An Unusual Sighting! North Yuba Naturalist [7/8]

By Katie O’Hara Kelly

This week my friend Judy and I went up to the high-elevation meadows I mentioned in my previous “Wet Meadows” blog. About two miles before our destination, a Sooty Grouse female hopped out onto the dirt road along with her two chicks! What a surprise!! The female quickly ran across the road and flew up into a nearby Douglas Fir tree. The two chicks crossed after her and disappeared into the bushes. We slowly got out of the car and looked for the

Sooty Grouse Female

female. We quickly spotted her fairly high up in the tree. To our utter amazement, we also spotted a big male in the same tree doing a full-on mating display for her! WOW!!!

The mating display went on for about two full minutes! The male inflated his warty-looking golden-yellow air sacs, raised up its bright-red crest feathers, spread its tail in a broad semi-circle, and paraded back and forth on a branch, while emitting a series of loud and low “hoots”. The female looked on from a lower branch while emitting a few whinny-like calls!!! We were entranced as we watched from 50 feet below!

Sooty Grouse Male

During mating season males sing almost continuously during the day and sometimes into the night! They sing to attract females and to warn off competing males from their territory. The sound is like no other birdsong. I think is sounds like a loud and low “galump, galump” mixed in with a throaty swallow! Definitely not your usual
owl “hoot”!

David Lucas describes it perfectly in the following quote from his book Sierra Nevada Birds. “…males give eerie, booming calls that resonate all day through the somber forests. Their calls are ventriloquial and deep in pitch, sounding somewhat like someone thumping on a waterlogged tub in the distance.”

At one point the two birds seemed to converge, but they were hidden by a tangle of branches so we don’t know if they mated. Apparently, a male Sooty Grouse will attempt to mate with any female coming into its territory, even females who already have chicks!!! Males mate with lots of females, but it is not known if females mate with more than one male.

After mating, the female alone makes a nest, incubates the eggs, and broods the young. The nest is just a shallow “scrape” on the ground either out in the open or under the cover of a log, stump, or shrub.

Sooty Grouse Chicks

They lay one clutch a year, containing 1-12 eggs. After 26 days of incubation, the eggs hatch. The chicks are born precocial, and leave the nest within 12-24 hours. The female will brood the chicks at night when they are small. For their first ten days chicks feed on insects, but then switch to a diet of flowers, leaves, berries, conifer needles, and seeds. The chicks stay with their mother until late summer or early fall. She doesn’t feed them but acts as a watchman/guard while they self-feed. In the winter adults and juveniles feed exclusively on conifer needles.

So that’s a brief synopsis of what I’ve learned about the Sooty Grouse! To see them in person was an amazing experience! Apparently it’s quite uncommon to witness a mating display! We will remember and treasure this incredible wild encounter forever!

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