Sperm whale surface activity from tracking by radio and satellite tags

Three 12-m sperm whales (Physeter catodon) were tagged and tracked west of Dominica in the southeast Caribbean to follow the surfacing patterns and mo vements of these presumed subadult males. Whale N was tagged in April 1993 with a 30-MHz radio tag and tracked for two days. Whale H was tagged in Apr il 1995 with a 30-MHz radio tag and tracked for 4.6 d. Whale A was tagged i n April 1995 with a satellite-monitored tag tracked by ARGOS for 21.5 d, th e first four of which were concurrent with the tracking of Whale H, an asso ciate. The tagged whales remained west of Dominica for at least 2, 5, and 1 3 d, respectively. Whales N and A then moved southward to waters off Martin ique. There were no apparent effects on the whales by tagging or the presen ce of the tags. The whales averaged speeds of 2.6-3.5 km/h. Surfacings, ind icated by tag signals, were of two types: short surfacings apparently prima rily for respiration, averaging 7-10.5 min between repeated longer dives, o ccurring day and night; and extended surfacings :seemingly for rest and soc ial interactions with conspecifics, occurring mostly in daylight. Whales we re near the surface for 20.4%-22.6% of the total time (26.6%-27.1% during t he day and 14.9%-17.1% at night). Delayed blowing was observed as Whale N s urfaced for 8.3 min between 47- and 45-min dives but delayed the first of i ts 31 blows for 1.5 min after surfacing.