As a wildlife photographer, Jocelyn Anderson has observed some incredible animal behavior. But the dynamics of a bird family she documented last week was unlike anything she’d ever seen before. Following a tip from the Michigan Bird Watching Facebook group, she tracked down a Sandhill Crane nest in Kensington Metropark in Milford. Anderson found the mother standing over a tottering crane chick, or colt. Nearby the father was digging up worms, while the duo’s other young charge scuttled about. It would have been an unremarkable, if lovely scene—except that the second chick was a Canada Goose. The crane parents have apparently adopted the gosling.
“The Sandhill Crane colt is fuzzy and gangly and the gosling is just so round and chubby,” she says. “They look so different and the parents treat them exactly the same.”
It’s not unusual in the bird world for members of one species to raise the young of another. Cuckoos, for instance, purposefully lay their eggs in the nests of other, unsuspecting birds, which care for the young as their own. Another such case of brood parasitism, in which the biological parents offload their responsibilities for rearing their young, is the owl raising a duckling that blew up online this year.
Sandhill Cranes, however, aren’t known to be tricked into nurturing the offspring of other species, though there are reports of them fostering Whooping Crane chicks, which are close relatives. The situation in Kensington Metropark marks the first time Sandhill Cranes have been documented caring for the young of a bird from another genus, says Geoff LeBaron, director of Audubon's Christmas Bird Count. Yet while this fostering situation is new to the record books, that doesn’t mean it has never happened before. LeBaron explains that because cranes are “cryptic” and “secretive” during their nesting season, such behavior might have simply gone unnoticed.
Nobody knows for certain how the mixed family came to be. It’s possible Canada Geese nested near the cranes, and the gosling somehow made its way to its neighbors’ abode, where it was welcomed, says LeBaron. The theory among members of the Facebook group that tipped off Anderson is that a goose abandoned its nest with an egg inside; then the cranes moved into the vacant spot, laid their own egg, and nurtured both of the chicks that hatched.
Sandhill Cranes raise one to two chicks per year, so having an extra mouth to feed isn’t out of the ordinary. What’s more, the parents seem to be feeding the young birds the same diet of worms and grubs—a fine menu for a goose, which typically eats an array of insects and plants.
While a gosling and colt might look nothing alike, the ways in which their parents care for them, both in the nest and after they fledge, are very similar, LeBaron says. “Cranes will migrate in family groups. So will geese,” he says. “It’s possible that this goose will end up flying south with cranes in the fall.”
If that happens, Anderson, who continues to keep tabs on the unlikely quartet, might photograph the scene: A portrait of an unusual family in flight, a short, plump goose winging it alongside its lanky adopted kin.