PSGB Winter Meeting 2003

Here's Looking at You: 100 Years of Baboon Research

PSGB Meeting, London Zoo, December 3rd 2003

8.45-9.50 a.m. Registration

9.50 Opening remarks

10.00 Peter Henzi
Baboon natural histories and futures

10.30 Robin Dunbar
The gelada: a model baboon?

11.00 - 11.30 Coffee

11.30 Sarah Elton
Over the hill at 40? How baboon models are still useful in palaeoanthropology, middle-age spread and all.

12.00 Dietmar Zinner
Causes and consequences of the social system of hamadryas baboons

12.30 - 2.00 p.m. PSGB AGM and Lunch

2.00 Louise Barrett
Whose life is it anyway? Maternal investment, infant developmental trajectories and life-history in baboons.

2.30 Drew Rendall
The mute prince: what will lifting a half-century gag-order on baboon vocal communication reveal about the Machiavellian primate's mind?

3.00 Joan Silk
Friends and/or allies: the function of social bonds among female baboons

3.30 - 4.00 Tea

4.00 Russell Hill
Interpopulation analyses of baboon socioecology: past, present and future

4.30 Discussant: Phyllis Lee
What does the future hold?

5.00 Closing remarks followed by Wisepress wine reception

Registration fees: Members and student non-members £15.00, Student members £10.00, Non-members £20.00 Registration at the door on the day of the conference.

Please note that we have been forced to increase the registration charge due to the increased costs associated with running the conference. PSGB generally makes no profit from running meetings.

Abstracts:

Whose life is it anyway? Maternal investment, infant developmental trajectories and life-history in baboons.
Louise Barrett
School of Biological Sciences, The University of Liverpool, UK
louiseb@liv.ac.uk

Due to their ecological adaptability, baboons are excellent candidates to investigate maternal investment strategies and infant development in relation to environmental variability. Here, I review data from several long-term studies, comparing and contrasting investment patterns and developmental trajectories within and between populations, and exploring the life-historical and demographic consequences of variability in these parameters. What this reveals is that there are still more questions than answers when it comes to understanding baboon life history in relation to socioecology. Specifically, more and better data are required on 'care-independent' or 'extrinsic' sources of mortality (with more attention paid to disease in particular) and we need to determine whether 'care-independent' mortality is truly independent of the level of investment an infant receives from its mother.

The gelada: a model baboon?
Robin Dunbar
School of Biological Sciences, The University of Liverpool, UK
rimd@liv.ac.uk

While the Papio baboons are often seen as the pre-eminent exploiters of open savannah grassland, that accolade should, in fact, be shared with the theropithecines and their last surviving representative, the gelada. Studies of the gelada, along with those of Papio, have been hugely influential in setting the agenda for the socioecological studies of primates since the 1960s. My aim here is to review how the research linking the distinctive social organisation of the gelada with its unusual ecology helped lay much of the groundwork for uncovering the array of socioecological patterns that exist within and beyond the papionines.

Over the hill at 40? How baboon models are still useful in palaeoanthropology, middle-age spread and all.
Sarah Elton
Department of Anatomy, Hull York Medical School, The University of Hull, UK
sarah.elton@hyms.ac.uk.

Old World monkeys, particularly those that are closely related to baboons (known as the papionins), have been used to provide a comparative context for human evolution for over forty years. During this period their adaptations have been used to shed light on hominin locomotion, dietary strategies, potential social behaviours, brain size change, language development, speciation, and habitat exploitation. There are several explanations for the enduring popularity of papionin models in palaeoanthropology. Not least, as will be demonstrated at this meeting, baboons have been extensively studied over a long period of time, so there is a wealth of data to be used in models. It is also becoming increasingly clear that hominin ecology and habitat use was much more similar to that of papionins than it was to that of great apes, so in models that seek to explore ecological rather than cognitive factors, papionins appear to be appropriate referents. In addition, the papionin fossil record for the Plio-Pleistocene, the time in which there was an extensive adaptive radiation of hominins, is very well known, and this provides further depth of context when considering human evolutionary history.

In this paper, the history and utility of papionin models in palaeoanthropology will be reviewed, and data on extant and fossil papionins used to provide a context for species diversity and habitat use in Plio-Pleistocene hominins. Papionin data are also used to assess whether three of the main adaptive changes in human evolutionary history (brain size increase, the reliance on terrestrial locomotion, and body mass increase) were the result of abiotic pressures such as climate change. It is argued that the locomotor patterns of hominins and papionins were similar, with a move to terrestriality in both lineages that could be attributed to the pressures of a shared, and increasingly open, environment. However, although brain size increased in at least two hominin taxa over the course of the Plio-Pleistocene, there was no brain size change in the papionin species under investigation. Thus, brain size increase was not common to all large-bodied primates in the Plio-Pleistocene. Body mass increase occurred in at least one hominin and one papionin lineage, but the timings and magnitudes of the increases were different in the two groups, suggesting that different selective pressures were operating to change body mass in hominins and papionins. These results suggest that, for the most part, hominins had evolutionary trajectories that were very different to those seen in other large-bodied Plio-Pleistocene primates, and it can be argued that the evolutionary trends evident in hominins were not a straightforward result of purely abiotic environmental pressures.

