Anas platyrhynchos) during forced submergence and recovery". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25044.
Testo completoAbstract (sommario):
Acid-base balance in plasma was studied in forcibly submerged Pekin ducks (Anas platyrhynchos). All important variables determining acid-base balance (arterial CO₂ tension (PαCO₂) strong ion difference ([SID]) and total protein content which approximates total weak acid concentration in plasma) were measured.
During forced submergence PαCO₂ increased and pHa steadily decreased with time. There was also an increase in [lactate⁻], which was accompanied by an increase of equal magnitude in [Na⁺]. There were no significant changes in the concentrations of other strong ions (K⁺, Ca²⁺, Mg²⁺ and Cl⁻). Strong ion difference did not change during the first two minutes of submergence, but there was about a 4 mequiv/L increase by the end of the four-minute dive. Theoretically an increase in [SID] should cause plasma to be alkaline, but since plasma became progressively acidic, this condition can only be due to the increase in PαCO₂.
During recovery from dives, the plasma remained as acidic one minute after emersion as at the end of the dives. On the other hand, arterial pH slowly increased towards the pre-dive level during recovery. Arterial CO₂ tension decreased much more rapidly and was already at or below the pre-dive level one minute after emersion. Therefore, PαCO₂ could no longer affect plasma pH. There was, however, a great increase in [lactate-] in the first minute of recovery. Although [Na⁺] and [K⁺] were elevated, from pre-dive values after the four minute dive, the increase in [lactate⁻] resulted in a marked reduction in [SID]. Since there was no change in the total plasma protein content, the acidic condition observed in recovery could only be due to decreased [SID]. Breathing 0₂ before diving prevented circulatory adjustments and pH returned to pre-dive levels one minute after emersion, confirming that the acidic condition observed in recovery is a consequence of the lactate produced in the hypoperfused tissues during submergence.Science, Faculty of
Zoology, Department of
Graduate
16
Men, Bui Xuan. "Feeding and management systems for smallholder duck production in the Mekong Delta of Vietnam /". Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009768689&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Testo completo
17
DiBona, Matthew T. "Seasonal food availability for wintering and migrating dabbling ducks and its implications for management at the Hackensack Meadowlands of New Jersey". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 104 p, 2008. http://proquest.umi.com/pqdweb?did=1459904201&sid=12&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Testo completo
18
Evans, Darren Mark. "The ecology and spatial dynamics of wintering waterfowl on Lough Neagh". Thesis, University of Ulster, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268567.
Testo completo
19
Henderson, Jane Victoria. "Flocking behaviour of ducks in response to predator stimuli". Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284861.
Testo completo
20
Lavallée, Sophie. "Application of ultrasound technology for selection and production of lean Pekin ducks". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0002/MQ44202.pdf.
Testo completo
21
Manson, Fiona J. "Life history traits, social mating system and genetic variation in the buff-banded rail Gallirallus philippensis on Heron island /". St. Lucia, Qld, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17757.pdf.
Testo completo
22
Ménard, Louise. "Aspects of the ecology of the larval stages of Cyathocotyle bushiensis Khan 1962 (Digenea)". Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66176.
Testo completo
23
Lepitzki, Dwayne Allen William. "Epizootiology and transmission of snail-inhabiting metacercariae of the duck digeneans Cyathocotyle bushiensis and Sphaeridiotrema globulus". Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41160.
Testo completoAbstract (sommario):
Cyathocotyle bushiensis and Sphaeridiotrema globulus were previously implicated in the annual mortality of wild ducks in southern Quebec. Of 21 snail species collected from nine aquatic communities in southern Quebec and southeastern Ontario, May to October 1989 and 1990, only Bithynia tentaculata was heavily and consistently infected with C. bushiensis metacercariae. Although infection levels varied spatially, a consistent concave seasonal pattern of prevalence and abundance was found which may be due to overwintering metacercariae and the almost simultaneous onset of cercarial transmission and recruitment of new snails in mid-summer. Even though S. globulus metacercariae were found in 18 of 21 snail species, B. tentaculata is believed to contribute most to transmission to ducks. The variety of seasonal patterns and large scale spatial heterogeneity in the prevalence and abundance of S. globulus suggested that cercariae may be from more than one source. Some of the spatial variation in metacercarial levels may be due to small scale processes; extensive spatial heterogeneity at a scale of 10 m was detected in S. globulus cercarial transmission to sentinel snails. This small scale heterogeneity may be due to B. tentaculata having small home ranges as suggested by mark-recapture studies on movement. In aquaria, even though smaller B. tentaculata were more active than larger ones and intraspecific microhabitat preferences were found, preliminary results from ducks (Anas discors) feeding on snail communities in pools suggested that snails are ingested in proportion to their presence. Therefore, the importance of a snail species or size class in the transmission of the two parasites to ducks may depend only on its density and metacercarial abundance. Finally, another mode of transmission is proposed for S. globulus: ducks may become infected by consuming empty snail shells containing viable cysts.
