Environmental correlates of gastrointestinal parasitism in montane and lowland baboons in Natal,South Africa

We compared the gastrointestinal parasites of the baboon,Papio cynocephalus ursinus, living in montane (altitude, >1800 m) and coastal lowland (altitude, 100–200 m) habitats in Natal, South Africa, using fecal analysis. While the montane animals harbored a smaller number of species, helminth egg-output rates were higher in them than in the lowland animals. The decrease in parasite diversity with increasing altitude was expected, but the difference in helminth egg output was not. It may be due to a combination of food shortage, which characterizes the montane environment, especially at the end of winter, and the high proportion of soil-contaminated items in the diets of the montane animals.     

Why does the herring gull lay three eggs?

Food supplements placed daily beside the nests of herring gulls, Larus argentatus, for the first 5 days after the first chick hatched produced improved weight gains over this initial period and higher fledging success, particularly in the third chick. The fledging success of the fed group appears to be due to increased weight gain and not to increased parental protection in the supplemented period. Since there is indirect evidence that food is available this suggests that the parents are putting less effort into foraging for their chicks than they are able to, and less than is in the interests of the third chick, in the first days after hatching. On a separate colony we found that having three chicks in the brood for more than 5 days resulted in lower weight gains for the second chick, but not the first. We suggest that fledging three chicks rather than one or two greatly increases the parents' reproductive effort, and consequently interpret the third egg as primarily insurance against the loss of the first or second.     

Coalition Formation by Male Vervet Monkeys (Chlorocebus pygerythrus) in South Africa

Unrelated male primates frequently cohabit in bisexual groups and, despite being reproductive competitors, have been shown to cooperate in ways that are associated with reproductive success. Such coalitions between males are common in some taxa, where they can serve two primary functions – status management and improved mating opportunities – that subserve long‐ and short‐term objectives. Here, we use observational data to provide information on male coalitions in vervet monkeys (Chlorocebus pygerythrus), a guenon with a multimale group structure. We recorded a total of 62 coalitions from two troops across a 10‐mo period at Samara Game Reserve, South Africa. We found that males who were more frequently associated spatially and who had groomed one another were more likely to form coalitions and did so against higher‐ranking opponents. This was not linked to any evidence that coalitionary aggression provided either short‐ or long‐term reproductive benefits for the aggressors and coalitions were not restricted to the mating season. There was little evidence that particular individuals were targeted, reciprocation between partners was not observed, and recent immigrant males were not targeted disproportionately. Our data suggest that within‐group coalition formation between vervet males may represent something close to an ancestral state whereby males form ad hoc coalitions opportunistically, joining an ongoing dyadic contest to target an opponent without facing the possible risks of dyadic contest, such as a greater chance of injury.     

Indices of environmental temperatures for primates in open habitats

Studies of thermoregulation in primates are under-represented in the literature, although there is sufficient evidence to suggest that temperature represents an important ecological constraint. One of the problems in examining thermoregulation in primates, however, is the difficulty in quantifying the thermal environment, since shade temperatures, solar radiation, humidity and wind speed all serve to alter an animals perceived temperature. Since animals respond to their perceived temperature, we need methods to account for each of these factors, both individually and collectively, if we are to understand the integrated impact of the thermal environment on primates. Here, we present a review of some thermal indices currently available. Black bulb temperatures can account for the effect of solar radiation, with wind chill equivalent temperatures and the heat index providing quantifiable estimates of the relative impact of wind speed and humidity, respectively. We present three potential indices of the perceived environmental temperature (PET) that account for the combined impact of solar radiation, humidity and wind speed on temperature, and perform a preliminary test of all of the climatic indices against behavioural data from a field study of chacma baboons (Papio cynocephalus ursinus) at De Hoop Nature Reserve, South Africa. One measure of the perceived environmental temperature, PET2, is an effective thermal index, since it enters the models for feeding and resting behaviour, and also accounts for levels of allogrooming. Solar radiation intensity is an important factor underlying these relationships, although the wind chill equivalent temperature and humidity enter the models for other behaviours. Future studies should thus be mindful of the impact of each of these elements of the thermal environment. A detailed understanding of primate thermoregulation will only come with the development of biophysical models of the thermal characteristics of the species and its environment. Until such developments, however, the indices presented here should permit a more detailed examination of the thermal environment, allowing thermoregulation to be given greater precedence in future studies of primate behaviour.     

