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No boomer pouch, tough toenails, hatching eggs
![Boomers don’t have pouches. An eastern grey male kangaroo, Australia. [Roophilia, © Marko Laine, used with permission]](images/2004-04-02-boomer.jpg) Q: Do male kangaroos have pouches? Babs, England.
A: No, male kangaroos (boomers) don’t have pouches. Only
females do.
Boomers don’t have pouches. An eastern grey male kangaroo,
Australia. [Roophilia, © Marko Laine, used with permission]
By the way, kangaroo pouches and how the females give birth
puzzled early scientists. In 1629, a Dutch sea captain, Francois Pelsaert, who
wrecked off southwest Australia, was the first to discover a baby in the pouch.
He thought it was born in the pouch. The Aborigines may have thought the same.
In 1830, a British ship’s surgeon, Alexander Collie, concluded
that the baby was born the usual way and then crawled into the pouch. That’s
right — the 0.029-ounce (0.8-g) tiny naked baby, still attached to the umbilical
cord, struggles for three minutes across fur and then clambers into the pouch.
Further Surfing:
Roophilia: Kangaroos
Tough toenails
Q:
Why are toenails thicker than
fingernails? Rachel, Kankakee, Illinois
![Toenails take a beating. [Corel]](images/2004-04-02-cowboy-boot.jpg) A: Friction and fungus thicken toenails. Toenails take a
beating from socks, shoes, and generally being at the foot end of the human body
where the weight bearing goes on. They’re made from the same dead skin tissue as
fingernails but are two to three times thicker.
Nail fungus is another culprit, affecting 30 million
Americans. The fungus destroys the protective outer layer of nails (the keratin)
and causes the nail to go into overproduction. The excess becomes thick,
yellowed, and hard.
Toenails take a beating. [Corel]
Hatching eggs
Q: In your recent article on tough eggs, you say the chick
picks the more fragile middle "side" of the egg to peck its way out. This sounds
like the hatchling has some choice in the matter – doesn’t it start pecking
where its beak is? Kevin, Penyn, California
![Chicks hatching [Ardo Meyer, NOAA]](images/2004-04-02-chicks-hatching.jpg) A: The hatchling, as it happens, does have a choice in
the matter. He turns himself so his beak can access the bubble of air at the
blunt end of the egg. That's his first breath of air. It also puts him in
position to peck an entire circle around the egg, below the blunt end, so he can
push the "cap" off and struggle out.
Chicks hatching [Ardo Meyer, NOAA]
Further Surfing:
WonderQuest: Eggs have a tough side
University of Illinois, Urbana-Champaign: A hatching chick (photo).
(Answered April 2, 2004)
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