Report: Oregon's wolf population growth 'weak' in 2016
SALEM — Oregon had only two more confirmed wolves at the end of 2016 than it did the year before, a growth rate the state wildlife department described as "weak" and a sharp drop from the 27 to 36 percent growth rates the previous three years.
The state visually documented 112 wolves at the end of 2016, according to ODFW's annual report. At the end of 2015, Oregon had 110 confirmed wolves.
Department spokeswoman Michelle Dennehy acknowledged the low population gain but said ODFW is not concerned.
"It's one year, one data point, based on what we saw," she said. "It's not a trend of growth rates decreasing."
Russ Morgan, ODFW's wolf program manager, said the weak population gain is a "byproduct of our counting methodology," in which wolves aren't counted without a confirmed sighting. He called that method "very conservative."
"You get what you get," he said. "It's not the actual population, but the actual minimum. You know there can't be fewer."
In the future, the department may rely more on pack counts than on breeding pair counts, he said, and include population estimates based on known birth rates and other information.
Oregon Wild, a conservation group long involved in wolf management issues, holds an opposite view.
In a prepared statement, Conservation Director Steve Pedery noted the report shows population growth is "stalled" and the number of breeding pairs and packs declined from 2015.
"This raises troubling questions about ODFW's continuing drive to pursue hunting and trapping," Pedery said. Oregon Wild and other activists believe the state may ultimately allow hunting of wolves, as it does cougars and bears.
The ODFW report lists several reasons why the wolf count is low, including disease.
Blood samples taken from wolves commonly show high rates of exposure to parvovirus; the same is true of domestic dogs, said Morgan, the ODFW wolf program manager. But in 2016, 68 percent of samples taken were positive for a specific marker that shows active or recent infections. Parvovirus can increase pup mortality rates, which would affect short-term population growth rates. However, the report indicates the finding is not expected to impact the wolf population long-term.
Another possibility is what the report calls known or unknown "human-caused" mortality. Seven wolves are known to have been killed during the year, including four by ODFW itself. The department shot members of the Imnaha Pack, including longtime alpha wolf OR-4, in March 2016. The wolves had attacked and eaten or injured calves and sheep in private pastures five times that spring.
Meanwhile, Oregon State Police continue to investigate two other wolf killings, and one wolf was legally shot by a herder when it was caught in the act attacking livestock.
Other reasons for the small population gain may include "decreased breeder success, diseases affecting pup survival, and dispersal out-of-state," according to the report.
Dennehy, the ODFW spokeswoman, said the 2016 count was hindered by severe winter weather that grounded observation flights at times. Wolves may have been present but not counted, the ODFW report says.
Also in the report:
• Depredation investigations confirmed wolves killed 11 calves, seven sheep, one goat and a llama in 2016, compared to three calves, 10 sheep and a herding or guard dog in 2015.
• The state distributed $129,664 to 13 counties to compensate producers for dead, injured or missing livestock and to pay for prevention and deterrence programs. About $5,000 of the amount was for grant administration.
The population numbers are part of a draft wolf management plan that will be considered by the ODFW Commission at two public hearings this spring: April 21 in Klamath Falls and May 19 in Portland.