Social Dispersion and Lekking in Uganda Kob

AbstractLek-breeding in Uganda kob was associated with extremely high population density (c. 140 animals/km2). Kob were typically found in unstable aggregations of more than one hundred animals, including several adult males. Females occupied unusually large, overlapping home ranges, but reasons for such widespread movements were unclear. The social dispersion of Uganda kob was therefore similar to that of other lekking ungulates, and confirms predictions of several recent hypotheses of lek evolution. However, resolution of alternative models is nevertheless difficult, since in practice these make very few exclusive predictions.

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Home ranges, time budgets and food-tree use in a high-density tropical population of greater gliders, Petauroides volans minor (Pseudocheiridae : Marsupialia)

Wildlife Research ◽

10.1071/wr9960401 ◽

1996 ◽

Vol 23 (4) ◽

pp. 401 ◽

Cited By ~ 36

Author(s):

SS Comport ◽

SJ Ward ◽

WJ Foley

Keyword(s):

Population Density ◽

Home Range ◽

Kernel Method ◽

Radio Telemetry ◽

High Population ◽

Home Ranges ◽

Time Budgets ◽

High Population Density ◽

Mean Values ◽

Males And Females

The socio-ecology of Petauroides volans has been studied for subtropical and temperate populations, but not for the northern tropical subspecies, Petauroides volans minor. Data on the effects of a high population density on home ranges, time budgets and food-tree use were obtained by means of radio-telemetry. Three techniques were used to estimate home-range area (kernel, MCP and harmonic mean) and the kernel method was preferred. Estimates of home-range area (defined by the 95% kernel) gave mean values of 2.5 and 1.3 ha for males and females, respectively. Broad overlap of home ranges of males was observed, which has not been reported previously for populations of P. volans. Behaviour patterns for males and females were similar to those in previous studies, although the mating system may differ, possibly because of the high population density. Dietary patterns were similar to those previously reported for this species, the most important food items being young leaves and flower buds of particular eucalypt species, notably Eucalyptus acmenoides.

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PHASE TRANSITION IN HIERARCHY MODEL OF BONABEAU

International Journal of Modern Physics C ◽

10.1142/s0129183103004425 ◽

2003 ◽

Vol 14 (02) ◽

pp. 237-239 ◽

Cited By ~ 19

Author(s):

DIETRICH STAUFFER

Keyword(s):

Phase Transition ◽

Population Density ◽

Social Inequality ◽

High Population ◽

High Population Density ◽

Sharp Transition ◽

Social Hierarchies ◽

The Social ◽

Egalitarian Society ◽

Hierarchy Model

The model of Bonabeau explains the emergence of social hierarchies from the memory of fights in an initially egalitarian society. Introducing a feedback from the social inequality into the probability to win a fight, we find a sharp transition between an egalitarian society at low population density and a hierarchical society at high population density.

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The Social Consequences of High Population Density

Law and Contemporary Problems ◽

10.2307/1190689 ◽

1965 ◽

Vol 30 (1) ◽

pp. 120 ◽

Cited By ~ 59

Author(s):

Halliman H. Winsborough

Keyword(s):

Population Density ◽

Social Consequences ◽

High Population ◽

High Population Density ◽

The Social

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Dispersal patterns in a regional koala population in south-east Queensland

Wildlife Research ◽

10.1071/wr02043 ◽

2003 ◽

Vol 30 (3) ◽

pp. 281 ◽

Cited By ~ 46

Author(s):

David S. Dique ◽

Jim Thompson ◽

Harriet J. Preece ◽

Deidré L. de Villiers ◽

Frank N. Carrick

Keyword(s):

Urban Areas ◽

Home Ranges ◽

Adult Males ◽

Dispersal Patterns ◽

Young Males ◽

Straight Line ◽

The Social ◽

Straight Line Distance ◽

Males And Females ◽

Natal Home

Koala dispersal was investigated as part of a detailed ecological study of a nationally significant koala population located 20 km south-east of Brisbane, Queensland. From 1996 to 2000, 195 koalas from three sites were captured and fitted with radio-collars. A total of 40 koalas (23 males and 17 females) dispersed from these sites. Most (93%) dispersing individuals were 20–36 months of age. Three adult females (more than 36 months old) dispersed and no adult males dispersed during the study. A significantly higher proportion of young males dispersed than females. Dispersal occurred between June and December, with most dispersal of males commencing in July and August and that of females commencing between September and November prior to, and early in, the annual breeding season. The mean straight-line distance between the natal and breeding home ranges for males and females was similar and was measured at 3.5 km (range 1.1–9.7 km) and 3.4 km (range 0.3–10.6 km) respectively. Dispersing males and females tended to successfully disperse south and west of their natal home ranges and were generally unable to successfully disperse to urban areas within the study area, as a high proportion of the mortality of dispersing koalas was associated with attacks by domestic dogs and with collisions with vehicles on roads. Information from other studies indicates that most young koalas disperse from their natal areas. It is likely that the social behaviour and mating systems of koala populations provide mechanisms for young koalas to disperse. The potential role of dispersal in the dynamics of regional koala populations is discussed.

