Showing posts with label Current Biology. Show all posts
Showing posts with label Current Biology. Show all posts

Friday, March 15, 2024

some friends in the sea

 






A white whale called NOC began, spontaneously, to make unusual sounds. 
We interpreted the whale’s vocalizations as an attempt to mimic humans. 
Whale vocalizations often sounded as if two people were conversing
 in the distance just out of range for our understanding. 

These ‘conversations’ were heard several times before the whale was identified
 as the source. The whale lived among a group of dolphins and socialized
 with two female white whales. The whale was exposed to speech 
not only from humans at the surface — it was present at times when divers
 used surface-to-diver communication equipment. The whale was recognized
 as the source of the speech-like sounds when a diver surfaced outside
 this whale’s enclosure and asked “Who told me to get out?” 

Our observations led us to conclude the “out” which was repeated 
several times came from NOC.

As soon as NOC was identified as the source of these sounds, 
we recorded his speech-like episodes both in air and underwater.
 Recordings revealed an amplitude rhythm similar to human speech.
 Although there was variation, vocal bursts averaged about three per second .
 The rhythm of vocal bursts also reminded us of human speech.





~ from Current Biology Vol 22 No 20


Belugas are well adapted to life in northern waters. 
They have a thick skin and a deep layer of blubber to keep them warm
 and act as an energy store. This can account for 40% of their weight.

Their stark white colouring also helps camouflage them against the ice.
 Although beluga whales are predators, feeding on fish, crustaceans,
 and molluscs, they are also hunted by polar bears and orcas.

Belugas lack the dorsal fin that stands up from the back of many whales –
 think of orcas' tall, upright fin. These fins help to keep whales upright
 while swimming. But for belugas, which swim close under ice, 
a dorsal fin might have been more of a hindrance. Instead, a dorsal ridge
 down their spine and a rotund body may help them to move through
 the water more easily. Lacking a dorsal fin may also help them keep warm,
 as fins have a large surface areas that can lose heat fast.

When looking at belugas you can't miss their bulbous heads.
 The large fatty sack between their blowhole and upper jaw is known as a melon.
 It helps them focus and project sound, making belugas especially good
 at echolocation - using sound to detect prey and communicate.