Benefits, Costs, and Determinants of Dominance in American Black Ducks

Behaviour ◽  
1989 ◽  
Vol 109 (3-4) ◽  
pp. 222-234 ◽  
Author(s):  
Gary R. Hepp
Keyword(s):  
Body Mass ◽  
Dominance Rank ◽  
Positive Association ◽  
Adult Males ◽  
Restricted Diet ◽  
Significant Positive Association ◽  
Young Males ◽  
Young Females ◽  
American Black ◽  
Ad Libitum

AbstractBehavioural dominance was studied in captive American black ducks (Anas rubripes) during October-December 1984. Eighty ducks were marked individually, and groups of 10 ducks consisting of 5 adults (3 males and 2 females) and 5 juveniles (3 males and 2 females) were assigned to each of 8 experimental pens. Ducks in 4 pens received an ad libitum diet, and ducks in the other 4 pens were given a restricted diet. Dominance structure within pens was linear. Adults were dominant to young, and body mass had no influence on dominance rank. The effect of sex on dominance rank was age-specific. Adult males were dominant to adult females and to young black ducks of both sexes; however, dominance rank of young males did not differ from adult or young females. Paired adults were dominant to unpaired adults and to young individuals that were either paired or unpaired. Paired young black ducks were similar in dominance rank to unpaired adults and unpaired young indicating that pairing did not make these individuals more dominant. Ducks on the restricted diet gained less body mass than ducks on the ad libitum diet (HEPP, 1986), but dominant and subordinate black ducks within treatment groups experienced similar changes in body mass during the early winter. Dominant black ducks interacted more frequently and were more likely to form pair bonds than subordinates, thus higher energy costs of dominant individuals may explain the poor relationship between physical condition and dominance rank. There was a significant positive association between the dominance ranks of pair members.

Effects of adults on survival and recruitment of Peromyscus leucopus

1987 ◽  
Vol 65 (10) ◽  
pp. 2519-2523
Author(s):  
Gregory H. Adler ◽  
Mark L. Wilson ◽  
Michael J. DeRosa
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Peromyscus Leucopus ◽  
Survival Rates ◽  
Adult Males ◽  
Control Grid ◽  
Young Males ◽  
Young Females ◽  
Breeding Seasons ◽  
And Control

A population of Peromyscus leucopus (white-footed mouse) in northeastern Massachusetts was manipulated for 3 years to determine the effects of adults on survival and recruitment. Two experimental grids were established, from which either all adult males or all adult females were removed continually. The effects of these two manipulations were compared with demography on a control grid. Manipulations had no apparent effect on breeding intensity of young, survival rates of adults, or residency rates of adults and young. Recruitment of adult males was higher on the adult male removal grid than on the control grid. Recruitment rates of adult males and of young males and young females were lower on the adult female removal grid than on the control grid. Survival rates of young males were higher on the adult female removal grid than on the control grid; this effect may have been due to either reduced adult female residency or adult male recruitment. All differences between experimental and control grids were noted only during breeding seasons. Adult males apparently limited recruitment of adult consexuals. The effects of manipulations on other measured parameters were inconclusive because of high immigration rates of adult males onto the adult male removal grid and reduced recruitment of adult males and decreased production of young on the adult female removal grid.

scholarly journals Reproductive seasonality, sex ratio and philopatry in Argentina's common vampire bats

2017 ◽  
Vol 4 (4) ◽  
pp. 160959 ◽  
Author(s):  
H. A. Delpietro ◽  
R. G. Russo ◽  
G. G. Carter ◽  
R. D. Lord ◽  
G. L. Delpietro
Keyword(s):  
Specific Information ◽  
Adult Males ◽  
Reproductive Seasonality ◽  
Tropical Regions ◽  
Young Males ◽  
Young Females ◽  
Vampire Bats ◽  
Lactating Females ◽  
Free Ranging

