Environment

Final score: Broad-winged Hawks-1, Mourning Doves-0

Upper right windowpane collision site

| Tom Driscoll |

A startling BOOM was heard throughout the house! Young William shouted in distress, “A hawk grabbed the mourning dove!!!” He could barely believe what he just witnessed through our living room window where we all enjoy daily birdwatching. All three of today’s birdwatchers – son John, grandchildren Hannah (16) and William (10) – were astounded up-close eyewitnesses.

As usual, the lone dove and various local songbirds were breakfasting on sunflower seeds at our south-facing hanging feeders. Hawks are rarely seen here in the forest on the northwest side of Peacock Hill, though they have been returning home to Maine during the recent spring migration. (Bradbury Mountain Hawk Watch 2022)

Saturday was mostly cloudy and a time when south-facing windows are most dangerous for birds. The glass reflects the trees and clouds and appears to birds as a place to fly through.

The hawk locked its eyes on its prey and swooped down in a fast, steep dive. The dove, sensing immediate danger, instantly made a steep climb in front of the windows, attempting to escape its fate. The hawk slammed into the dove and literally but briefly pressed it against the glass windowpane, dissipating the force of its dive.

The dove made direct contact with the glass. Like a vehicle airbag, its body softened the collision for the hawk which pressed into the soft backside of the dove. The sound of impact was astonishingly LOUD!

Down to the ground they fell and disappeared just below the southside deck. The hawk, apparently stunned, sat holding the dove for about 15 seconds. Then it proudly raised its head, glanced briefly left and right, and flew off into the woods with the lifeless dove grasped firmly in its talons.

Running in from another room I arrived just in time to look out the window and see the hawk’s getaway. I sped out the door and across the yard in pursuit. As my human speed was no match for hawk’s low trajectory flight, I returned to join everyone paging through bird-book mugshots to make a positive ID of the hawk suspect. By unanimous consensus, it was a broad-winged hawk, no doubt.

Though it was a natural event, the hawk was not popular at this moment in time, and all the mourning was for the dove.

Mourning dove imprint on house window the morning after with direct sunlight

Looking at the close-up photo of the window you can clearly see the imprint of the dove in astonishing detail. It looks like a chalk outline at a crime scene, but with fine detail.

Note the high upward angle of the dove wing imprints, and if you look closely, you see what appear to be the hawk talon imprints just below the dove’s main body impact mark.

Identifying with the dove, as a former military pilot I know that helicopter blades (wings) “cone up” at a similar steep angle when in a high-power fast climb, such as when trying to avoid a ground-to-air missile.

Identifying with the hawk, when I flew Cobra attack helicopters, we conducted a maneuver called “diving fire,” like a hawk. A prime danger for a pilot is “target fixation,” which is focusing only on the target and losing situational awareness. If you don’t snap out of the fixation, you may forget to pull up and out of the dive and crash into the ground. This can happen only once for any given pilot.

My bird accident investigation concluded that the dove was in a steep fast getaway climb, and the hawk succumbed to target fixation. The hawk did not notice that the trees and clouds reflected in the windows were an illusion. It likely intended to continue the arc of its trajectory and pull up and out of the dive with the dove in its talons.

The hawk and the dove had a midair collision that was survived only by the hawk, thanks to the cushioning effect of the dove as they both continued onward together as one, to crash into the glass.

Though quite exciting, this window collision will hopefully be remembered as a one-time event.

Hawk suspect soaring over northwest Peacock Hill the morning after