(This 832nd Buffalo Sunday News column was first published on March 4, 2007.)
Golden-crowned Kinglet photo
by Jim Gilbert. Visit his gallery
to see more of his superb photos.
After he read my column about kinglets last October, Chuck Wolf e-mailed to tell me about Bernd Heinrich's 2003 book, Winter World. "This book is full of interesting information on animal survival," he said and he continued, "There is a running discussion of how kinglets survive the winter."
Heinrich has long been a favorite author of mine. A University of Vermont biology professor, he has written several books about the wildlife near his vacation home in Maine. Among those I have enjoyed are Ravens in Winter, One Man's Owl (about his pet great horned owl), and Bumblebee Economics. Heinrich also provided personal information for my column about the 1998 ice storm that punished the Northeast.
So I was surprised not to know about Winter World. I immediately headed for the library and, now having read it, I too commend this book. Indeed it does include a great deal of content about golden-crowned kinglets.
Heinrich is especially impressed with this smallest of our passerines. (Passerines -- aka perching birds or song birds -- make up the largest bird order. The only bird smaller than the kinglet that occurs locally is the ruby-throated hummingbird, which is not a passerine.)
The golden-crowned kinglet is aptly named for it sports a golden headdress. Both male and female have a bright yellow topknot surrounded by a black rim underscored by a white eyeline.
What impresses Heinrich -- and me as well -- is how some of these birds stay in the north through the winter. This year, for example, 137 of these diminutive mites were recorded on the Algonquin Park, Ontario Christmas Bird Count, a hundred miles north of Toronto. And some of the even smaller western race winter along the Pacific coast all the way up to Alaska.
These kinglets are not common in winter like our chickadees and nuthatches, with whom they often consort, but play a recording of their high pitched call near a spruce or pine grove and you will often draw a few into view.
You'll then get to watch the delightful antics of an insect-gleaning acrobat. Weighing in at only a fifth of an ounce, about the weight of two pats of butter, they seem not to hold on to the twigs they search, often upside down, for miniscule food.
The question Heinrich tried to gather evidence about in Winter World, is: How do these birds withstand the cold? Despite much effort, he and his students do not come up with clear-cut answers. All they can offer are a series of suppositions.
First, like so many wintering birds the kinglets fluff out their feathers to surround themselves with a kind of comforter or muff. Heinrich's sketch shows that this feather blanket is much thicker than the bird's body. These feathers not only keep out the cold but they also trap air that takes on warmth from the bird's body.
But the author takes measurements that suggest even this thick layer is not enough to protect the kinglet against the kind of cold and wind we've had this February.
There are two other physical responses the bird can use in extraordinary circumstances. One of them is shivering. This is the same defense against cold that wintering moths use and even our own bodies use. We call our shivering chills and think of them as simply a warning sign of approaching hypothermia. However, this motion is also creating body heat through friction.
The second defense Heinrich hypothesizes is retreat into a kind of torpor with their body temperature declining. This is not like hibernation, however, and there is a limit to such cooling beyond which lies death.
But Heinrich concludes: "Lucky for a kinglet, it does not know the odds stacked against it. Whenever I've watched kinglets in their nonstop hopping, hovering, and searching, seen their intimate expressions, and heard their constant chatter, I've felt an infectious hyperenthusiasm flow from them, and sensed a grand, boundless zest for life. They could not survive without that in their harsh world. Like us, they are programmed for optimism."
By the end of March these brave wintering individuals will be joined by many more of their kind and for a few weeks our woodlands will be filled with migrating golden-crowned and later ruby-crowned kinglets.