Temporal distribution of the most sighted baleen whales in Azores: fin whales (Balaenoptera physalus) and sei whales (Balaenoptera borealis).

Abstract

Sei whales (Balaenoptera borealis) and fin whales (Balaenoptera physalus) are migratory
baleen whales that pass the Azores archipelago each year. Like other baleen whales they are
sighted mostly frequently during the spring months, but generally with a much higher sighting
rate than the other species. We analysed data collected along the south coast of São Miguel
Island during whale watching tours with Futurismo Azores Whale Watching from 2006 to 2012.
Photographs taken during encounters with fin whales were analysed and compiled into a
photographic catalogue of individuals. In total, we recorded 131 encounters with fin whales
and 130 with sei whales. According to these results they are the most frequently sighted
baleen whale species in the Azores. Around 55% of sei whale encounters and 68% of fin whales
were in April and May. Both species were sighted less frequently during the winter months
(November-February), making up only the 3% of the total encounters. We photographically
identified 45 different fin whales, mostly from encounters in the past three years, as
photographic effort was very low in previous years. This fact may contribute to the absence of
resightings of individuals, highlighting the importance of ongoing research in order to gain a
better understanding of fin whales and other baleen whale species in this area.

Full text

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(1)Futurismo+Azores+Whale+Watching,+Marina+Pêro+de+Teive,+9500‐771,+Ponta+Delgada,+São+Miguel,+Azores;+(2)Department+of+
Applied+Physics,+Vigo+University.+
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