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.

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.

Blood parasite infection linked to condition of spring-migrating Lesser Scaup (Aythya affinis)

2018 ◽  
Vol 96 (10) ◽  
pp. 1145-1152 ◽  
Author(s):  
L. Merrill ◽  
J.M. Levengood ◽  
J.C. England ◽  
J.M. Osborn ◽  
H.M. Hagy
Keyword(s):  
Body Fat ◽  
Reproductive Output ◽  
Parasite Infection ◽  
Malaria Vectors ◽  
Infection Prevalence ◽  
Haemosporidian Parasite ◽  
Aythya Affinis ◽  
Lesser Scaup ◽  
Haemosporidian Parasites ◽  
The Impact

Numerous organisms exhibit carry-over effects, in which previous environmental conditions impact current performance. For example, reproductive output for many migratory birds can be impacted by events during the preceding migration. Lesser Scaup (Aythya affinis (Eyton, 1838); hereafter scaup) declined dramatically during 1970s–2000s, and there is evidence linking reduced reproductive output to reduced body condition during spring migration. In addition to food availability and quality, haemosporidian parasites (Plasmodium spp., Haemoproteus spp.) may be associated with condition of spring-migrating birds. We examined whether haemosporidian parasite infection status was linked to measures of size (mass, wing length, tarsus length, and keel length) and condition (body fat, size-corrected mass, wing-loading) in female spring-migrating scaup. Infection prevalence varied by year (21.7% in 2014; 47.1% in 2015) and percent body fat was negatively associated with the probability of infection. Body fat levels declined from 2014 to 2015, but at a similar rate for infected and uninfected birds. This pattern suggests that the increased prevalence in 2015 may have been related to the greater proportion of poor-condition birds being more susceptible to infection or recrudescence of latent infections. In light of forecasted range shifts and expansions of avian malaria vectors, the impact of haemosporidian parasites on migratory waterfowl condition warrants further investigation.

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.

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

Auditory brainstem response in the lesser scaup (Aythya affinis), a species of diving duck.

2010 ◽  
Vol 127 (3) ◽  
pp. 1893-1893
Author(s):  
Sara C. Therrien ◽  
Catherine E. Carr ◽  
Elizabeth F. Brittan‐Powell ◽  
Alicia M. Wells‐Berlin
Keyword(s):  
Auditory Brainstem Response ◽  
Auditory Brainstem ◽  
Diving Duck ◽  
Aythya Affinis ◽  
Lesser Scaup ◽  
Brainstem Response

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.

Variation in structural size and wing stripe of Lesser and Greater scaup

1988 ◽  
Vol 66 (9) ◽  
pp. 2045-2048 ◽  
Author(s):  
Steven F. Wilson ◽  
C. Davison Ankney
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Structural Data ◽  
Component Analysis ◽  
Sexual Differences ◽  
Aythya Affinis ◽  
Structural Size ◽  
Lesser Scaup ◽  
Size Groups ◽  
Aythya Marila

Heads, wings, and feet of Lesser Scaup (Aythya affinis) and Greater Scaup (Aythya marila) were obtained from 365 birds killed by hunters to investigate differences in structural size and in the intensity and extent of the white wing stripe. Twelve morphological measurements were taken on each bird and wing stripes were quantitatively scored using soil colour charts. Principal component analysis of the structural data separated the birds into two nonoverlapping size groups. We considered the group of large birds and the group of small birds to be Greater and Lesser scaup, respectively. Variation in the wing stripe character was extensive; 9% of the birds in our sample could not be correctly classified as Lesser or Greater scaup on the basis of wing stripe alone. However, most of the variation was due to sexual differences, i.e., female Greater Scaup with unusually dark wings and male Lesser Scaup with unusually white wings.

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