Flexibility in the Foraging Strategies of the Galapagos Sea Lion Inferred from a Multiple Approach Analysis

Abstract

Studies concerning the foraging behavior of the endangered Galapagos sea lion (Zalophus wollebaeki) are essential to understand long-term conservation challenges and predict population fluctuations. This study provides a comparative analysis of variables related to the foraging habits and trophic niche flexibility of Z. wollebaeki. Complementary stable isotopes and remote sensors were used to measure space-time variables concerning Z. wollebaeki foraging habits among populations in the Galapagos Archipelago. In spatial terms, isotopic values (n = 321) showed differences regarding foraging grounds ($δ$13C: p = 0.015). These results also show test subjects maintained equilibrium in the trophic level of their diet ($δ$15N: p = 0.152). The results of this study confirm the evolutionary behavior of Z. wollebaeki has resulted in a high level of flexibility in foraging habits. This adaptability affords a higher advantage for survival in the Galapagos: a confined ecosystem with limited resources.