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t h e t h r e e - m i n u t e o u t d o o r s m a n 216 scent-eliminating shower and your scent-free clothing, hat, boots, and gum? Even whitetails will eat eggs and young if they find a nest. All these predators make the probability of a successful nest rather low, and thus, there is intense natural selection on nesting hens to avoid detection. Of course, nature is never static. If you’re a predator thwarted by birds’ chemical switch to diesters during the nesting season, the onus is on you to be better at detecting them. The more we learn, the more we realize that nature is an ever-evolving arms race between predator and prey. Darwin would have loved it. 56 our chickadees are smarter than theirs The Black-capped Chickadee is one of eastern North America’s most familiar birds. We see them in many places all year long, from deer stands to duck blinds to bird feeders, from the forests in the far north to woodlots in the prairie. It is one of the first birds to announce the upcoming spring, when in January the males begin giving their two-toned whistles (sounding like “pheebeee ”), which are used to set up and defend territories. One of the most striking and impressive things about these little birds, which weigh four-tenths of an ounce, is their winter tolerance. While we huddle around a hot cup of coffee first thing on a subzero morning, the chickadees are at the feeder—active, interacting, seemingly oblivious to the cold that could kill you or me in short order without proper attire. So, recalling that they were here long before we started putting out feeders, we ask, how do they make it through the winter? Well, they can spend the night in a cavity, out of the wind, maybe huddling with some close friends, as this will help conserve energy A N I M A L I N T E L L I G E N C E 217 during the night. But during the day, it’s eat eat eat. They have to eat constantly to survive, and very long without food, maybe only a day or two, will likely spell doom. And studies have shown that carrying around a lot of fat is not a good idea, as it reduces aerodynamic efficiency and makes the bird easier for a predator to catch. There aren’t many bugs flying around my place in the winter. None, actually. But chickadees hunt for small insect larvae overwintering in the bark of trees, eat seeds still left on weeds, and maybe visit a feeder or two. But these sources probably don’t provide enough food to keep the birds from freezing to death. A trick of chickadees is food caching. When times are good, chickadees store food in tree bark, which they can retrieve during winter when food is harder to find. The problem is finding it again when you’re hungry. You have to remember where the heck you put that seed, was it here or over there, or maybe halfway up the first branch on the north side of that big oak in the backyard with that English setter? Birds remember? Yes, chickadees have memory. They either remember specific storage places or just have an idea of where they would have stored a seed last fall, like having a search image. I must admit that as I am losing more and more memory in my late fifties, I try to put things in logical places so that I can find them later after only two or three tries (after first blaming my wife, incorrectly, for moving some item). Chickadees, by finding and eating food that they stored in the fall, supplement what they find, and make it through the winter. But they need a good memory, which I guess makes it fortunate that chickadees aren’t big drinkers. A 2009 scientific paper by Tim Roth and his colleagues described their studies of chickadee brains, and I have to warn you that the methods are a bit dramatic. Under permit from state and federal agencies, they went to several places around the country, captured chickadees, and then humanely killed them. Next, they did some special tricks and sectioned their brains so they could measure the areas associated with memory (specifically the hippocampus , a part of the brain involved in spatial memory...

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