scholarly journals Behaviour and recruitment of translocated black rhinoceros diceros bicornis

Koedoe ◽  
1977 ◽  
Vol 20 (1) ◽  
Author(s):  
A.J. Hall-Martin ◽  
L. Penzhorn
Keyword(s):  
Population Density ◽  
National Park ◽  
Late Summer ◽  
High Population ◽  
Calving Interval ◽  
Wild Animals ◽  
High Population Density ◽  
Mating Activity ◽  
Black Rhinoceros ◽  
Diceros Bicornis

Black rhinoceros were translocated to the Addo Ele- phant National Park from Kenya and released into a small fenced enclosure. Serious fighting attributed to the conditions under which the animals were released, the unusually high population density, the meeting of strange animals, aggression associated with mating and individual temperament resulted in the deaths of three animals within three weeks. Later fighting between bulls accounted for two more animals. A peak in mating activity was recorded during spring to mid-summer, followed by a peak calving period in late summer. The calving interval (35 months) is longer than that of unrestricted populations but ages at first mating in cows (4 years 6 months, 4 years 7 months) are comparable. First parturition at Addo occurs later (8 years, 8 years 5 months) than in wild animals and the young are hidden for the first few days after birth. Under conditions of stress a subadult bull readily took to swimming as a means of escaping from other animals.

scholarly journals Female monopolizability promotes within-community killing in chimpanzees

2021 ◽  
Author(s):  
Michael L. Wilson ◽  
Anthony Massaro ◽  
Emily Wroblewski ◽  
Deus Mjungu ◽  
Emily Boehm ◽  
...  
Keyword(s):  
Population Density ◽  
Pan Troglodytes ◽  
National Park ◽  
High Population ◽  
Published Data ◽  
High Population Density ◽  
Gombe National Park ◽  
Using Data ◽  
Study Sites

Abstract Male chimpanzees (Pan troglodytes) defend group territories and sometimes kill members of rival communities — a pattern often compared to human warfare1-3. Male chimpanzees also sometimes kill grown males from their own community4-9. Such within-community killings are puzzling, as they reduce the coalition strength needed to win inter-community contests5,10. Here we examine the contexts of within-community killing using data from two neighboring communities at Gombe National Park, Tanzania, as well as published data from other long-term chimpanzee study sites. At Gombe, more killing occurred within the smaller Mitumba community, where fertile females were more monopolizable. Attackers increased their share of mating and paternity following known and inferred killings. Other factors proposed to explain such killings, including the degree of intercommunity threat, male-biased sex ratios, high population density, or generalized aggression, did not explain the high rates of killing in Mitumba. Comparing across study sites, the best predictor of within-community killing was an index of the degree to which fertile females can be monopolized by the highest ranking male11. Our findings therefore support the hypothesis that within-community killing is a strategy to eliminate reproductive rivals that is more likely to pay off when fertile females are more easily monopolized.

Observations on the Pathology of Lesions Associated with Stephanofilaria dinniki Round, 1964 from the Black Rhinoceros (Diceros bicornis)

1964 ◽  
Vol 38 (1-2) ◽  
pp. 171-174 ◽  
Author(s):  
J. G. Tremlett
Keyword(s):  
South Africa ◽  
National Park ◽  
Black Rhinoceros ◽  
Diceros Bicornis ◽  
Made In

In South Africa, a filarioid infestation has been associated with lesions in the skin of the black rhinoceros (Schulz and Kluge, 1960). Similar lesions had been reported earlier from Kenya, as consistently occurring in these animals but their aetiology was unknown (Spinage, 1960). Recently the opportunity occurred to examine lesion material from four black rhinoceros located in the Royal Tsavo National Park Kenya. From this material adult helminths were recovered and identified (Round, 1964), and further pathological studies made. In addition, one rhinoceros showed evidence of an otitis.

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

2003 ◽  
Vol 81 (8) ◽  
pp. 1306-1311 ◽  
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.

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 ◽  
2006 ◽  
Vol 70 (1-2) ◽  
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.

scholarly journals Lake Nakuru Black Rhinoceros Sanctuary

Oryx ◽  
1990 ◽  
Vol 24 (2) ◽  
pp. 90-94
Author(s):  
Christopher Lever
Keyword(s):  
National Park ◽  
Education Programme ◽  
Lake Nakuru ◽  
Black Rhinoceros ◽  
Diceros Bicornis

In an attempt to stem the decline of the black rhinoceros Diceros bicornis in Kenya, the Rhino Rescue Charitable Appeal Trust was formed in England in 1985. Within a year work on the first sanctuary, in the Lake Nakuru National Park, had begun. The sanctuary was opened in 1987, when 17 rhinos from Mr Courtland Parfet's private ranch at Solio joined the wo animals already in Nakuru. A further 11 females are due to be added to the park shortly. Rhino Rescue, of which the author is a patron and trustee, is also developing its own education programme, and is contributing to other rhino sanctuaries in Kenya.

Trypanosomiasis and the conservation of black rhinoceros (Diceros bicornis) at the Ngulia Rhino Sanctuary, Tsavo West National Park, Kenya

1992 ◽  
Vol 30 (2) ◽  
pp. 103-115 ◽  
Author(s):  
STEVE MIHOK ◽  
ELI MUNYOKI ◽  
ROBERT A. BRETT ◽  
JOHN F. JONYO ◽  
DIETTER RÖTTCHER ◽  
...  
Keyword(s):  
National Park ◽  
Black Rhinoceros ◽  
Diceros Bicornis

Analysis of steroid hormone levels in female mice at high population density

1998 ◽  
Vol 64 (4) ◽  
pp. 529-533 ◽  
Author(s):  
John C Chapman ◽  
John J Christian ◽  
Mary Ann Pawlikowski ◽  
Sandra D Michael
Keyword(s):  
Population Density ◽  
Steroid Hormone ◽  
High Population ◽  
High Population Density ◽  
Hormone Levels ◽  
Female Mice
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