We recently wrote about the idea of which backyard bird is the toughest based on a study that pulled together observations of the victor in one-on-one encounters among different bird species. There’s no doubt that that competitive dynamic is one that many humans find pretty interesting. When he was around 10 years old, our son loved a game when he would ask us to consider which of two fierce animals would win in a fight. “Polar bear versus killer whale?” he would ask. Or “elephant versus alligator?”

It didn’t matter for him whether the two would ever actually ever have a way to face-off in reality. The competition was just fascinating for his 10-year-old brain to consider at the time.

We all have some of that curiosity about the competitiveness of the natural world.

But with so much aggression showing up in the human world lately, it made us wonder more about ways in which birds and other animals may be able to show tolerance to each other or even communicate or cooperate.

It was while observing the birds on our platform feeder that we first considered the idea. A song sparrow in one corner of the square was scratching through the seeds with its feet while several house sparrows stood on the edge of the opposite corner and pecked into the seeds. That arrangement held fine for quite some time but eventually two new house sparrows arrived. They landed closer to the song sparrow. And although the song sparrow was much smaller, that bird flew at the closer house sparrows, beak open menacingly and clawed feet ready to strike. The offending house sparrows quickly exited, and things were calm once again.

Beyond tolerating each other’s presence, birds can also benefit from being with each other. This is also quite evident in and around backyard bird feeders. Cooper’s hawks are crow-sized predators that specialize in eating other birds. In the winter, many learn that birds congregate around feeding stations, and they swoop in to try to surprise and capture an unsuspecting bird for their dinner. We have one that we see regularly in our neighborhood. We are more likely to spot this crafty Cooper’s hawk when we are listening to the sounds of birds in the neighborhood. That’s because various species give particular calls when they see a hawk and don’t feel in danger of becoming prey. When the hawk is too close, they all become completely silent and freeze in place, waiting until the hawk leaves before resuming their activity. Birds pay attention to these predator alarm calls from other bird species and change their behavior to make themselves less likely to be taken.

There are probably many more interesting ways that birds (whether of the same or different species) tolerate, cooperate, and communicate for survival. Maybe the most striking example could be individuals that end up pairing with and reproducing with a bird of a different species. Sometimes it happens regularly among very closely related species like mallards and American black ducks. Other times, it’s a more rare event that results in hybrids that birders puzzle over, trying to understand the two species involved. Why does it happen? Who knows! There may be lots of reasons, but when it results in a successful offspring, you have to conclude that two individuals of different species that would not normally mate had to tolerate, cooperate, and communicate despite their differences.

The birds tell us it can be done!

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology and Vice President of Boreal Conservation for National Audubon. Dr. Wells is one of the nation's leading bird experts and conservation biologists. He is a coauthor of the seminal “Birds of Maine” book and author of the “Birder’s Conservation Handbook.” His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization working statewide to protect the nature of Maine. Both are widely published natural history writers and are the authors of the popular books, “Maine’s Favorite Birds” (Down East Books) and “Birds of Aruba, Bonaire, and Curaçao: A Site and Field Guide,” (Cornell University Press).