Our Window on Nature

Don’t even try to imagine lying down on an ant hill. If you think ants should be avoided, it’s a good thing you’re not a bird. Many species of birds occasionally seek out ants for what may be a beneficial procedure – it is called “anting.” They will plop down on an ant hill and spread their wings. The question is, “Why do they do it?”

Some scientists suggest that the ant’s secretions help kill parasites in the bird’s feathers, an example of Mother Nature’s insecticide. Others think that, since anting occurs more often during the molting season, birds and ants get together because those ant secretions help to sooth the skin irritation caused when emerging feathers break through the skin. (They can’t be certain, however, since birds are also known to rub their feathers with moth balls, cigarette butts, and other odd objects.)

Sometimes the birds, instead of spreading their wings and lying on an ant hill, will pick up individual ants and rub them on their feathers. Perhaps the answer lies in the scientific name for ants, Formicidae. Ants produce an excretion that contains formic acid, and it acts as an insecticide in their nests, protecting them from parasites.

Whatever the reason, if you see a bird consorting with ants without eating them, it may just be performing a type of bird hygiene. Bird watching is much more than identifying birds – solving the puzzles of their behavior can be a constant challenge.

October is a month when the world is full of young spiders leaving home. Wisps of silken thread fill the air. Sunlight glints off gossamer parachutes following the whims of the wind. Young spiders break their ties with home by flying away on wings they build themselves.

Most of the 3,000 kinds of spiders in the United States have three things in common: eight eyes, eight legs, and six spinnerets that create the strongest natural fiber known - silk. Spiders might replace silkworms except for one problem. Silkworms eat plants and are easy to raise in captivity. But when you try to raise spiders in confined spaces, they have a strong tendency to eat each other. (Read the rest …)

Here’s a shocker. The Sooty Shearwater, an 18” long seabird, migrates up to 40,000 miles a year, along a route that crosses the Pacific Ocean.

Working down in New Zealand, a crew of UC Santa Cruz biologists electronically tagged the legs of 33 shearwaters in early 2005. They recovered working tags when over half of them returned, carrying a record of where each bird flew.

Leaving in April, the Shearwaters crossed the Pacific Ocean (about 500 miles), pausing long enough to grab enough fish, squid, and krill to keep them alive. Part of their food they could gather from the ocean surface – to get the rest, they had to dive up to 200 feet into the water!

Sooner or later all the tagged birds landed to spend their winter in one of three areas - off the coast of Japan, Alaska, or California.

There was no traveling from place to place – each bird started south from its own wintering area. And all the tagged Shearwaters crossed the equator within a 10-day period in October. Is that impressive, or what!