Food abundance and weather influence habitat‐specific ranging patterns in forest‐ and savanna mosaic‐dwelling red‐tailed monkeys (Cercopithecus ascanius)

Abstract

Objectives: Primates that live in predominantly forested habitats and open, savanna mosaics should exhibit behavioral responses to differing food distributions and weather. We compared ecological constraints on red-tailed monkey ranging behavior in forest and savanna mosaic environments. Intraspecific variation in adaptations to these conditions may reflect similar pressures faced by hominins during the Plio-Pleistocene.Methods: We followed six groups in moist evergreen forest at Ngogo (Uganda) and one group in a savanna-woodland mosaic at the Issa Valley (Tanzania). We used spatial analyses to compare home range sizes and daily travel distances (DTD) between sites. We used measures of vegetation density and phenology to interpolate spatially explicit indices of food (fruit, flower, and leaves) abundance. We modeled DTD and range use against food abundance. We modeled DTD and at Issa hourly travel distances (HTD), against temperature and rainfall.Results: Compared to Issa, monkeys at Ngogo exhibited significantly smaller home ranges and less variation in DTD. DTD related negatively to fruit abundance, which had a stronger effect at Issa. DTD and HTD related negatively to temperature but not rainfall. This effect did not differ significantly between sites. Home range use did not relate to food abundance at either site. Conclusions: Our results indicate food availability and thermoregulatory constraints influence red-tailed monkey ranging patterns. Intraspecific variation in home range sizes and DTD likely reflects different food distributions in closed and open habitats. We compare our results with hypotheses of evolved hominin behavior associated with the Plio-Pleistocene shift from similar closed to open environments. K E Y W O R D S guenon, hominin adaptation, movement ecology, resource distribution, savanna-woodland mosaic

Behavioral adjustments and support use of François' langur in limestone habitat in Fusui, China: Implications for behavioral thermoregulation

“…The seasonal variation in activities and microhabitat use is thought to be related to thermoregulation in a number of primates (e.g., Alouatta palliate : Thompson, Williams, Glander, & Vinyard, 2016). For instance, when T a is high, primates reduce their daily travel distance (McLester, Brown, Stewart, & Piel, 2019), spend more time resting in the shade ( Callithrix jacchus : Abreu, De la Fuente, Schiel, & Souto, 2016; Fuente, Souto, Sampaio, & Schiel, 2014; Colobus polykomos : Dasilva, 1992; Papio cynocephalus: Stelzner, 1988), and stay in cooler microhabitats (e.g., caves) during the day ( Pan troglodytes verus : Pruetz, 2007; A. palliate : Thompson et al, 2016). On the other hand, when T a is low, primates respond by adopting alternative behaviors: They may change social relationships (increasing physical contact with others) within their group to benefit their thermal competences (McFarland et al, 2015), adjust nest architecture to increase thermoregulation (Stewart, Piel, Azkarate, & Pruetz, 2018), preferentially use heat‐conserving postures in sunny areas or stay under direct sunlight ( Alouatta caraya: Bicca‐Marques & Calegaro‐Marques, 1998; Callicebus nigrifrons: Gestich, Caselli, & Setz, 2014; P. cynocephalus: Stelzner & Hausfater, 1986), form huddles ( Macaca fuscata: Ogawa & Wada, 2011; Ueno & Nakamichi, 2018), select warmer microhabitats during the day ( A. palliate: Thompson et al, 2016), or remain for longer in caves ( P. hamadryas ursinus: Barrett, Gaynor, Rendall, Mitchell, & Henzi, 2004).…”

“…The seasonal variation in activities and microhabitat use is thought to be related to thermoregulation in a number of primates (e.g., Alouatta palliate: Thompson, Williams, Glander, & Vinyard, 2016). For instance, when T a is high, primates reduce their daily travel distance (McLester, Brown, Stewart, & Piel, 2019), spend more time resting in the shade (Callithrix jacchus: Abreu, De la Fuente, Schiel, & Souto, 2016;Fuente, Souto, Sampaio, & Schiel, 2014; Colobus polykomos: Dasilva, 1992; Papio cynocephalus : Stelzner, 1988), and stay in cooler microhabitats (e.g., caves) during the day (Pan troglodytes verus: Pruetz, 2007;A. palliate: Thompson et al, 2016).…”

Red-tailed monkeys (Cercopithecus ascanius) prey upon and mob birds in the Issa Valley, western Tanzania

“…The study site is characterized as a mosaic of miombo woodland, dominated by Brachystegia and Julbernardia spp., and small strips of riverine forest (Piel 2018). Mean annual rainfall since 2012 is ~1250mm, and daily mean temperatures in forest range from 10-33 o C throughout the year (McLester et al 2019).…”

Vocal communication in wild chimpanzees: a call rate study

“…While previous studies have shown that chimpanzees frequently panthoot at food sources (Clark & Wrangham, 1993;Fedurek, Donnellan & Slocombe, 2014;Wrangham, 1977), call rate did not change with the proportion of time spent feeding in our study. However, our brief field season took place during the late dry season, when fruit availability is highest (McLester et al, 2019). The abundance of food might reduce competition among individuals and thus depress the need for calling.…”