Bird at the window

Lately, the past three weeks or so, a young mocking bird has been battering his head against the window of our living room. we havethose lorered windows that open at a slant and self destruct after a decade in the sun.
the young bird flies against the glass over and over. I can hear his beak against the glass ant the thud of his head and chest. he takes a break from time to time, perching on the edge of the half opened window, his head feathers ruffled from the attack. then he flies at the glass again.
Ive gone so far as to call him, wave my hands and even put my face against the glass where he is attacking. He'll sometimes fly to a safe distance and perch on a wire only to resume again.
In Richard Wilbur's Poem, the bird wanted to get out.