Human beings have figured out a number of ways to beat the cold – heavy coats, blankets, wood stoves, central heating – but animals have everything they need to stay warm, either already on their bodies or through what can be found in their environment, according to one Harford County naturalist.
"It's fascinating," Frank Marsden, naturalist and program director at the Eden Mill Nature Center in Pylesville, said. "We're the only ones that have to wear a coat; these guys have it figured out pretty well... These guys get it all naturally."
Marsden, along with Kim Peabody, a naturalist at the Anita C. Leight Estuary Center in Abingdon, discussed how critters in Harford County, including birds, mammals, fish, amphibians and reptiles, get through the winter.
Marsden said creatures have three options as the cold weather approaches.
"They can either migrate, hibernate or adapt," he explained.
Peabody said some species of fish that live in Otter Point Creek and the surrounding ecosystem, which is studied and preserved through the Estuary Center and its partners, have already headed out to larger bodies of water such as the Chesapeake Bay to avoid the ice.
The aquatic species that remain are staying at the bottom of the creek and the marshes "to try to get to a low point where it's a little bit warmer," Peabody explained.
She said the waterways do not freeze straight to the bottom, and there is more oxygen for fish at the lowest point.
"They go to the bottom," Peabody said. "They don't necessarily go into the mud, but they go to the bottom of whatever body of water they're in."
Marsden said mammals such as otters and muskrat will also seek open, unfrozen water when looking for food.
"Find a spring and you'll find every critter on earth, from otters to mink to muskrat," he said. "If there's no ice everybody's fine."
Peabody said most reptiles and amphibians that call the Otter Point Creek ecosystem home, such as frogs, salamanders, snakes and turtles, are hibernating by this time of year.
They have buried themselves in leaves or the earth to stay warm.
As an example, Peabody said, box turtles will dig holes under the leaves in the woods.
"They're all hunkered down and their heart rate slows and they go into kind of a torpor, so they're OK, they're going to be fine," she said.
Marsden said the population of birds in Harford County has shifted during the winter months as geese and some birds of prey move south, and other birds of prey such as species of owls, hawks and eagles take their place.
He noted the various animals in Harford are able to get through the winter for the most part, based on their ability to either find food, store food or hibernate.
Marsden said the types of birds of prey in Harford County during the winter depend on how cold it is; if it is too cold for the birds in Maryland they will go even farther south.
He said the birds of prey that stick out during the winter of 2013-2014 include snowy owls, one of which was seen around Havre de Grace in December, and a rough-legged hawk, which he saw in the Pylesville area recently.
"I haven't seen one of those in a decade," he said of the hawk, which gets its name from the feathers on its legs.
Those feathers give its legs a rough appearance.
Marsden, 66, has been with the Eden Mill Nature Center throughout its 22-year existence, but he has seen more and more bald eagles, who usually remain around the Conowingo Dam and the Susquehanna River, on the 117-acre Eden Mill property during the past seven to eight years.
"I don't think I go a week anymore without seeing a couple of eagles," Marsden said.
Eden Mill is along Deer Creek, about 19 miles west of the dam, and the deep mill pond is a draw for eagles as a fishing area as their population increases and they compete for food.
"It's all based on food," Marsden said. "They're going to follow the food supply."
Marsden said birds of prey have the biggest challenges when it comes to finding food during the winter.
The rodents they eat have burrowed underground – chipmunks go as far as to create three separate chambers for living, food storage and waste – or under thick grasses.
When it snows, rodents will live under the snowpack and create a "subnivean world" of tunnels that allow them to get to and from food sources such as the bark of young trees, Marsden said.
"They can actually move around quite a bit more and they're protected [from predators] by the snow," he explained.
Marsden said that makes it harder for birds of prey to find rodents. He said owls can be seen walking along the snow crust, listening for the small mammals.
Once they hear a creature scurrying around, they will leap through the snow and grab it.
"They'll sort of leap up and go talons first right down into the snow," he said.
Foxes will do the same thing when hunting for rodents in the snow. Marsden said they will jump into the air and pounce to grab their prey.
Birds of prey can also be seen hunting along roads that have been cleared after a snowstorm and the earth is thawing out.
"If they can't get through the crust of the snow, then they don't get anything to eat," he said.
Active all winter
Peabody said mammals along Otter Point Creek, such as otters and beavers, remain active all winter thanks to their warm dens and heavy fur coats.
She said their layers of fat and fur allow them to continue to go in the water and find food.
"They're made to be in the cold water, so they're usually not affected," she explained.
Otters carve their dens in the banks of creeks and marshes, and beavers line their lodges with vegetation to keep them warm.
Even with warm and cozy dens, beavers and otters can be seen outside during the winter.
"They'll be out playing in the snow, so they're definitely built to withstand the snow and cold weather," Peabody said. "They're going to be comfortable up in their dens and they're even going to be comfortable outside."Copyright © 2015, The Baltimore Sun