Factors affecting brood abandonment in gadwalls (Anas strepera)

2000 ◽  
Vol 78 (2) ◽  
pp. 327-331 ◽  
Author(s):  
Michel Gendron ◽  
Robert G Clark
Keyword(s):  
Body Condition ◽  
Brood Size ◽  
Female Body ◽  
Confounding Factor ◽  
Factors Affecting ◽  
Proximate Factors ◽  
Anas Strepera ◽  
Brood Desertion ◽  
Brood Success

Brood desertion by radio-equipped female gadwalls (Anas strepera) was examined to test three hypotheses regarding proximate factors responsible for post hatch brood abandonment in waterfowl. Gadwall broods with the greatest duckling mortality, independent of brood size, were more likely to be abandoned, providing support for the "brood-success" hypothesis. Our results do not support the "brood-size" hypothesis, as the size of broods immediately prior to female abandonment was no smaller than the size of broods not abandoned. Although brood fate was not related to female body condition, the "salvage-strategy" hypothesis could not be rejected, because experience was a confounding factor and could not be sampled adequately; younger, possibly less-experienced females were more likely to abandon their broods than older females. Further studies, preferably involving experimental manipulations, are needed to adequately address the full array of hypotheses.

scholarly journals Ecological and Physiological Factors Affecting Brood Patch Area and Prolactin Levels in Arctic-Nesting Geese

The Auk ◽  
2006 ◽  
Vol 123 (2) ◽  
pp. 405-418 ◽  
Author(s):  
Jón Einar Jónsson ◽  
Alan D. Afton ◽  
Ray T. Alisauskas ◽  
Cynthia K. Bluhm ◽  
Mohamed E. El Halawani
Keyword(s):  
Body Condition ◽  
The Body ◽  
Nest Size ◽  
Patch Area ◽  
Physiological Factors ◽  
Factors Affecting ◽  
Chen Caerulescens ◽  
Brood Patch ◽  
Snow Geese ◽  
Ross's Geese

AbstractWe investigated effects of ecological and physiological factors on brood patch area and prolactin levels in free-ranging Lesser Snow Geese (Chen caerulescens caerulescens; hereafter “Snow Geese”) and Ross's Geese (C. rossii). On the basis of the body-size hypothesis, we predicted that the relationships between prolactin levels, brood patch area, and body condition would be stronger in Ross's Geese than in the larger Snow Geese. We found that brood patch area was positively related to clutch volume and inversely related to prolactin levels in Ross's Geese, but not in Snow Geese. Nest size, nest habitat, and first egg date did not affect brood patch area in either species. Prolactin levels increased as incubation progressed in female Snow Geese, but this relationship was not significant in Ross's Geese. Prolactin levels and body condition (as indexed by size-adjusted body mass) were inversely related in Ross's Geese, but not in Snow Geese. Our findings are consistent with the prediction that relationships between prolactin levels, brood patch area, and body condition are relatively stronger in Ross's Geese, because they mobilize endogenous reserves at faster rates than Snow Geese.Factores Ecológicos y Fisiológicos que Afectan el Área del Parche de Incubación y los Niveles de Prolactina en Gansos Nidificantes del Ártico

scholarly journals Influence of Female Age and Body Mass on Brood and Duckling Survival, Number of Surviving Ducklings, and Brood Movements in Redheads

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 926-929
Author(s):  
Tina Yerkes
Keyword(s):  
Body Mass ◽  
Female Body ◽  
Survival Rates ◽  
Female Age ◽  
Duckling Survival ◽  
Daily Survival ◽  
Brood Movement ◽  
Female Body Mass ◽  
Brood Success

AbstractI documented brood and duckling survival, the number of surviving ducklings, and brood movements of Redheads, and examined the association between these variables and female age and body mass. Redhead brood success was 55% and duckling daily survival rates averaged 0.868. Female body mass, but not age, was related to brood and duckling survival and the number of surviving ducklings. Successful females were heavier and produced more ducklings. All brood-movement measures differed between successful and unsuccessful females, however, the distance of the first move between wetlands accounted for the most variability in brood success. Increased body mass, but not age, was associated with longer first brood movements.

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.

Sex Ratios of Ring-Billed Gulls in Relation to Egg Size, Egg Sequence and Female Body Condition

1987 ◽  
Vol 10 (1) ◽  
pp. 72 ◽  
Author(s):  
Catherine E. Meathrel ◽  
John P. Ryder
Keyword(s):  
Body Condition ◽  
Female Body ◽  
Egg Size ◽  
Sex Ratios

The effect of female body condition on egg laying in Lesser black-backed gulls Larus fuscus

2009 ◽  
Vol 200 (4) ◽  
pp. 509-520 ◽  
Author(s):  
D. C. Houston ◽  
P. J. Jones ◽  
R. M. Sinly
Keyword(s):  
Body Condition ◽  
Female Body ◽  
Egg Laying ◽  
Larus Fuscus

Factors affecting abandonment and adoption of young in common eiders and other waterfowl: a comment

1995 ◽  
Vol 73 (8) ◽  
pp. 1575-1577 ◽  
Author(s):  
Hannu Pöysä
Keyword(s):  
Survival Rate ◽  
Final Decision ◽  
Somateria Mollissima ◽  
Factors Affecting ◽  
Lower Survival Rate ◽  
Investment Theory ◽  
Common Eiders ◽  
Parental Investment Theory ◽  
Brood Success ◽  
Care Period

Factors affecting abandonment and adoption of young have been studied extensively in waterfowl. Several hypotheses have been advanced to account for these behaviours, and Bustnes and Erikstad (J.O. Bustnes and K.E. Erikstad. 1991. Can. J. Zool. 69: 1538–1545) recently evaluated these in common eiders (Somateria mollissima). They found, among other things, that young of "abandoners" had a lower survival rate than young of "tenders," but were not able to accurately time the mortality of ducklings. I propose a hypothesis based on brood success and parental investment theory to explain why some parents abandon their young exceptionally early and why some parents tend their own as well as foreign young. According to the hypothesis, parents provide relatively less care for offspring that are surviving less than average during the parental care period. The low survival of the young of abandoners while they are still with their own mother may have influenced the final decision of common eider females to abandon their broods early.

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