Quantcast
Channel: Deccan Herald - Supplements
Viewing all articles
Browse latest Browse all 37602

SNIPPETS

$
0
0
Fairywren's password call

Some species of cuckoo are known as brood parasites for their tactic of laying their eggs in other species' nests so those birds can care for the cuckoos' young. Now scientists have discovered that an Australian bird called the fairywren has evolved a way around this tactic: The mothers teach their unborn chicks a unique begging call - a sort of password. "We call this an incubation call," said Mark Hauber, an animal behaviorist at Hunter College at the City University of New York and an author of the study, which appears in the journal Current Biology. "The more times the mother calls, the better the mimicry of the chicks." The teaching begins a few days before the birds hatch. And while "the cuckoo chick is very adaptable and tries out many begging calls until it sounds similar to the fairywren," Hauber said, it also has a shorter incubation period. So it hatches several days before fairywren chicks, leaving it little time to practise and perfect the passwordlike call of the fairywren mother. Generally, when a cuckoo hatches it throws out the other eggs in the nest. hen a mother does not hear her unique call from her babies, she abandons the nest. Male fairywrens help their mates care for their young, so the mother teaches her mate and any other helpers the password through a special song.

A prickly dino before triceratops

Scientists in Alberta have identified a new type of horned dinosaur that looked like triceratops but lived 15 million years earlier. Called xenoceratops foremostensis, it was a two-ton vegetarian that flourished 80 million years ago, making it the oldest known large-bodied horned dinosaur to be found in Canada. "This guy was the size of a large bull, with two big brow horns over its eyes and a big shield off the back of its skull," said Michael Ryan, head of vertebrate paleontology at the Cleveland Museum of Natural History and an author of a study describing the species in The Canadian Journal of Earth Sciences. Fossils of xenoceratops, first collected in 1958, were left unidentified at the Canadian Museum of Nature in Ottawa. Most known dinosaurs from Alberta were found farther north, in Dinosaur Provincial Park and Drumheller. The dinosaurs to the south, like xenoceratops, lived at least 15 million years earlier than those in the north, Ryan said.


Viewing all articles
Browse latest Browse all 37602

Trending Articles