24
Lacombe, A. M. A. "Effects of circulating catecholamines on diving in ducks (Anas platyrhynchos)". Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30724.
Testo completoAbstract (sommario):
Plasma catecholamines have been measured in chronically adrenalectomised (ADX) ducks, in chronically adrenal denervated ducks (DNX), in their respective sham-operated controls (SH-adx, SH-dnx) as well as in intact ducks after 3 minutes forced submergence. The results showed that 100% of the plasma Epinephrine (EP) and 40 to 80% of plasma Norepinephrine (NE) released during the dive came from the adrenal glands. 20 to 60% of plasma NE came from endings of the autonomic vascular sympathetic nerves which are strongly stimulated during diving.
Adrenal catecholamines were released by nerve activation only; non neural mechanisms did not play any role in their release.
Maximum dive times (MDT) in chronically adrenalectomised ducks (ADX: 5 min. 19 ± 20 sec.) and in chronically adrenal denervated ducks (DNX: 7 min. 10 ± 13 sec.) were significantly
lower than in sham-operated controls (respectively SH-adx: 9 min. 58 ± 45 sec., SH-dnx: 12 min. 10 ± 28 sec). Venous infusion of catecholamines in ADX and DNX during the dive increased MDT: MDT of DNX ducks perfused with catecholamines (9 min. 46 ± 20 sec.) were significantly higher than in DNX perfused with saline (7 min. 21 ± 17 sec.), but did not reach the MDT observed in the SH-dnx: other adrenal products must be involved. Diving heart rates of ADX and DNX (at 4 min. dive respectively: 62 ± 16 and 31 ± 2 beats/min.) were significantly
higher than in their sham-operated controls (23 ± 3 and 17 ± 2 beats/min.) . Blood pressure during the dive was signifi-
cantly lower in ADX and DNX (at 4 min. dive respectively: 93 ± 8 and 98 ± 4 mmHg) compared with their sham-operated controls (131 ± 12 and 118 ± 6 mmHg). Infusion of catecholamines in DNX raised blood pressure towards SH-dnx values, but there was no change in heart rate. PaO₂, CaO₂, pHa and lactate levels in DNX (respectively: 42 ± 2 mmHg, 4.5 ± 0.8 ml 02 /100ml blood, 7.233 ± 0.016, 3.1 + 0.3 mM) were significantly lower than in SH-dnx after 5 minutes submergence (53 ± 1 mmHg, 6.8 ± 0.4 ml 02 /100 ml blood, 7.301 ± 0.007, 4.8 + 0.4 mM). There was also a significant increase of plasma N⁺ (+ 5.4 ± 1.7 mEq/L) in SH-dnx after 5 minutes submergence, but this was not the case in DNX where it was K⁺ (+ 1.1 ± 0.4 mEq/L) which increased. This suggested that adrenal catecholamines increase tolerance to underwater submersion by enhancing peripheral vasoconstriction,
thus preserving the O₂ stores for the heart and brain. Moreover, they may affect the acid-base equilibrium during diving by increasing the activity of the Na⁺K⁺ pump and may also have a direct effect on the rate of glycogenolysis.
Preventing the actions of catecholamines on the heart by injecting beta-blocker during forced submersion did not decrease
MDT; however the cardiovascular response was markedly affected. During beta-blockade, diving heart rate rose steadily
from 24 ± 6 beats/minute after 2 minutes to 52 ± 8 beats/minute after 6 minutes diving. In contrast, heart rates remained close to the levels reached at 2 minutes (17 ± 3 and 19 ± 4 beats/minute) throughout the control dives.
Perfusion pressure and blood flow have been recorded simultaneously in both hind limbs of ducks. One leg was perfused
with different blood mixtures devoid of catecholamines (Test leg) and compared with the other, perfused with the ducks'own blood (autoperfused leg). This showed that hyper-capnia has a depressant effect on the neural component of the peripheral vasoconstriction. Perfusion of test legs with hypoxic-hypercapnic blood to which catecholamines were added, showed that circulating catecholamines are needed to increase peripheral vasoconstriction during diving.
