Variation in digestive organ size among five species of diving ducks (Aythya spp.)

1985 ◽  
Vol 63 (10) ◽  
pp. 2339-2342 ◽  
Author(s):  
F. Patrick Kehoe ◽  
C. Davison Ankney
Keyword(s):  
Body Weight ◽  
Diving Ducks ◽  
Aythya Affinis ◽  
Interspecific Differences ◽  
Lesser Scaup ◽  
Aythya Americana ◽  
Aythya Valisineria ◽  
Intestine Length ◽  
Morphological Differences ◽  
Interspecific Comparisons

Ceca length, small intestine length, and gizzard weight were measured for individuals of five species of diving ducks collected at Long Point Bay, Lake Erie, and Mitchell's Bay, Lake St. Clair, Ontario, in the falls of 1982 and 1983. The five species were Lesser Scaup (Aythya affinis, N = 84), Ring-necked Duck (Aythya collaris, N = 57), Greater Scaup (Aythya marila, N = 54), Redhead (Aythya americana, N = 58), and Canvasback (Aythya valisineria, N = 112). The diets of these species reportedly differ in diversity as well as in amount of fibre, and interspecific differences in gut morphology, not explained by differences in body weight, were accounted for by general differences in diet. Canvasbacks, although the heaviest species, had the shortest ceca, short intestines and light gizzards, presumably because their diet contains the least fibre. Conversely, the relatively small-bodied scaup species had the longest small intestines, likely because of their diverse diets which include animal and plant material. Our results show that morphological differences in waterfowl guts reflect dietary differences at a particular time and location and also illustrate the importance of adjusting gut measurements to body weight before making interspecific comparisons.

Interspecific differences in bill and tongue morphology among diving ducks (Aythya spp., Oxyura jamaicensis)

1989 ◽  
Vol 67 (11) ◽  
pp. 2694-2699 ◽  
Author(s):  
Barbara A. Lagerquist ◽  
C. Davison Ankney
Keyword(s):  
Morphological Characters ◽  
Diving Ducks ◽  
Size And Shape ◽  
Interspecific Differences ◽  
Lesser Scaup ◽  
Aythya Valisineria ◽  
Bill Morphology ◽  
Intermediate Size ◽  
Ruddy Ducks ◽  
Oxyura Jamaicensis

Twelve morphological characters of the bill and tongue were measured in six species of diving ducks (Aythya and Oxyura spp.). We used multivariate analyses to describe interspecific differences in morphology and related these differences to published information about food habits and feeding behavior of the six species. Canvasbacks (Aythya valisineria) have long, narrow, deep bills that are well suited to probing and grasping plant tubers from the substrate. Greater (A. marila) and Lesser Scaup (A. qffinis) and Ruddy Ducks (Oxyura jamaicensis) have short, wide, shallow bills suited to straining food items. Lesser Scaup and Ruddy Ducks have the greatest lamellar density and this enables them to strain very small plant and animal material. Redheads (A. americana) and Ring-necked Ducks (A. collaris) have bills of intermediate size and shape that are suited to straining seeds and grazing leafy parts of plants. Lesser and Greater Scaup, on the basis of bill morphology, are more similar to Ruddy Ducks than they are to other Aythya species. Overall, bill size and shape were more important in distinguishing the six species than were lamellar density or tongue characteristics.

scholarly journals Winter Waterbird Community Composition and Use at Created Wetlands in West Virginia, USA

Scientifica ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hannah L. Clipp ◽  
Michael L. Peters ◽  
James T. Anderson
Keyword(s):  
West Virginia ◽  
The United States ◽  
Created Wetlands ◽  
Age Difference ◽  
Canada Geese ◽  
Diving Ducks ◽  
Aythya Affinis ◽  
Lesser Scaup ◽  
Vegetation Water ◽  
Anas Strepera

