dinsdag 23 februari 2010

Good news for San Juans orcas: Newborn calf sighted, the fifth in a year

It's not quite an orca baby boom, but the latest birth of a calf, L114 — that's how science-types like to name subjects — is cause for optimism for whale researchers here.

There now have been five orca babies born in the past year in this group, which spends much of its time in the San Juans and Puget Sound.

"I wouldn't yet call it a boom, but it's exciting because every new calf born is an indication that this endangered population may be on the road to recovery," says Lynne Barre, marine-mammal specialist with National Oceanic and Atmospheric Administration Fisheries.

L114 would bring the southern resident killer-whale population to 89. It had declined to 81 in 2001, a drop of 17 percent from its high of 98 in 1995.

The new baby and mom (L77) were first reported Sunday afternoon off southern Vancouver Island by the Center for Whale Research in Friday Harbor.

Dave Ellifrit, a research assistant at the center, went out on an 18-foot inflatable motorboat, along with the center's director, Ken Balcomb, to where 11 of the whales had been spotted.

Ellifrit said he took some 300 photos of the baby whale.

By now, 20 years into whale spotting, Ellifrit says he's quite good at telling the whales apart by their dorsal fin and "saddle patches," the gray area behind the dorsal fin.

"It comes with practice, lots of pictures and seeing lots of them," he says of spotting individual whales.

He has not gotten tired of mingling with the whales. "They're the coolest things around. They're really beautiful animals," he says. "And you get to watch calves grow up, and have their own calves. You get hooked on it."

The newest baby whale still has fetal folds. Barre says having fetal folds means that while the baby was inside the mom, it was so big that its tail was folded.

A baby orca pops out at about 440 pounds and eight feet in length, Barre says.
The gestation period is 17 months, so, understandably, females give birth only every four or five years, the researcher says.

"It takes a considerable amount of maternal investment to have the pregnancy and to nurse the calf," Barre says. "It takes time to get back into condition."

Female orcas have somewhat similar patterns to humans. Females can start reproduction at age 15, be able to get pregnant until around age 40, and can live up to 80 or 90 years, Barre says.

Males don't live as long; their bodies call it quits at age 60 or 70.

The offspring stay with their moms their entire lives.

The male J1, for example, who's about 60 years old, still is with mom, J2, who is nearly 100, Barre says.

1 opmerking:

Anoniem zei
Deze reactie is verwijderd door een blogbeheerder.