In summary, during forced submergence circulating catecholamines,
released mainly by the adrenal glands, compensate
for the depressant action of hypercapnia on the neural component of peripheral vasoconstriction. Maintenance of this peripheral vasoconstriction during forced diving ensures that O₂ stores are not wasted on peripheral tissues, and this explains how MDT is prolonged.Science, Faculty of
Zoology, Department of
Graduate
25
Robertson, Gregory J. "Pair formation, mating system, and winter philopatry in Harlequin Ducks". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24345.pdf.
Testo completo
26
Robb, Joseph Russell. "Physioecology of staging American black ducks and mallards in autumn /". The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487943610783118.
Testo completo
27
Perry, Cahanin Jacqueline Marie. "Abundance and Habitat Preferences of Introduced Muscovy Ducks (Cairina moschata)". Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6741.
Testo completoAbstract (sommario):
Muscovy ducks are native only to Central and South America, Mexico, and parts of southern Texas and are considered invasive in some areas outside of their native range. Although they have been introduced worldwide, they remain largely unstudied. The primary focus of this study was to relate Muscovy duck abundance to habitat characteristics of wetlands in Tampa, Florida. Muscovy abundance was measured using point count methods at 21 wetland sites that occur within an eight km radius of the University of South Florida’s main campus. Habitat features at these sites were assessed using field methods and Geographic Information Systems (GIS) (Arc 10.1v). Mann-Whitney U tests and Chi-squared tests were performed to identify significant differences between quantitative data groups. A Chi-squared test determined that there was not a positive correlation between Muscovy abundance and fountains or water regime, yet identified a significant relationship between Muscovy abundance and fencing, in which Muscovies did not frequently occupy ponds with fencing. Mann-Whitney U tests did not identify significances between Muscovy abundance and other habitat groups. Since Muscovy ducks are listed as an invasive species, identifying habitat preferences and deterrents will assist land managers and property owners with habitat modifications in preventing or controlling nuisance Muscovy populations.
28
Farhat, Antoine G. "Growth and IGF-I response to breast muscle selection by ultrasound and dietary protein programs in Pekin ducks". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ55327.pdf.
Testo completo
29
Carter, S. P. "Studies of the Goosander Mergus merganser". Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6578/.
Testo completoAbstract (sommario):
This thesis describes a series of studies to investigate the predator-prey relationships between the Goosander Mergus merganser, a fish-eating duck, and populations of game fish in northern Britain. The distribution and numbers of birds during the breeding season, in northern England and Scotland, were investigated and variations in density, between and within rivers, studied. Relationships between densities in spring and summer survey periods were also investigated. Possible biases in survey data are discussed. Studies of the growth of ducklings reared in captivity allowed estimates to be made of food and energy requirements from hatching up to approximately the time of fledging, at c70 days. Seasonal changes in the body mass and body condition of adult and immature Goosanders were investigated and daily and seasonal food and energy requirements estimated. Time-budget data were collected to investigate how birds partitioned their time between various behaviours. Of particular concern was the temporal and spatial distribution of foraging activities between and within broad habitat types, viz. rivers, standing waters known to be roost sites, and non-roost standing waters. Feeding behaviour was also recorded. The species composition of the diet and the numbers of individual fish represented, were determined by the gut analysis of 54 birds received from various sources. Possible biases in this method are discussed. For salmonids, the size of individual prey items was investigated from regression equations of fork length on vertebrae length, based on a reference collection. Conflicting evidence of damage to fisheries from other studies chiefly in North America, is re-assessed in the light of current knowledge of the population dynamics of salmonids and of results presented here. The potential contribution of depredations by Goosanders to mortality at successive life stages of fish is considered.
30
Eamer, Joan. "Winter habitat for dabbling ducks on southeastern Vancouver Island, British Columbia". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24634.
Testo completoAbstract (sommario):
This study is an examination of the use of coastal estuaries and nearby farmland as habitat by dabbling ducks (mallard and American wigeon) during migrating and wintering periods. Its aim was to identify aspects of British Columbia coastal habitat of importance to dabblers through an analysis of the ducks' movements among habitat types and through a description of where and on what ducks feed. Data were collected in 1979 and 1980 along a 30 km stretch of coastline on southeastern Vancouver Island. Results are presented in 3 parts.