Common vampire bats ( Desmodus rotundus ) are a key rabies vector in South America. Improved management of this species requires long-term, region-specific information. To investigate patterns of demography and dispersal, we analysed 13 642 captures of common vampire bats in Northern Argentina from the period 1969–2004. In contrast with findings from more tropical regions, we found reproductive seasonality with peak pregnancy in September and peak lactation in February. Curiously, sex ratios were consistently male-biased both in maternity roosts and at foraging sites. Males comprised 57% of 9509 adults caught at night, 57% of 1078 juveniles caught at night, 57% of 603 juveniles caught in roosts during the day, and 55% of 103 newborns and mature fetuses. Most observed roosts were in man-made structures. Movements of 1.5–54 km were most frequent in adult males, followed by young males, adult females and young females. At night, males visited maternity roosts, and non-pregnant, non-lactating females visited bachelor roosts. Males fed earlier in the night. Finally, we report new longevity records for free-ranging vampire bats: 16 and 17 years of age for a female and male, respectively. Our results are consistent with model predictions that sex-biased movements might play a key role in rabies transmission between vampire bat populations.

scholarly journals Some endocrine traits of transgenic rabbits. I. Changes in plasma and milk hormones

2008 ◽  
pp. 735-744
Author(s):  
AV Sirotkin ◽  
P Chrenek ◽  
J Rafay ◽  
R Omelka ◽  
H Vetr ◽  
...  
Keyword(s):  
Blood Plasma ◽  
Body Mass ◽  
Litter Size ◽  
Transgenic Animals ◽  
Adult Males ◽  
Young Females ◽  
Adult Females ◽  
Transgenic Rabbits ◽  
Human Factor Viii ◽  
Igf I

The aim of these studies was to compare some endocrine and non-endocrine characteristics of transgenic (carrying mammary gland-specific mWAP-hFVIII gene construct) and non-transgenic rabbits. The concentrations of corticosterone, progesterone, testosterone, estradiol, insulin-like growth factor I (IGF-I) and human factor VIII (hFVIII) in the blood plasma of adult females (9 months of age, 3rd generation transgenic animals), adult males, and young females (1-2 months of age, 4th generation of transgenic animals), as well as in the milk of lactating adult females, were analyzed by using RIA. In addition, litter size and body mass of pups born by transgenic and non-transgenic females from the 3rd generation were compared. Transgenic animals were compared with their non-transgenic siblings (the same genetic and epigenetic background). Transgenesis did not influence plasma hFVIII, but significantly increased corticosterone (in all animals), reduced IGF-I (in adult males and females), testosterone and estradiol, (in young females) and altered progesterone (increase in adult males and decrease in adult females) concentrations in blood plasma. In addition, transgenic females had higher milk concentrations of testosterone, but not progesterone or IGF-I than their nontransgenic sisters. These endocrine changes were not associated with changes in litter size. Transgenic male (but not female) pups have smaller body mass than control animals. These observations demonstrate the influence of transgenesis per se on the animal growth and endocrine system (secretion of reproductive and stress steroid hormones as well as growth factors) over four generations.

Factors Affecting the Distribution of Mallards Wintering in the Mississippi Alluvial Valley

The Auk ◽  
1983 ◽  
Vol 100 (4) ◽  
pp. 932-946 ◽  
Author(s):  
James D. Nichols ◽  
Kenneth J. Reinecke ◽  
James E. Hines
Keyword(s):  
Population Size ◽  
Mississippi Alluvial Valley ◽  
Adult Males ◽  
Alluvial Valley ◽  
Factors Affecting ◽  
Young Males ◽  
Young Females ◽  
Winter Distribution ◽  
Wintering Areas ◽  
Males And Females

Abstract The Mississippi Alluvial Valley (MAV) is the principal wintering area for Mallards (Anas platyrhynchos) in the Mississippi Flyway. Here, we consider it a distinct habitat (sensu Fretwell 1972), i.e. fitness is relatively homogeneous among ducks within the MAV but different from that of ducks in other such habitats. We analyzed recovery distributions of Mallards banded preseason (July-September 1950-1980) to test hypotheses concerning the effects of winter temperatures, precipitation, and population levels on Mallard winter distribution. When two groups of years that comprised extremes of warm and cold winter weather were compared, recovery distributions of all four age and sex classes (adult males and females, young males and females) differed significantly; recoveries were located farther south in cold years. Recovery distributions also differed between wet and dry years in the MAV for all groups except adult males, higher proportions of recoveries of adult females and of young males and females occurring in the MAV during wet winters. Although differences in continental Mallard population size were associated with differences in recovery distributions only of adult males and young females, the proportion of young males and of all young Mallards recovered in the MAV increased during years of low populations. We conclude that temperature, water conditions, and population size affect the habitat suitability of Mallard wintering areas and that Mallards exhibit considerable flexibility in winter distribution associated with these factors.

