The Influence of Natural Sounds on California Ground (Otospermophilus beecheyi) Vigilance and Predator Detecon Christopher M. Garvin1, My-Lan T. Le1 and Dr. Clinton D. Francis1 1California Polytechnic State University, San Luis Obispo, San Luis Obispo, CA 93407 Background Behavior Trials Coyote Detecon Trials o These trials involved 5 minutes of constant observaon. The California is a social o This trial tested ’ ability to o Behaviors were separated into 11 categories: vigilant on two legs, vigilant on detect an incoming predator with that lives in burrows. Colonies range in size from four legs, foraging and vigilant, foraging, moving, social, grooming, resng, dust a few individuals to dozens. Living in colonies bathing, digging and tail flagging. or without the addion of sound provides protecon from predators such as o Time spent performing each acvity was converted to a percentage spent to the environment. hawks, coyotes, and ralesnakes. For protecon, performing each acvity. o A roboc coyote was made by

colonies usually have a sennel that is vigilant combining a RedCat Racing Rock Crawler and a coyote decoy.

for predators. Addionally, each squirrel must weigh the risk of foraging Focal Individual o The roboc-coyote started 50m

versus being vigilant so they can beer detect incoming predators. During this trial, a single individual was observed for the duraon of the test. away from the focal squirrel. Using a spong scope, this individual was randomly selected from the Many factors affect how a ground squirrel behaves, but in this study o It was driven at a steady pace we are looking at how a changing soundscape affects their behavior. visible populaon. toward the squirrel to simulate the This is relevant because the sound- Results: 100 hunng style of a coyote. scape of the US has changed drascally o There was not a significant Results o The Flight Iniaon Distance (FID) difference between the 80 was recorded. due to human acvity. This change is o This plot shows that the FID was me individuals spent not significantly different causing the behavior of prey to 60 vigilant for the control and 1 depending on the treatment. 4.0 change . In parcular CA ground insect (cicada) treatment. 40 This is not what our predicons squirrels become more vigilant and o o However, during the river % Total Vigilance and hypothesis expected.

forage less in response to increased 3.0 trials individuals spent 20 o Factors that are more important 2 anthropogenic (human-induced) noise . significantly more me in determining FID are: log(FID1)

0 However, it is not known how vigilant for predators. • distance of squirrel to its

2.0 o Other important factors: Control Insects River natural sounds affect the behavior of burrow Soundscape of changes of noise level in • Average group size squirrels. The intent of this study is to Treatment • number of other squirrels the United States. Brighter colors indicate • Group composion 1.0 explore this relaonship. a greater increase in ambient noise. present • Composion of surrounding Control Insects River Group colony Basic Design Treatment This trial was done simultaneously with the individual trial. A scan of all o This experiment will use 3 treatments to test the effects of natural sound on behavior: visible squirrels was performed every 30 seconds and each individual’s • Cicada Calls (low frequency) behavior was recorded. Discussion • Rushing Water (river noises, high frequency) Results: 2.0 • Control (a “no energy” track played on a speaker to control for EM energy) o These inial results are crypc and o These natural sounds are broadcast ~ 50 meters away from a colony at the level of 85 o There is very lile difference dBFLT at 1m between the three further analysis is necessary.

• Squirrels thus experience a biologically relevant smuli of 50-80 dBFLT3 treatments. 1.5 o Squirrels do not respond to high o Invesgators were 30-50m away from the colony in a hunng blind to hide their presence o This suggests that other frequency noises (cicada). o 9 colonies were chosen for tesng variables are more important o Squirrels respond more consistently to o Each colony underwent 3-6 tests 1.0 in determining group • 1 test for each of the three sound condions- cicada, river, and control / Vigilance Foraging low frequency noises (river). • If possible each of these three condions was completed once with adults behavior than the noise o Many variables besides the sound level and once with juveniles treatments. 0.5 contribute to squirrel behavior, notably o These variables include: Control Insects River the average group size, group • Average group size • Treatment composion, and age of the individual. Hypothesis Group composion An increase in natural noise will increase the vigilance of the California ground squirrel. Predicons: References o Individual and group of squirrels will spend less me foraging and 1. Shannon, Graeme, et al. "Road traffic noise modifies behaviour of a keystone species." Animal Behaviour 94 (2014): 135-141. 2. Rabin, Lawrence A., Richard G. Coss, and Donald H. Owings. "The effects of wind turbines on anpredator behavior in more me vigilant when exposed to natural sound treatments. California ground squirrels ( beecheyi)." Biological Conservaon 131.3 (2006): 410-420. 3. Francis CD, Barber JR (2013) A framework for understanding noise impacts on wildlife: an urgent conservaon priority. o Squirrels will be quicker to flee from a perceived predator as a result Froners in Ecology and the Environment 11, 305-313.

of increased vigilance when exposed to natural sound treatments. The 2017 STEM Teacher and Researcher Program and this project have been made possible through support from Chevron (www.chevron.com), the Naonal Marine Sanctuary Foundaon (www.marinesanctuary.org), the Naonal Science Foundaon (www.nsf.gov) and the California State University Office of the Chancellor, in partnership with the California State University of San Luis Obispo.