Part 1 examines the relative use of farm and coastal habitat through a series of censuses conducted weekly at 8 farm and 8 coastal sites. The strong negative correlation between counts at farm and coastal sites indicates that dabblers treat them as alternative habitats. The numbers of ducks on farms was positively correlated with the area of standing water on the fields. Farm habitat, apparently preferred during warm, wet weather, was not used when fields were dry or frozen.
Part 2 is a description of feeding location on fields, at estuaries and at a shallow, nonestuarine bay. It is based on observations at selected sites at high and low tide levels. Each duck in each observation period was classified as to location and activity. Both species fed primarily in shallow water, their feeding location shifting with the tides. Both marsh and marine sections of estuaries were used extensively for feeding. The shallow bay was used especially by American wigeon at low tide in fall and early winter. The high marsh areas at estuaries were particularly attractive to mallards when flooded by exceptionally high tides. Feeding intensities were consistently high at farm sites for both species.
In Part 3, 23 mallards and 40 American wigeon were shot while feeding in estuarine locations commonly used for feeding. Analysis of gullet contents revealed that both species ate a wide variety of items. Main foods were, for mallards, seeds, invertebrates and green algae and, for American wigeon, green algae, roots, seeds and green vegetation. Algae and marine Invertebrates are not usually considered to be important dabbler foods in estuaries.
Major conclusions and recommendations are:
1) Both farm and coastal sites are important to dabblers, with fields being favoured as feeding locations under good flood conditions and coastal habitat being vital during dry or freezing periods. As dabblers move among sites, assessment and management of wintering dabbler habitat should be by wetland complexes rather than by individual estuaries.
2) Dabblers feed in or near shallow water. Fields that do not flood are not worth maintaining as dabbler habitat. Assessment of estuarine
marshes should consider the availability of food at all points of the tidal cycle.
3) As both species feed on a wide variety of items, factors affecting shallow water flooding and thus food availability are more important
than plant species composition.
4) Marine deltas and beaches are important as refuges from disturbance and as feeding grounds. They form an integral part of dabbler coastal habitat.Science, Faculty of
Zoology, Department of
Graduate
31
Heieis, Mark Rudolf Alois. "Blood volume distribution in and bioenergetics of swimming and diving ducks". Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26417.
Testo completoAbstract (sommario):
Blood flow distribution during forced and voluntary diving in ducks, and the energetic cost of diving was investigated.
It has been suggested that in order for the leg muscles to generate enough power for ducks to dive, blood flow to those tissues must be maintained. A technique to determine blood flow distribution which could be used during voluntary diving was first developed and tested during forced laboratory dives of ducks. This technique was then used to determine the blood flow distribution during voluntary diving. Regional blood flow distribution was visualized by utilizing a radioactive tracer technique (macro aggregated albumin labelled with ⁹⁹ⅿ technetium). The tracer when injected into an animal is trapped and held by capillaries. During forced dives in dabbling (Anas platyrhynchos) and diving (Aythya affinis) ducks the blood flow distribution was found to be restricted to the thoracic and head areas. Whereas during a voluntary dive in A. affinis blood flow distribution was shown to be preferentially directed towards three tissue areas, the heart, brain, and active leg muscles.
The work required to dive was determined from the measurement of subsurface drag forces and buoyancy in A. affinis. Subsurface drag increased as a nonlinear function of swimming velocity. At a velocity of 1 m•s⁻¹, the drag force was approximately 1.067 N. The average measured buoyant force of 11 ducks was 0.953 N. The calculated mechanical work done by ducks during a 14.4 s unrestrained dive was 9.34 J. The power output during voluntary was estimated to be 0.751 W (0.0374 ml 0₂•s⁻¹). During diving buoyancy is clearly the dominant force (8.8 J) against which ducks have to work while drag (0.54 J) adds little (~6%) to the energetic cost of diving.Science, Faculty of
Zoology, Department of
Graduate
32
Gunness, Michelle A. "Nest defence by female dabbling ducks, life history and methodological considerations". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ36929.pdf.
Testo completo
33
Tisdall, Carol. "Aggression among captive mallards and black ducks during the breeding season". Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23302.
