摘要:

This paper describes and discusses events observed in the Madrid colony of hamadryas and hybrid baboons, when a novel group of 3 adult males, 3 adult females and 1 unweaned infant was introduced to the resident colony comprising 12 adult females, 11 juveniles and 6 unweaned infants. Novel males took over resident adult females in any reproductive condition, and all acyclic females (i.e. lactating, pregnant and immature) exhibited a dramatic enhancement of sexual activity. Lactating females shortened their post-partum amenorrhoea periods and resumed oestrous cycles around day 14 following the introduction of the novel males, without infanticide occurring. Their return to breeding condition was not affected by the age of their current infant or the day they were taken over by the males. A female in an early stage of pregnancy aborted spontaneously and resumed oestrus on day 26. The other pregnant female significantly shortened her gestation time, delivered a viable infant on day 13, and resumed breeding activity 39 days post-partum (on day 52), while suckling her infant. A cycling female adopted and suckled a 74-day-old infant, continued showing oestrous cycles and conceived. Immature females reached menarche significantly earlier than expected and only then joined one of the newly established harem units. It is argued that the observed enhancement of sexual activity was not imposed by the males’ aggressive behaviour but rather was a spontaneous female response to male novelty. This single causal factor was potent enough to override the role that nutrition and lactation normally play in the control of the females’ reproductive activity. Differences in latency until the appearance of the response were probably due to the different constraints imposed by the female’s current reproductive state. It was also hypothesized that when (a) sexual swellings are attractive to males, (b) novel males are especially active in the process of bonding with new females, and (c) males are important sources of coalitionary support, females might by developing sexual swellings compete more successfully against other females and attain a higher position in the female hierarchy of the newly established unit. This would have the ultimate effect of increasing their potential reproductive success. In several cases females did gain socially by coming into oestrus, but attained no immediate reproductive adva

ISSN:0015-5713    

DOI:10.1159/000156343

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Over 350 h of observations were collected using focal animal sampling of scent-marking behavior by 2 troops of ring-tailed lemurs (Lemur catta) in the field in Madagascar. Although they did not mark any branch species preferentially, they did have preferred marking sites. Significantly more scent marks were deposited in the area of home range overlap between troops than in the area of exclusive use. However, few marks were deposited at the periphery of the area of overlap. Instead, the majority of the marks were in a narrow band within the area of overlap that coincided with the positions of intertroop confrontations. Female genital marks and male arm marks, as well as the accompanying male shoulder rubs thus appear to demarcate territorial borders.

ISSN:0015-5713    

DOI:10.1159/000156344

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Aspects of a monogamous relationship can be inferred by observing reactions of mated individuals to unfamiliar conspecifics. The present study examined the behaviours shown by male and female titi monkeys (Callicebus moloch) toward an opposite-sex stranger, and the effect of their pairmate’s absence or presence on these encounters. Behaviours within unfamiliar heterosexual pairs showed superficial similarities to behaviours of mated pairs. Although there were few affiliative behaviours between unfamiliar individuals, animals were often in spatial proximity and even performed sexual behaviour. The visual presence of a pairmate clearly affected encounters between unfamiliar heterosexual pairs in several respects. The presence of a male pairmate had a much stronger influence on all behavioural measures compared to the presence of a female pairmate. Possible functional aspects of these results are discusse

ISSN:0015-5713    

DOI:10.1159/000156345

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Five male and four female grey lesser mouse lemurs, Microcebus murinus, were trapped with Sherman traps in the Forestry Reserve of Ampijoroa, near Majunga, N.W.Madagascar and equipped with individual radio-transmitters with a range of 220–300 m. These 9 individuals were then followed and observed (alternatively or simultaneously) for a total of 30 nights spread over a period of 6 weeks (26 September to 11 November 1985). In this dry deciduous forest zone, the subpopulation of 9 M. murinus observed occupied a total area of 7 ha. The home ranges of 4 males were significantly larger than those of 4 females (means: 3.2 ± 0.2 and 1.8 ± 0.1 ha, respectively). Nevertheless, because of the larger degree of overlap between home ranges of males, the available mean area per individual did not differ greatly between the sexes (a total of 5.5 ha for 4 males, with 65 % overlap, versus a total of 4.2 ha for 4 females, with only 44% overlap). Overlapping of all nine home ranges produced a ‘common zone’ in the centre of the study area, where meetings between animals of either sex took place. This pattern can be interpreted as representing a pregregarious form of social structure. During nocturnal activity, the animals foraged individually, though an average of 11 % of time was spent less than 10 m away from a conspecific. The tendency for dispersion of individuals was most pronounced during foraging for insects, when travel speeds were also relatively high. The most obvious social interactions occurred when females were on their way back to a common nest, calling and following each other. Such behaviour was not exhibited by males, even by those that shared a nest. Away from the nest, physical contacts were rare and brief. During the few days preceding oestrus, females were approached by several males, without agonistic interactions between males being observed at this period. Most observed agonistic interactions were initiated by females and directed agains

ISSN:0015-5713    

DOI:10.1159/000156346

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156347

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156348

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156349

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156350

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156351

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156352

出版商:S. Karger AG    

年代:1988

数据来源: Karger