Behavior and seasonal variation in the relative abundance of Commerson's dolphin (Cephalorhynchus commersonii) in northern Patagonia, Argentina

Commerson's dolphins (Cephalorhynchus commersonii) along the Patagonian coast of South America suffer incidental mortality in fisheries and are the target of a dolphin-watching industry. We describe the daily activity patterns and assess the variation in the relative abundance of the species ne...

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Detalles Bibliográficos
Autores: Coscarella, Mariano Alberto, Pedraza, Susana Noemi, Crespo, Enrique Alberto
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/93446
Acceso en línea:http://hdl.handle.net/11336/93446
Access Level:acceso abierto
Palabra clave:BEHAVIORAL ECOLOGY
COMMERSON'S DOLPHIN
PATAGONIA
SEA SURFACE TEMPERATURE
TERNS
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:Commerson's dolphins (Cephalorhynchus commersonii) along the Patagonian coast of South America suffer incidental mortality in fisheries and are the target of a dolphin-watching industry. We describe the daily activity patterns and assess the variation in the relative abundance of the species near the northern boundary of its range. Information was gathered with a spotting scope from a cliff-top vantage point applying the method of scan sampling. Behaviors were categorized as individual feeding, cooperative feeding, directional swimming, socializing, and resting. These behaviors are similar to those observed in other species of small cetacean, but differences were found regarding the patterns of directional swimming and feeding techniques. Hunting tactics favored the association of terns with dolphin groups. No clear dial behavioral pattern was observed, but seasonal changes in the frequency of behaviors were recorded. Group and school sizes were larger during periods with colder sea surface temperature (SST). Seasonal abundance was correlated with SST, suggesting that at higher SST the species forsakes the area, probably in favor of coastal areas to the south with lower SST.