Harvey Webster: Winter Solstice
Dan Polletta welcomes the Cleveland Museum of Natural History's director of wildlife resources Harvey Webster to look to the winter solstice (Wednesday, December 21) & explore the implications of the year's shortest day on the animals of the Perkins Wildlife Center.
Polletta: Why is this such an important part of the year in nature?
Webster: It's kind of like a reset button in nature. You've had this steady progression of ever-shortening days leading up to December 21st. We'll be celebrating I believe at 5:44 in the morning. Then following that date the days get a little bit longer. It turns out this notion of photoperiod day length is something that's hard wired into all of us. There's a lot of organisms for whom that's how they reset their internal calendar. For example, if you show up at the Ralph Perkins 2 Wildlife Center, our brand new outdoor gallery at the museum one of the species we have on display is the snow shoe hares. Snow shoe hares at first glance in the summertime look like rabbits and you might dismiss them just as rabbits. Except it turns out their legs are a little bit bigger than rabbits. Their back feet are much larger than rabbits. Curiously starting maybe in mid-October and definitely by the time you get to the solstice in about 10 weeks they go from all brown to all white. This is a preparation that's cued into decreasing daylight that happens predicatably at the same time every year. So by the time you get to the solstice you expect that there's going to be snow around, they are now camouflaged. It turns out their back feet act like snow shoes hence their name so that if you do get deep snow pack they can actually walk along the surface of it. This is about as far south as the snow shoe hare occurs right here in Ohio.
Polletta: How about some of the other animals at Perkins how are they affected by the Winter Solstice?
Webster: If you take a look at our coyotes or red fox or grey fox or a bobcat or even our North American river otters their coats are just spectacular. They're as bushy as they can possibly be. There's a gloss and sheen to the hair. The reason for that is that you have to have your coat and the integrity of the coat at its absolute prime as you go into the winter season because that's the difference between survival and death.
You have a dense under wool. The red fox looks almost twice the size that it normally looks or twice the girth that it normally looks in the summertime because it's got so much extra hair on it. The otters as semi-aquatic mammals they get in the water just as much as they would in the summer time and it turns out the hairs on their body are so densely concentrated on the surface of the skin that if they dive into the water their skin remains dry. So this is excellent insulation and they can spend hours in the water even though the water is forty degrees. It doesn't bother them at all.
Tune in at 12:33pm and 1:40pm Friday, December 16 to 90.3 WCPN to hear Dan Polletta talk with Harvey on Here and Now featuring The Sound of Applause.
Harvey Webster, director of wildlife resources Cleveland Museum of Natural History