7:02 a.m. (sunrise one minute earlier than yesterday). 28 degrees, win NNW 6 mph. Sky: at first, gray congestion with a dash of pastel peach or pink (toss-up color) in the south. Thins and opens as I walk. Hosts five crows before the sun. Permanent streams: voice yet stifled by snow and ice, barely a whisper, more a gargle than a gurgle. Mink tracks less distinct; he's either still in the marsh or has decamped up one of the western feeder streams, which spill down the shoulder of Robinson Hill. Wetlands: a sleepy white depression flanked by sag-limbed conifers, too stubborn to shed snow. Over the north end of the marsh, while I fill the feeders, an unorganized flock of thirty-plus songbirds, mid-sized, dark silhouettes spread under gray clouds. Robins, maybe. Not stubby like grosbeaks. Not noisy like crossbills. Not small like redpolls. Pond: deer, out of the woods and onto the plowed surface, investigates hockey rink. Faint imprints on ice, much deeper in fresh snow.
Turkeys on the eastern rim of the hill scratch up acorns. A run of hollow gobbles. Chickadees calling, ignore my off-the-mark whistles. Sounds good to me . . . not to them. (The dogs seem to enjoy the musical outburst. Look expectantly, hoping for a treat.) Both species of nuthatches calling. Not titmice, however. Doves make more noise with wings than throats. I can always count on jays, boisterous and belligerent, to fill the airwaves with honks, toots, shrieks, and an occasional mimic of a hawk, most often red-shouldered.
Blue jay high in ash faces north, feathers swept by the wind. Bare legs exposed, thin and uninsulated, seemingly at the mercy of the elements. No shivering. No shaking. No bouncing to produce heat. And, most importantly, no frostbite. Like my nana's steam radiator, the arteries and veins in a bird's legs (and wings) have a countercurrent circulation. Warm arterial blood leaving the body transfers heat to cold venous blood returning from the legs. In the upper legs, veins and arteries split into many smaller vessels and entwine (like so many hibernating rattlesnakes). Outgoing blood (arterial) cools down. Incoming blood (venous) warms. A continuous transfer of heat all the way to the toes. By the time blood reenters the jay's body, it has regained eighty-five percent of the heat loss. Result: legs don't freeze.
Beaver, muskrat, and otter have countercurrent circulation in their tails. Snowshoe hare in their ears, wolves in their legs. Whales and porpoises in their fins and flukes. We even have a very rudimentary countercurrent circulation in our arms. Countercurrent circulation meant nothing to me, of course, as I sat wallowing on my nana's radiator on the Upper Westside of Manhattan, eating fancy cookies and looking down at bright yellow cabs.
Blue jay shuffles. Dislodges snow, exudes frosty disapproval for a seed-eating downy woodpecker.
Great info. Thanks! Always like how you end your pieces with some personal history.
"countercurrent circulation"--yet another "wow" piece of information to add to my AWE folder! Thanks for making my eyes and brain "pop" this morning.