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A E Pusey

Publications and source records attributed to A E Pusey.

10 recordsLinked to original sources
PubMed2006

Using retrospective health data from the Gombe chimpanzee study to inform future monitoring efforts.

Disease outbreaks, either in isolation or in concert with other risk factors, can pose serious threats to the long-term persistence of mammal populations, and these risks become elevated as population size decreases and/or population isolation increases. Many chimpanzee study sites are increasingly isolated by loss of habitat due to human encroachment, and managers of parks that contain chimpanzees perceive that disease outbreaks have been and continue to be significant causes of mortality for chimpanzees. Major epidemics at Gombe National Park include suspected polio in 1966; respiratory diseases in 1968, 1987, 1996, 2000, and 2002; and sarcoptic mange in 1997. These outbreaks have led park managers and researchers working in Gombe to conclude that disease poses a substantial risk to the long-term survival of Gombe's chimpanzee population. We surveyed behavioral data records spanning 44 years for health-related data and found a combination of standardized and nonstandardized data for the entire period. Here we present the types of data found during the survey, discuss the usefulness of these data in the context of risk assessment, and describe how our current monitoring effort at Gombe was designed based on our findings.

Animals↗
PubMed2001

Egalitarianism in female African lions.

Because most cooperative societies are despotic, it has been difficult to test models of egalitarianism. Female African lions demonstrate a unique form of plural breeding in which companions consistently produce similar numbers of surviving offspring. Consistent with theoretical predictions from models of reproductive skew, female lions are unable to control each other's reproduction because of high costs of fighting and low access to each other's newborn cubs. A female also lacks incentives to reduce her companions' reproduction, because her own survival and reproduction depend on group territoriality and synchronous breeding. Consequently, female relationships are highly symmetrical, and female lions are "free agents" who only contribute to communal care when they have cubs of their own.

Animals↗
PubMed2001

Noninvasive paternity assignment in Gombe chimpanzees.

The relative success of chimpanzee male mating strategies, the role of male dominance rank and the success of inbreeding avoidance behaviour can only be assessed when paternities are known. We report the probable paternities of 14 chimpanzees included in a long-term behavioural study of chimpanzees (Pan troglodytes schweinfurthii) at Gombe National Park, Tanzania. DNA samples were collected noninvasively from shed hair and faeces and genotyped using 13-16 microsatellite loci characterized in humans. All 14 offspring could be assigned to fathers within the community. While there is a positive relationship between male rank and reproductive success, we demonstrate that a range of male mating strategies (possessiveness, opportunistic mating and consortships) can lead to paternity across all male ranks. Several adult females were at risk of breeding with close male relatives. Most successfully avoided close inbreeding but in one case a high-ranking male in the community mated with his mother and produced an offspring. In contrast to recent data on chimpanzees (P. t. verus) from the Taï forest, Côte d'Ivoire, no evidence of extra-group paternity was observed in our study. Reanalysis of Taï data using a likelihood approach casts doubt on the occurrence of extra-group paternity in that community as well.

Animals↗
PubMed1996

Development of cooperative territoriality in juvenile lions.

African lions, Panthera leo, engage in many cooperative activities including hunting, care of young, and group territoriality, but the contribution of juvenile lions to these activities has never been documented. Here we present experimental evidence that juvenile lionesses make a gradual transition to group-territorial defence between weaning (8 months) and sexual maturity (42 months). When challenged by simulated intruders played from a loud-speaker, juvenile females (but not males) become progressively more likely to join the adult females in territorial defence with age, and their behaviour is affected by both the number of defending adults and the number of intruders. We interpret the ability of juveniles to assess relative numbers as an adaptation for assessing the risk of territorial conflict according to their own fighting ability, and the ability of their pride of successfully defend the territory. The difference between the sexes reflects the greater value of the natal territory to philopatric females. Adult females display a variety of strategies when defending the territory, including unconditional and conditional forms of cooperation. We show here that individuals display the rudiments of these strategies as juveniles.

Animals↗
PubMed1993

Hormonal characteristics of free-ranging female lions (Panthera leo) of the Serengeti Plains and Ngorongoro Crater.

