Winter survivalist: White-breasted Nuthatch
WHITE-BREASTED NUTHATCH (Sitta carolinensis) is the featured creature for our admiration on this very cold February morning. As far as the bird itself is concerned, it must go about its business as usual of finding something to eat. Without food, its body core temperature cannot be maintained. Fortunately, there are adequate backyard feeders this species can forage from to get suet, peanuts or sunflower seeds. And when this bird found food at this author’s backyard feeding station, a camera and long lens recorded it. Now we can enjoy it at close range via today’s newspaper photos.
I included two images on purpose. This bird is well known for using its long curved and sharp toenails to grasp tree branches or bark layers, in any direction, up or down. In fact, seeing the bird go head down is very typical. And an additional reason for a second photo is to show the details of its feather colors and pattern on its back side. Lots of black feathers with white edges and a gray back blend into a black nape of its neck with the black color going all the way over the top of its head. The sides of its head and throat are white. And its chest is also white with a touch of rusty brown near the flanks.
A close cousin of the White-breasted Nuthatch is the Red-breasted Nuthatch. The former is more of a deciduous forest dweller while conifer forests may be the preferred habitat for the latter. If you see a nuthatch with a distinct black eye line from bill base all the way past the eye toward its neck, it is the Red-breasted Nuthatch. And there are a lot more rusty red feathers on its sides, chest and flanks. Do we ever see the Red-breasted in Iowa? Yes, just not as often.
Spring, summer and fall foods for nuthatches are primarily insects, wood-boring beetle larvae, other beetles, tree hoppers, scale insects, ants, gall fly larvae, caterpillars, stink bugs, click beetles and spiders. Seeds and nuts remain on the menu. Feeder stations with peanut butter, peanuts, suet and sunflower seeds will draw them in.
Ornithologists with the North American Breeding Bird Survey, Partners in Flight, estimate the breeding population at 9.2 million birds with 85 percent occurring in the USA, five percent in Canada and ten percent in Mexico.
WINTER SURVIVAL for lots of native wildlife, mammal or bird, has these two priorities…. don’t freeze and don’t starve. While to you and me the odds seem huge for birds being able to find enough food when deep snow cover lays over the landscape, and insects are temporarily out of sight or underground. Yet in spite of all the adversaries of winter, they all endure. It is a credit to Mother Nature who has its figured out.
Small birds have a normal body core temperature of 105 degrees F. Body feathers can be fluffed outward to create more dead air spaces. Trapped air is an insulation layer. It works. And the birds also are less active during winter times than during other seasons. Less activity during winter minimizes calorie burn.
Winter season in the Midwest can be benign or brutal. This weekend leans toward the brutal side of the ledger. But in due time weather patterns will fluctuate and milder winter time air masses will replace frigid air. The lesson learned is to adapt to local conditions.
If we go back in history, and I’m speaking of geologic history of the earth during the past 2.6 million years, rock layers have left a record of climates long gone. Rocks tell scientists of a normal cyclic patterns of glaciation stages and inter-glacial warm intervals between glacial maximums. Old geology textbooks from the 1970s and 1980s told of about 4 glacial maximums across all northern latitudes of America and Europe. And each glacial maximum was interspersed with 4 inter-glacial warm times.
Well, it is time for a correction, a big correction, based on evidence that has been checked and rechecked. The evidence is contained in core samples from deep ocean muddy sediments. Here is where relatively still water allowed tiny sea living organisms, when they died, to slowly accumulate in those bottom mud layers. Animals such as foraminifera, and other microscopic critters, with shells, had varying percentages of oxygen isotopes in their shell structures.
Oxygen isotope 16 and 18 are what the scientists looked for. Normal ocean water has both O-16 and O-18. It was only the lighter O-16 that evaporated from ocean water, formed clouds and as weather systems moved overland, eventual precipitation from those clouds to the land was all O-16. Given enough time, geologic time, snow accumulation in huge amounts over tens to hundreds of thousands of years, formed glaciers. When glaciers eventually melted back, water runoff contained molecules with O-16 isotopes. These periodic and cyclic events altered the ratios of O-16 and O-18 in ocean waters. Animals living in those oceans absorbed and incorporated O-16 and 18 in their shells like living time clocks, in synchronized patterns with glacial events ebb and flow on the continents.
What was learned by geologists is that all of North America, during the past 2.6 million years had 33, read this again, 33 cycles of glaciation, and 33 inter-glacial warm times. To try and picture these glacial/inter-glacial phases, a timeline would show a graph repeating going back and forth to illustrate climatic phases from cold to warm, cold to warm, over and over again…33 times. We presently live and thrive in the midst of one of earth’s inter-glacial warm time frames. Be glad you are where you are right now because the alternative is not hospitable to life as we know it.
Not all of each glacial maximum was of the same duration or magnitude. Not every inter-glacial warm time was of the same duration or magnitude. However, in general, once a glacial ice building event was underway, it tended to last about 100,000 years, and inter-glacial warmer times for only 20,000 years. Our last glacial maximum, known as the Wisconsinan, had its leading edge of ice from Puget Sound of Washington State all the way across Canada and northern portions of Idaho, Montana, the Dakotas, Minnesota, Iowa, Wisconsin, Michigan, Illinois, Indiana, Ohio, New York and eastward into Maine and Newfoundland. Europe had its identical counterpart glacial maximums.
I note this geology lesson for you for several reasons. Understand that the earth and its mood swings of glacial/inter-glacial time frames dances to the tune only of celestial and long geologic influences.
Included in earth’s natural history are its responses to Milankovitch Cycles. These cycles involve the shape of earth’s orbit around the sun…circular to somewhat elliptical on a 100,000 year cycle; earth’s varying axial tilt between 22.1 and 24.5 degrees on a 41,000 year cycle; and precession (axial wobble) on a 26,000 cycle. It is how these interactions upon our earth determine long range climates that dominate.
Politicians that try to tell us otherwise are lying to us, while they attempt to do a magician’s trick of distraction while using their other hand to slip our wallets away to steal our money.
“Science is an endless frontier. The only thing wrong with doing science is to say we’ve found the absolute answer, because then there would be no more to do. Therefore we can’t call it science anymore. So, every scientist has to be happy that there is a lot more to investigate. The pleasure is in the process.”
— Dr. Vic Baker, University of Arizona, Professor of Geosciences.
Garry Brandenburg is the retired director of the Marshall County Conservation Board. He is a graduate of Iowa State University with a BS degree in Fish & Wildlife Biology.
Contact him at:
P.O. Box 96
Albion, IA 50005