Cuckoos, cowbirds, and other species outsource their parental duties. Scientists are uncovering new twists in this sneaky—and ...

When she’s ready to lay an egg, a female Cuculus canorus swoops to the unattended nest of a smaller species. She then swallows one of the eggs that’s been laid there and lays one of her own ...

It has been, say scientists, "a mammoth journey". The satellite-tagged common cuckoo (Cuculus canorus), named Onon after a Mongolian river, set off from its winter home in Zambia on 20 March.

The male Yosemite toad (Anaxyrus canorus) can mate like mad every year—for about two weeks. Only in late spring. And only in wet meadows, at elevations above 4,800 feet, in California’s Sierra ...