It’s time to turn the calendar page to February and, depending on the prognostication of the groundhog, winter may or may not be on the wane. Regardless, some of our feather friends are already acting like spring has sprung.
Perhaps it’s simply confusion when days can veer from sunny, short-sleeve conditions to frigid snowstorms, but I tend to trust the instincts of our fine feathered friends.
An email from Unicoi County resident Amanda Austwick proved timely.
“I saw a post on Facebook from a woman in Ontario, Canada, and she had a photo of a bluebird in a tree surrounded by red berries, with a touch of snow on them,” Amanda wrote. “I thought bluebirds migrated south in winter.”
I responded to Amanda’s email and will share some information in this week’s column. For the most part, local bluebirds do not migrate out of the region in winter. Bluebirds living farther north do often, but not always, migrate farther south.
As I mentioned to Amanda, I notice bluebirds almost daily on my drive from home to work. On sunny mornings, male Eastern bluebirds are producing their enthusiastic, warbling song even if there’s been a touch of frost overnight.
The Eastern bluebird is one of North America’s best-known cavity-nesting birds. About 85 species of North American birds use cavities in trees for nesting purposes. Cavity-nesting birds include ducks, such as buffleheads and wood ducks, as well as birds of prey such as Eastern screech-owls and American kestrels. Woodpeckers and nuthatches can excavate their own cavity in a dead or decaying tree.
Others, such as the bluebirds, must find a cavity already in existence. Such cavities are scarce real estate and can be subject to some intense competition.
The Eastern bluebird is at a disadvantage when forced to compete with non-native introduced birds such as aggressive European starlings and house sparrows. Even native competitors such as house wrens and tree swallows are serious rivals when it comes down to staking a claim to prime nesting sites.
Over the years, I have found bluebirds nesting in cavities inside wooden fence posts, but there are fewer wooden fence posts every year. This reinforces the idea of how changing landscapes have affected these birds. Instead of wooden fence posts, many farmers now use metal ones, and dead or dying trees — a much sought-after resource for cavity-nesting birds — are often removed from woodlands. Winter storms this season, along with accompanying high winds, have brought down numerous trees in the woodlands around my home, no doubt removing some current or future nesting possibilities.
When it comes to choosing a nesting cavity, male bluebirds take the lead, investigating and exploring potential sites before introducing females to the chosen real estate. If she accepts his choice, she will build the nest.
Cavities can also find use by bluebirds for secure locations for roosting overnight. According to the website Tennessee Watchable Wildlife, observers have documented bluebirds using nest boxes to stay warm during cold winter nights, packing eight to 12 individuals into one box. With the generated body heat from all those birds, I imagine that was one cozy box!
The website also noted that the oldest known Eastern bluebird in the wild reached an age of 10 years and six months. Given that most songbird live fairly short lives, that was quite an achievement.
For those interested in becoming bluebird landlords, check out nest box designs at the Tennessee Watchable Wildlife website. Several different nest box designs are available at the profile for the Eastern bluebird at tnwatchablewildlife.org.
If you’re not a do-it-yourself individuals, most lawn and garden centers, farm supply stores and speciality bird shops carry readymade bluebird boxes for purchase.
In addition to housing, food and water can be used to lure Eastern bluebirds closer. This bird doesn’t eat seeds, but it can be attracted with an offering of mealworms — live or freeze-dried – or commercially prepared peanut butter nuggets. A water feature in a yard is also a magnet for bluebirds and a host of other bird species.
To ask a question, make a comment or share an observation, please email me at firstname.lastname@example.org.