Camera trap monitoring of the haul-out behavior of Mediterranean monk seals on Gökçeada Island in the North Aegean Sea

Abstract

Gökçeada Island, on the northern Aegean Sea coast of Türkiye, is an important habitat for endangered Mediterranean monk seals (Monachus monachus), where their presence has long been known. This is the first study to document the number, individual identity (sex and age), seasonal distribution, and habitat use (duration and time of haul-out) of these seals. One cave and one beach site on the northwest coast of Gökçeada Island were monitored using camera traps from 2017 to 2019 (777 days). Seals were photographed at 5-minute intervals for 177 days at the cave site and 64 days at the beach site. Seals’ diel patterns varied by month, with reduced activity during daytime at both sites. Eight seals (one adult male, five adult females, one young female, and one newborn) were documented using the sites. Five individuals were detected gregariously in the cave. A female was observed nursing a newborn in the cave in October 2017. One seal remained in the cave for more than 5 days without interruption. This study shows that the northwest coast of Gökçeada Island is year-round habitat and a breeding area for Mediterranean monk seals. Additional monitoring on neighboring islands is necessary to better understand the population size, distribution, habitat use, and haul-out behavior in the North Aegean Sea, so that this endangered species may be better protected for potential recovery.