Ravens are opportunistic feeders that will eat sage grouse eggs and chicks.

Sage grouse have been struggling in Baker County over the past 20 years or so. The data are clear on that point, based on surveys done by the Oregon Department of Fish and Wildlife.

The population in the chicken-size bird’s primary range east and north of Baker City, which covers about 336,000 acres, declined by an estimated 73% between 2006 and 2016.

What’s not so certain is which factors pose the biggest threat to sage grouse, which have been a candidate for protection under the Endangered Species Act for more than a decade.

(The U.S. Fish and Wildlife Service declined in 2015 to add the bird to the endangered species list.)

According to a sage grouse threat reduction plan from 2017, written by biologists from ODFW and the federal Fish and Wildlife Service, several things can contribute to shrinking sage grouse numbers.

The list includes livestock grazing, invasive weeds, West Nile virus, off-road vehicles and other recreation, wildfires and home construction.

Although the 2017 plan doesn’t estimate the effects of each type of threat, they are given a priority for addressing. Among the high priorities are predation, recreation, noxious weeds and other invasive plants, habitat fragmentation, improper grazing, wildfires and human development, including power lines and other structures.

The biggest likely factor in predation, according to the report, is ravens.

Based on surveys from 2016-19, the density of ravens in sage grouse habitat in Baker County exceeded levels that researchers in Nevada concluded can cause sage grouse populations to drop.

Ravens eat sage grouse eggs and chicks. Ravens take advantage of human activities, too, using fences, power poles and other structures for nests, and foraging on animals killed by cars on highways and other roads.

Based on the data, ODFW applied for, and in 2021 received, a permit from the U.S. Fish and Wildlife Service allowing the state agency to remove raven nests, and kill ravens, over four years.

The permit was necessary because ravens, unlike sage grouse, are federally protected (although not by the Endangered Species Act; ravens are protected by the 1918 federal Migratory Bird Act).

The four-year experiment is a reasonable step to try to determine, based on local, relevant data, what role ravens are actually playing in the sage grouse population decline.

There’s no evidence that the experiment, which limits the number of ravens that can be kiiled to 800 (an estimated 49 were killed last year, the first year in which killing birds, in addition to destroying nests, was allowed by the permit), will threaten the local raven population.

And the permit requires ODFW and the federal Wildlife Services agency, whose personnel are authorized to kill ravens with poisoned chicken eggs and meat, or by shooting the birds, to take precautions to reduce the risk of harming other wildlife (the poison used is especially toxic to ravens and other corvids, which include jays, magpies and crows).

ODFW should publicly release its findings about the potential benefit to sage grouse, even the preliminary version, as soon as the data are available.