Sunday, March 15, 2015

An Arctic Visitor: Common Redpoll plus Horned Lark

[DNR Point, MI. March 2015]

The global family of true finches, Fringillidae, includes species known commonly not only as finches but also honeycreepers, grosbeaks, siskins, euphonias, crossbills, and redpolls. It would be no exaggeration to suggest that our avifauna has been immeasurably enriched by the presence of these distinctive seed-eating birds that have been so generously bequeathed to the American continent by the evolutionary forces of Nature.

Indeed, in this blogger's own avian wanderings, a number of fascinating finch species such as Cassin's Finch, House Finch, Red Crossbill, Pine Siskin, Grey-crowned Rosy-finch, Brown-capped Rosy-finch, Black Rosy-finch, American Goldfinch, Lesser Goldfinch and Antillean Euphonia have all been encountered in the field and subsequently profiled within the modest confines of this very blog.

However, one finch species, the Common Redpoll (or, Fri.com.rp in trinomial shortform) has long been on this blogger's "most wanted" list; long enough that its position on this list threatened to acquire a sense of despondent permanency.  A condition, no doubt, due to the fact that this tiny finch of the high Arctic is an unpredictable visitor to temperate North America in Winter and, while reported annually in Michigan, it had thus far proved to be remarkably resistant to attempts at photographic observation.

Thus, when temperatures in early March crossed boldly into the balmy 40's (on the Fahrenheit scale), it afforded a perfect excuse to venture for birding opportunities at DNR Point (Department of Natural Resources) in Harrison Township on the shores of Lake St. Clair.

Common Redpoll seen at DNR Point
Breeding in the high arctic tundra, these hardy finches are known to withstand temperatures down to 65 Fahrenheit below zero and tunnel themselves into snow for warmth.

Common Redpoll seen at DNR Point
Thriving in the tens of millions in the circumpolar regions of the world, Redpolls are truly "global citizens" -- birds banded in Michigan have been sighted in Siberia; and, those in Belgium have been seen in China!

Common Redpoll seen at DNR Point
The winter range of com.rp is highly variable -- they can winter as far North as Northern Canada and as far South as the Central US.

Common Redpoll seen at DNR Point
These voracious seed eaters were seen working the dessicated shrubbery on the edges -- they are known to consume up to 40% of their body mass every day.

Common Redpoll seen at DNR Point
Identification of these finches should be fairly straightforward -- similar species such as Pine Siskin can be easily disambiguated thanks to the striking red crown patch; however, the much rarer Hoary Redpoll (Fri.hoa.rp) is a tougher candidate to eliminate. The Hoary looks almost identical; the differences boiling down to the paler, less-streaky look of the Hoary Redpoll vs. the Common (analogous to Nelson's vs. Saltmarsh Sparrow).

Common Redpoll seen at DNR Point
While this small flock of Redpolls monopolized observation, a couple of larger songbirds alighted nearby:

Horned Lark seen at DNR Point

With striking facial markings and small "horns", the Horned Lark (Ala.hor.l), is the only member of the Lark family natively found in the New World.

Every avian family offers a fascinating study of the characteristics that group related species together. And while, say, the tropical Antillean Euphonia and the Arctic Common Redpoll couldn't seem more dissimilar, a deeper dive offers subtle insights into why these finches are more alike than not.

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