The glomerular filtration rate,effective renal plasma flow,and renal blood flow in the adult male chacma baboon (Papio ursinus)

Abstract: The radionuclide determination of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) has been validated in man, but not in the primate. GFR, ERPF, and renal blood flow (RBF) were measured in a group of 12 adult male chacma baboons using radiopharmaceuticals. GFR was determined using ^99mtechnetium-labelled diethylenetriamine-pentacetic acid. ERPF was measured with ¹³¹iodine-labelled hippuran. RBF, body surface area, and kidney weights were calculated using standard formulae. GFR was 49 ± 11 ml/min and ERPF was 237.9 ± 54.2 ml/min. Calculated RBF was 430.7 ± 111.9 ml/min and 507.4 ± 138.4 ml/min/100g of renal tissue. The results are in agreement with those obtained using more laborious nonradioisotopic techniques such as para-aminohippurate (PAH) and creatinine clearance and could serve as baseline normal values in the adult male chacma baboon.     

Social relationships of mountain baboons: Leadership and affiliation in a non-female-bonded monkey

Instead of close and differentiated relationship among adult females, the accepted norm for savanna baboons, groups of Drakensberg mountain baboons (Papio ursinus) showed strong affiliation of females towards a single male. The same male was usually the decision-making animal in controlling group movements. Lactating or pregnant females focused their grooming on this “leader” male, producing a radially patterned sociogram, as in the desert baboon (P. hamadryas); the leader male supported young animals in the group against aggression and protected them against external threats. Unlike typical savanna baboons, these mountain baboons rarely displayed approach-retreat or triadic interactions, and entirely lacked coalitions among adult females. Both groups studied were reproductively one-male; male-female relationships in one were like those in a unit of hamadryas male at his peak, while the other group resembled the unit of an old hamadryas male, who still led the group, with a male follower starting to build up a new unit and already monoplizing mating. In their mountain environment, where the low population density suggests conditions as harsh for baboons as in deserts, adults in these groups kept unusually large distances apart during ranging; kin tended to range apart, and spacing of adults was greatest at the end of the dry, winter season. These facts support the hypothesis that sparse food is responsible for convergence with hamadryas social organization. It is suggested that all baboons, though matrilocal, are better categorized as “cross-sex-bonded” than “female bonded”.     

Fishing baboons at desert waterholes

Live fish capture by wild chacma baboons is described. Fish were captured from drying desert pools and then covered with sand to immobilize active fish or to facilitate handling. Possible reasons omnivorous primates elsewhere do not capture live fish are considered.     

Population structure,demography, and dynamics of mountain baboons: An interim report

Counts of 61 baboon troops (Papio cynocephalus ursinus) at four localities in the Drakensberg mountains confirmed earlier reports of a small mean troop size. This troop size of 22.49 animals changed neither with latitude nor elevation. Data from two of the sites suggested that population density increases from south to north, while a working assumption of 2.5 animals/ km² allowed us to set the population size at 7,540 animals, living in 335 troops. Both the adult sex ratio of 2.07 females/male and the immature/ adult female ratio of 1.17 were unaffected by troop size. Repeated counts from nine known troops revealed that the population is at equilibrium. © 1995 Wiley-Liss, Inc.     

Persistence of maternal effects in baboons: Mother's dominance rank at son's conception predicts stress hormone levels in subadult males

Dominance status and reproductive experience are maternal characteristics that affect offspring traits in diverse taxa, including some cercopithecine primates. Maternal effects of this sort are widespread and are sources of variability in offspring fitness. We tested the hypothesis that maternal dominance rank and reproductive experience as well as a male's own age and dominance rank predicted chronic fecal glucocorticoid (fGC) concentrations in 17 subadult wild male baboons, Papio cynocephalus (median age 6.5 years), in the Amboseli basin, Kenya. Among these variables, maternal dominance rank at a subadult male's conception was the sole significant predictor of the male's fGC and accounted for 42% of fGC variance; sons of lower ranking mothers had higher fGC than did those of high-ranking mothers. This result is striking because subadult male baboons are approximately 4-6 years past the period of infant dependence on their mothers, and are larger than and dominant to all adult females. In addition, many males of this age have survived their mothers' death. Consequently, the influence of maternal dominance rank persisted well beyond the stage at which direct maternal influence on sons is likely. Persistence of these major maternal influences from the perinatal period may signal organizational effects of mothers on sons' HPA axis. Although short-term, acute, elevations in GC are part of adaptive responses to challenges such as predators and other emergencies, chronically elevated GC are often associated with stress-related pathologies and, thereby, adverse effects on fitness components.     

Polymorphism of erythrocyte G-6-PD in the baboon

Blood samples from several populations of baboons (genus Papio) were examined for G-6-PD variants. Several G-6-PD phenotypes were detected by starch gel electrophoresis. The so-called fast variant phenotypes of G-6-PD in baboons differ from human variant phenotypes in several physicochemical constants.     

The ecology of motherhood: the structuring of lactation costs by chacma baboons

1. Data from a long-term study of Papio hamadryas ursinus (L.) in the De Hoop Nature Reserve, Western Cape, South Africa, were used to test the assumptions and predictions of Altmann's model of maternal time budgets. 2. Female baboons' feeding time was below model predictions, and there was no evidence for a consistent increase in feeding time with infant age. In addition, female feeding time was not significantly higher than observed baseline feeding times for nonlactating females. 3. Female baboons reduced activity levels in the first few months post-partum, as reflected in significant increases in resting time, and there was some indication that females lost body mass over the course of lactation. When feeding demand was high, females sacrificed social time, and conserved resting time. 4. Females increased vigilance levels during the first 4 months of infant life and were more vigilant overall during lactation than when nonlactating. There was a negative relationship between feeding time and vigilance, but a positive relationship between resting time and vigilance. 5. Female baboons at De Hoop appear to cope with the energetic costs of lactation by reducing activity levels, although this cannot compensate completely for increased energetic costs. This may not be so much an'energy-sparing' strategy as a response to threats presented by infanticidal males in this population. Females therefore trade-off feeding time against vigilance.