Pituitary responses to gonadotrophin-releasing hormone (GnRH) and prolactin and steroid secretory profiles were examined in two populations of adult, female lions in the Serengeti (one outbred in the Serengeti Plains and one inbred in the Ngorongoro Crater) to determine whether reductions in genetic variability adversely affected endocrine function. GnRH-induced gonadotrophin secretion was also examined after adrenocorticotrophic hormone (ACTH) treatment to determine whether acute increases in serum cortisol altered pituitary function. Anaesthetized lions were administered (i) saline i.v. after 10 and 100 min of blood sampling, (ii) saline at 10 min and GnRH (1 micrograms kg-1 body weight) after 100 min; or (iii) ACTH (3 micrograms kg-1) at 10 min and GnRH after 100 min of sampling. Basal serum cortisol and basal and GnRH-induced gonadotrophin secretion were similar (P > 0.05) between females of the Ngorongoro Crater and Serengeti Plains. After ACTH, serum cortisol increased two- to threefold over baseline values and the response was unaffected (P > 0.05) by location. ACTH-induced increases in serum cortisol had no effect on subsequent basal or GnRH-stimulated luteinizing hormone (LH) or follicle-stimulating hormone (FSH) secretion. Overall mean serum progesterone concentrations ranged from 0.2 to 5.4 ng ml-1 with the exception of four females (two in the Serengeti and two in the Crater; progesterone range, 18.4-46.5 ng ml-1) that were presumed pregnant (three of these females were observed nursing cubs several weeks later).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1991

Developmental changes in pituitary-gonadal function in free-ranging lions (Panthera leo leo) of the Serengeti Plains and Ngorongoro Crater.

Pituitary-gonadal function was examined in male lions free-ranging in the Serengeti Plains or geographically isolated in the Ngorongoro Crater of Tanzania. Lions were classified by age as adult (6.1-9.8 years), young adult (3.3-4.5 years) or prepubertal (1.4-1.6 years, Serengeti Plains only). Each animal was anaesthetized and then bled at 5-min intervals for 100 min before and 140 min after i.v. administration of saline or GnRH (1 micrograms/kg body weight). Basal serum LH and FSH concentrations were similar (P greater than 0.05) among age classes and between locations. In Serengeti Plains lions, net LH peak concentrations after GnRH were approximately 35% greater (P less than 0.05) in prepubertal than in either adult or young adult animals. GnRH-stimulated LH release was similar (P greater than 0.05) between adult and young adult lions, and these responses were similar (P greater than 0.05) to those measured in Ngorongoro Crater lions. Basal and GnRH-stimulated testosterone secretion was higher (P less than 0.05) in adult than in young adult lions and lowest (P less than 0.05) in prepubertal lions. Age-class differences in testosterone production were related directly to the concentrations of LH receptors in the testis (P less than 0.05). Basal and GnRH-stimulated testosterone secretion and gonadotrophin receptor concentrations within age classes were similar (P greater than 0.05) between lions of the Serengeti Plains and Ngorongoro Crater. Lower motility and higher percentages of structurally abnormal spermatozoa were observed in electroejaculates of young adult compared to adult Serengeti Plains males (P less than 0.05) and were associated with decreased steroidogenic activity. In contrast, there were no age-related differences in ejaculate characteristics of Ngorongoro Crater lions. Seminal quality in the Crater population was poor in adult and young adult animals and was unrelated to alterations in pituitary or testicular function. In summary, only seminal quality in adult male lions was affected by location, whereas age significantly affected both basal and GnRH-stimulated testosterone secretion and seminal quality (Serengeti Plains only) in sexually mature males. The striking seminal/endocrine differences among pride (breeding) males of different ages raises questions about the impact of age on individual reproductive performance in this species.

Aging↗
PubMed1979

Female aggression and male membership in troops of Japanese macaques and olive baboons.

A detailed comparison of Macaca fuscata and Papio anubis reveals that female aggression to males has an effect on male association with females in both species, but only in M. fuscata do females appear to be able to limit the number of males in their troop. It is suggested that this is the reasons why 'solitary' males are commonly reported in M. fuscata, but rare in P. anubis, and may be related ultimately to the different degrees of sexual dimorphism in the two species.

Aggression↗
PubMedDate not supplied

Analytical DNA fingerprinting in lions: parentage, genetic diversity, and kinship.

The application of hypervariable minisatellite genomic families to the reconstruction of population genetic structure holds great promise in describing the demographic history and future prospects of free-ranging populations. This potential has not yet been realized due to unforeseen empirical constraints associated with the use of heterologous species probes, to theoretical limitations on the power of the procedure to track genic heterozygosity and kinship, and to the absence of extensive field studies to test genetic predictions. We combine here the technical development of feline-specific VNTR (variable number tandem repeat) families of genetic loci with the long-term demographic and behavioral observations of lion populations of the Serengeti ecosystem in East Africa. Minisatellite variation was used to quantify the extent of genetic variation in several populations that differed in their natural history and levels of inbreeding. Definitive parentage, both maternal and paternal, was assessed for 78 cubs born in 11 lion prides, permitting the assessment of precise genealogical relationships among some 200 lions. The extent of DNA restriction fragment sharing between lions was empirically calibrated with the coefficient of relatedness, r, in two different populations that had distinct demographic histories. The results suggest that reliable estimates of relative genetic diversity, of parentage, and of individual relatedness can be achieved in free-ranging populations, provided the minisatellite family is calibrated in established pedigrees for the species.

Animals↗