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Juvenile Experience with Male Cues Triggers Cryptic Choice Mechanisms in Adult Female Redback Spiders

Insects ◽

10.3390/insects12090825 ◽

2021 ◽

Vol 12 (9) ◽

pp. 825

Author(s):

Maydianne C. B. Andrade ◽

Aiswarya Baskaran ◽

Maria Daniela Biaggio ◽

Maria Modanu

Keyword(s):

Population Density ◽

Strong Evidence ◽

Chemical Cues ◽

Mate Preferences ◽

Social Cues ◽

Adult Males ◽

Volatile Chemicals ◽

Male Density ◽

The Social ◽

Female Choosiness

Female choice may be linked to population density if the expected encounter rates with potential mates affects choosiness (the energy and risk engaged to express mate preferences). Choosiness should covary with male availability, which could be assessed using the social cues available during development. We tested whether the exposure of juvenile females to cues of male density affected the mechanisms of choosiness of adult Latrodectus hasselti spiders in two experiments simulating natural contexts. The juvenile females were exposed to (1) volatile chemicals from two densities of adult males (airborne cues), and (2) tactile, vibrational and chemical cues from adult males or other females (cohabitation cues). As adults, the females mated readily, regardless of the treatment, but there was strong evidence for post-copulatory mechanisms of choosiness in females exposed to cues of high male availability. These included abbreviated matings (in both experiments), cannibalism of the males before the mating was complete (cohabitation), and, remarkably, a reduction in the successful placement of internal sperm plugs (cohabitation). These shifts decrease the likelihood that the first mate would monopolize paternity if the female chose to mate again. We conclude that female choosiness may impose a strong selection on males despite the high mating rates, and these effects can hinge on the cues of male availability detected by juveniles.

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Recruitment sex ratios in gray-tailed voles (Microtus canicaudus) in response to density, sex ratio, and season

Canadian Journal of Zoology ◽

10.1139/z03-116 ◽

2003 ◽

Vol 81 (8) ◽

pp. 1306-1311 ◽

Cited By ~ 7

Author(s):

Monica L Bond ◽

Jerry O Wolff ◽

Sven Krackow

Keyword(s):

Population Density ◽

Sex Ratio ◽

Resource Competition ◽

Sex Ratios ◽

Female Offspring ◽

High Population ◽

Reproductive Value ◽

High Population Density ◽

Adult Sex Ratio ◽

Sex Ratio Adjustment

We tested predictions associated with three widely used hypotheses for facultative sex-ratio adjustment of vertebrates using eight enclosed populations of gray-tailed voles, Microtus canicaudus. These were (i) the population sex ratio hypothesis, which predicts that recruitment sex ratios should oppose adult sex-ratio skews, (ii) the local resource competition hypothesis, which predicts female-biased recruitment at low adult population density and male-biased recruitment at high population density, and (iii) the first cohort advantage hypothesis, which predicts that recruitment sex ratios should be female biased in the spring and male biased in the autumn. We monitored naturally increasing population densities with approximately equal adult sex ratios through the spring and summer and manipulated adult sex ratios in the autumn and measured subsequent sex ratios of recruits. We did not observe any significant sex-ratio adjustment in response to adult sex ratio or high population density; we did detect an influence of time within the breeding season, with more female offspring observed in the spring and more male offspring observed in the autumn. Significant seasonal increases in recruitment sex ratios indicate the capacity of female gray-tailed voles to manipulate their offspring sex ratios and suggest seasonal variation in the relative reproductive value of male and female offspring to be a regular phenomenon.

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Observations on Activity Patterns, Population and Den Characteristics of The Water Rat Hydromys chrysogaster Along Badger Creek, Victoria.

Australian Mammalogy ◽

10.1071/am95071 ◽

1995 ◽

Vol 18 (1) ◽

pp. 71

Author(s):

J.L. Gardner ◽

M. Serena

Keyword(s):

Population Density ◽

Activity Patterns ◽

Home Ranges ◽

Adult Males ◽

Fish Farms ◽

Age Classes ◽

Irrigation Channels ◽

In Captivity ◽

In The Wild ◽

Hydromys Chrysogaster

The Water Rat Hydromys chrysogaster is Australia's largest amphibious rodent, occupying freshwater rivers, lakes, and coastal and estuarine habitats throughout the continent (Watts and Aslin 1981). Little is known of the species' social organisation or use of space in the wild although Harris (1978) suggested that adults might be intrasexually aggressive. The home ranges of all sex and age classes overlap to some extent but home ranges of adults of the same sex appear to overlap less (Harris 1978). Adult males occupy the largest home ranges which overlap those of one or more females. In captivity individuals kept in groups form hierarchies in which only the dominant females usually breed successfully (Olsen 1982). Fighting occurs primarily among males, with the highest incidence of injuries observed at the beginning of the main September-March breeding season (Olsen 1980, 1982). The results of trapping studies indicate that population density may vary considerably, with the greatest numbers of animals typically occupying man-modified habitats such as irrigation channels or fish farms (McNally 1960, Watts and Aslin 1981, Smales 1984). Aggressive behaviour appears to be related to pelage colour (phenotype) and population density; the higher the density the greater the number of injured individuals (Olsen 1980).

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Aggregations of masked shrews ( Sorex cinereus ): density-related mating behavior? / Agrégation de musaraignes masquées ( Sorex cinereus ): accouplement relatif à la densité de la population?

Mammalia ◽

10.1515/mamm.70.1-2.86 ◽

2006 ◽

Vol 70 (1-2) ◽

Cited By ~ 2

Author(s):

Thomas J. Maier ◽

Katherine L. Doyle

Keyword(s):

Population Density ◽

Mating Behavior ◽

High Population ◽

High Population Density ◽

Genetic Analyses ◽

Highly Active ◽

Sorex Cinereus

AbstractLarge aggregations of shrews have been reported and various explanations offered for this seemingly rare behavior; however, there has been little evidence to support any particular interpretation. We observed two small aggregations of highly active vocalizing Sorex cinereus while performing wildlife surveys in forested habitats in central Massachusetts, USA. These observations, in conjunction with a review of other reports, including genetic analyses, strongly suggest that such aggregations of adult Sorex are associated with mating behavior, more readily observed during periods of high population density. Published accounts of such behavior may be rare because primarily large aggregations have been reported; however, smaller breeding aggregations may be common.

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