For the Birds Radio Program: Mother-in-Laws, human and avian
(Recording of a Canada Goose)
People often ridicule mothers-in-law on the human scene, which set me to wondering how well birds get along with their mothers-in-law. Actually, most birds probably never get a chance to meet their mothers-in-law. The life expectancy of many species is so short that probably only a few songbirds ever see their parents or their offspring again after leaving the breeding grounds in fall. Most small birds die their first year, but if they so make it through a migration and winter, their life expectancy goes up sharply.
Robins have survived for over 11 years in the wild, and cardinals for over 13. The record lifespan of a hummingbird is over 11 years–one adult female Broad-tailed Hummingbird banded in Colorado in 1976 returned to the same banding station in 1986. This bird may have been even older than 11, since there was no way scientists could determine exactly how old she was in 1976. That little bird was quite likely a great-grandmother with nine greats, and she probably had quite a few daughters-and sons-in-law. Hummingbirds are usually aggressive toward their own kind, and this one in particular was observed to run other hummingbirds away from the feeders at the Colorado banding station, so chances are if her children and their mates recognize her at all, she’s still none-too-popular with them.
The young of many songbirds often return to the place that they were hatched and fledged in the spring, but if their parents have also survived, the older birds drive the young off. The territorial imperative combined with the experience and dominance of older birds probably makes most younger generation birds blacklist their mothers-in-law.
On the other hand, Canada Geese probably both know and get along with their in-laws. Geese live much longer, on average, than small songbirds–the life expectancy of an adult goose in the wild is over 20 years. Although mated pairs spend the summer on isolated territories, they join up with their children from previous summers along with their children’s offspring, during fall migration and on wintering grounds. The first and last positions in a long string of geese are usually taken by the oldest, most experienced geese. They apparently learn their migration routes and wintering grounds from their parents, and spend all but the breeding season in tightly-knit clans. Not only do Canada Geese mate for life, they stick together with their parents, siblings, cousins, and in-laws all winter, too. Flocks wintering in central Minnesota and Wisconsin are made up of quite a few mothers-in-law. Unlike humans, geese usually have babies every year during their entire adult lives, so mother-in-law geese often have new babies as well as great-granchildren to look after. They and their mates act as sentinels for a feeding flock, calling a warning if a fisher, a large hawk, or a human enters the scene. So mother-in-law geese are well respected, unlike their beleaguered human counterparts.
The nicest human mother-in-law I know not only alerts me to fishers and hawks and rare birds at her Port Wing bird feeder—she also gave me my first pair of binoculars. Today is her 70th birthday, and I sure hope it’s a happy one.
(Recording of a Canada Goose)
This is Laura Erickson, and this program has been “For the Birds.”