Influence of reduced food availability on growth of captive American kestrels

1994 ◽  
Vol 72 (12) ◽  
pp. 2084-2089 ◽  
Author(s):  
Diane Lacombe ◽  
David M. Bird ◽  
Kathy A. Hibbard
Keyword(s):  
Body Mass ◽  
Prey Availability ◽  
The Body ◽  
Lower Body ◽  
Restricted Diet ◽  
Growth Constant ◽  
Asymptotic Size ◽  
American Kestrels ◽  
Ad Libitum ◽  
Growth Constants

Captive American kestrels (Falco sparverius) were used to model the effect of low prey availability on growth and survivorship potential in nestling raptors. The experimental design consisted of 4 treatments: nestlings were fed ad libitum (100% diet) or on increasingly restricted diets (90, 80, and 70% of the ad libitum diet). Nestlings fed a reduced diet grew significantly more slowly than those fed the ad libitum diet, as shown by the body mass growth constant. The restricted diet had no significant effect on the asymptotic size of the kestrels, i.e., body mass and tarsus and antebrachium lengths. However, young kestrels fed reduced diets (80 and 70%) had a lower body mass at fledging than those fed ad libitum and the 90% diet, although they fledged at the same age. The growth of the ninth primary was slower for birds on restricted diets than for those fed ad libitum. Sexual dimorphism was observed for body mass and antebrachium growth constants, with males growing faster than females. However, females reached a higher asymptotic body mass and antebrachium length, as well as a higher body mass at fledging, than males. Thus, when prey availability is reduced by as much as 30%, nestling kestrels grow more slowly and store less fat, which could lead to poorer postfledging survivability.

Obesity and ovarian cancer risk: A systematic review

2017 ◽  
Vol 23 (4) ◽  
pp. 183-198 ◽  
Author(s):  
Ke Wei Foong ◽  
Helen Bolton
Keyword(s):  
Ovarian Cancer ◽  
Body Mass Index ◽  
Cancer Risk ◽  
Body Mass ◽  
Positive Association ◽  
Final Analysis ◽  
Ovarian Tumour ◽  
Normal Weight ◽  
Ovarian Cancer Risk ◽  
Significant Positive Association

The association between obesity and ovarian cancer risk has been extensively investigated, but studies have yielded inconsistent findings. This review aims to summarise and discuss the evidence generated to date. Articles published in English prior to August 2016 were retrieved from PubMed. Keywords included obesity, overweight, body size, body mass index, waist–hip ratio, waist circumference, body weight, ovarian cancer, ovarian carcinoma, ovarian neoplasm, and ovarian tumour. Eligible studies compared two or more groups of women, with at least one group in the overweight or obese category and one comprising normal weight controls. Summary data in the form of relative risk, hazard ratio, or odds ratio for each comparison group from individual studies were collated and reviewed. Forty-three studies were included in the final analysis, with a total of 3,491,943 participants. All studies included body mass index as an exposure measure, and a majority relied on self-reported measures from participants; 14 studies found a statistically significant positive association between ovarian cancer risk and higher body mass index, 26 studies found no significant association, and 3 studies found a negative association between ovarian cancer risk and higher body mass index. This review concludes that there is limited, inconsistent evidence of a positive association between obesity and ovarian cancer risk.

scholarly journals Exogenous hormone use, reproductive factors, and risk of intracranial meningioma in females

