Pleistocene Cuckoos (Coccyzus sp.)

I frequently hear yellow-billed cuckoos (C. americanus) during summer, but I almost never see them.  They spend most of their time perched in tree tops and they blend in well, so they are difficult to spot.  I’ve never even seen this species perched, but I have occasionally spotted them flying in front of me, while I’m jogging or driving.  They are long birds with reddish brown wings and a checkered tail.  I discovered this species lives in my neighborhood a few years ago when I was learning bird calls from the Cornell University ornithology website.  I searched for yellow-billed cuckoos on this site and was pleasantly surprised to recognize their distinctive call.  Here’s a link.

https://www.allaboutbirds.org/guide/Yellow-billed_Cuckoo/sounds

Video of a perched cuckoo.  I’ve never seen one perched. Old timers called these birds rain crows because they will sometimes call in response to thunder.

Yellow-billed cuckoos spend summers in North America and winter in South America.  Caterpillars are the most important item in their diet, and they specialize in eating large spiny caterpillars that taste bad to most other species of birds.  They are so well-adapted to eating caterpillars that when their stomachs become clogged with spines, they vomit up their stomach lining and grow a new one.  They also feed on other large insects such as cicadas, locusts, and dragonflies.  Fruit balances out the rest of their diet.  They lay their eggs at intervals, and their nests often contain different aged nestlings.  The young are covered in porcupine like quills, and they are capable of climbing trees to avoid predators.  They leave the nest just 17 days after hatching.

Yellow-billed cuckoo range map.

2 other species of cuckoos in the coccyzus genus live in North America–the black-billed cuckoo (C. erythropthalmus) and the mangrove cuckoo (C. minor).  Surprisingly, genetic evidence suggests the black-billed cuckoo is not a sister species of the yellow-billed cuckoo.  The black-billed cuckoo also summers in North America and winters in South America, but it breeds in more northerly locations.  These species independently evolved the habit of migrating north to find summer breeding ranges.  The pearly-breasted cuckoo (C. euleri), restricted to South America, is a sister species to the yellow-billed.  I looked at a photo of this species and I can’t tell the difference between the 2.  The mangrove cuckoo ranges from South Florida and the Bahamas to the coasts of Mexico and Central America.

Fossil evidence of cuckoos in the coccyzus genus has been excavated from sites in Florida, Virginia, the Bahamas, Dominican Republic, and Bolivia.  They are a bird of deep forest and therefore the process of preservation is rare in their habitat, explaining why they are absent in much of the fossil record.  Coccyzus cuckoos likely increased in abundance during warmer wetter stages of climate.

Cuckoos belong to the Cucilidae family which includes 135-147 species, depending upon the taxonomist’s opinion.  All Eurasian species are parasitic–they lay their eggs in other birds nests.  (These are the species depicted in cuckoo clocks.)  Yellow-billed cuckoos are occasionally parasitic.  During times of plenty when there are outbreaks of fall webworms or tent caterpillars, they will lay an egg in the nests of other cuckoos, robins, catbirds, or woodthrushes.  The cuculidae family also includes anis of South America and Mexico, coucals of Melanesia and Australia, and New World ground cuckoos.  Roadrunners belong to the New World ground cuckoos.  Most other species of New World ground cuckoos are parasitic, and 1 species specializes in preying upon army ants.

References:

Forbush, Ed

A Natural History of American Birds of Eastern and Central North America

Bramhall House 1955

Hughes, Janice

“Phylogeny of the Cuckoo Genus Coccyzus (Aves: Cuculidae): a test of monophyly”

Systematics and Biochemistry 2006

Tags: black-billed cuckoo, cuculidae, yellow billed cuckoo