Bird of the Week: Yellow-billed Cuckoo

Yellow-billed Cuckoos are slender, elusive birds. Like other cuckoos, such as the rare Bay-breasted, they seem stealthy even in flight, slipping through the trees on long, pointed wings. More often heard than seen, the Yellow-billed Cuckoo's croaking call-sounding on hot summer days before storms-led to its folk name, "rain crow."

Habitat loss and fragmentation have led to long-term declines. In the West, riparian habitat has been lost to farmland and housing; invasive plants such as salt cedar also degrade habitat. This western population is now listed as threatened under the Endangered Species Act; its range in the West is so diminished that it hardly appears on this small range map.

Yellow-billed Cuckoos that breed in North America migrate long distances at night and are frequent victims of collisions with glass, towers, wind turbines, and other man-made structures.

Yellow-billed Cuckoos are stealthy hunters, often sitting motionless on a hidden perch as they wait for their prey to move-then they pounce. The birds glean insects from leaves and pluck lizards, frogs, and grasshoppers from tree branches or the ground. They are among the few birds able to eat tent caterpillars and other hairy caterpillars, which are a favorite prey item. During tent caterpillar outbreaks in the East, cuckoos gorge on them, eating as many as 100 at a time.

Unlike the Eurasian Common Cuckoo, Yellow-billed Cuckoos usually lay eggs in their own nests, but their breeding behavior is quite variable. They have been recorded cooperatively breeding, as well as laying eggs in the nests of other Yellow-billed Cuckoos or 11 other bird species, including Black-billed Cuckoo, American Robin, Gray Catbird, and Wood Thrush.

Like other cuckoos, the Yellow-billed Cuckoo has zygodactyl feet, with two forward-facing toes and two backward-facing toes. This arrangement is most common in birds that climb tree trunks or clamber through foliage. Parrots such as Military Macaw, woodpeckers including Kaempfer's, and owls like Elf Owl also have this toe arrangement.

http://www.abcbirds.org/