Following the recent excitement on our Littleton farm after I discovered a chestnut-sided warbler here in mid November (see Late for the Tropics), four lesser goldfinches visited the property yesterday, gathering at the thistle feeder. Common residents along the Colorado Front Range during the warmer months, these small songbirds have nested on the farm in the past but generally head for the Desert Southwest or Mexico by mid October at the latest.
Yesterday's visitors were thus a pleasant surprise and, of course, I filed a report with eBird. Unlike the warbler, which is an insectivore, lesser goldfinches eat small seeds (primarily from thistle and various sunflowers) and are thus more likely to survive periods of cold weather. Nevertheless, they are not usually found this far north in early December and I suspect that the mild autumn temperatures are (once again) responsible for their late departure.
Such rare discoveries, especially on one's own property, fuel the excitement of birding and prompt more vigilance in the months to come. After all, winter is usually the best season for observing vagrants and irruptive species; this year, it seems to be a good time to observe summer residents as well!