By GENE BULLOCK
Kitsap Audubon
Back in the 1960s, my job was to interview leading scientists and engineers and write articles about emerging technology. One of these was a comparatively new field of computer modeling called “systems analysis.” It grew out of World War II efforts to cut the terrible loss of ships transporting supplies to troops across the globe. German U-boats could easily stalk and sink lone ships and then slip away.
Computer simulations taught these scientists something that birds and wildlife have known for millennia. There is safety in numbers! The more ships in a convoy, the more made it safely across. A lone-wolf submarine could sink only one before exposing its position and becoming the hunted, instead of the hunter.
Traveling in flocks or herds is a form of social behavior that serves many species well. Birds pair up and separate from the flock to nest and raise families, but may join in flocks to migrate, socialize, forage and attend to their mutual defense.
But it’s not just related family groups that congregate for mutual benefit. In winter, many join mixed flocks that can include robins, chickadees, nuthatches, brown creepers, kinglets and others. Members of these foraging flocks benefit in a variety of ways. The most obvious are the additional sets of eyes, making it harder for predators sneak up undetected.
Mixed flocks also combine different skills. On their tropical wintering grounds, nearsighted red-eyed vireos have been known to move in groups with far-sighted flycatchers. It has been shown experimentally that downy woodpeckers use chickadees as sentinels. On the African plains, near-sighted zebras with keen hearing associate with wildebeests and giraffes with keen eyesight.
Another benefit is that some, like the sassy little chickadee, are bolder, and seem to be better at finding food. Knowing this, other birds watch and follow to improve their chances of finding food. When food is scarce, cooperative foraging in flocks has been shown to improve the feeding efficiency of the whole flock.
Like schools of fish, the graceful murmurations of bird flocks also serve the purpose of visually confusing predators. It’s harder for a falcon or hawk to single out one bird in the synchronized movements of a large flock. When thousands of snow geese take flight at the sight of an approaching eagle, they can resemble a sky full of snowflakes.
The familiar V-formations of Canada geese use another cooperative strategy. By taking turns in the lead and closely trailing each other, they conserve energy by “winding” for each other. Bicycle racers use the same strategy to save energy for the final sprint as the trailing biker encounters less wind resistance in the wake of the other biker.
Of course, there are other flocking behaviors, such as communal roosts and the mobbing of owls and hawks by aptly named “murders” of crows.
We’ve learned a lot by observing birds and wildlife and gaining insight from the behavior patterns that have enabled them to survive.
