Charleston lawyer Doren Burrell, a guest of the Pocahontas Nature Club, gave a talk on winter birds at the McClintic Public Library in Marlinton Saturday.
Adding to his talk from his visit in the spring, Burrell explained that not all birds migrate to the south during the winter. Some brave the storm, so to speak, and stay right here in the state.
“Not all birds fly south,” he said. “There’s actually quite a lot. You had your Christmas Bird Count and there were over fifty different species that were sighted in one day in December. So there are birds here, you’ve got to know where to look.”
Several birds, like chickadees, cardinals, woodpeckers and hawks stay in West Virginia through the winter, while others migrate from farther north to spend the winter here.
“For some birds, we are their south,” Burrell said. “These are the birds that come from farther north to here to spend the winter. Evening grosbeak and the red crossbill, which is also seen sometime in the summertime on top of the mountain.”
Burrell explained the factors that help birds survive the winter. They must have a good source of food and water, shelter and a place to raise young for those that mate during the winter.
While food is scarce, there are still options for birds during the winter.
“You know your feeder birds, they eat seeds,” Burrell said. “They don’t have to be right there like an insect. They don’t have to hunt that down. Seeds are something you can store. Seeds are a great food for birds. They don’t weigh a lot but they pack a lot of nutrition and in particular, a lot of energy.”
During the winter, birds also flock together more than other seasons, which makes it easier to find food. Seed eaters will alert one another when they find an abundance of seeds, or a bird feeder in the yard of a friendly human.
For birds that eat meat, there are grubs and pupa living in tree bark and insects which lay eggs in seed heads. Mice, moles, squirrels and other small mammals are also a viable source of food during the winter.
Adaptation is key for all birds living in cold temperatures during the winter. Owls and hawks have developed a technique for frozen meat that they store.
“[They] have a technique known as prey thawing where, like the penguin [when it holds its young in its feet], they can take frozen prey and they will hold it against their bodies with their feet and thaw them out,” Burrell said.
Warmth and shelter is very key to survival in the cold weather. Birds use several techniques to maintain their body temperatures and collect heat from one another.
“The grouse has developed the ability to fly right into the snow and dig a grouse tunnel,” Burrell explained. “The snow works as an insulator to protect them from the extreme cold. They can be in there in their little downy jackets and they’re not going to lose as much heat as if they were out in the open.”
A common technique used by birds to stay warm is usually misconstrued as sleeping. When a flock of birds – geese and ducks in particular – are seen with their heads under their wings, they aren’t taking a nap, they are conserving body heat.
“Birds have good insulation over the majority of the body,” Burrell said. “The two areas that they don’t are the legs and the bill. They can lose a lot of heat from their bill, so they’re tucking their bill into their wings and feathers to avoid heat loss.”
Birds also conserve heat by going into a hibernation-like stasis called torpor.
“All their processes – heart beat, body temperature – goes down and during the longest parts of the winter, the longest nights, it can be like that up to twenty hours,” Burrell said. “You can find a bird that is roosting in a nest or some sort of sheltered area and it can be hard to rouse them. It is a type of temporary hypothermia but it doesn’t adversely affect the birds because they are adapted to this situation. You can pick it up in your hand and it won’t react because it’s in that reduced metabolic state.”
While many birds avoid breeding during the winter, some will have offspring in the winter if there is enough of a food source.
“For the most part, we don’t have birds breeding in the wintertime,” Burrell explained. “But the lifecycle of birds is going on and it’s critical if you are a bird looking to raise young, you take advantage of food when it’s available. Crossbills don’t have a breeding season. They can breed anytime there is sufficient food.”
Just like maintaining warmth for themselves, birds must ensure that their nests will maintain warmth for the eggs and young. Many birds pluck their down – their warmest feathers – and make a nice warm nest in which to lay their eggs.
Smaller birds, like the kinglet, make nests using lichen, moss and spiderwebs.
“They use lots of soft insulating material,” Burrell said. “They’ll lay nine to eleven eggs and they’ll lay them in two layers in the nest. Not all those eggs are going to survive but by the number and the fact they’ve got this mass of eggs, there’s kind of insulation in the eggs too and some will survive.”
After his talk, Burrell opened the floor for questions and thanked the Pocahontas Nature Club for the invitation to share his information.
For more information on the club, visit the Pocahontas Nature Club Facebook page.
Suzanne Stewart may be contacted at firstname.lastname@example.org