[MARMAM] new publication

krasmussen at mlml.calstate.edu krasmussen at mlml.calstate.edu
Thu Apr 5 10:57:33 PDT 2007

We are pleased to announce the publication of the following article in
Biology Letters. For a PDF copy please send requests to:
krasmussen at mlml.calstate.edu

Rasmussen, K., D.M. Palacios, J. Calambokidis, M. Saborio, L. Dalla-Rosa,
E. Secchi, G. Steiger, J. Allen, and G. Stone. 2007. Southern Hemisphere
humpback whales wintering off Central America: insights from water
temperature into the longest mammalian migration. Biology Letters,


We report on a wintering area off the Pacific coast of Central America for
humpback whales (Megaptera novaeangliae) migrating from feeding areas off
Antarctica.  We document seven individuals, including a mother/calf pair,
that made this migration (~ 8,300 km), the longest movement undertaken by
any mammal.  Whales were observed as far north as 11°N off Costa Rica, in
an area also used by a boreal population during the opposite winter
season, resulting in unique spatial overlap between Northern and Southern
Hemisphere populations.  The occurrence of such a northerly wintering area
is coincident with the development of an equatorial tongue of cold water
in the eastern South Pacific, a pattern that is repeated in the eastern
South Atlantic.  A survey of location and water temperature at the
wintering areas worldwide indicates that they are found in warm waters
(21.1-28.3°C), irrespective of latitude.  We contend that while
availability of suitable reproductive habitat in the wintering areas is
important at the fine scale, water temperature influences whale
distribution at the basin scale.  Calf development in warm water may lead
to larger adult size and increased reproductive success, a strategy that
supports the energy conservation hypothesis as a reason for migration.

Kristin Rasmussen

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