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.

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.

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.

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.

scholarly journals How accurately do behavioural observations predict reproductive success in free-ranging lizards?

2019 ◽  
Vol 15 (2) ◽  
pp. 20190030 ◽  
Author(s):  
Mats Olsson ◽  
Tonia S. Schwartz ◽  
Erik Wapstra ◽  
Richard Shine
Keyword(s):  
Reproductive Success ◽  
Adult Males ◽  
Microsatellite Data ◽  
Term Study ◽  
Long Term Study ◽  
Lacerta Agilis ◽  
Free Ranging ◽  
Number Of Males ◽  
Variance In Reproductive Success

Behavioural ecologists often use data on patterns of male–female association to infer reproductive success of free-ranging animals. For example, a male seen with several females during the mating season is predicted to father more offspring than a male not seen with any females. We explored the putative correlation between this behaviour and actual paternity (as revealed by microsatellite data) from a long-term study on sand lizards ( Lacerta agilis ), including behavioural observations of 574 adult males and 289 adult females, and paternity assignment of more than 2500 offspring during 1998–2007. The number of males that contributed paternity to a female's clutch was correlated with the number of males seen accompanying her in the field, but not with the number of copulation scars on her body. The number of females that a male accompanied in the field predicted the number of females with whom he fathered offspring, and his annual reproductive success (number of progeny). Although behavioural data explained less than one-third of total variance in reproductive success, our analysis supports the utility of behavioural-ecology studies for predicting paternity in free-ranging reptiles.

Occupational Segregation and Youth Employment

1985 ◽  
Vol 27 (1) ◽  
pp. 49-60 ◽  
Author(s):  
K.R. Mackay
Keyword(s):  
Labour Market ◽  
Service Sector ◽  
Occupational Segregation ◽  
Youth Employment ◽  
Occupational Structure ◽  
Young Males ◽  
Young Females ◽  
The Impact ◽  
Dominant Influence

The aim of the paper is to assess the impact of changes in occupational structure on the level and composition of youth employment. Substantial occupational segrega tion of youth employment persists, suggesting the existence of identifiable 'youth jobs' and 'adult jobs'. When a shift and share approach is applied to changes in the levels of youth employment over the 1971-81 period, changing youth shares of employment within occupations are found to be a dominant influence on youth employment levels. This suggests the importance of competitive factors in the labour market and is consistent with existing research. There is also evidence that occupa tional segregation and changes in occupational structure have had an important influence on the employment of youth. These will probably continue to be impor tant, given continuing long-term growth in service sector occupations, and the decline in trades and prodtrction process worker occupations. The former trend will work to the advantage of young females, who are concentrated in these growth occupations, while the latter will act as a constraint on the employment of young males, particularly 15 to 20-year-olds.

Long-term variability in serum thyroglobulin and thyroid related hormones in healthy subjects

1980 ◽  
Vol 95 (3) ◽  
pp. 328-334 ◽  
Author(s):  
U. Feldt-Rasmussen ◽  
P. Hyltoft Petersen ◽  
O. Blaabjerg ◽  
M. Hørder
Keyword(s):  
Healthy Subjects ◽  
Reference Ranges ◽  
Serum Thyroglobulin ◽  
Young Males ◽  
Young Females ◽  
Coefficients Of Variation ◽  
Individual Variations ◽  
Uptake Test ◽  
Healthy Persons

Abstract. From 5 young males and 5 young females blood was drawn under highly standardized conditions at 6 to 10 occasions during 4 months. The serum constituents thyroglobulin, thyroxine, triiodothyronine, T3-uptake test, TBG and TSH were determined, and four indices were calculated. The biological intra-individual coefficients of variation were below 0.14 for thyroglobulin, and the inter-individual coefficients of variation ranged from zero for T3-uptake test to 0.35 for thyroglobulin. All results were within the generally accepted reference ranges for normals. Within these ranges the calculations of indices for free thyroxine and triidothyronine according to T3-uptake test and TBG, did not significantly reduce the coefficients of variation for these serum constituents. Thyroglobulin concentrations did not correlate to any of the measured or calculated constituents. The knowledge of these intra- and inter-individual variations of serum thyroglobulin in healthy persons is of importance for the interpretation of variations found in patients.

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.

Musth and its effects on male–male and male–female associations in Asian elephants

2019 ◽  
Vol 101 (1) ◽  
pp. 259-270 ◽  
Author(s):  
P Keerthipriya ◽  
S Nandini ◽  
Hansraj Gautam ◽  
T Revathe ◽  
T N C Vidya
Keyword(s):  
Southern India ◽  
Adult Males ◽  
Age Classes ◽  
Asian Elephants ◽  
Young Males ◽  
Gain Access ◽  
Older Males ◽  
Term Data

Abstract Musth is an annual, asynchronous, rut-like phenomenon observed in male elephants. We examined whether musth is a roving strategy, and whether musth provides a temporary advantage to young males through increased access to female groups. We collected long-term data on the musth status, associations, and locations of male elephants in the Kabini population in southern India. We sighted older males more frequently in musth than younger males. We found a greater turnover of musth than non-musth males in the study area, suggesting that musth is a roving strategy, enabling males to travel widely and away from their non-musth range. Contrary to our expectation, young (15–30 years old) males spent a smaller proportion of their musth time than their non-musth time associating with females, and associated with similarly sized female groups irrespective of musth status. Old (&gt; 30 years old) males spent only a slightly higher proportion of their musth time than non-musth time with female groups, but associated with larger female groups during musth. Although old males in musth associated with young non-musth males more often in the presence, than in the absence, of females, young males in musth were never sighted with old non-musth males in the presence of females. Therefore, the payoff from musth, as a strategy to gain access to females, was age-specific; musth in old males allowed for increased association with females, while musth in young males restricted their access to females. There was no spatial avoidance between musth and non-musth adult males at scales larger than immediate associations. Our results suggest that musth seems to be primarily a roving strategy for old males to find and associate with females and not a strategy for young males to gain a temporary advantage over old males, within the broad age-classes that we examined.

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.

scholarly journals POLA PENGGUNAAN RUANG DAN WAKTU RUSA SAMBAR (Rusa unicolor) DI RAGUNAN

2021 ◽  
Vol 1 (3) ◽  
pp. 129-135
Author(s):  
Julaili Irni
Keyword(s):  
Time Use ◽  
Time Allocation ◽  
Time Budget ◽  
Daily Activities ◽  
Adult Males ◽  
Young Males ◽  
Young Females ◽  
Age Class ◽  
Allocation Of Time ◽  
Sambar Deer

Daily activities are all activities carried out by animals daily starting from the morning out of the nest until late in the evening and back again to the nest. This study aims to determine the activity pattern of sambar deer (Rusa unicolor). This observation was carried out at the Ragunan zoo which was carried out in 3 stages, namely morning, afternoon and evening. This study observed the patterns of time use and space use observed in sambar deer with 5 age class categories, namely adult males, adult females, young males and young females. The results of the research obtained from the activity of the sambar deer in the morning, namely the allocation of time for daily activities in the morning for each different age class, the allocation of time for feeding, moving, and resting activities during the daytime period for each individual age class of the deer is different and the time allocation for daily activities in the afternoon for each age class is different. Most of the sambar deer in Ragunan prefer to be in the grass below the stands for their activities. Time allocation (time budget) for sambar deer in age class and sex is influenced by the time of activity (morning-afternoon-evening).

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