By Dennis Olson
In the early autumn I lunched above timberline in Glacier National Park with a small group of hikers, overlooking the vast prairie lands to the west. The wind was howling through a saddle and we were sheltered in the upper reaches of a cliff dropping thousands of feet to the valley floor.
A flock of about 20 Gray-crowned rosy finches flew in against the wind, silvery under-wings flashing, following a sweeping curve. Suddenly they turned on a dime, as they say, and dropped down to our right. When they landed, most of them simply disappeared into the rocks, but the ones we could see sat straight upright and froze, with their crowns ruffled.
A flash of motion to our left revealed the reason for their instant change of plans. A prairie falcon lasered into the flock, and a few panicked and scattered. They all disappeared over the saddle behind us, and the hidden finches rose as a smaller group and flew over to us, a bit curious about the new, colorful visitors, I suspect. Just day in the life of arguably the toughest bird in North America.
The Gray-crowned variety we have here has a medium gray cap and temples, mostly brown body with a rose-colored wash on the wing primaries and the back half of their body – top and bottom. The males have a black forehead and neck and, like a lot of birds, their colors get brighter in the breeding season. Coastal (called “Hepburn’s” mostly breeding in the Cascades) subspecies have a gray cheek as well, and frequently join our local rosy finches in winter flocks.
They have quite long wings for a finch, and that likely helps them in the fierce alpine winds and in evasive maneuvering from predators, as we witnessed.
Two other species (or subspecies – still in debate) of rosy finches, the Brown-capped (breeding mostly in the Colorado Rockies tundra) and the Black rosy finch (breeding from Southwestern Montana to the Utah Uintas) flock together with the Gray-crowned in winter, but the Brown-capped rarely make it this far north. Sometimes the flocks number in the thousands, and they are very nomadic, in wide-open areas, venturing out onto the western prairies from the Dakotas to New Mexico. There is a rosy finch website (www.rosyfinch.com) and an observatory at Sandia Crest, just outside of Albuquerque for a growing rosy finch subculture. Who’d-a-thought?
No bird lives and breeds higher than the rosy finches. They are strictly alpine tundra birds, and they often begin building their nests in the first patches of snow-free ground in the June alpine “spring”. They seem to like cliff crevices near moving water for the nest site, and the females incubate eggs into July.
Gray-crowned rosy finches have an odd gender ratio – six males to every female on the Coast Ranges and about four to one here in Northwest Montana. Researchers suspect that female mortality during the first year is the primary reason, although they have not identified why females are so vulnerable. Under usual conditions, bird males are often brighter and show off more, making them the most vulnerable to predators. Biological principles would suggest that females would be more “valuable” in the scheme of things and that usually holds true, with camouflaged cryptic coloring helping them out. Individual males, under some breeding strategies, can spread their genes around to many females. Not so with rosy finches, for so far unknown reasons.
Of course, the gender ratio causes a chaotic and competitive breeding season, which often commences in late January on wintering grounds. Males puff their plumage to intimidate, and if they land after chasing another male away, they hunch their backs and puff their neck and shoulder feathers, in “I showed you!” body-builder style. This heavy male competition may be responsible for the scattered locations of nest sites among the rosy finches, but the perhaps accidental result is more area to forage for the pair.
When females are around, their plumage is sleeked and they fan their wings, droop and spread them, and sometimes elevate one wing and hop in an off-balanced (Saturday Night Fever?) sort of way.
They eat mostly seeds, but when they are feeding young, the insect proportion of their diets rises dramatically – probably because the nestlings require higher-protein diets. Like some of the Corvids (Gray jay, Clark’s nutcracker), Pine grosbeaks and some other finches, the male and female develop gular, or “buccal” pouches in their lower cheek area to carry loads of food to the nest.
Their breeding sites are remote, and they have very little contact with humans, for the most part. For that reason (to the delight of photographers and birders), they seem to be almost fearless about us, often landing within a few feet of us. Bird banders actually “herd” them into waiting mist-nets.
Gray-crowned rosy finches are “tough” because of where they live during most of the year. But, despite their durability, they are, like most species, vulnerable to habitat loss. In most cases the habitat loss of other birds is incremental – a housing development or clear-cut at a time, but climate change poses special and worldwide problems for high altitude birds like the rosy finch. Because of the special geometry of mountaintops, a rising tree line, due to a warming climate, shrinks their habitat (1) everywhere, and (2) exponentially. We would do well to monitor the highest and toughest inhabitants very carefully – perhaps in our own best interest.