King
penguin parents spend about 14 months incubating their egg, then
rearing their chick. They take it in turns to find food, so the strength
of their bond is crucial. Biologists want to know how they make this
important mate selection, and even how the birds tell a male from a
female; the two sexes look almost identical.
Prof Stephen Dobson from the National Centre for Scientific Research in
Montpellier, France, playfully sums up his research: "I'm trying to work
out what makes a sexy penguin." His studies of the birds on Kerguelen
Island have revealed that penguins often struggle to spot a member of
the opposite sex.
Prof Dobson also found that males on the island in the Southern Indian
Ocean often had to compete particularly hard to snag a female mate. He
and his team noticed that, during mating season, trios of penguins would
"parade" around together. DNA analysis showed that the trios were
usually two males pursuing a female.
When the penguins do find a mate that they take a shine to they carry
out an intimate dance – stretching their necks from side to side in what
appears to be an elaborate embrace. Occasionally, two males will engage
in this mating dance, but the pair usually separate when one finds a
female partner.
Prof Dobson’s team, which also includes researchers from the Centre for
Functional and Evolutionary Ecology in Montpellier, France, has found
that the penguins' bright yellow ear patches play an important role in
attraction.
The researchers measured the size and colour intensity of these ear
patches to find out how they affect penguin attractiveness. They also
used black hair dye to artificially reduce the size of the ear patches.
Males with artificially-reduced ear patches seemed to have less success
finding a female. Females also appeared to choose males with larger ear
patches, and the researchers think that larger ear patches might convey a
male's ability to defend his chick and his territory in the crowded
colony.
The scientists hope to unpick the evolutionary mystery of how these
birds select a suitable partner who will co-operate in the care of their
egg and chick. They also hope to find out more about the penguins'
natural behavior to see how they are being affected by environmental
change.
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