Brown Mouse Lemurs (Microcebus rufus) May Lack Opportunities to Learn about Predator Calls

Abstract

Diurnal primates commonly modify their behaviour in response to predator vocalizations, but little is known about how nocturnal primates perceive predator calls. Mouse lemurs do not innately perceive predator calls as dangerous but may learn to do so in the wild. I hypothesized that wild brown mouse lemurs (Microcebus rufus) in Ranomafana National Park, Madagascar, differentiate between predator and non-predator vocalizations and exposed 29 adult subjects to calls of 3 sympatric predators (goshawk, fossa and owl), 3 sympatric non-predators and 4 controls. Brown mouse lemurs did not differentiate among stimuli, and there was no evidence that any recording was associated with danger, as neither activity nor spatial preferences changed in response to a stimulus, nor did subjects exhibit obvious behaviours indicative of danger such as flight or position on the branches. The failure to perceive predator calls as dangerous is common among small nocturnal solitary prey species and could be explained by a lack of learning opportunities. In social species acquired behaviours can spread quickly by social learning. Solitary species like mouse lemurs have to individually learn to associate predator calls with danger which is dependent on encounter rates. Unlike diurnal prey mouse lemurs lack the opportunity to observe diurnal raptors and associate their calls with the bird, and owls are proficient predators, which are difficult to observe in a rain forest where they hunt cryptically from perches. While sometimes nocturnal, the fossa is solitary and largely silent, and is also particularly rare at my study site. Cryptic, rare or nonvocal predators provide prey with few opportunities to associate their calls with danger. Mouse lemurs are subject to high predation rates by a wide range of predators and need to balance the costs and benefits of antipredation behaviours. Their cryptic lifestyle and

Occurrence of Conspecific in the Neighboring Space Influence on Flight Initiation Distance in Cape Hare <i>Lepus capensis</i> under Human Stimuli

“…Conversely, it is also possible that warier-albeit solitary-animals such as hares could increase the probability of predator detection through vigilance (e.g. Brown Mouse Lemurs Microcebus rufus [25]). FID is an outstanding metric for measuring an individual's fearfulness under certain conditions [26], and flight response is also studied to recognize the areas where the species are not influenced by humans [27].…”

Impact of predator model presentation paradigms on titi monkey alarm sequences

“…Moreover, several primate species do not seem to recognize their current predators’ calls (e.g. Hettena et al 2014 ; Deppe 2020 ). Felid vocalization recognition is mostly learnt, but since cats are low-density, solitary animals that rarely vocalize, especially when hunting, learning opportunities are scarce (Hettena et al 2014 ).…”

“…These mixed results have also questioned whether prey recognize their predators’ vocalizations. While some species show innate reactions to predator calls, even if extinct in the study area (Li et al 2011 ; Hettena et al 2014 ; Makin et al 2019 ), or can quickly learn the vocalizations of newly introduced predators (Berger et al 2001 ; Gil-da-Costa et al 2003 ), some species do not seem to recognize their current predators’ calls (Blumstein 2000 ; Friant et al 2008 ; Hettena et al 2014 ; Deppe 2020 ). These differences could be explained, in part, by the vocal behaviour of the predator: with the exception of some predatory birds, most predators do not vocalize while hunting (Barrera et al 2011 ), which can represent a lack of opportunity to learn a predator’s call.…”