Column: Bluebirds should be arriving soon
According to my calendar, bluebirds should be arriving soon. A prize for the eyes for any birdwatcher, bluebirds are one of the most "watchable" avian friends and are members of a very pleasant group of birds.
Mention bluebirds in a room where wildlife enthusiasts — particularly birders — abound, and you're certain to make plenty of friends.
Bluebirds are thrushes that belong to an avian family comprised of such species as American robin, Swainson's thrush, and veery. Our species of bluebird here in Minnesota is the eastern.
Two other species, the western and mountain bluebirds, are typically observed throughout western United States. Even so, all three species of bluebirds' ranges overlap and occasional hybridization occurs. Mountain bluebirds are rarely seen in Minnesota, but do in fact show up and surprise a number of birders every year. Some people have even reported mountain bluebirds nesting in the state.
The cavity nesting behavior of the eastern bluebird has made this bird vulnerable to habitat degradation and, subsequently, nest-site competition, especially from non-native species of birds like European starlings. But thankfully the birds readily accept artificial human-made structures, and hence the reason bluebirds have rebounded in some parts of its range.
And you know it's not too late to put out new nest boxes, even if a few bluebirds have already trickled into the countryside. Male birds are generally the first to arrive on the breeding grounds (though not always) and the females will soon follow. Male bluebirds will seek prospective territories or return to the same fields they occupied the year before.
I recall one spring day several years ago near my Becida area home not far from Itasca State Park, when I observed what I believed was the simultaneous arrival of a courting pair of bluebirds on their breeding and nesting territory.
It was late March when I happened to see the male alight on top of a nest-box while singing and performing "wing-waving" behaviors. The female joined him by fluttering near the entrance hole of the house.
She momentarily suspended herself in front of the opening until she grasped the face of the box with her feet, propped herself upright with her tail for support, and poked her head inside the house for a look-see.
As quickly as she performed the inspection, she flew off across the field to another birdhouse (with her suitor seemingly leading the way) where the pair completed the same ritual again.
After courtship, during which the males often bring food to the female, the pair begins nest-building chores. Both birds assist each other in material collection, but it's usually the female that constructs the actual nest-bowl.
Fine grasses and stems are normal nest material, but so are white pine needles if readily available. Feathers are rarely used, if at all.
Following a weeklong nest construction project, the female lays four to five blue eggs — sometimes white. She alone incubates the eggs (about two weeks) until the eggs hatch. But because the nestlings are born without feathers, the female continues to brood, keeping the youngsters warm and safe, while the male brings much needed food for mother and babies.
Soon afterwards when nestlings are a little larger and are graced with a few feathers, mama joins papa for a relentless two to three-week feeding routine.
In all, from incubation to fledging, a month's time, maybe a little longer, has been consumed. And chances are good that after Mr. and Mrs. Bluebird have ensured that their babies can fend for themselves, will do it all over again and raise another clutch.
Indeed, it is time to clean your bluebird houses if you haven't already done so; or make new houses and repair old houses, as we get out and enjoy the great outdoors.