Black swans…
Black swans? hehehe. just nothin’ actually.. I’ve heard them in a NEWS program few days ago and they simply intrigued me.. Especially their pairing behaviour:
"A recent (2007) exhibition at the University of Oslo Natural History Museum in Norway called Against nature? explored homosexual behaviours in a number of species, including Black Swans.
Several swan species exhibit lifelong homosexual behaviours, and the same phenomenon can also be found in a number of other water-birds, notably geese and flamingos, where it serves as a flexible life strategy.
In swans, the pair is the central social unit. The birds reinforce
the unit with frequent preening and sex. Should one die, the other will
usually live out the remainder of its life alone. The pair builds
nests, raise cygnets and defends a territory. Two cobs, being bigger
and stronger than a cob and a pen, can hold down a larger territory,
and provide their cygnets with more to eat.
Such homosexual pairs represents a major fitness bonus to a pen, and pens without partners will seek out these couples,
have sex with one or other of the cobs and lay eggs in their nest. She
is then chased off, not being a part of the pair, and the cobs raise
the cygnets themselves. Having access to more food the brood have up to
ten times the survival rate of a brood with a heterosexual swan couple.
From an evolutionary point of view, this is a very rewarding strategy
for the cobs as well.
This situation only holds true as long as a nest and a territory is
in short supply. The two males will have a fitness loss in that they have no guarantee they are the actual fathers of the cygnets (not
being bonded with the female) and will anyway have to split
reproduction between them.
A homosexual lifestyle will be advantageous in some situations, but
not in others. However, having a partner is a requisite for building a
nest and keeping a territory, and an opposite sex partner may not
always be available when forming pairs. Thus, the ability to form a
homosexual male pair is a normal part of the Black Swans social
behaviour and an example of a flexible life strategy in the species."(Wikipedia.com)
Amazing huh?..
No other thoughts..
ALTASHHETH™
September 29, 2007
5:28PM
