Upon pointing out a Killdeer to groups, I have heard this question many times. It does defy belief that a 10-inch-long bird could kill a deer which weighs between 100 and 400 pounds.
Killdeer, like Chickadees and Whip-poor-wills, are named after the sound of their calls. “Kill-dee-er, Kill-dee-er.” We saw several today along the Humber River at Lambton Woods.
A bee that was searching for sweets one day
Through the gate of a rose garden happened to stray.
In the heart of a rose he hid away,
And forgot in his bliss the light of day,
As sipping his honey he buzzed in song;
Though day was waning, he lingered long,
For the rose was sweet, so sweet. – Paul Laurence Dunbar (1872–1906)