Information on nonbreeding waterbirds using created wetlands in the Central Appalachian region of the United States is limited. We compared waterbird communities of two managed wetlands, created in 2013 and 2001, in West Virginia. We observed 27 species of waterbirds. Species richness and diversity were generally similar between the wetlands, but species composition and use differed.Branta canadensis(Canada Geese),Anas strepera(Gadwall),Bucephala albeola(Buffleheads),Aythya affinis(Lesser Scaup), andAythya collaris(Ring-Necked Ducks) used the older wetland most frequently. Disparities in species use were the highest in March. The older wetland differed from the younger in supporting species such as diving ducks, possibly due to differences in size, vegetation, water depth, and microtopography. However, the ability to provide habitat for waterbirds during the winter was determined to be comparable between wetlands, despite their age difference.

Interspecific nest parasitism by redheads on islands in southeastern Alberta

1981 ◽  
Vol 59 (11) ◽  
pp. 2053-2057 ◽  
Author(s):  
Jean-François Giroux
Keyword(s):  
Reproductive Output ◽  
Host Nest ◽  
Nest Parasitism ◽  
Aythya Affinis ◽  
Lesser Scaup ◽  
Aythya Americana ◽  
Nesting Density ◽  
Nest Desertion ◽  
Drought Conditions ◽  
Parasitic Activity

I studied interspecific nest parasitism by redheads (Aythya americana) from 1976 to 1978 in a population of upland nesting ducks on artificial islands in southeastern Alberta. Of 685 duck nests, 19% were parasitized by redheads with a mean of 2.68 parasitic eggs per host nest. The proportion of nests parasitized increased with the density of host nests on the islands. There is also some evidence that the rate of parasitism was influenced by the nesting density of redheads. Mallards (Anas platyrhynchos) had the greatest percentage of nests parasitized by redheads whereas lesser scaup (Aythya affinis) had the largest number of parasitic eggs per nest. Redhead parasitism affected reproductive output of hosts by increasing nest desertion. Finally, the parasitic activity of redheads was reduced during a season characterized by drought conditions.

Lesser Scaup (Aythya affinis)

2014 ◽  
Author(s):  
Michael J. Anteau ◽  
Jean-Michel DeVink ◽  
David N. Koons ◽  
Jane E. Austin ◽  
Christine M. Custer ◽  
...  
Keyword(s):  
Aythya Affinis ◽  
Lesser Scaup

Hepatic Element Concentrations of Lesser Scaup (Aythya affinis) During Spring Migration in the Upper Midwest

2010 ◽  
Vol 61 (1) ◽  
pp. 144-150 ◽  
Author(s):  
Angela E. Pillatzki ◽  
Regg D. Neiger ◽  
Steven R. Chipps ◽  
Kenneth F. Higgins ◽  
Nancy Thiex ◽  
...  
Keyword(s):  
Spring Migration ◽  
Upper Midwest ◽  
Aythya Affinis ◽  
Element Concentrations ◽  
Lesser Scaup

scholarly journals Survival of Female Lesser Scaup: Effects of Body Size, Age, and Reproductive Effort

The Condor ◽  
2003 ◽  
Vol 105 (2) ◽  
pp. 336-347 ◽  
Author(s):  
Jay J. Rotella ◽  
Robert G. Clark ◽  
Alan D. Afton
Keyword(s):  
Body Size ◽  
Natural Selection ◽  
Female Body ◽  
Reproductive Effort ◽  
Cost Of Reproduction ◽  
Aythya Affinis ◽  
Female Body Size ◽  
Lesser Scaup ◽  
Adult Females ◽  
Breeding Propensity

