Mate guarding constrains foraging activity of male baboons

For many species, mate guarding results in dramatic departures from normal behaviour that reflect compromised attention to feeding and other activities. Such departures have previously been difficult to document in primates, however. Data were gathered on two aspects of male behaviour that were predicted to be constrained during consortships, individual travel distance and duration of feeding bouts, for wild male baboons, Papio cynocephalus, in and out of mate-guarding episodes. In each case, consorting males were compared with themselves outside of consortships, and, in the case of distance travelled, they were compared also with non-consorting males matched for sample time and location. Males travelled significantly shorter distances while consorting than while not consorting, with the result that consorting males travelled distances similar to those travelled by females. Males also had significantly shorter feeding bouts while consorting. The shorter travel distances and feeding bouts experienced by consorting males may represent important constraints on male foraging activity, and probably result in decreased energy intake during mate guarding. Seasonal and non-seasonal breeding patterns will have different consequences for the magnitude of fluctuations in energy stores and depletions experienced during mate guarding, and costs of mate guarding in species that breed non-seasonally will be more difficult to document because they are necessarily smaller and temporally dispersed. When considered across the lifespan, however, mate guarding costs to non-seasonal breeders may equal or exceed costs to seasonal breeders. ? 1996 The Association for the Study of Animal Behaviour Mate guarding, when it occurs over short, concentrated periods of breeding, imposes constraints on males that often result in dramatic departures from normal behaviour. These constraints may entail extreme energetic costs or may compromise the male’s ability to engage in other important activities such as thermoregulation or predator avoidance (dragonflies, Sympetrum spp.: Singer 1987; Convey 1989; blackbirds, Turdus merula: Cuthill & Macdonald 1990; mountain sheep, Ovis canadensis and O. dalli: Geist 1971; elephant seals, Mirounga angustirostris: LeBoeuf 1974; red deer, Cervus elaphus: Clutton-Brock et al. 1982; elephants, Loxodonta africana: Poole 1989). Indeed, it may be a general rule across a wide range of taxa that animals incur a variety of costs when they mate-guard. Primates ought to be no exception. Although short-term guarding of reproductive females is not the prevailing mating pattern among primates, it occurs in a number of species that live in multi-male, multi-female groups, including savannah baboons (Hall & DeVore 1965; Seyfarth 1978), rhesus macaques, Macaca mulatta (Carpenter 1942; Altmann 1962; Lindburg 1971), Japanese macaques, M. fuscata (Enomoto 1974), chimpanzees, Pan troglodytes (Tutin 1979), mantled howler monkeys, Alouatta palliata (Carpenter 1934; Crockett & Eisenberg 1987), and spider monkeys, Ateles spp. (Robinson Correspondence to: J. Altmann, Department of Conservation Biology, Chicago Zoological Society, Brookfield, IL, 60513, U.S.A. (email: ALTJ@MIDWAY. UCHICAGO.EDU). S. C. Alberts is at MCZ Laboratories, and M. L. Wilson is at the Department of Anthropology, Harvard University, Cambridge, MA 02138, U.S.A. 0003–3472/96/061269+09 $18.00/0 ? 1996 The Association for the Study of Animal Behaviour