Meeting Abstract

P1-132   -   Variation in fox squirrel (Sciurus niger) alarm calls in response to varying threat levels Eddington, VE*; Nichols, H; Calistri-Yeh, A; Young, VKH; Kloepper, LN; Saint Mary's College, Notre Dame, IN; Saint Mary's College, Notre Dame, IN; Northwestern University, Evanston, IL; Saint Mary's College, Notre Dame, IN; Saint Mary's College, Notre Dame, IN veddington01@saintmarys.edu

Distress or alarm calls are vocalizations made when animals are in stressful situations or faced with a predator. Squirrels (family Sciuridae) are known for being very vocal, however most of the studies on alarm vocalizations have been conducted on ground squirrels and little is known about the alarm vocalizations of arboreal squirrels. The objectives of this study were to (1) determine how varying threat levels affect alarm call rates and (2) determine whether sex and/or capture history affects the acoustic behavior of fox squirrels (Sciurus niger). Data were collected at Saint Mary’s College over a 9 week period from May-July 2021. We obtained acoustic recordings on 9 female and 11 male adult fox squirrels and quantified the call rate (calls/sec) in four time periods of varying threat levels: alone after trap has closed, during human approach to trap, during human manipulation of trap, and when inside a fabric handling/measurement cone. Threat level significantly affected calling rate, with the highest call rate occurring during cage manipulation. Sex and capture history had no significant effect on call rate for all four of the threat levels. While alone in the cage, squirrels almost exclusively produced chatter call types, which are considered low threat vocalizations. During human approach, cage manipulation, and handling, squirrels predominantly produced kuks and barks, which have been associated with higher threat levels. This study demonstrates that squirrels respond differently to perceived threat-levels by increasing alarm call rate and call type as threat level increases.