AbstractIn birds, larger females generally have greater breeding propensity, reproductive investment, and success than do smaller females. However, optimal female body size also depends on how natural selection acts during other parts of the life cycle. Larger female Lesser Scaup (Aythya affinis) produce larger eggs than do smaller females, and ducklings from larger eggs survive better than those hatching from smaller eggs. Accordingly, we examined patterns of apparent annual survival for female scaup and tested whether natural selection on female body size primarily was stabilizing, a frequent assumption in studies of sexually dimorphic species in which males are the larger sex, or was directional, counteracting reproductive advantages of large size. We estimated survival using mark-recapture methods for individually marked females from two study sites in Canada (Erickson, Manitoba; St. Denis, Saskatchewan). Structurally larger (adults) and heavier (ducklings) females had lower survival than did smaller individuals in Manitoba; no relationship was detected in adults from Saskatchewan. Survival of adult females declined with indices of increasing reproductive effort at both sites; consequently, the cost of reproduction could explain age-related patterns of breeding propensity in scaup. Furthermore, if larger females are more likely to breed than are smaller females, then cost of reproduction also may help explain why survival was lower for larger females. Overall, we found that advantages of large body size of female scaup during breeding or as young ducklings apparently were counteracted by natural selection favoring lightweight juveniles and structurally smaller adult females through higher annual survival.Sobrevivencia de Aythya affinis: Efectos del Tamaño Corporal, Edad y Esfuerzo ReproductivoResumen. En las aves, las hembras de mayor tamaño generalmente presentan una mayor predisposición a la reproducción, mayor inversión reproductiva y mayor éxito que las hembras de menor tamaño. Sin embargo, el tamaño óptimo de la hembra también depende de cómo la selección natural opera durante otras etapas del ciclo de vida. Hembras de Aythya affinis más grandes producen huevos de mayor tamaño que hembras más pequeñas, y los polluelos provenientes de huevos más grandes sobreviven mejor que aquellos que eclosionan de huevos más pequeños. Consiguientemente, examinamos los patrones de sobrevivencia anual aparente para hembras de A. affinis y probamos si la selección natural sobre el tamaño del cuerpo de las hembras era principalmente estabilizadora (una suposición frecuente en estudios de especies sexualmente dimórficas en que los machos son el sexo mayor), o era direccional, contrarrestando las ventajas reproductivas de un tamaño mayor. Estimamos la sobrevivencia de hembras utilizando métodos de marcaje y recaptura en dos sitios de estudio (Erickson, Manitoba; St. Denis, Saskatchewan). Hembras estructuralmente más grandes (adultas) y más pesadas (polluelos) tuvieron una menor sobrevivencia que individuos más pequeños en Manitoba; no se detectó una relación entre adultos de Saskatchewan. En ambos sitios la sobrevivencia de hembras adultas decreció con los índices de incremento de esfuerzo reproductivo; consecuentemente el costo reproductivo podría explicar los patrones de predisposición reproductiva relacionados a la edad en A. affinis. Además, si las hembras de mayor tamaño presentan mayor probabilidad de reproducirse que las hembras pequeñas, entonces el costo reproductivo también podría ayudar a explicar porqué la sobrevivencia fue menor para hembras más grandes. En general encontramos que en las hembras de A. affinis las ventajas de un tamaño corporal grande durante la cría o como juveniles fueron aparentemente contrarestadas por la selección natural que favorece juveniles de peso liviano y hembras adultas estructuralmente más pequeñas a través de una mayor sobrevivencia anual.

scholarly journals Nutrient Reserves of Lesser Scaup (Aythya Affinis) During Spring Migration in the Mississippi Flyway: A Test of the Spring Condition Hypothesis

The Auk ◽  
2004 ◽  
Vol 121 (3) ◽  
pp. 917-929 ◽  
Author(s):  
Michael J. Anteau ◽  
Alan D. Afton
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Body Condition ◽  
Female Body ◽  
Population Decline ◽  
Spring Migration ◽  
Aythya Affinis ◽  
Lesser Scaup ◽  
Nutrient Reserves ◽  
Mineral Reserves

