Juncos experienced difficulty finding a natural source of food, grass seeds, because so much was covered with snow. photo by Renee Landuyt.
April 03, 2014There is no doubt. It's been a long, hard winter and the march toward spring has been delayed by at least three weeks.
If the freezing temperatures and snow have been hard on humans, think how difficult the winter of 2014 has been on the 15 bird species that winter in Michigan.
Finding food and water has been hard on cardinals, black-capped chickadees, white-breasted nuthatches, downy woodpeckers, mourning doves, American goldfinches, blue jays, the tufted titmouse and house sparrows, among others, because the natural food and water sources have been covered with snow and ice.
"This is the time of year when our resident birds are looked upon with empathy and respect," said resident bird expert and certified bird feeding specialist Rosann Kovalcik. "(They are) braving the cold of winter instead of choosing migration. Resident birds that don't typically leave have run out of resources because the grasses are covered."
They are in dire straits so humans have given them a hand by providing a mixture of seeds, suet and heated bird baths used not only for drinking but for preening.
"The numbers of feathers that a bird has increases in the colder months by as much as 30 percent, adding to their ability to keep out the cold," she said. "Smaller birds have more feathers per unit of body weight than larger birds. The lower legs and feet of birds are tendinous as opposed to having fleshy parts exposed as in mammals. Therefore, there is no heat loss from that area. A birds' bill is made of horn similar to our fingernails and does not suffer heat loss either.
"Birds use their metabolism to produce heat and run a hotter engine in the winter than in summer months. They produce this additional heat by consuming more food — up to 20 times more on a winter day than during warmer months."
Growing additional feathers, molting and growing new feathers takes a lot of energy, therefore, birds must keep feathers conditioned by preening for warmth, flexibility and to be waterproof.
"Birds must keep feathers in good condition. Barbels are at the end of each feather and (birds) must unlock each. It's a matter of strength so they can fly," Kovalcik said.
She went on to say birds do shiver, but not for the reasons humans shiver.
"During the daytime, a bird may shiver, with this muscular energy producing heat. Another adaptation to cold is some birds' ability to store seeds in a crop, an enlargement of the esophagus. This food is used during the night to maintain higher metabolism, especially finches," she said.
As the migration of birds begins and birds, such as turkey vultures, humming birds and the great blue heron, stop to rest, they compete with resident birds for resources.
"Birds are programmed by the day (light) length. That's what prompts them to migrate. They will start to come. They take it a day at time. They sense a storm or air pressure and will stop. They will come from South American and progress through North America. It will be slower but there is the urge to migrate," Kovalcik said.
Migrating birds will now compete for what can be found, which isn't much, since the resident birds have stripped what food was available and not covered with snow.
Along with the purchased feed and water, residents can attract and help birds with landscaping to provide both shelter and natural food.
For example, evergreens provide both shelter and seeds. Plants such as cone flowers, asters and golden rod have seeds for birds while holly and dogwood provide fruit for birds.
Another example, is the serviceberry shrub that has a spring fruit high in lipid sugar that is specifically helpful to birds.
"Plants must be specific to the area," she said.
A native plant here, a tree there, would provide sufficient food and shelter for birds to better weather another polar vortex.