Behavioural Processes 100 (2013) 197–199 Contents lists available at ScienceDirect Behavioural Processes jou rn al h om epa ge: www.elsevier.com/locate/behavproc Short report Barbados green monkeys (Chlorocebus sabaeus) recognize ancestral alarm calls after 350 years of isolation Melissa Burns-Cusato a,* , Brian Cusato a , Amanda C. Glueck b a Centre College, Danville, KY, United States b Texas Christian University, Fort Worth, United States a r t i c l e i n f o Article history: Received 1 May 2013 Received in revised form 1 August 2013 Accepted 25 September 2013 Keywords: Chlorocebus Vervet Green monkeys Anti-predator behavior Predator isolation Alarm call a b s t r a c t Vervet monkeys (Chlorocebus pygerythrus) produce alarm calls and anti-predator behaviors that are spe- cific to a threatening predator’s mode of attack. Upon hearing a leopard alarm, the monkeys will run up trees where they are relatively safe. In contrast, eagle alarms prompt the monkeys to run under bushes and snake alarms stimulate bipedal standing. Early researchers proposed that the meaning of each alarm call is conveyed by observational learning. If this true then absence of the predator that elicits the alarm call may lead to alteration or decay of the alarm’s meaning since there is no longer opportunity for obser- vational learning to occur. The present study tested this hypothesis by presenting alarm calls to a closely related species of monkeys (Chlorocebus sabaeus) that have been isolated from their ancestral predators for more than 350 years. The monkeys ran up trees in response to a leopard alarm, but not when the same alarm was played backwards and not in response to a snake alarm. Snake alarms failed to reliably elicit bipedal standing. These results suggest that the leopard alarm call conveys the same information to Barbados green monkeys as West African green monkeys despite generations of isolation from leopards. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Many species that live in groups produce alarm calls in response to potential threats (Hollen and Radford, 2009). In some of these species, the ability to recognize predators, produce accurate alarms, and respond to the alarm calls of conspecifics is mediated by genetic mechanism (e.g., Reichert and Hedrick, 1990). In others species comparable anti-predator behaviors are learned though experi- ence (Jamieson and Ludwig, 2012). Further still, evidence suggests that for a third set of species alarm call behaviors are mediated by both genetic and experiential mechanisms (Curio, 1993; Hollen and Radford, 2009). Vervet monkeys (Chloroecbus pygerythrus) have evolved a com- plex alarm call system with corresponding anti-predator behaviors that are specific to the predator’s mode of attack (Seyfarth et al., 1980). Vervet predators fall into three general categories: avian, terrestrial, and snake-like and each category evokes an acoustically distinct alarm call. For instance, the monkeys emit a loud bark at the sight of a leopard, a double-syllable cough when a crowned eagle is spotted, and a soft chutter when a snake is detected (Struhsaker, 1967; Cheney and Seyfarth, 1990). The response to the alarm calls * Corresponding author at: Centre College, 600 West Walnut Street, Danville, KY 40422, United States. Tel.: +1 859 238 5384. E-mail address: m.cusato@centre.edu (M. Burns-Cusato). is also predator-specific so monkeys that hear an alarm for a partic- ular predator category will respond with an anti-predator behavior that warrants the best chance of escape. Predators in the terrestrial category, such as leopards, tend to attack monkeys on the ground so vervets respond to a leopard alarm by running high into a tree (Seyfarth et al., 1980). In contrast, because avian predators attack monkeys from the air, the monkeys are most likely to escape an avian attack by hiding under a bush. Consistent with this, Cheney and Seyfarth (1990) observed that vervets are more likely to run under a bush than up a tree after hearing an avian alarm call. Monkeys can often drive snakes out of the area by mobbing them. Thus, when a monkey sees a snake and utters the snake alarm, other monkeys in the area will rise to a bipedal stance, look down to locate the snake, then approach the snake to mob it with fel- low troop-members. Thus, evidence suggests that each alarm call is referentially functional, conveying a distinctly different message about a potential predator (i.e., the presence of a predator and the best means of escape). Recent research indicates that the alarm calls and correspond- ing anti-predator behavior of green monkeys is very similar to that of vervet monkeys (Price and Fischer, 2013). Once considered a subspecies of vervets, the green monkey (Chlorocebus sabaeus) is now widely considered to be a separate species altogether (Groves, 2001). Nevertheless, the two species share many predators and anti-predator vocalizations and behaviors. For example, both species are preyed upon by leopards and snakes in their African 0376-6357/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.beproc.2013.09.012