AbstractThe continental scaup population (Lesser [Aythya affinis] and Greater [A. marila] combined) has declined markedly since 1978. One hypothesis for the population decline states that reproductive success has decreased because female scaup are arriving on breeding areas in poorer body condition than they did historically (i.e. spring condition hypothesis). We tested one aspect of that hypothesis by comparing body mass and nutrient reserves (lipid, protein, and mineral) of Lesser Scaup at four locations (Louisiana, Illinois, Minnesota, and Manitoba) between the 1980s and 2000s. We found that mean body mass and lipid and mineral reserves of females were 80.0, 52.5, and 3.0 g higher, respectively, in the 2000s than in the 1980s in Louisiana; similarly, body mass and lipid and mineral reserves of males were 108.8, 72.5, and 2.5 g higher, respectively. In Illinois, mean body mass and lipid reserves of females were 88.6 and 56.5 g higher, respectively, in the 2000s than in the 1980s; similarly, body mass and lipid and mineral reserves of males were 80.6, 76.0, and 2.7 g higher, respectively. Mean body mass of females were 58.5 and 58.9 g lower in the 2000s than in the 1980s in Minnesota and Manitoba, respectively; mean body mass of males, similarly, were 40.7 g lower in Minnesota. Mean lipid reserves of females in the 2000s were 28.8 and 27.8 g lower than those in the 1980s in Minnesota and Manitoba, respectively. Mean mineral reserves of females in the 2000s were 3.2 g lower than those in the 1980s in Manitoba. Consequently, females arriving to breed in Manitoba in the 2000s had accumulated lipid reserves for 4.1 fewer eggs and mineral reserves for 0.8 fewer eggs than those arriving to breed there in the 1980s. Accordingly, our results are consistent with the spring condition hypothesis and suggest that female body condition has declined, as reflected by decreases in body mass, lipids, and mineral reserves that could cause reductions in reproductive success and ultimately a population decline.

Comparative migration, growth and development of Typhlocoelum cucumerinum sisowi in dabbling ducks and Typhlocoelum cucumerinum cucumerinum in diving ducks

Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 333-350 ◽  
Author(s):  
Marilyn E. Scott ◽  
M. E. Rau ◽  
J. D. McLaughlin
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Definitive Host ◽  
Host Species ◽  
Growth And Development ◽  
Abdominal Cavity ◽  
Dabbling Ducks ◽  
Diving Ducks ◽  
Air Sacs ◽  
Aythya Valisineria

SUMMARYExperimental infections of mallards (Anas platyrhynchos L.) with Typhlocoelum cucumerinum sisowi (Skrjabin, 1913) and of canvasbacks (Aythya valisineria (Wilson)) with Typhlocoelum cucumerinum cucumerinum (Rudolphi, 1809) revealed significant differences in various parameters of the life-cycle in the definitive host. Both T. c. sisowi and T. c. cucumerinum migrate to the trachea via the abdominal cavity, air sacs and lungs, although T. c. cucumerinum migrate more quickly and more synchronously than T. c. sisowi. Typhlocoelum c. sisowi has a shorter expected life-span than T. c. cucumerinum but grows and reaches maturity more quickly than T. c. cucumerinum. Evidence suggests that T. c. cucumerinum has a higher fecundity than T. c. sisowi. These differences in the patterns of migration, growth and development are related not only to differences between the two host species but also to differences intrinsic to the parasites, and serve to provide biological support for considering them as separate sub-species.

An Outbreak of West Nile Virus Infection in Captive Lesser Scaup (Aythya affinis) Ducklings

2009 ◽  
Vol 53 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Chelsea G. Himsworth ◽  
Kirsty E. B. Gurney ◽  
Aleksjia S. Neimanis ◽  
Gary A. Wobeser ◽  
Fredrick A. Leighton
Keyword(s):  
West Nile Virus ◽  
Virus Infection ◽  
West Nile Virus Infection ◽  
West Nile ◽  
Aythya Affinis ◽  
Lesser Scaup
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