Predation and Predation Attempts on Red Titi Monkeys (Callicebus discolor) and Equatorial Sakis (Pithecia aequatorialis) in Amazonian Ecuador

Abstract

Anecdotal reports of predation as well as observed predation attempts and rates of animal disappearance provide some of the most relevant data for evaluating the influence that predation risk may have on primate behavioural ecology. Here, we report rates of disappearance from six groups of red titi monkeys (Callicebus discolor) and two groups of equatorial sakis (Pithecia aequatorialis) followed over a period of four and a half years at a lowland site in Amazonian Ecuador. We also describe the first direct observation of a harpy eagle (Harpia harpyja) preying upon a titi monkey, as well as 3 unsuccessful attacks by tayras (Eira barbara) on titi monkeys and 4 unsuccessful attacks by various raptors on sakis. Our data indicate that pitheciid primates may face a wider array of possible predators than previously recognized, and that titi monkeys and sakis are susceptible to different major classes of predators. Our observations also suggest differences in the sex role during predator defence that could be related to the evolution and maintenance of monogamous systems.

The alarm call system of wild black-fronted titi monkeys, Callicebus nigrifrons

“…Raptors are likely to represent the greatest predatory threat because they can attack at all heights, whereas most mammalian carnivores are terrestrial and rely on ambush. As generally true for field studies, the presence of human observers is likely to have a bigger dissuasive effect on terrestrial than aerial predators (de Luna et al 2010). …”

“…The area is also inhabited by several mammalian carnivores, including tayras (Eira barbara) and at least four species of cats; ocelots (Leopardus pardalis), oncillas (Leopardus tigrinus), jaguarondis (Herpailurus yagouaroundi), pumas (Puma concolor), and possibly jaguars (Panthera onca). All but oncilla and jaguarondis are confirmed primate predators (Miranda et al 2006;Bianchi and Mendes 2007;Ludwig et al 2007;Bezerra et al 2009;Ferrari 2009;de Luna et al 2010). Finally, titi monkeys have also been observed being preyed upon by capuchin monkeys (in Freese and Oppenheimer 1981;Lawrence 2003;Sampaio and Ferrari 2005).…”

“…Individuals are considered to be adults around 30 months of age when they become sexually reproductive (Valeggia et al 1999). For this study, we considered adults as any fully-grown individual (>30 months), sub-adults as slightly smaller individuals than adults (18-30 months), juveniles as individuals about half the size of adults (6-18 months), and infants as smaller than juveniles (0-6 months) (adapted from Moynihan 1966;de Luna et al 2010). Group identification and composition during the study are presented in Table 1.…”

“…and owls (Vasconcelos and Melo Junior 2001;Vasconcelos 2001). For several genera (Harpia, Spizaetus, Accipiter, Morphnus, Leucopternis, Spizastur), there is direct evidence of predation on Neotropical primates (Klein et al 1988 ;Robinson 1994;Boinski and Chapman 1995;Oversluijs Vasquez and Heymann 2001;Miller and Treves 2007;Ferrari 2009;de Luna et al 2010). The area is also inhabited by several mammalian carnivores, including tayras (Eira barbara) and at least four species of cats; ocelots (Leopardus pardalis), oncillas (Leopardus tigrinus), jaguarondis (Herpailurus yagouaroundi), pumas (Puma concolor), and possibly jaguars (Panthera onca).…”

“…Apart from these studies, very little work has been conducted on titi monkey vocal behaviour and virtually nothing is known about their vocalisations in the predation context (Cisneros-Heredia et al 2005;Sampaio and Ferrari 2005;Ferrari 2009;de Luna et al 2010). Although predatorspecific alarm calls are well described in Old World monkeys (see Zuberbühler 2009 for a review), this is not the case for most New World monkeys (but see Digweed et al 2005;Fichtel et al 2005;Kirchhof and Hammerschmidt 2006;Wheeler 2010), which besides having undergone an independent radiation within the primate lineage also differ in essential life-history and socio-ecological characteristics from cercopithecines and lemurs (Strier 2007).…”