In the newly unfolding regions of delicate leaves a prairie warbler sings “Tsee-tsee-tsee-tsee-tsee-tsee” very rapidly, on an upward crescendo. A slim little bird, with a yellow breast streaked with black, its sharp trim beak opens wide as the notes swell out of its throat, and it seems to send song as far as it can. I think of constant effort, constant quick hearts. It picks up a light green caterpillar from the oak leaves and sings as it holds it in its beak. Then the warbler beats at the insect a little, pecks and shakes it, then swallows it down; and goes on singing. An oven bird perches on the oaks and sings, with breast uplifted, tail shaking, making a glorious effort. How could I dare say that this bird or another down the road, which accompanies it, is only singing something that sounds to our ears like “Teacher-teacher-teacher”? No bird song is alike, even in members of the same species. Each individual has its variation and seems to derive strength and pleasure from it. And it seems to me that they not only declare their rights and titles but are expressing something on behalf of spring. It is as if they sang: “It is not I. It is not I” but rather, all flowering, crossing, taking or accumulating, all growth. The song is a part of earth. Then there is that bird, a member of the family of mimics, the brown thrasher, which seems to make a mockery of the whole business. It is a cinnamon-winged, speckled-breasted, long-tailed bird, with a long bill and sharp, quick yellow eyes. The male thrasher is certainly as intense and serious about the duty of staking out his territory as any other species, but what issues loudly from his open bill seems like the most comical sort of parody. He may not be as good a mimic as the mocking bird--which has been known to imitate a flock of blue jays--but he manages a wonderful take-off on the whole race of birds. He is a master of a grab bag of trills, chatters, pips and cries, of rasps and sweetnesses, of sudden blurts, and obvious pauses as if for effect. Translated into a rapid tempo of words, his song might sound like this: “Jeremy! Jeremy! Ready here. Right here. Wide awake. Wide awake. Chipper! Chipper! Shake a leg. Up! Up! Here’s a joker. This way. This way.” ... an interpretation which probably makes me as ridiculous as he intended, if he is a serious humorist. In the middle of this exhortation I hear a comic little “Cucaracha!” or quite a good imitation of a whippoorwill, as if he saved his more exact skills for a casual moment.