Acoustic and visual observations of Sperm Whales, Physeter macrocephalus, off the Southeast Coast of Sri Lanka, April 2013

Abstract

Abstract An opportunistic study was carried out from a 113’ motor-sailing vessel along the southeast coast of Sri Lanka from April 11 to 19, 2013. Passive acoustic monitoring allowed pods of sperm whales (Physeter macrocephalus) to be detected and tracked before being sighted. Key observations included sightings of whales along the 1000 m drop-off, repeated breaching of whales on two separate occasions within 50 m of a driftnet, and the presence of a single bull male with mating-related behaviour and jaw-clapping. These observations and other visual observations during the ship’s voyages indicate that sperm whales are located in Sri Lanka waters for feeding, breeding and calving.

Keywords

• bull
• calves
• clang
• driftnet
• jaw clap