Baboon natural histories and futures
Peter Henzi
Department of Psychology, University of Central Lancashire, UK

Savannah baboons have played an important part in the development of our understanding of both human evolution and primate sociality. Some lapses of concentration to one side, we have directed theoretically-focused attention at them for a century, much of it in situ on the savannah itself. Here I review aspects of this research and its associated conceptual themes. I use current interpretations of Papio's own history to highlight some reasons for continuing to work on the species.

Interpopulation analyses of baboon socioecology: past, present and future
Russell Hill
Department of Anthropology, University of Durham, UK
R.A.Hill@durham.ac.uk

Baboons (Papio spp.) have been the subject of some of the longest running field studies of primates. Furthermore, baboon populations have probably been studied or surveyed at a greater number of sites than any other primate species. This 'popularity' has generated a wealth of comparative data on features of baboon socioecology such as group size, home range size, time budgets, diets and life-history parameters. As a consequence, baboons are the ideal species with which to address questions relating to interpopulation variation in primate socioecology. Here I present a review of the major analyses conducted to date, illustrating how many features of baboon socioecology can be predicted or understood on the basis of simple ecological parameters such as rainfall and temperature. I also highlight areas where data is lacking, indicating that despite the considerable history of baboon research, there is still plenty of scope for future study.

The mute prince: what will lifting a half-century gag-order on baboon vocal communication reveal about the Machiavellian primate's mind?
Drew Rendall
Department of Psychology and Neuroscience, University of Lethbridge, Canada
d.rendall@uleth.ca

"It is better to remain silent and be thought a fool (or mistaken for a prince) than to open your mouth and remove all doubt." Although not formally among the tips Machiavelli offered aspiring leaders, or at least not one heeded by most politicians who invariably end ingloriously impaled on their own (s)words, this prescription is effectively abided by baboons. Arguably the best-studied nonhuman primate, baboons have featured centrally in virtually all aspects of behavioral ecology, including theoretical treatments of sociality and cognition that have cast primates as adept, Machiavellian social strategizers. Remarkably, then, they have barely featured in research on vocal communication, even though this aspect of behavior is often held to offer an especially clear window into the workings of the mind. However, their silence has been broken recently with a surge of work on baboon vocal communication in the last decade. What such work will reveal about the Machiavellian primate's mind remains to be seen, but recent developments in cognate disciplines suggest that it might be somewhat less vaunted than previously imagined, and that, as a result, researchers both in communication and in behavioral ecology might need to re-work their theoretical frameworks, cashing-in key metaphorical constructs (e.g., 'meaning', 'strategy') that may have outlived their utility.

Friends and/or allies: the function of social bonds among female baboons
Joan B. Silk
Department of Anthropology, University of California, Los Angeles, USA
jsilk@anthro.ucla.edu

Socioecological theory predicts that when ecological conditions favor collective defense of resources, natural selection will favors investment in social relationships with those who are likely to provide coalitionary support. The primary features of social organization in female-bonded groups, including female philopatry, linear dominance hierarchies, acquisition of maternal rank, and well-differentiated female relationships are thought to be functionally linked to the existence of alliances among females. However, empirical evidence regarding this connection is equivocal. Kin tend to support one another at high rates in many female-bonded species. In some groups, females exchange grooming for support, but in other groups there is no consistent relationship between how often females groom others and how often they are supported by their grooming partners. Finally, there is some evidence that close female bonds are sometimes decoupled from coalitionary support. At many sites in Africa, female baboons display all the features of that characterize female-bonded groups, female philopatry, linear matrilineal dominance hierarchies and form well-differentiated grooming relationships. In some of these groups, coalitionary support among adult females is reported to be common, but in others coalitionary support among adult females is rare or absent altogether. This raises important questions about the function of social bonds among female baboons, and about the evolutionary pressures shaping social bonds in primate groups.

Causes and consequences of the social system of hamadryas baboons
Dietmar Zinner
Abt. Verhaltensforschung & Ökologie, Deutsches Primatenzentrum, Göttingen, Germany
dzinner@gwdg.de

The early studies by Zuckerman and Kummer revealed that hamadryas baboons live in a different social system than other baboon taxa and that their multi-level society is unique among primates. Since then, several hypotheses about the evolution of the hamadryas social system have been proposed. Food dispersed in relatively small patches, scarcity of safe sleeping sites, and medium predation pressure have been assumed to have favoured the formation of the hamadryas fission-fusion system. However, ecological data to test this hypothesis are not available, mainly because of political and safety problems in the countries of hamadryas origin. Although the social processes within hamadryas bands and one-male units have been well studied in the 1960s and 70s by Kummer and his colleagues, virtually nothing is known about the behavioural consequences for males and females living in such a social system. Most notably, data on individual foraging success, female mate choice and reproductive success, as well as data on the genetic consequences at the population level are missing. However, such data, in combination with ecological information, are essential to analyse baboon social evolution.

I will present selected results from my studies of individual feeding success, grooming relationships and reproductive strategies in captive hamadryas baboons to begin filling these gaps. Moreover, I will present data on the habitats of hamadryas and olive baboons from a comparative study in Eritrea. Finally, I will provide preliminary information on the genetic population structure of hamadryas baboons in Eritrea.