Testo completoAbstract (sommario):
The behaviour of captive mallards (Anas platyrhynchos) and black ducks (Anas rubripes) was studied from the end of March to mid-June in 1991 and 1992 to determine the extent of interspecific aggression exhibited and the effect of sympatry and allopatry on interactions between the two species.Mallards were more aggressive than black ducks regardless of sex and origin, though both species were equally attacked in both years, male ducks were more aggressive and more attacked than female ducks regardless of species and origin in both years, and ducks of sympatric origin were more aggressive than ducks of allopatric origin in 1991 regardless of sex and species while the opposite was true in 1992.
Site attachment was observed in 7 of 9 experiments performed in 1992. In the experiments involving site attachment, almost all of the activity centered around the feeding stations, not around the nesting platforms.
34
Carrière, Suzanne. "Habitat selection by sympatric black ducks and mallards in Abitibi, Quebec". Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59984.
Testo completoAbstract (sommario):
Habitat use by sympatric black ducks (Anas rubripes) and mallards (A platyrhynchos) was studied in Abitibi, Quebec during May-August 1988 and 1989.Black duck broods preferred emergent and shrub-rich areas in both years. Mallard broods' habitat use differed from 1988 to 1989 (from emergent to shrub-emergent areas) when average water levels were higher. Diversity of habitats seems more important to rearing black ducks than to mallards. Rearing mallards seem to modify their use of habitats according to changing habitat availability. Daily survival rates differed only slightly between "species".
Telemetry was used to study wetland use by six mallard and three black duck non-breeding females. Swamps were preferred whereas ericaceous shrub wetlands were avoided by both "species". Beaver (Castor canadensis) ponds were extensively used during the moulting period. Home ranges averaged 302.7 ha for black ducks and 201.2 ha for mallards.
35
Ross, Ben Paul. "Manipulation of the feeding behaviour of diving ducks on mussel farms". Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342005.
Testo completo
36
Nelson, Joel Thomas. "The Genomics of Speciation within the Globally Distributed Blue-Winged Ducks". Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1463854966.
Testo completo
37
Laguë, Sabine Lina. "Cardiorespiratory responses to hypoxia in high- and low-altitude geese and ducks". Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/58484.
Testo completoAbstract (sommario):
High-altitude (HA) life is challenging due to the reduced partial pressure of oxygen (hypoxia). Hence, HA vertebrates have evolved increased capacities in their oxygen transport cascade enhancing oxygen transfer. The extent of interspecies variation in these responses within waterfowl, a taxon prolific at HA, remains largely unknown. This thesis investigated 17 waterfowl groups at different altitudes to address the overarching hypotheses that waterfowl use multiple cardiorespiratory strategies to maintain oxygen supply during hypoxia, and that HA exposure alters the waterfowl hypoxic ventilatory and cardiovascular responses.
A comprehensive analysis of metabolic, cardiovascular, and ventilatory responses to progressive decreases in equivalent fractional composition of inspired oxygen was made on resting low-altitude (LA) barnacle geese, LA bar-headed geese, HA bar-headed geese, Andean geese, and crested ducks. Andean geese and crested ducks, lifelong HA residents, exhibited fundamentally different mechanisms for maintaining oxygen supply during hypoxia than bar-headed geese, transient HA migrators. Bar-headed geese robustly increased ventilation and heart rate, whereas Andean species increased lung oxygen extraction and stroke volume. Also, HA-reared bar-headed geese exhibited reduced oxygen consumption during hypoxia compared to LA-reared bar-headed geese. Similar cardiovascular studies were performed on five HA duck species (yellow-billed pintail, cinnamon teal, ruddy duck, speckled teal, and Puna teal) in Peru and six related LA duck species (northern pintail, cinnamon teal, ruddy duck, green-winged teal, gadwall, and mallard duck) in the USA. Heart rate and oxygen pulse remained generally unchanged. Instead, most HA ducks exhibited higher blood-oxygen carrying capacity and lower heart rate variability than LA ducks. While heart rate, stroke volume, oxygen pulse, and blood-oxygen carrying capacity contributed to all 17 groups’ hypoxic cardiovascular responses, the predominant responses were increased stroke volume and, in HA taxa, blood-oxygen carrying capacity. Only bar-headed geese increased heart rate appreciably.
This thesis identifies multiple cardiovascular and respiratory strategies by which waterfowl maintain oxygen supply during hypoxia, and provides insight into how HA rearing impacts these responses. This thesis also suggests that short-term HA performance utilizes primarily functional enhancements (e.g. rapid heart rate and ventilation increases), whereas lifelong HA residency is supported predominantly by structural changes (e.g. lung and cardiac morphology enhancements).Science, Faculty of
Zoology, Department of
Graduate
38
Mutumi, Gregory Lilgee. "Using stable isotopes to trace the movements of ducks in southern Africa". Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/9801.
