Thursday, 29 March 2012

Risso's dolphins make a splash!

typical high, falcate dorsal fin

mature adult showing skin lightening and scarring

female with calf

Cracking weather again today with excellent sea conditions. 800 metres out I noticed a high, sickle-shaped dorsal fin break the sea surface during one of my many binocular sweeps. Five minutes later a nice school of Risso's dolphins (Grampus griseus) swam across our bow. As far as I could determine there were a dozen or so- eight or nine adults, including at least two mature males and two or three smaller calves. They closed to within 400 metres of the ship, allowing me to get a few shots off. Mature adults are renowned for their pale skin and scarring- particularly in the head region and the scarring is caused from multiple previous encounters with other sharp-toothed individuals and, to a lesser degree squid.  This species also shows a good deal of variation in the height and shape of their dorsal fins. The individuals here certainly showed these characteristics rather nicely. After watching them for 10 minutes they gradually moved off to the east and were lost from view in the heat haze.

On the birding front a wheatear was a first for this voyage and a nice flock of 10 (Little?) egrets looked resplendent despite the distance, with their pristine white plumage making for a lovely contrast against the  sea!

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