Resumo

BARTES, Saia Nahir; SVENDSEN, Guillermo Martin; ROMERO, María Alejandra  e  GONZALEZ, Raúl Alberto. DECREASE IN THE OCCURRENCE OF THE SOUTH AMERICAN FUR SEAL (Arctocephalus australis) IN SAN MATÍAS GULF AFTER A SUDDEN EPISODE OF REOCCUPATIONDisminución en la ocurrencia del lobo marino sudamericano Arctocephalus australis en el Golfo San Matías después de un episodio repentino de reocupación. Mastozool. neotrop. [online]. 2020, vol.27, n.2, pp.228-233.  Epub 19-Ago-2020. ISSN 0327-9383.

The colonies of South American fur seals, Arctocephalus australis (SAFS), are currently experiencing population recovery, and as a consequence many coastal areas have been reoccupied. These areas are often haul-out sites used by SAFS for resting during the post-reproductive (winterly) season, and may be playing a key role in the population recovery process since they seem to be located close to winter feeding areas that are far from the breeding colonies. This study reports on the trend in abundance of SAFS in a recently reoccupied winter area, the San Matías Gulf (SMG). The trend was evaluated with generalized linear models between 2007 and 2017 in two sectors of the SMG, Islote Lobos, the only rookery of this species in the area, and the northwest marine area of the gulf. Both sectors showed a negative trend. For Islote Lobos, the best selected models estimated a mean annual rate between -12.2% and -17.6%, and for the northwest area, between -19.02% and -29.9%. The population context suggests that most SAFS observed in 2007 may have been selecting other habitats over the following years; however, simultaneous censuses throughout their distribution range are needed in order to understand the redistribution and recolonization processes.

Palavras-chave : abundancia; apostadero no reproductivo; recolonización; tendencia.

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