Raised by Others, Birds Use Code to Find Their Kind

Publication: National Geographic News   Date: October 15, 2004   View Article

Reproduction success hinges on several factors, not least of which is finding a mate within the same species. While this is an easy enough task for humans, it is seemingly more complicated for brown-headed cowbirds (Molothrus ater).

The animals are one of the more than 90 known parasitic bird species, so called because they lay their eggs in the nests of other bird species and leave the chick-rearing to other parents.

Cicada Swarm Proves a Feast for Predators

Publication: National Geographic News   Date: May 24, 2004   View Article

A female thumb-size wasp known as a cicada killer might sound like the perfect predator to combat the billions of periodical cicadas swarming much of the eastern U.S. this May and June.

The wasp (Sphecius speciosus) paralyzes a cicada with her sting, carries it back to a chamber in her underground burrow, lays an egg on it, and seals the chamber. A few days later the egg hatches and the wasp larva eats the cicada alive.

Scientists Discovery Mystery Krill Killer

Publication: National Geographic News   Date: July 17, 2003   View Article

Scientists have discovered a tiny, one-celled parasite that causes a grisly and fatal infection in krill. Masses of the parasite grow inside the krill, eat its organs, divide, and then burst out of their host’s dead body in search of new victims.

The discovery sheds more light on a key player in ocean’s food chain. Scientists previously thought most animals like krill were either eaten by larger predators or simply starved to death. The find shows that parasites also play an important role.

When Mistletoe Attacks: Investigating a Forest Parasite

Publication: National Geographic News   Date: December 24, 2002   View Article

It’s that time of the year when a white-berried, leafy green plant hangs above doorways around the world and provokes lovers and serendipitous strangers to share a kiss.

There are more than 1,300 species of mistletoe, including the two varieties popularly hung as a lure to sweethearts. All species can grow as parasites on trees and shrubs, stealing their food and water.

© 2008-2010 Collected Writings By John Roach