GET BREAKING NEWS IN YOUR BROWSER. CLICK HERE TO TURN ON NOTIFICATIONS.

X

This rare leucistic (mostly without pigment) gray-crowned rosy finch munches on ponderosa pine seeds on Mount Sanitas in December. (Joel Such courtesy photo)
PUBLISHED: | UPDATED:

“Where have our backyard birds gone?” Probably up to the foothills, where a trifecta of conifer cone crops has provided a cold-weather banquet.

When we saw clouds of yellow pollen sweeping across the Flatirons in June of 2018, we knew that within 18 months we’d see the ponderosa pines loaded with plump cones.

But this year that bumper cone crop, something that occurs about once every five years, coincides with lingering cone crops for Colorado blue spruces and Douglas-firs as well. During December’s Boulder Audubon Christmas bird count, observers reported massive flocks of seedeaters. Some may have flown from as far away as the northern Rockies to feast on the protein-rich seeds.

Red crossbills fly hundreds of miles seeking out bumper conifer cone crops. They insert their crossover bills between the cone scales, crunch down, then extract the seeds with their tongues. (Stephen Jones courtesy photo)

On the flanks of Eldorado Mountain, Steve’s team reported Christmas count record numbers of red-breasted nuthatches and red crossbills. The crossbills dangled upside-down from the seed-laden cones, using their cross-over beaks to pry open the scales and their tongues to extract the seeds.

On Mount Sanitas, Joel Such and Topi Martines watched 350 gray-crowned rosy finches, summer breeders in the alpine tundra, extracting seeds from pine cones that had fallen to the ground. Rosy finches are rarely seen in Boulder’s foothills, especially in such massive concentrations.

The predators are out as well. On Eldorado Mountain we watched a bald eagle chasing Steller’s jays through the forest and a sharp-shinned hawk diving on the flocks of feasting finches. The forest came to life with chirps, cries, and soft warbles.

By late January things had settled down a bit, but the cones are still abundant, and if you go walking on any of the trails in the foothills this month and stop, you’re likely to hear the calls of feeding seedeaters.

We find the loud, “kip-kip-kip” calls of the red crossbills the most distinctive as they fly above the pines before landing on a cone-laden tree. Every once in awhile, one of the crossbills issues a surprisingly melodic warble, a sure sign that it is considering nesting.

These opportunistic seed specialists will nest during any month of the year so long as there are plenty of cones around.

Other sounds to listen for are the “peep-peeps” of pygmy nuthatches, nasal “ank-ank-ank” calls of red-breasted nuthatches, and “dee-dee-dees” of mountain chickadees. A loud, woodpecker-like “cack-cack-cack” signals a Cooper’s hawk zeroing in on a plump, seed-sated songbird.

Hairy and downy woodpeckers accompany the songbird flocks, using the chickadees and nuthatches as sentries to warn of approaching predators. In turn, the woodpeckers hammer away at the soft bark of dying trees, exposing caterpillars and beetles for the songbirds to pick off one by one.

Squirrels seem especially active as well. We’ve been seeing jet-black Abert’s squirrels scurrying head-first down ponderosa trunks with plump cones in their mouths and querulous pine squirrels dropping recently-clipped Douglas-fir cones on the heads of unsuspecting hikers.

Things will settle down within a few months. But early February remains a great time to head up to Green Mountain, Eldorado Mountain, or Walker Ranch to experience the dynamics of periodic bumper seed crops, a reproductive strategy that benefits bird populations while ensuring that a few ripe seeds will drop out of their beaks, spreading conifer genes across the landscape.

Stephen Jones and Ruth Carol Cushman are authors of Wild Boulder County and The North American Prairie.

Other February events

  • Golden eagles lay their eggs in cliff nests in the foothills; and bald eagles in giant stick nests in cottonwoods on the plains.
  • Early Easter daisies bloom on bare shales north of Boulder.
  • Coyotes dig out their dens and prepare for the arrival of pups.

blog comments powered by Disqus