Testo completoAbstract (sommario):
Includes bibliographical references.Despite the importance of movement ecology studies, the field faces a prevailing challenge of methodological limitations in tracking individual organisms. This research investigated the utility of the stable isotope technique to trace movements of ducks in southern Africa. I sampled and analysed feathers of ten duck species for stable isotope proportions of Carbon (δ13C), Nitrogen (δ15N) and Hydrogen (δD), from five wetlands (Strandfontein and Barberspan in South Africa, the Manyame catchment in Zimbabwe, Lake Chuali in Mozambique, and Lake Ngami in Botswana) as test cases.Sampling was carried out at different seasons to account for seasonal isotope signature variations. Isotope signatures of feathers grown at different moulting locations were compared to test whether southern Africa shows stable isotope spatial patterns (distinct isotopic regions). Feathers grown at different life-phases were compared to test whether different sites had been used and if more mobile species showed more and stronger isotope distinctions. Finally, growing flight feathers grown at moulting locations were compared across species to query how much information on diet and foraging behaviour can be inferred from southern African duck feather stable isotopes.Feather isotope signatures were distinct by site in at least one of the tested isotopes, for the majority of ducks tested. Strandfontein had more and stronger distinctions of isotope signatures between feathers grown at different life phases. This site is the closest to the sea and most likely to have marine-influenced isotope signatures especially in δ15N, it falls within the Mediterranean climatic conditions experiencing winter rainfall unlike all the other sites. Vegetation compositions (C3 and C4 plant distributions) therefore vary across sites influencing δ13C patterns. More mobile species (only Egyptian Goose Alopochen aegyptiacus from Strandfontein, and Cape Shoveler Anas smithii from Barberspan; determined by mobility scores from other studies) had more and stronger distinctions between flight and body feathers. All the other species did not comply with mobility scores. They showed weaker and fewer tissue signature distinctions than their mobility scores suggested. There were high isotopic signature overlaps in δ13C and δ15N across and within feeding guilds at each moulting site implying dietary overlaps during moulting. More overlaps occurred during the dry seasons (summer in Strandfontein and winter in Lake Chuali, Manyame catchment site, and Lake Ngami). Higher isotopic variances (higher dietary flexibility) were associated with isotope signature divergence to mobility scores especially in Cape Teals and Yellow-billed Ducks.The isotope technique is flawed with uncontrollable sources of variation which potentially confound movement inferences. It is best used when accompanied by conventional methods to detect and counter against species specific biology and dietary behaviour imposed biases in tissue isotope signatures. Further research on how species specific biological processes affect the reflection of spatial patterns of isotopes in feathers is recommended. Multi-isotope time explicit approaches and trace element analysis were also recommended. Scientists should be wary about basing management strategies or building theory about movement patterns of species based on the technique at least in stochastic environments such as southern Africa. My results provide empirical evidence that the technique is unreliable at this scale of analysis. In particular, the majority of ducks in this region are not good candidates for use of isotopic signatures in distinguishing movement patterns of southern African ducks.4983
39
Kruse, Tamara. "Field Use of Alfaxalone and Potential Complications in Mallard Ducks (Anas platyrynchos)". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563491829618893.
Testo completo
40
Morton, John. "Habitat use and energetics of American black ducks wintering at Chincoteague, Virginia". Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/53147.
Testo completoAbstract (sommario):
The habitat use and energetics of American black ducks (Anas rubripes) wintering at Chincoteague National Wildlife Refuge, Virginia, were investigated. Twenty-two female black ducks were systematically radiotracked on the 25,600 ha study area between 15 December 1985 and 28 February 1986. Diurnal time and energy budgets were constructed by distributing 1,471 scans (collected in 1985-86 and 1986-87) over a time-tide matrix within refuge, saltmarsh, and tidal water habitats. Sixty-four ducks were collected during early, mid, and late winter in 1985-86 to determine changes in carcass composition. The Habitat Suitability Index (HSI) model for wintering black ducks was evaluated. Age affected range and core areas but did not affect habitat selection. Tide, ice, and time of day affected habitat use. Refuge pools were used during the day and saltmarsh was used at night. Subtidal water was used during periods of icing. Black ducks fed least and rested most when in refuge pools but fed most and rested least when in tidal waters. Black ducks curtailed feeding and increased time spent in alert and locomotion behaviors in response to disturbance. Whole carcass analysis indicated that black ducks were at least as fat and heavy in the spring as they were in the fall. Comparisons with similar work in Maine suggested that black ducks wintering in Maine and Virginia expend the same energy at a given temperature. However, because of lower temperatures, black ducks collected at Chincoteague were in relatively better condition than ducks wintering in Maine.Master of Science
41
Wendt, John Stephen Carleton University Dissertation Biology. "Population dynamics of ducks in Canada; the ratio of immatures to adults". Ottawa, 1985.
