GOLDEN EAGLES OF WASHINGTON – POPULATION STATUS, ECOLOGY, & THREATS
Jim Watson, raptor researcher for the Washington Department of Fish and Wildlife, educated ABCers on November 29, 2016, about one of our most iconic avian raptors, the Golden Eagle.
Jim Watson at ABC, Nov 29, 2016
First Jim covered the lore of this worldwide species, covering the gamut from love to hate, victim to villain. Myths about Goldens carrying off humans and large livestock much heavier than the their carrying capacity were dispelled, as well as other beliefs. Although they can kill large prey, they can’t carry it off. That story of the eagle taking all day to kill one weakened pronghorn was especially interesting.
Golden Eagle attack on Pronghorn
Distribution across our state was interesting, since most of us only see this bird in eastern Washington. The Olympics and San Juans have continuing small populations, though seldom seen.
Using much of his own original research, Jim covered the alarming decreases in populations, especially in adult raptors in a species that takes at least 5 years to reach reproductive age. Official population statistics treat immatures and adults the same, so can be misleading about the condition of the species since they treat “normal” losses of young birds as equivalent to the dire losses of successful adults. With populations at historic lows in Washington, Jim had numbers for us on threats: Unspecified trauma (23%), lead poisoning (18%), electrocution (10%, perhaps lessening), wind turbines (8%, definitely increasing), etc. Shooting deaths still happen, but are slowly decreasing (3%). Jim gave actual mechanisms of lead poisoning on the isotope level for both direct ingestion and ingestion of poisoned prey. Wildfire has not been proven to significantly impact the birds, perhaps actually improves their ability to find prey sometimes, although this manifestation of a warming world needs to be watched.
Golden Eagle mortality in WA shrubsteppe-grasslands
The wind turbine story is disheartening, as wind farms tend to be erected along the same air current corridors that raptors use for lift, migration, etc. Many wind farms were licensed before there was any research available. Most licenses are for 30 years, so in Washington a lot more birds will die. There is much evidence of wind farm people downplaying raptor deaths, as well as passerine and bat mortality. Jim has been involved in much of the original research including 3 papers which studied 17 Golden Eagles in Washington from 2004 to 2013 near wind turbines. Regulations about placement of turbines near known nests fail to take into account the slopes and ridges that eagles need to fly, which we were able to enjoy in 3-D animations that Jim’s team had made. This topic really caught the attention of the ABCers, and there was some discussion of European model turbines which are much more benign and that the current industry in the U.S. may be too entrenched in its own more destructive models.
WDFW studies of Golden Eagles vs Wind Turbines
It was interesting to find that a few of these immature birds do travel, some south, some north, but usually do return to their birthplaces to settle down and raise their families. The adults in Washington are sedentary, however. Goldens have proved to be adaptable as to diet in this state where their favorite food, rabbit, has dwindled. Marmots are now 23% of their diet, deer fawns 13%, upland birds 12%, and coyote pups 8%.
Jim finished up with a fun “quiz” to help dispel the gloom and doom about these beautiful birds.
Golden Eagle Quiz – Fact or Fiction?
Jim also recommended the Smartphone app, Raptor ID, from Hawkwatch International. You can get it for iPhone or iPad from the iTunes marketplace and now for Android from Google Play. $9.99.
Jim Watson of WDFW at ABC with Cool Raptors fans (the Willettes)
Thanks, Jim Watson, for sharing your knowledge with us and leaving us hungering for more. It’s reassuring to us to know that people like you are out there actually working on the problems we know exist.
