Something big is happening at the Enabling Garden this winter. Four bird species that usually live in northern boreal and mixed coniferous forests are feasting on birch catkins, alder seeds, and spruce cone seeds as well as on thistles in feeders right here at the Chicago Botanic Garden. Birders and photographers are pointing binoculars and cameras to the trees and feeders to get a closer view or snapshot of these handsome northerly visitors. Amid the chatter of birders and photographers are the insistent, buzzing calls of pine siskins, the most common of the four winter birds visiting the Garden.
Typically you'll see some siskins in northern Illinois and at the Garden every winter, but this is a banner year for these lovely little birds—with more than 30 visible at one time. Just within the last two weeks of January, flocks of common redpolls have been joining the siskins, and some birders have even spotted the rarest of the rare, a hoary redpoll. A flock of 50 white-winged crossbills has been seen sporadically for several days in a row enjoying the seeds from cones of a black hills spruce near the Enabling Garden. They come and go, and it's anybody's guess when they'll be back for a snack.
Why they are here?
Siskins, redpolls, and crossbills belong to the finch family and usually feed on seeds from trees growing in the northern forests of the United States and Canada. Siskins eat seeds from conifers and readily come to thistle feeders in winter. Redpolls prefer birch seeds, also adding alder, pine, and elm seeds to the menu when necessary. They will also come to feeders with thistle. Occasionally, from the Lenhardt Library in front of the large window facing birch trees, birders may find common redpolls having a meal. White-winged crossbills prefer seeds of spruces with small cones, as well as tamaracks, hemlocks, and to a lesser extent, white pines. They will also eat sunflower seeds from a feeder.
In the summer, all of these birds eat insects and feed them to their young—but in winter, they must rely on tree seeds. And in some winters, smaller-than-normal seed production forces these birds to fly south looking for food at feeders, in garden plantings, and in the wild. Seed production on trees varies from year to year. It is the tree's way of saving energy. But this fall, many trees across the northern region took a break from producing so many seeds. And as huge snowfalls covered the seeds on trees, these birds had to fly further south to look for food. Places like the Chicago Botanic Garden offer respite for these northerly visitors in winter.
How to identify them