Cerca il testo completo
42
Gammonley, James H. "Seasonal use of Montane wetlands by waterbirds on the rim of the Colorado Plateau /". free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9712801.
Testo completo
43
McKean, Josephine Kay. "Effects of alcohol on the development of the cardiovascular system in Pekin Ducks (Anasplatyrhynchos): An assessment of current empirical findings and the development of aresearch protocol utilizing Pekin Ducks". Capital University Honors Theses / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=caphonors1619709990242982.
Testo completo
44
Rhodes, Walter E. "Habitat use by juvenile female canvasbacks wintering on the upper Chesapeake Bay". Thesis, This resource online, 1989. http://scholar.lib.vt.edu/theses/available/etd-03122009-040719/.
Testo completo
45
Hunt, William Andrew. "The ecology of harlequin ducks, Histrionicus histrionicus, breeding in Jasper National Park, Canada". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq37555.pdf.
Testo completo
46
Fernando, Raniero. "Brood parasitism and genetic parentage in Goldeneye ducks, an analysis using DNA fingerprinting". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0027/MQ51602.pdf.
Testo completo
47
Hewitson, Stacy. "Habitat selection by breeding American black ducks (Anas rubripes) in northeastern Nova Scotia". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22739.
Testo completoAbstract (sommario):
Habitat selection by breeding black ducks (Anas rubripes) was studied in Antigonish County, Nova Scotia during April-September 1990 and 1991.Black duck pairs selected deciduous shrub ponds and sparsely vegetated ponds and avoided estuarine marsh and large lake habitat. Hens with broods preferred the deciduous shrub habitat while they avoided large lakes.
Black duck pairs appeared to use the distance to a brood-rearing pond as a cue in site selection. The closer a pond was to a suitable rearing pond the more likely it was occupied by a pair, regardless of food or cover resource availability. Black ducks, however, likely used site attributes such as the perimeter of the pond, the availability of aquatic invertebrates and the relative abundance of alder, willow and dead timber as cues in the selection brood-rearing habitat.
Black duck duckling survival, an estimate of recruitment, was the highest on preferred deciduous shrub ponds. Duckling survival was also higher on ponds with only one brood as opposed to ponds with several broods.
The most productive habitat for black ducks in the Antigonish study area were isolated, deciduous shrub ponds influenced by beaver activity. Black duck population numbers can be enhanced by managing local beaver populations.
48
Marshall, Ann Patterson. "The behavior of Laysan ducks (Anas laysanensis) in captivity and on Laysan Island /". The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487670346874209.
Testo completo
49
Behney, Adam Christopher. "FORAGING BEHAVIOR OF DUCKS DURING SPRING MIGRATION IN THE WABASH RIVER REGION, ILLINOIS". OpenSIUC, 2014. https://opensiuc.lib.siu.edu/dissertations/937.