Habitual cave use and thermoregulation in chacma baboons (Papio hamadryas ursinus)

The willingness to utilise caves as shelters is held to have been important to early humans but dependent on pyrotechnology. Despite anecdotal evidence that non-human primates will also exploit caves there has as yet been no detailed account of such exploitation or of the reasons underlying it. Here we provide the first such data, on the frequency and patterning of the use of an underground cave system by baboons (Papio hamadryas)—and show that usage is determined, at least in part, by above-ground temperatures.     

Fecal cortisol levels in free-ranging female chacma baboons: relationship to dominance, reproductive state and environmental factors

Savannah baboons are one of the few mammalian species that do not exhibit seasonal reproduction patterns and are therefore ideally suited to study the effect of female reproductive states (cycling, pregnant, lactating) on cortisol levels independent of seasonal factors. Fecal samples from 10 free-ranging female chacma baboons (Papio hamadryas ursinus), collected during a period of 17 months, were analyzed using a steroid-extraction method. Reproductive state had a significant effect on fecal cortisol, with lowest levels found in estrous females. Fertility was not related to fecal cortisol levels; we found no significant differences between samples collected on conceptive and nonconceptive cycles. Environmental factors explained most of the variance of fecal cortisol levels. Cortisol measures were strongly correlated with seasonal differences such as daylight duration, temperature and the amount of time that baboons spent resting. We measured higher cortisol levels during winter months and suggest that this could be related to shorter resting periods and to the cold minimum ambient temperatures at this study site. Finally, we found no relationship between social rank nor the rate of agonistic interactions with basal fecal cortisol levels.     

Taking sociality seriously: the structure of multi-dimensional social networks as a source of information for individuals

Understanding human cognitive evolution, and that of the other primates, means taking sociality very seriously. For humans, this requires the recognition of the sociocultural and historical means by which human minds and selves are constructed, and how this gives rise to the reflexivity and ability to respond to novelty that characterize our species. For other, non-linguistic, primates we can answer some interesting questions by viewing social life as a feedback process, drawing on cybernetics and systems approaches and using social network neo-theory to test these ideas. Specifically, we show how social networks can be formalized as multi-dimensional objects, and use entropy measures to assess how networks respond to perturbation. We use simulations and natural 'knock-outs' in a free-ranging baboon troop to demonstrate that changes in interactions after social perturbations lead to a more certain social network, in which the outcomes of interactions are easier for members to predict. This new formalization of social networks provides a framework within which to predict network dynamics and evolution, helps us highlight how human and non-human social networks differ and has implications for theories of cognitive evolution.     

Treatment of established postoperative nausea and vomiting: a quantitative systematic review

Background  

The relative efficacy of antiemetics for the treatment of postoperative nausea and vomiting (PONV) is poorly understood.     

Consortship and Mating Success in Chacma Baboons (Papio cynocephalus ursinus)

Chacma baboons (Papio cynocephalus ursinus) show a lower consortship take‐over rate and longer consortship duration than the other savannah baboons ( Bulger 1993 ). It has been argued that researchers have focused on atypically small troops with few adult males, resulting in low competition for access to oestrous females. Consortship data from two mountain baboon troops containing seven and four males, respectively, were analysed to determine whether the troop with the greater number of males showed a weaker correlation between mating success and rank due to an expected higher consortship take‐over rate. No consort take‐overs were observed in either study troop and mating success in both troops was correlated strongly with male rank. The distribution of days spent in consortship amongst the males could be explained by the priority‐of‐access‐model. The degree of cycle overlap determined the number of males observed consorting oestrous females, whereas the number of males did not influence the relationship between rank and consorting activity.