This is the second and last in a series about hunting to save natural diversity.

Last week we explored a time when a herd of deer was cut in half one hunting season, yet returned to full strength within a year or two. Overpopulation of a native species or an invasive species can cause problems with native animal and plants.

Fish and Wildlife has a problem in San Juan and Island counties. Deer are over browsing native vegetation, which means less habitat for other species. This problem is a century old.

One species effected is the Island Marble butterfly, found nowhere except on San Juan Island. Thought to be extinct since 1908, the butterfly was re-discovered in San Juan Island National Historical Park in 1998.

The butterfly largely depends on tumble mustard. They lay their eggs on mustard flower buds. The newly hatched larvae depend on mustard blossoms and leaves for food.

Deer eat the mustard when other plants have been depleted and thereby threaten the butterflies with extinction.

Fish and Wildlife has come up with a solution: Use hunting as a tool to reduce deer populations. How will this be accomplished when much of the land involved is privately owned?

The exact details have not been explained to me, but this information was provided in a press release: “Landowners who participate may qualify for up to $1,000. Funds for the hunting access portion of this project come to Fish and Wildlife through the United States Farm Bill.”

The department cannot expect the funding to continue into future years, so the ability to pay landowners is for this fall’s deer season only.

Basin invasive species

Fish and Wildlife deals with Columbia Basin invasive species in different ways, mainly by reducing the population of the intrusive critter.

There may be several plants and animals considered undesirable. Two coming to mind are nonnative crawfish and the Eurasian collared dove.

Nonnative crawfish

No license is required to go after nonnative crawfish. The season is the first Monday in May through Oct. 31. There is no daily limit, size or sex. Must be kept in a separate container, from natives, and must be dead before being removed the immediate vicinity of water body.

Read the fishing regulations carefully, as there is a need to identify the native and nonnative species.

Eurasian collared dove

This bird is larger than a mourning dove and can be hunted year-round with a Washington hunting license. There is no limit on the Eurasian collared doves.

Hunters help control populations

Once again, hunters play a big part in the control of wildlife populations.