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Conservation-Cuckoos (but you may have called them something else) By: Kevin Williams, Grundy County Conservation Director

I am going to start a column about Cuckoos talking about insects. Not so strange when you think that insects are an important food source for so many birds. So to begin let’s think about tent caterpillars. I have written about them before. These caterpillars are the larva of a small moth that is of such minimal importance that, unlike most other species, it gets its name from its own young. It is called the eastern tent caterpillar moth. These colonial caterpillars hatch back in early March when they spun their silken tent usually in a tree crotch. They are crepuscular, that is most active during early morning or evening twilight when they leave the tent to feed on leaves. They also feed at night when it isn’t too cool. They remain in the tent during the heat of the day or rainy weather. When they emerged from their eggs back in March, those tent caterpillars were small. But by the middle of summer, the caterpillars are large and their tent is large. Enter the hero of this column, the cuckoo, the deadly enemy of the tent caterpillar. Two species, yellow-billed and black-billed cuckoos, are found here. They are members of an international family that includes roadrunners. That European cuckoo is the bird of the cuckoo clock with its “kuck’-oo” call. They build their own flimsy nests – not much better than those of mourning doves. I should also mention that one other cuckoo is often seen in grocery shelves in the cereal isle. Cuckoos normally remain hidden in foliage. I rarely see them and, when I do, my view is usually a brief glimpse of a blue jay-sized bird flying arrow-like through the trees, its flight somewhat like that of a mourning dove. They are brown backed and white bellied, the two species with only minor differences in markings. More often I hear them. The yellow-billed cuckoo’s call is described by Peterson as “a rapid throaty ka-ka-ka-ka-ka-ka-ka-ka-ka-ka-ka-ka-kow-kow-kow-kowp-kowlp-kowlp-kowlp-kowlp (retarded toward end)”. He describes the black-billed cuckoo’s call as “a fast rhythmic cucucu, cucucu, cucucu, etc.” At church the other Sunday, I visited with Harold McKinney about the cuckoo. Growing up, he and I had both learned the bird by its nickname the “Raincrow”. On warm, humid afternoons, the call of the bird many times preceded the thunderstorm. Hence the name. Now back to the caterpillars. Tent caterpillars have hairy bodies and for this reason are not attractive as food for many birds. But cuckoos feed on them regularly. Back when ornithologists analyzed such things, one report told of an average of almost 23 caterpillars in each of 121 cuckoo stomachs. Tent caterpillars are not the only species eaten. Bugs, beetles and grasshoppers are consumed, as well. But they are best known for their attacks on tent caterpillars. Sometimes cuckoos have been observed stripping the hair from caterpillars before eating them but most often they merely eat the entire insect, later disgorging pellets of hair in a manner similar to that of owls. There you have it. Likely everything you always wanted (or didn’t want) to know about cuckoos.

Conservation-Cuckoos (but you may have called them something else) By: Kevin Williams, Grundy County Conservation Director

I am going to start a column about Cuckoos talking about insects. Not so strange when you think that insects are an important food source for so many birds. So to begin let’s think about tent caterpillars. I have written about them before. These caterpillars are the larva of a small moth that is of such minimal importance that, unlike most other species, it gets its name from its own young. It is called the eastern tent caterpillar moth. These colonial caterpillars hatch back in early March when they spun their silken tent usually in a tree crotch. They are crepuscular, that is most active during early morning or evening twilight when they leave the tent to feed on leaves. They also feed at night when it isn’t too cool. They remain in the tent during the heat of the day or rainy weather. When they emerged from their eggs back in March, those tent caterpillars were small. But by the middle of summer, the caterpillars are large and their tent is large. Enter the hero of this column, the cuckoo, the deadly enemy of the tent caterpillar. Two species, yellow-billed and black-billed cuckoos, are found here. They are members of an international family that includes roadrunners. That European cuckoo is the bird of the cuckoo clock with its “kuck’-oo” call. They build their own flimsy nests – not much better than those of mourning doves. I should also mention that one other cuckoo is often seen in grocery shelves in the cereal isle. Cuckoos normally remain hidden in foliage. I rarely see them and, when I do, my view is usually a brief glimpse of a blue jay-sized bird flying arrow-like through the trees, its flight somewhat like that of a mourning dove. They are brown backed and white bellied, the two species with only minor differences in markings. More often I hear them. The yellow-billed cuckoo’s call is described by Peterson as “a rapid throaty ka-ka-ka-ka-ka-ka-ka-ka-ka-ka-ka-ka-kow-kow-kow-kowp-kowlp-kowlp-kowlp-kowlp (retarded toward end)”. He describes the black-billed cuckoo’s call as “a fast rhythmic cucucu, cucucu, cucucu, etc.” At church the other Sunday, I visited with Harold McKinney about the cuckoo. Growing up, he and I had both learned the bird by its nickname the “Raincrow”. On warm, humid afternoons, the call of the bird many times preceded the thunderstorm. Hence the name. Now back to the caterpillars. Tent caterpillars have hairy bodies and for this reason are not attractive as food for many birds. But cuckoos feed on them regularly. Back when ornithologists analyzed such things, one report told of an average of almost 23 caterpillars in each of 121 cuckoo stomachs. Tent caterpillars are not the only species eaten. Bugs, beetles and grasshoppers are consumed, as well. But they are best known for their attacks on tent caterpillars. Sometimes cuckoos have been observed stripping the hair from caterpillars before eating them but most often they merely eat the entire insect, later disgorging pellets of hair in a manner similar to that of owls. There you have it. Likely everything you always wanted (or didn’t want) to know about cuckoos.