Postcopulatory mate guarding by vocalization in the Formosan squirrel

Abstract

The Formosan squirrel, Callosciurus erythraeus thaiwanensis, emitted different vocalizations in response to terrestrial and aerial predators and snakes. Each vocalization caused nearby individuals to adopt a different type of anti-predator behaviour. In mating bouts, males produced two types of loud calls: precopulatory calls, emitted before copulations, and postcopulatory calls, emitted after copulations. The latter continued for 17 min on average. The estrous female and other males attending the mating bouts stopped moving during the postcopulatory call, so that the calling male was able to tend the female without interruption. The sound characteristics of anti-terrestrialpredator and postcopulatory calls recorded in the captivity were compared, and none of the ten characters of duration and frequency measured differed between the two calls. Playback experiments also showed that responses to the sounds in two different contexts, escape behaviour and defensive immobility, did not differ. The similarity between anti-predator and postcopulatory calls is discussed with reference to the possibility of manipulation and other explanatory hypotheses.

The potential to encode sex, age, and individual identity in the alarm calls of three species of Marmotinae

“…Potentially, the cues to sex should be important in other social contexts, such as post-copulatory mate guarding. Alarm calling during post-copulatory mate guarding has been reported in male Formosan squirrels Callosciurus erythraeus thaiwanensis and Columbian ground squirrels Spermophilus columbianus (Tamura 1995; Manno et al 2007), but not in any of our species. In other species, emitting alarm calls in mating-related contexts have been reported for male topi antelope Damaliscus lunatus which use alarm snorts for retaining estrous females on their territories to secure mating opportunities (Bro-Jorgensen and Pangle 2010) and among birds for ornamented male fowl, Gallus gallus (Wilson et al 2008).…”

Think Before They Squeak: Vocalizations of the Squirrel Family

“…Additionally, these squirrels can add a chuck syllable (only 22.5 ms long and decreasing in frequency from about 6 to 2 kHz) to the end of either the chirp or whistle when predators are nearby, eliciting increased vigilance from receivers after their initial behavioral response (Sloan et al, 2005) and like marmots, Richardson's ground squirrels will increase the repetition of their calls as the threat level increases (Warkentin et al, 2001). When predator-specific alarm calls are used in a species, the caller most often only distinguishes between terrestrial and aerial predators [Callosciurus (Tamura and Yong, 1993;Tamura, 1995), Cynomys (Ackers and Slobodchikoff, 1999;Loughry et al, 2019), Marmota (Taulman, 1977;Davis, 1991;Blumstein and Arnold, 1995;Blumstein, 1999a), Otospermophilus (Owings and Virginia, 1978;Owings and Leger, 1980), and Urocitellus (Balph and Balph, 1966;Melchior, 1971)], though some Asian tree squirrels have a third call which elicits snake mobbing behavior in conspecifics (Tamura and Yong, 1993).…”

Monkeys crying wolf? Tufted capuchin monkeys use anti-predator calls to usurp resources from conspecifics

“…Even without support for the latter prediction, it seems that capuchin monkeys, similarly to some avian and rodent taxa (e.g. Munn 1986;Tamura 1995), use alarm calls to distract others during competitive situations, alleviating some of the costs associated with contest competition for food. Functionally deceptive signalling is thought to have to be rare and/or have a low cost for the 'deceived', otherwise the signal will simply be ignored and become ineffective (Fitch & Hauser 2002;Searcy & Nowicki 2005).…”