Reproduction

Ancient Flying Reptiles Likely Had Sex As Youths

Publication: National Geographic News   Date: March 12, 2008   View Article

Pterosaurs, like their dinosaur relatives, didn’t wait until they were fully grown to have sex, a new study suggests.

Big Dinosaurs Had “Teen Sex”

Publication: National Geographic News   Date: January 14, 2008   View Article

Big dinosaurs, like humans, reached sexual maturity during the messy growth spurts of adolescence, according to a new study.

The reproductive strategy of dinosaurs was unlike that of their reptilian ancestors or their bird descendants, the study concludes.

Big Testes or Big Horns? It’s One or the Other for Male Beetles

Publication: National Geographic News   Date: October 16, 2007   View Article

Big horns or big testes? It’s one or the other for maturing male dung beetles looking to ensure reproductive success, a new study suggests.

The finding confirms a theory that beetles have evolved in response to trade-offs between the two traits.

Males of most species either get weapons to guard their access to females or a greater shot at successful insemination when they mate.

“Toad Tunnels” Built to Help Amphibians Cross Roads

Publication: National Geographic News   Date: April 15, 2005   View Article

Later this month, when the next warm, wet rain soaks the northeastern U.S., it will signal thousands of American toads to hop to their breeding ponds. To get there, many of the toads will cross roads that slice through their habitat.

John Serrao, a naturalist in Pennsylvania’s Pocono Mountains, says that unless Buffo americanus and other amphibians get help crossing the road, their local populations will disappear.

Dinosaur Eggs Discovered Inside Mother – A First

Publication: National Geographic News   Date: April 14, 2005   View Article

Scientists have discovered for the first time a dinosaur with shelled eggs inside her belly. The find yields insight into how dinosaurs made babies and supports the theory that modern birds and dinosaurs are close relatives.

“I don’t think too many people had expected [us] to discover a specimen that actually had eggs inside its body. It’s something we wanted to have, but it’s very surprising we actually got it,” said Tamaki Sato, a paleontologist at the Canadian Museum of Nature in Ottawa.

Vanishing Borneo Pheasants Look Great but Won’t Mate

Publication: National Geographic News   Date: April 6, 2005   View Article

In zoos Bulwer’s pheasants’ stunning looks elicit oohs and ahhs from visitors. But the birds themselves seem to find each other somewhat less than appealing.

As a result, they’re producing no offspring—a concern to conservationists who hope to build up the species’s numbers in captivity as they decline in the wild.

Does Extinction Loom for Australia’s Wild Dingoes?

Publication: National Geographic News   Date: December 10, 2004   View Article

Wild populations of Australian dingoes may go extinct within 50 years unless steps are taken to prevent crossbreeding with domestic dogs, scientists and conservationists say.

Like North American gray wolves, dingoes maintain strong social structures. Genetic evidence suggests Australian dingoes descended from a small group of ancient dogs—perhaps a single pregnant female—brought to Australia from Indonesia about 5,000 years ago.

© 2008-2010 Collected Writings By John Roach