Testo completoAbstract (sommario):
Strategies animals use to find and consume food in the face of conflicting forces such as competition and predation are central questions in the fields of ecological theory and management. Whereas theoretical models abound, proper empirical tests of these theories are less abundant. In studying the relationship between food abundance, predation risk, and competition there exists an array of confounding factors, which need to be accounted for by manipulating some aspect of the system. I used a guild of spring migratory ducks as a model system and manipulated food abundance in areas differing in presumed risk to assess the relative effects of food abundance, predation risk, competition, and life history characteristics on foraging strategies used by ducks. Using a randomized block design, I established a pair of 0.4 ha plots (block) in emergent, open water, and forested wetlands in the Wabash River Floodplain in eastern Illinois. I randomly selected one plot within each block to supplement with 2000 kg/ha of corn (Zea mays), creating an area of very high duck food abundance next to a control area with no added food. I conducted instantaneous focal animal samples and used video recorders to estimate the proportion of time mallard (Anas platyrhynchos), blue-winged teal (Anas discors), wood duck (Aix sponsa), ring-necked duck (Aythya collaris), and lesser scaup (Aythya affinis) devoted to feeding, identify the specific behaviors used, and estimate feeding stint lengths and frequencies. I used these metrics as an index of risk that ducks were willing to engage in for a known food reward. I predicted that species with a faster life history strategy, factors that increase perceived predation risk (cover, water depth, group size), and increase energetic demand (due to nesting or temperature), would elicit more risk-taking behaviors in ducks. This would be realized by an increase in the proportion of time spent feeding, longer feeding durations, and deeper feeding behaviors in treatment plots compared with control plots. Consistent with my life history prediction, species with a faster life history strategy were willing to engage in more risky behavior (feeding more) for a greater food reward (food treatment). Mallards, lesser scaup, and wood ducks exhibited risk-taking behavior consistent with perceived predation risk. Mallards devoted more time to feeding and used longer feeding stints when in areas with less cover. Alternatively, lesser scaup devoted more time to feeding when in areas of more cover. Wood ducks devoted more time to feeding in treatment plots, when in shallow areas, and larger flocks. When blue-winged teal fed on the surface (eyes above water), they devoted more overall time to feeding indicating that surface feeding is less risky than deeper feeding. Wood ducks and lesser scaup exhibited behavior consistent with an increase in energetic demand as observed by an increase in the proportion of time devoted to feeding later in the spring. I also examined how food abundance influenced aspects of ducks' foraging niches. I found that dabbling ducks used a greater variety of behaviors (behavior niche breadth) when in treatment plots compared to control plots and also shifted to slightly deeper feeding behaviors in treatment plots. This greater breadth when food was more abundant was due to individuals of the same species diverging from one another, rather than each individual using a broader array of behaviors. Overall, I found substantial variability among and within species in how they manage risk while foraging, although this was partially explained by life history theory, and what types of conditions they perceive as risky. I document the importance of taking the state of the forager (life history, perceived risk, energetic demand) into account when examining patterns of risk-taking.
50
Lindstrom, John Michael. "Effect of habitat management on dabbling ducks during spring migration in southwest Indiana". OpenSIUC, 2017. https://opensiuc.lib.siu.edu/theses/2118.
Testo completoAbstract (sommario):
Historically, management for migratory waterfowl was focused around providing hunting opportunity each fall. More recently habitat during spring migration has received attention as a potentially limiting factor for some species of waterfowl, considering the carry-over effects that have been observed in both capital and income breeders. Habitat needs have been compounded by the flashy flood events that now occur in the highly modified landscape. The discovery of carry-over effects has led to an increase in habitat management actions and a diversification of available management strategies. In my study I hoped to identify the best management strategies for spring migratory waterfowl. I also wanted to identify how quickly waterfowl can respond to flood events. In 2012 and 2013, I examined the effect of habitat management on dabbling duck behavior and distribution during spring migration in southwest Indiana. I investigated three management options for wetlands: active management, passive management, and agricultural food plots. Actively managed wetlands are wetlands where the hydrology is managed and controlled. In passively managed wetlands and agricultural food plots; the hydrology is provided naturally. I surveyed both duck behavior and abundance on 14 wetlands on the Patoka River National Wildlife Refuge and Management Area. I also surveyed short-lived wetlands to determine the response rate of waterfowl to inundation following rain events. The agricultural food plot areas had the lowest estimates of food availability followed by the actively managed areas with the passive managed wetlands having the highest estimate. Waterfowl abundances were highest on the actively managed wetlands with the food plots coming in second and the passive wetlands coming in a distant third. The passive wetlands had the highest proportions of time spent feeding followed by the active and food plot wetlands. Dabbling ducks were not distributing themselves relative to food density but are feeding in the highest proportions in these areas. Waterfowl use was recorded less than 24 hours after inundation on 14 of 21 short-lived wetlands. Short-lived wetlands may be important to migratory waterfowl. Conservation prioritization of passively managed areas would provide larger areas for dabbling ducks to feed, but active management provides habitat regardless of climatic variability. Moving forward, wetland complexes encompassing diverse wetland management approaches would be the best option for spring migrating waterfowl as these complexes can provide high quality habitats and buffer against uncontrollable climactic conditions.