2008年6月29日星期日

Fastest Sea Bird


Frigate birdsare not only the fastest, but also the most acrobatic ocean-going birds. Able to fly as fast as 93 miles per hour, they can steal food from other birds while in flight, and snatch flying fish right out of the air .
Specialized for flight, they are unable to land on the water and are awkward on land. They build crude nests under low bushes , and lay only one egg at a time.
The male frigate bird has a bright red pouch on the underside of his neck, which he can inflate to attract females. When inflated, the pouch can be seen for great distance.

2008年6月16日星期一

Wild parakeets splash color on Seattle's gray skies


They fly through the park shrieking and squawking, their chartreuse feathers flashing. Nobody in Florida, Mexico or another tropical place would give them a second look.
But under the Pacific Northwest's lead-gray skies, a feral flock of colorful parakeets flies around Seward Park, a 300-acre island of green in southeast Seattle where they have taken up residence.
Needless to say, they're not natives.
"They're such an anomaly here. You can have the quietest, most peaceful morning, and suddenly they're squawking and talking," said Christina Gallegos, a Seattle Parks and Recreation Department naturalist at Seward Park, who estimated the flock to be 20 to 24 strong.
The birds first showed up in Seward Park some time in the early 1990s. They're generally agreed to be crimson-fronted parakeets, native to Central America. Marked with red patches on their faces, the green parakeets are bigger than the typical pet budgie most people are familiar with.
"For us, it's just fun," said avian devotee Fred Bird, a past president of the Washington Ornithological Society who studies the little band of parakeets.
The flock usually call Seward Park home but have been known to migrate 5 miles north to another park in Seattle for part of the year.
The flock of parakeets undoubtedly began as pets who escaped from their owners, Bird said. Such escapees are relatively common wherever pet birds are kept.
"But usually, they don't live that long," Bird said.
These parakeets seem to have beaten the odds for several reasons: They live in noisy flocks, which helps them stand guard against enemies who would eat them, such as hawks, and they can tolerate a wide range of food.
"They're very opportunistic," Bird said. "They're omnivores, and can eat anything, cedar tree seeds, fruit, things like that, apples."
Changing weather patterns and warmer temperatures in the region have likely helped the tropical birds survive, Bird said..
"The climate is comfortable for them," Bird said. "Whether they could have survived here 100 years ago when the climate was substantially cooler, I don't know."
Certainly, they're not the only exotic bird escapees living wild in the Northwest. Vancouver, Canada is home to some well-known Crested Mynahs.
Gayle Peters, the owner of Just Parrots, a shop near Seward Park, said the feral parakeets are reasonably intelligent birds, which likely helps them survive an alien environment.
"We don't have extreme temperatures here, extreme hot or cold," Peters said. "In winters, they're probably in trees, nesting together. They do adapt very well."
Birders in the area say that the parakeets will visit home bird feeders from time to time.
"I would think in this area, they would eat anything and everything they could find," Peters said.

2008年6月7日星期六

Is Your Sheep Stressed? Just Ask It


Stressed-out sheep bleat out their anguish, U.S. researchers reported. They found that,like humans, sheep communicate stress by changing the timbre of their voices. Mark Feinstein of Hampshire College in Amherst,Massachusetts, said his findings could help farmers and, of course, the sheep they herd. An expert in bioacoustics*, Feinstein did his work at Teagasc, an Irish government agricultural research organization. He isolated sheep and separated  lambs from their mothers as part of his experiments ?then recorded their bleats. His recordings suggest that sheep express stress by altering the timbre of their vocalizations, or the overall quality of sounds, rather than by changing pitch or loudness. Stress can be measured by taking an animal's blood, but it would be much easier, cheaper and, yes, less stressful to simply listen, Feinstein said.