01.14.18: Swallows debating

Male Tree Swallows debate atop a nesting box, Sharon Woods Metro Park, Westerville, Ohio. 

PHOTO OF THE WEEK ARCHIVES

Technical information

Date/time:
April 23, 2017,
9:05 a.m.

Location
40°6’58” N,
82°57'39" W
(Show in Google Maps)

Camera: 
Canon EOS 7D Mark II

Lens: 
Canon EF 600mm f/4L, Canon 1.4x teleconverter (840mm) 

Aperture: 
f/5.6

Shutter: 
1/1000th second

ISO: 
320

One thing I look forward to every spring — besides warmer weather and longer periods of daylight, of course — is the return of Tree Swallows to the fields of Central Ohio.

The birds are the ultimate aerialists as they conduct acrobatic flights to chase and catch flying insects. They dip, dart, dive, twist, turn, climb and hover, often in rapid succession. To those watching who can’t see the tiny insect being pursued, the aerial maneuvers are hugely entertaining. For the birds, the maneuvers are necessary to survive. 

I’ve had Tree Swallows fly straight toward my face in pursuit of an insect, changing directions moments before what seemed to be an unavoidable collision. I’ve learned to stand my ground in those situations, trusting the bird to miss me.

Tree Sparrows, especially the adult males, are distinctive. The males have blue-green feathers above and white below, trimmed with blackish flight feathers and a thin black eye mask. Adult females are duller with more brown in their upper parts.

Their name — Tree Swallow — comes from their preference of nesting sites in tree cavities and not from the bird’s usual habitat, which consists of open, treeless areas. Tree Swallows also use nesting boxes, if available. And that leads to conflicts with Eastern Bluebirds, another cavity dweller found in fields in Central Ohio in the spring.

I’ve watched ownership of a nesting box change hands multiple times within minutes. A bluebird will be standing on top, adopting a threatening pose whenever a Tree Swallow flies near. But eventually a swallow will be successful in its efforts to claim the box, chasing off the bluebird and replacing it on top of the box until a bluebird is successful in chasing away the swallow. The process is repeated many times each spring day.

That is why many parks in the area place two adjacent nesting boxes in fields. Bluebirds will not nest near another bluebird, so having adjacent nesting boxes increases the odds of bluebirds winning one and swallows claiming the other.

This photo shows two male Tree Swallows debating ownership of a nesting box on a spring morning in Sharon Woods Metro Park north of Columbus, Ohio. The birds adopt an open-beak posture when defending their perch. When multiple swallows are on the same perch, the posture creates the impression of a conversation.

Each week I will post a photo from my collection with an explanation of how I got the shot. Previous photos of the week are in the archives.