Across the state, people feed wild animals, giving themselves the satisfaction that they are helping the creatures and getting to see them up close. But in many cases they may be endangering the animals — and in some cases having other unexpected consequences.

In Koke'e, on Kaua'i, fed nene geese have tended to take up residence in parking lots, where they are are risk of being killed in traffic.

At Hanauma Bay on O'ahu, authorities believed that the feeding of fish caused the increase in numbers of the fish that took the food, at the expense of those that didn't. And the expanded fish populations tended to overgraze the reefs when the fish food wasn't present.

In various parts of the state, residents have engaged in feeding birds, feral cats, monk seals and other species.

It's not just a Hawai'i problem. Australian authorities worry about feeding of kangaroos. In Minnesota, there are problems with fed foxes. In some Asian countries, it's fed monkeys.

The reasons not to do it are numerous, wildlife officials say. Some reasons are clear — like the problem of fed bears becoming aggressive — and some are less obvious.

The National Park Service's Denali National Park in Alaska, at its Web site at www.nps.gov/dena/naturescience/keepwildlifewild.htm, cites a range of species with which feeding problems exist and reasons why they shouldn't be fed.

The park service says feedings can be unhealthy for animals with specialized diets. Feeding also can change animals' behavior, causing them to lose their fear of humans. It can unnaturally increase populations of animals in specific locations, creating a range of issues. Risks include disease from animal waste, problems with animals that no longer fear humans and cars, and the effects of the larger populations on the neighborhood, such as the fish at Hanauma and a fed flock of birds pillaging a neighbor's garden.

Another issue is that the targeted fed animals aren't always the only animal fed. For instance, a rat might finish up the cat food after the cats are gone — and go off to produce more rats. A flock of mynah birds might come by for a meal left by a feral dog. Chickens and doves might flock around grain left for a cute flock of mannikins and Java sparrows.

In the example of pigeons, fed pigeons become large flocks of pigeons. Flocks of pigeons make messes and anger the neighbors. And soon there are programs to cull the pigeon population. Fed pigeons, thus, can become dead pigeons.

If you have a question or concern about the Hawaiian environment, drop a note to Jan TenBruggencate at P.O. Box 524, Lihu'e, HI 96766 or jant@honoluluadvertiser.com. Or call him at (808) 245-3074.