Amboseli baboon

Early adversity predicts life span

Author: Susan Alberts

Elizabeth Archie 2 Copy

In humans and other animals, harsh circumstances in early life are linked to poor health and high mortality rates in adulthood. It is thought that these effects are greatest when multiple adverse conditions occur at the same, but this hypothesis has rarely been tested. We used prospective data on 196 wild female baboons in Amboseli to show that the number of adverse circumstances that a female experiences during her juvenile years predicts how long she lives as an adult. Specifically, we examined the effects of six different adverse circumstances: (i) being born in a drought, (ii) having a low ranking mother, (iii) having a socially isolated mother, (iv) having your mother die before you reach 4 years of age (the approximate age at sexual maturity for females), (v) having a younger sibling born when you yourself are still quite young (1.5 years of age or less), and (vi) living a very large social group. Females who experience 3 or more of these adverse circumstances tend to die 10 years earlier than females who experience no adverse circumstances. For comparison, the average female, once she reaches adulthood, lives to about 18.5 years of age, so 10 years is a very large difference in the life of a female baboon.
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Group Living: For Baboons Intermediate Size is Optimal

Author: Catherine Markham

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What are the costs and benefits for animals living in groups of different sizes? Balancing the trade-offs between within-group competition (which favors smaller groups) and between-group competition (which favors larger groups) suggests that intermediate sized groups may be best, yet empirical support for this prediction has largely been lacking.  Using long-term data on wild baboons, we provide novel evidence that individuals living in intermediate-sized groups have energetically optimal space-use strategies and lower glucocorticoid (stress hormone) concentrations than individuals in either large or small groups.  Our results offer new insight into the costs and benefits of group living. Read More

Self-organizing dominance hierarchies in a wild primate population

Author: Susan Alberts

Many social animals form linear dominance hierarchies, with a clear rank order among group members. Such hierarchies can profoundly influence health and access to resources, but the mechanisms underlying hierarchy formation and maintenance remain unclear. Do individual dominance ranks simply emerge from individual attributes – such as fighting ability? Or are linear hierarchies the product of social self-organization processes such as winner and loser effects – i.e. the phenomenon in which winners become more likely to win in subsequent encounters, and losers become more likely to lose? Here, we present the first evidence for social self-organization processes in a wild animal population.  Read More

Collaborating institutions

Princeton, Duke, and Notre Dame

Princeton University

Duke University

University of Notre Dame

 

Amboseli baboon research project

Located near Amboseli National Park in Kenya, ABRP is one of the longest-running studies of wild primates in the world. ABRP is directed by Dr. Jeanne Altmann at Princeton University, and Dr. Susan Alberts at Duke University. The Associate Directors are Dr. Beth Archie at the University of Notre Dame and Dr. Jenny Tung at Duke University. Click the links at left to learn more about the project and our research.The Amboseli baboons.

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