2013 ◽  
Vol 118 (3) ◽  
pp. 649-656 ◽  
Author(s):  
Elizabeth B. Claus ◽  
Lisa Calvocoressi ◽  
Melissa L. Bondy ◽  
Margaret Wrensch ◽  
Joseph L. Wiemels ◽  
...  
Keyword(s):  
Body Mass Index ◽  
San Francisco ◽  
Body Mass ◽  
Hormone Replacement ◽  
Premenopausal Women ◽  
Positive Association ◽  
Age At Menarche ◽  
Intracranial Meningioma ◽  
Significant Positive Association ◽  
Increased Risk

Object The 2-fold higher incidence of meningioma in women compared with men has long suggested a role for hormonally mediated risk factors, but specific mechanisms remain elusive. Methods The study included data obtained in 1127 women 29–79 years of age with intracranial meningioma diagnosed among residents of Connecticut, Massachusetts, North Carolina, the San Francisco Bay Area, and 8 Texas counties between May 1, 2006, and October 6, 2011, and data obtained in 1092 control individuals who were frequency matched for age group and geography with meningioma patients. Results No association was observed for age at menarche, age at menopause, or parity and meningioma risk. Women who reported breastfeeding for at least 6 months were at reduced risk of meningioma (OR 0.78, 95% CI 0.63–0.96). A significant positive association existed between meningioma risk and increased body mass index (p < 0.01) while a significant negative association existed between meningioma risk and current smoking (p < 0.01). Among premenopausal women, current use of oral contraceptives was associated with an increased risk of meningiomas (OR 1.8, 95% CI 1.1–2.9), while current use of hormone replacement therapy among postmenopausal women was not associated with a significant elevation in risk (OR 1.1, 95% CI 0.74–1.67). There was no association between use of fertility medications and meningioma risk. Conclusions The authors' study confirms associations for body mass index, breastfeeding, and cigarette smoking but provides little evidence for associations of reproductive and menstrual factors with meningioma risk. The relationship between current use of exogenous hormones and meningioma remains unclear, limited by the small numbers of patients currently on oral hormone medications and a lack of hormone receptor data for meningioma tumors.

A Previously Unknown Plumage of First-Year Indigo Buntings and Theories of Delayed Plumage Maturation

The Auk ◽  
1986 ◽  
Vol 103 (2) ◽  
pp. 281-292 ◽  
Author(s):  
Sievert Rohwer
Keyword(s):  
The United States ◽  
The Body ◽  
First Year ◽  
Adult Males ◽  
Young Males ◽  
Young Females ◽  
Female Mimicry ◽  
Breeding Plumage ◽  
Almost All ◽  
Wintering Ground

Abstract First-year, but not adult, Indigo Buntings (Passerina cyanea) have a previously unknown supplemental plumage. The presupplemental molt includes all of the rectrices, the outermost but not the innermost primaries, and, typically, the three innermost secondaries and all body feathers. In this molt, young females exchange one adult-femalelike plumage for another, while young males exchange an adult-femalelike plumage for one that matches that of adult males in winter. Thus, in their first year Indigo Buntings wear: first, the juvenile plumage, the body feathers of which begin replacement before the tail is fully grown; second, the first basic plumage, which in both sexes is entirely femalelike in coloration and includes the juvenile remiges and rectrices; third, the supplemental plumage, assumed either prior to fall migration (<10% of individuals) or on the wintering ground (>90% of individuals) and in which obvious sexual dichromatism is first achieved; and fourth, the first alternate plumage, acquired in a prolonged and often incomplete prealternate molt of body feathers that occurs during February, March, and April on the wintering ground and during the spring in the United States. Because almost all of the femalelike first basic plumage of young males is lost in the presupplemental molt, this plumage almost certainly is an adaptation to conditions encountered either in the fall or early in the first winter. Furthermore, the ensuing supplemental plumage cannot be compromised by color requirements of the first breeding season because of the intervening prealternate molt; thus, the adult-malelike plumage produced by the presupplemental molt likely evolved to meet a change in signaling requirements that occurs in early winter. The signaling function of this plumage is unknown. Because this supplemental plumage of young males resembles the winter plumage of adult males and because all feathers grown by young males in their first prealternate molt resemble those of the adult male breeding plumage, the female mimicry hypothesis of Rohwer et al. (1980) is untenable for the subadult breeding plumage of yearling male Indigo Buntings.

