Floods Kill 150 Rare Columbia White-Tailed Deer Weakened By Winter, Deer Died Of Stress

Flooding in southwestern Washington last month contributed to the deaths of 150 Columbia white-tailed deer, one of the Northwest’s rarest animals.

The deer perished when the 5,500-acre Julia Butler Hanson Wildlife Refuge was inundated with 2 to 3 feet of water from the Columbia River, said Alan Clark, a biologist for the U.S. Fish and Wildlife Service.

The deer are classified as endangered under the U.S. Endangered Species Act.

Clark said the animals did not drown.

Rather, the flooding pushed many old and winter-weakened deer beyond their limits for endurance, he said.

“It was late winter and the worst possible time for something like that to happen,” Clark said.

“They are at their worst physical condition of the year. We estimate half the deer on the refuge died.”

The deer have been federally protected since 1974, and the lack of hunting has filled the herd with older animals.

Clark said many deer are 8 to 10 years old and afflicted by parasites. He said the stress of fleeing inundated home ranges and dodging flood waters was too much for many older animals.

“Only the strongest deer survived,” he said.

“There could be some potential benefits for the herd, assuming we don’t have another problem here.”

Biologists spotted 42 carcasses on the refuge’s Tenasillahe Island during a helicopter survey last week. Ten more deer were killed by vehicles on Washington 4 as the deer sought higher ground. Six others washed up on shores of the lower Columbia River.

The region’s largest population of Columbia white-tailed deer - more than 5,000 animals - roam the grassy hills of Oregon’s Douglas County and was untouched by the flooding.

Another 200 deer inhabit Puget Island, upstream of the refuge, and 200 live on the Oregon shore near Westport, west of Clatskanie.

They survived the flooding quite well, Clark said.

Columbia white-tailed deer once ranged from The Dalles, Ore., to the Pacific Ocean and from Puget Sound south to Oregon’s Umpqua River.

Development and hunting diminished their numbers to two herds. In the last 20 years, they have rebounded dramatically.

The Fish and Wildlife Service is considering removing the animal from the endangered species list or reclassifying it as threatened.

Clark said flood losses probably would not change plans to ease protection for the deer.

He said the populations are still above standards set in a federal recovery plan.

“They could bounce back in a couple of years,” he said.