Behaviour 2019
Assessment of the impact of anthropogenic airborne noise on the behaviour of Cape fur seal 
Mathilde Martin1,2, Tess Gridey2,3, Simon Elwen2,3, Isabelle Charrier1. 1Université Paris-Saclay, CNRS, UMR 9197, Institut des Neurosciences Paris-Saclay, Orsay, Essonne, France; 2Sea Search Research and Conservation NPC, Cape Town, Muizenberg, South Africa; 3Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Stellenbosch, , South Africa

The increase of anthropogenic noise in the environment is a global phenomenon occurring in most habitats and impacting many taxa. Due to their amphibious lifestyle, pinnipeds are exposed to anthropogenic noise in both aquatic and aerial environments.  We assessed the impact of engine noise (car and boat) on the behaviour of Cape fur seals at Pelican Point breeding colony, Namibia. Playback experiments were conducted to 35 groups, each exposed either to low, mid or high amplitude levels of noise broadcast from land or sea side. During noise exposure, we found a significant increase in energetically costly behaviours for all noise levels: time spent awake, vigilance and locomotion for both females and pups, to the detriment of vital activities such as resting and nursing that decreased considerably compared to the pre-playback phase. However, the disturbance was found to be limited to the 2-min noise exposure and a rapid recovery was observed when the noise ceased. Responses to boat motor noise were stronger than those to car motor noise from the land side.  Development of regulations for both boats and vehicles around breeding seal colonies are needed to limit disturbance.