scholarly journals Effect of Differences in the Microbiome of Cyp17a1-Deficient Mice on Atherosclerotic Background

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1292
Author(s):  
Axel Künstner ◽  
Redouane Aherrahrou ◽  
Misa Hirose ◽  
Petra Bruse ◽  
Saleh Mohamed Ibrahim ◽  
...  
Keyword(s):  
Body Mass ◽  
Gut Microbiome ◽  
Alpha Diversity ◽  
Positive Association ◽  
Fat Distribution ◽  
Substantial Effect ◽  
The Body ◽  
Cytochrome P450 Enzyme ◽  
Significant Positive Association ◽  
Network Analyses

CYP17A1 is a cytochrome P450 enzyme that has 17-alpha-hydroxylase and C17,20-lyase activities. Cyp17a11 deficiency is associated with high body mass and visceral fat deposition in atherosclerotic female ApoE knockout (KO, d/d or -/-) mice. In the present study, we aimed to investigate the effects of diet and Cyp17a1 genotype on the gut microbiome. Female Cyp17a1 (d/d) x ApoE (d/d) (DKO) and ApoE (d/d) (controls) were fed either standard chow or a Western-type diet (WTD), and we demonstrated the effects of genetics and diet on the body mass of the mice and composition of their gut microbiome. We found a significantly lower alpha diversity after accounting for the ecological network structure in DKO mice and WTD-fed mice compared with chow-fed ApoE(d/d). Furthermore, we found a strong significant positive association of the Firmicutes vs. Bacteroidota ratio with body mass and the circulating total cholesterol and triglyceride concentrations of the mice when feeding the WTD, independent of the Cyp17a1 genotype. Further pathway enrichment and network analyses revealed a substantial effect of Cyp17a1 genotype on associated cardiovascular and obesity-related pathways involving aspartate and L-arginine. Future studies are required to validate these findings and further investigate the role of aspartate/L-arginine pathways in the obesity and body fat distribution in our mouse model.

scholarly journals Feeding ecology of Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) in a riparian flooded forest of Eastern Amazonia, Brazil

2011 ◽  
Vol 9 (3) ◽  
pp. 629-636 ◽  
Author(s):  
Tiago Magalhães da Silva Freitas ◽  
Vitor Hudson da Consolação Almeida ◽  
Roberta de Melo Valente ◽  
Luciano Fogaça de Assis Montag
Keyword(s):  
Amazon Basin ◽  
Diet Composition ◽  
Trophic Ecology ◽  
Feeding Habits ◽  
Biological Information ◽  
Adult Males ◽  
Terrestrial Invertebrates ◽  
Young Males ◽  
Young Females ◽  
Terrestrial Vertebrates

Feeding habits of the midnight catfish Auchenipterichthys longimanus collected in rivers of the Caxiuanã National Forest (Eastern Amazonia, Brazil) were investigated through the different hydrological periods (dry, filing, flood and drawdown). A total of 589 specimens were collected throughout seven samplings between July 2008 and July 2009, of which 74 were young males, 177 adult males, 89 young females and 249 adult females. The diet composition (Alimentary index - Ai%) was analyzed by a non-metric multidimensional scaling (nMDS) and by the analysis of similarity (ANOSIM), which included 37 items grouped into nine categories (Aquatic insects, Other aquatic invertebrates, Arthropods fragment, Fish, Plant fragment, Seeds, Terrestrial insects, Other terrestrial invertebrates, and Terrestrial vertebrates). We also calculated the niche breadth (Levins index) and the repletion index (RI%). Differences in the diet composition between hydrological seasons were registered, primarily on diet composition between dry and flood season, but changes related with sex and maturity were not observed. The midnight catfish showed more specialists feeder habit in the flood period (March 2009) and more generalist habits in the dry season (November 2008). The amount of food eaten by A. longimanus based on repletion index (RI%), did not differ significantly from sex and maturity. However, we evidenced differences in RI% when comparing the studied months. These results provide important biological information about the trophic ecology of auchenipterids fish. In view of the higher occurrence of allochthonous items, this research also underpins the importance of riparian forests as critical environments in the maintenance and conservation of wild populations of fish in the Amazon basin.

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