CORVALLIS - Gardeners should be glad to see snakes around the garden, according to Oregon State University snake expert Bob Mason. These much-maligned reptiles consume garden pests including slugs, grubs, mice, voles and rats. But he knows that snakes startle or terrify many folks.
"The vast majority of snakes in Oregon are very beneficial," said Mason, a professor of zoology at OSU. "Some, like garter snakes, eat slugs. Others, like the sharp-tailed snake, eat slugs and grubs, including the pest Japanese beetle grub. Rubber boas specialize in eating mice and voles, going down their tunnels after them.
"Gopher snakes eat mice and rats," he added. "I've even had farmers call me up and ask if I had any snakes available."
Garter snakes are the type of snake most often seen by urban and suburban gardeners, said Mason. Two species of garter snakes are commonly found throughout much of Oregon, except the mountains: the abundant western terrestrial garter snake and the common garter snake. In western Oregon, a third species is also present, the northwestern garter snake. An aquatic garter snake resides in southwestern Oregon.
Garter snakes generally breed in the spring and give birth to live young (they don't lay eggs) in the late summer or fall. Often, young are not seen until the following spring, after they emerge from hibernation after their first winter. "Most young garter snakes don't survive into adulthood," said Mason. "They are killed off by predators, cars and lawnmowers."
To make your property garter snake friendly, Mason advises:
- Walk your lawn before you mow it to scare the snakes into hiding. Lawn mowers are deadly to snakes because they can't hear like we do. Rather, they feel vibrations.
- Provide habitat for snakes if you have room. Old plywood or corrugated metal roofing left loosely on the ground in an out-of-the-way place on your property provides hiding and nesting places for slithering creatures. Old stumps and large rocks also make good snake habitat.
The western rattlesnake, the only species of truly venomous snake native to Oregon, feeds on mice, rats and other smaller animals. Rattlesnakes were once more commonly found on both the west and east sides of the Cascades. But they have all but been killed off on the west side, said Mason.
"Rattlesnakes are part of the natural environment," said Mason. "They should be respected. When you encounter one in its natural environment, away from homes and children, stay away and leave the snake alone. They are quite reclusive and rarely aggressive."
"Rattlers are rare in northwestern Oregon," he said. "They were shot out 100 years ago by early settlers. There are a few dens left, but only in really isolated places." In southern and eastern Oregon, however, rattlers are more common, he said. Caution should be exercised in rattlesnake country.
Mason recommends the photo-illustrated book, "Reptiles of Washington and Oregon," published by the Seattle Audubon Society and edited by Robert M. Storm and William P. Leonard.