Patterns of Water Use in Primates

Abstract

Aquatic resources are used extensively by many human populations but their role in the ecology of other primate species has been understudied. At least 10% of extant primates interact with aquatic environments, and a more complete understanding of these interactions is needed to get a complete view of primate behaviour. Five major factors appear to most strongly influence primate water use: thermoregulation, display behaviour, range, diet and predation. The ecological and evolutionary implications of these factors are discussed for extant primates as well as the possible influence of water on hominin evolution.

Keeping cool in the heat: Behavioral thermoregulation and body temperature patterns in wild vervet monkeys

“…Although it might seem intuitive that when an animal swims it would provide some cooling benefit while the animal is in contact with water that is cooler than the body (Kempf, ; Pruetz & Bertolani, ; van Schaik, van Amerongen, & van Noordwijk, ), there will also be an increase in evaporative heat‐loss from a wetted pelt in the aftermath of a swimming event. Other mammals, including humans, for example, show no decrease in body temperature during swimming events (Fuller, Oosthuyse, Maloney, & Mitchell, ; Hidden, ).…”

“…We implanted only adult monkeys, and so do not have body temperatures from any juveniles. One could argue that the increase in body and muscle mass of adults might offer them some thermal inertia, making them less heat stressed, and therefore less in need of the cooling effects of swimming (Kempf, , but see Mitchell et al, ). However, it seems more likely that the higher rates of swimming that were observed among juveniles was probably best regarded as play behavior.…”

“…The moderate short‐term thermal benefits afforded by swimming in the adults that we monitored, coupled with the hydration and evaporative sweating benefits afforded by regular access to drinking water, makes play the most likely explanation for the relatively infrequent occurrence of swimming among adults during the study period. Importantly, although swimming may have the potential to provide thermal benefits, due to the risks of predation (Cheney et al, ; Kempf, ) and water‐borne diseases (Rideout et al, ; Setchell et al, ) associated with exposure to open water sources, such opportunities are likely to be restricted to certain populations. Our vervet population is not exposed to aquatic predators, which might explain the tendency of our population, although rarely among adults, to engage in swimming behavior.…”

“…Swimming behavior among non‐human primates serves a range of functions, including expanded range use, aquatic foraging, and possible thermoregulation (Kempf, ). Although our vervet monkeys did not forage in the river itself, they live in a semi‐arid, riparian woodland habitat (Pasternak et al, ), that at times required them to traverse the river (~10‐m wide) to reach adjacent parts of their home range.…”

A unique hominin menu dated to 1.95 million years ago

“…Early hominins exploited a wide variety of habitats and now it appears, a diversity of resources within these habitats. Modern humans thrive on diverse foods, and a diverse diet may have been key to our lineage's success (16), although the aquatic component may have deep roots given that some nonhuman primates consume some aquatic foods (17). Braun et al (7) justifiably did not address whether the FwJj20 carcasses were obtained through hunting or scavenging.…”