The Aerialist

Meet Tachycineta bicolor - the Tree Swallow.   

April 2011 Photo Taken Turkey Hunting

This blue-green feathered bird is an early spring arrival and they are a delight to watch as they are spectacular aviators that hunt flying insects. 

As a cavity-nesting species it had historically been found in forested habitat where they would nest in tree cavities.  Hence the origin of its name.  However the distribution of nest boxes by songbird enthusiasts has allowed for an expansion of its range to include open habitats.  They compete with bluebirds and house wrens for rights to nest in our boxes. 

This bird will pair-bond to breed yet there is cheating from time-to-time. It is not unusual for a male to keep a second mate at a separate nest site.  Because this species frequently returns to the location from whence it previously bred it is possible for an individual bird to have the same mate several years in a row.  But this is a consequence of being faithful to the site and not to fidelity as we understand it. 

This time of year is courting time and the males are displaying for the ladies.  They frequently sit atop a nest box bobbing and bowing until a potential mate is coaxed into inspecting the suitability of the premises with the possibility of moving-in.  If the courting is successful the male will hover over and mount the female as he stretches his wings while grabbing her feathers by the neck with with his beak to copulate.  A careful observer may also see a mating pair touching their bills with one another. 

While both birds gather materials the female constructs a cup-shaped nest of grass lined with feathers.   Four to seven small white eggs follow about a week after mating. They are incubated by mom for a couple of weeks and after hatching both birds feed the young.  The young fledge at about three weeks of age.

Nest predation typically occurs by snakes, raccoons, weasels and cats.  Birds on the wing can be picked-off by most any of the resident raptors.  It is during this critical nesting period I have to wear a cap when walking the dog as we get dive-bombed when approaching a nest site.  

By the time August rolls-around these birds are gone!  They leave their breeding grounds to congregate in large flocks in marshy areas with plenty of flying insects to feed-upon.  From there they migrate south to Florida, Cuba, Central and South America.  

Other than the dive-bombing it is a hoot to watch this talented aerialist.  Stay-tuned for further updates.