Influence of rainfall on sleeping site choice by a group of anubis baboons (Papio anubis)

Abstract

For diurnal nonhuman primates, shifting among different sleeping sites may provide multiple benefits such as better protection from predators, reduced risk of parasitic infection, and closer proximity to spatially and temporally heterogeneous food and water. This last benefit may be particularly important in sleeping site selection by primates living in savanna‐woodlands where rainfall is more limited and more seasonally pronounced than in rainforests. Here, we examined the influence of rainfall, a factor that affects food and water availability, on the use of sleeping sites by anubis baboons (Papio anubis) over two 13‐month study periods that differed in rainfall patterns. We predicted that during wet periods, when food and water availability should be higher, the study group would limit the number of sleeping sites and would stay at each one for more consecutive nights than during dry periods. Conversely, we predicted that during dry periods the group would increase the number of sleeping sites and stay at each one for fewer consecutive nights as they searched more widely for food and water. We also predicted that the group would more often choose sleeping sites closer to the center of the area used during daytime (between 07:00 and 19:00) during wet months than during dry months. Using Global Positioning System data from collared individuals, we found that our first prediction was not supported on either monthly or yearly timescales, although past monthly rainfall predicted the use of the main sleeping site in the second study period. Our second prediction was supported only on a yearly timescale. This study suggests that baboons’ choice of sleeping sites is fluid over time while being sensitive to local environmental conditions, one of which may be rainfall.

Adoption by olive baboons (Papio anubis) of newly constructed electricity pylons as sleeping sites in Laikipia, Kenya

“…We report a rare observation of three troops of olive baboons utilizing electrical transmission pylons as sleeping sites in Laikipia County, Kenya. Usually, in this landscape, tall Acacia trees and rocky cliffs are predominantly selected as sleeping sites by baboons (Bidner et al, 2018;Hamilton, 1982;Suire et al, 2020). Typically, tall A. xanthophloea with vines and branches overhanging rivers remain preferred sleeping site (Bidner et al, 2018;Isbell et al, 2021).…”

“…While other primate species have been observed using anthropogenic structures such as rooftops and electricity poles (Bracken et al., 2021 ; Brotcorne et al., 2014 ; Hoffman & O'Riain, 2012 ), this behavior has not been reported before in Laikipia, Kenya (Bidner et al., 2018 ; Butynski & De Jong, 2014 ; Danish & Palombit, 2014 ; Isbell et al., 2017 ; Matsumoto‐Oda, 2015 ; Strum, 2005 ; Suire et al., 2020 ). For example, at Mpala Research Centre in Laikipia, despite the availability of pylons from the same transmission line within known baboon home ranges, baboons still use cliffs and tall trees as their preferred sleeping sites (Bidner et al., 2018 ; Isbell et al., 2018 ; Suire et al., 2020 ) and have yet to be observed using pylons. We document olive baboons using high‐tension electrical transmission towers (hereafter “pylons”) recently installed to transmit power between Kenya and Ethiopia (EEPCO & KETRACO, 2012 ) as sleeping sites, and we discuss the implications of this behavior for understanding natural sleeping site preferences.…”

“…However, they often show a preference for particular trees or rocky cliff faces, by sleeping more often at some sites than at others (Bidner et al., 2018 ; Markham et al., 2016 ). In addition to predation risk, thermoregulatory benefits (Anderson & McGrew, 1984 ; Koops et al., 2012 ), parasite infestation and fecal‐matter load within sleeping sites can influence their frequency of use (Hausfater & Meade, 1982 ), and the limited availability of good quality sites is generally thought to regulate baboon distribution and forage access (Cowlishaw, 1997 ; Hamilton, 1982 ; Markham et al., 2016 ; Suire et al., 2020 ). While other primate species have been observed using anthropogenic structures such as rooftops and electricity poles (Bracken et al., 2021 ; Brotcorne et al., 2014 ; Hoffman & O'Riain, 2012 ), this behavior has not been reported before in Laikipia, Kenya (Bidner et al., 2018 ; Butynski & De Jong, 2014 ; Danish & Palombit, 2014 ; Isbell et al., 2017 ; Matsumoto‐Oda, 2015 ; Strum, 2005 ; Suire et al., 2020 ).…”

“…In addition to predation risk, thermoregulatory benefits (Anderson & McGrew, 1984 ; Koops et al., 2012 ), parasite infestation and fecal‐matter load within sleeping sites can influence their frequency of use (Hausfater & Meade, 1982 ), and the limited availability of good quality sites is generally thought to regulate baboon distribution and forage access (Cowlishaw, 1997 ; Hamilton, 1982 ; Markham et al., 2016 ; Suire et al., 2020 ). While other primate species have been observed using anthropogenic structures such as rooftops and electricity poles (Bracken et al., 2021 ; Brotcorne et al., 2014 ; Hoffman & O'Riain, 2012 ), this behavior has not been reported before in Laikipia, Kenya (Bidner et al., 2018 ; Butynski & De Jong, 2014 ; Danish & Palombit, 2014 ; Isbell et al., 2017 ; Matsumoto‐Oda, 2015 ; Strum, 2005 ; Suire et al., 2020 ). For example, at Mpala Research Centre in Laikipia, despite the availability of pylons from the same transmission line within known baboon home ranges, baboons still use cliffs and tall trees as their preferred sleeping sites (Bidner et al., 2018 ; Isbell et al., 2018 ; Suire et al., 2020 ) and have yet to be observed using pylons.…”