Dear Marmamers,
We are pleased to announce the publication of the following
article in Marine Mammal Science:
S. Gero and H. Whitehead (2007) Suckling behaviour in sperm
whale calves: observations and hypotheses. Marine Mammal Science 23(2):
398-413.
Abstract:
This study is the first to
describe quantitatively the apparent suckling behaviour of sperm whale, Physeter
macrocephalus (Linnaeus, 1758), calves using observations from both above
and below the surface. Peduncle dives are short (mean 14 s) dives made by sperm
whale calves beside the peduncle of an adult female, which were
previously assumed to be
indicative of suckling. Photo-identification and focal calf follows were used
to collect data during 177 peduncle dive bouts from 22 different
calves (11 calves from the
Caribbean Sea, 11 from the Sargasso Sea), one of which was followed on forty
different days. We found that peduncle diving in sperm whale
calves is laterally asymmetrical
with a bias to the left side of the escorting adult (69.8% of peduncle dives)
and that calves generally do not switch sides during a bout
of peduncle dives (switches
occurred in only 10.8% of bouts). Further subsurface observations gave insight
into potential alternative functions of peduncle diving.
These alternative hypotheses,
including nasal suckling, and the existing supporting evidence for each are
discussed. It is likely that peduncle diving is related to suckling
but that the exact function of
the dives and manner in which sperm whale calves ingest milk remains unclear.
The article is available online and will be in print in the
April Issue.
Sincerely,
Shane Gero
**********************************
Shane Gero, M.Sc.
NSERC Ph.D. Candidate
Whitehead Lab
Biology Dept.
Dalhousie University
Halifax, NS
B3H 4J1 Canada
http://whitelab.biology.dal.ca/sge/