TY - JOUR
T1 - Specialized foraging habits of adult female California sea lions Zalophus californianus
AU - Rosas-Hernández, Martha P.
AU - Aurioles-Gamboa, David
AU - Hernández-Camacho, Claudia J.
N1 - Publisher Copyright:
© 2019 Society for Marine Mammalogy
PY - 2019/10/1
Y1 - 2019/10/1
N2 - Individual foraging specialization occurs when organisms use a small subset of the resources available to a population. This plays an important role in population dynamics since individuals may have different ecological functions within an ecosystem related to habitat use and prey preferences. The foraging habitat fidelity and degree of specialization of California sea lions (Zalophus californianus) were evaluated by analyzing the stable isotopes values of carbon and nitrogen in vibrissae collected from 16 adult females from the reproductive colony on Santa Margarita Island, Magdalena Bay, Mexico, in 2012 and 2013. Based on the degree of individual specialization in δ15N, 62.5% of the females assessed can be considered specialist consumers focusing on the same prey or different prey from the same trophic level. The degree of individual specialization in δ13C indicated that 100% of the individuals showed fidelity to their foraging habitat as some fed in the lagoon, others foraged along the coast, and a third group preferred prey from the pelagic environment during both the breeding and nonbreeding seasons, suggesting diversification of foraging areas. Foraging area fidelity persisted despite the 2°C increase in the sea surface temperature over the course of the study period.
AB - Individual foraging specialization occurs when organisms use a small subset of the resources available to a population. This plays an important role in population dynamics since individuals may have different ecological functions within an ecosystem related to habitat use and prey preferences. The foraging habitat fidelity and degree of specialization of California sea lions (Zalophus californianus) were evaluated by analyzing the stable isotopes values of carbon and nitrogen in vibrissae collected from 16 adult females from the reproductive colony on Santa Margarita Island, Magdalena Bay, Mexico, in 2012 and 2013. Based on the degree of individual specialization in δ15N, 62.5% of the females assessed can be considered specialist consumers focusing on the same prey or different prey from the same trophic level. The degree of individual specialization in δ13C indicated that 100% of the individuals showed fidelity to their foraging habitat as some fed in the lagoon, others foraged along the coast, and a third group preferred prey from the pelagic environment during both the breeding and nonbreeding seasons, suggesting diversification of foraging areas. Foraging area fidelity persisted despite the 2°C increase in the sea surface temperature over the course of the study period.
KW - California sea lion
KW - Zalophus californianus
KW - environmental change
KW - foraging area fidelity
KW - individual variation
KW - stable isotopes
KW - vibrissae
UR - http://www.scopus.com/inward/record.url?scp=85065018268&partnerID=8YFLogxK
U2 - 10.1111/mms.12603
DO - 10.1111/mms.12603
M3 - Artículo
AN - SCOPUS:85065018268
SN - 0824-0469
VL - 35
SP - 1463
EP - 1488
JO - Marine Mammal Science
JF - Marine Mammal Science
IS - 4
ER -