Site fidelity and population parameters of short-finned pilot whales (Globicephala macrorhynchus ) in the Eastern Caribbean through photographic identification

Abstract

The short-finned pilot whale (Globicephala macrorhynchus) is distributed throughout the Caribbean and within the Agoa Sanctuary, where it is protected. This top predator is overlooked in the Caribbean, and no data is available on the variability of the degree of fidelity to the islands, or even on the demographic parameters and social structure of this species, which is essential for its conservation and the understanding of its behavior. This study focuses on the islands of Guadeloupe and Martinique and is based on 24,374 photos collected between 2014 and 2022. This data was analyzed using the CMR method via photo-identification, then open population modeling under the POPAN formulation and via SOCPROG for the study of social links. This revealed two interconnected populations. Within each of these populations, there are three patterns of residence: core residents, residents, and visitors. A total of 193 core residents and residents were estimated in Guadeloupe, and 565 core residents, residents, and visitors in Martinique. Survival rates for both populations were high. Abundance was constant in Guadeloupe for core residents and residents, but a decline has been observed for the three patterns of residencies in Martinique - special attention must be given to this population. International collaboration throughout the Lesser Antilles is essential in order to estimate the number of populations and understand the behavior of the short-finned pilot whale in the Caribbean Sea. Keywords: catch-mark-release, pattern of residence, photo-identification, short-finned pilot whale, site fidelity, social links