February Bird Group Report
Birdgroup Meeting February 2016
The birdgroup met on February 11 2016, at the home of Athena Antiochos. There were eight members present to hear a discussion of the two species of the Cuculidae family which breed in Canada, the Yellow-billed Cuckoo (YBCU) and the Black-billed Cuckoo (BBCU).
Martin Chen started the discussion with the names of the YBCU. Its scientific name is Coccyzus americanus. In the past its English name was California Cuckoo, in Canadian folklore it was called the Rain-crow from the fact that it is most clamorous before a rain storm. Apart from this there is historically little known about this species. Athena followed with an outline of the bird’s range and migration. Its breeding range is mostly the Eastern USA with a small incursion into southern Ontario, the only range in Canada. It has disappeared from Western USA. It winters in Panama and parts of South America as far south a northern Argentina. Charlene talked about mating, behaviour and enemies. The male calls and lands perched on the female, then climbs on her shoulders, feeds her and then mates. The YBCU isdifficult to watch. It moves quietly through tangles of vegetation and often sits motionless on a branch, looking for food. The birds are monogamous. They will respond well to taping. Their chief enemy is the loss of their riparian habitat, habitat which tends to be choked with vegetation or cut down. Barbara mentioned that the YBCU is difficult to see, but is easily drawn out by its ‘knocking’ call, a rapid staccato ‘kuk-kuk-kuk’ which slows down and descends to a wooden hollow-sounding KAKAKOWLPKOWLP. The food of this cuckoo are large hairy caterpillars (gypsy moths, tent caterpillars) and insect like cicadas, as well as lizards, berries and eggs of other birds. Their liking of caterpillars is beneficial when there is an outbreak of these insects. Carolyn told the group about the nesting, eggs and habitat of the YBCU. They nest in a tree or shrub, 2 – 12′ above ground, making a nest which is a flimsy platform of short twigs on a horizontal branch. Three to four eggs are incubated for up to 14 days. The chicks are altricial, almost naked with black skin and some sparse down feathers. The chicks fledge 17 days after hatching. YBCU occasionally lay eggs in nests of other bird species. They are not obligate brood parasites, unlike the Eurasian Cuckoo (Cuculus canorus). The breeding habitat of the species is deciduous woods, generally moist thickets and overgrown pastures.
The names, history and status of the second species, the BBCU, were discussed by Martin. Its scientific name is Coccyzus erythrophthalamus, the name comes from greek: kokkyzein means ‘calling cuckoo’, erythros means red and ophthalmos means the eye. Like the YBCU this species is not globally threatened. Athena folllowed Martin. She talked about the breeding range of this species. In Canada this extends across the southern parts from Alberta all the way to western Nova Scotia. In the USA it covers the north-eastern parts south to North Carolina, Arkansas, Oklahoma and Tennessee and west to the Rockies. It migrates through the southern USA and in Central America to north-western South America for wintering. Charlene told us about the courtship which is very simple: the male calls, the female comes, the male offers food and starts mating. While mating food is still given. The birds are monogamous. They are stalkers in their behaviour: they move through thick vegetation in shrubs and trees. They will also sit quietly on a branch scanning or food. They respond well to taping and can then readily be seen. Their chief enemy is man who destroys some of their habitat by cutting down forests and even secondary woods. According to Barbara this species is also more often heard than seen. It tends to call when breeding sometimes at night as well as during the day. Voice and Song: The chicks produce first a buzzing insect-like sound, then after a few days a barking sound. The adult call is a series of soft, mellow cu-cu-cu-cu notes in groups of 2 – 5, all on the same pitch. The notes are highly pitched, rapid and repetitive. The food of the BBCU consists of caterpillars, insects, beetles, grasshoppers etc. which it obtains by moving through dense bushes and trees. It eats also snail, fish, eggs of other birds, berries and fruit. Carolyn talked about nesting, eggs and habitat. Nests are flimsy, shallow made of twigs and lined with grass. They are placed a few feet off the ground in dense thickets. The BBCU is known for its parasitism, laying eggs in the nest of its own as well as other species of birds. However, unlike the Eurasian Cuckoo (the common cuckoo) they are not obligate parasites. This species lays 2 – 3 blue-green eggs which take on a marbled appearance after a few days. The chicks hatch after 10 – 13 days. The adults leave the nest some 7 – 9 days later. The chicks are altricial, covered after hatching with sparse white down on black skin. They leave the nest before they can fly by hopping from branch to branch. They fly after 21 – 24 days. The habitat of this species is most commonly around the edge of mature deciduous or mixed forest with a lot of shrubs and moist thickets. However they are also known to inhabit more open areas such as abandoned farmland, golf courses and even residential parks, but they are usually well hidden. Their habitat is always near flowing or still water. On their wntering grounds they inhabit tropical rainforests, open woodlands, as well as scrub forests.
Gene summarised the discussion by comparing the two species, the YBCU and the BBCU. Both are secretive skulkers and they are usuallly detected by their calls and response to taping. BBCU also responds to Screech-Owl calls. When they respond they stay in the shrubs and just show their heads. Differences between the two, useful for identification, are in their tails. The YBCU shows distinctive white base with black bars on the bottom of the tail, whereas the BBCU shows a black tail with small white spots. The BBCU has a red orbital ring, on the YBCU the lower mandible is yellow. Both species are roughly the size of a Mourning Dove, with the YBCU being plumper, more robust than the BBCU. Theo added a personal comment. He said that growing up in a European countryside he was used to hearing the European Cuckoo, from which many of the cuckoos got their name, calling very loudlly and consistently day and night as a sign of spring and beginning of the breeding season. He still finds it difficult to dissociate the name cuckoo from the “real” cuckoo. The song is well reproduced in the cuckoo clocks from the German Black Forest.
The meeting finished with a quiz that had been sent by Mike via email. It provided an interesting challenge on the group’s knowledge of the behaviour of some birds.
Here’s a link to a Black-billed Cuckoo pic. Black-billed Cuckoo
And here is one to a Yellow-billed cuckoo pic:ybcu