It is not easy being an insectivore in winter in Michigan.
This month I have four different times seen a Golden-crowned Kinglet in Eliza Howell Park in Detroit — perhaps the same one each time, perhaps not. It is always exciting to see one of these fascinating “little kings,” but I am conscious of the fact that surviving the winter here is a major challenge for them.
This photo and the next one (taken during last fall’s migration at a different location in Michigan) provide a sense of both the beauty and the tiny size of species.
Golden-crowned Kinglets breed in conifers further north and can often be seen foraging in conifers during migration.
They eat insects and spiders almost exclusively — the adults, larvae, pupae, eggs. Most insectivores (many warblers, for example) travel to much warmer climates for the winter. But Golden-crowned Kinglets are short-distance migrants, with a few staying in Michigan. This is the third year in the last 18 that I have seen them in the park in January.
This range map is from the Audubon Field Guide. We are in the “uncommon” wintering area.
Other species that eat insects in the summer and are in this area in the winter consume other foods at this time. Kinglets do not come to seed/suet -filled feeders, as do chickadees, woodpeckers, and nuthatches. Kinglets do not eat fruit as bluebirds do.
Where there are no or very few conifers, Golden-crowned Kinglets forage for insects in the understory of deciduous forests, energetically moving from branch to branch, stem to stem, of small trees and shrubs. They never seem to stop moving, taking up all of the winter daylight hours trying to get enough food to make it through the night. (Some have reported that they may occasionally eat seeds, but I have not seen any indication of that here.)
This is the kind of habitat where I find them in winter.
Insects, of course, have their own strategies for surviving winter, often in egg or larva stage that is well hidden or camouflaged. I am always impressed that birds that move as quickly as kinglets manage to find them as often as they do.
Naturalists who have studied Golden-crowned Kinglets report that they do, in fact, have a very high mortality rate. In their northernmost wintering grounds, many do not survive.
They have, however, developed their own survival strategy as a species. Golden-crowned Kinglets have a very high reproduction rate. Their nests, in the spruce-fir northern forests, usually have 8-9 eggs each, more than most species. And immediately after the first brood fledges, the female is incubating 8-9 more eggs while her mate feeds the first brood.
This strategy is successful enough that the species is holding its own. It is not one whose overall numbers are declining significantly, despite the high mortality rate.
I do not know what will happen to the bird (or birds) I have been seeing this month, but I can expect that, come early April, I will again see other Golden-crowned Kinglets as they move through here on their way north for breeding. And I can be confident that they will still be on their insect diet.