By Bryan Stevens
Since we honored fathers this week with a special day in their honor, I thought it might be a good time to look to the bird world for some examples of what fatherhood means among our fine feathered friends.
Among many of the raptors, which includes hawks, falcons and eagles, females are significantly larger than males. Unsurprisingly, much of the job of protecting the nest and young falls to the larger and stronger females. Male raptors, for the most part, are good parents and hunt prey and deliver food to the nest. Sometimes, though, there can be trouble in paradise. For example, researchers are giving a new look at the dynamics between mated bald eagles. The prevailing theory once supposed that bald eagles mate for life.
In an article published Nov. 9, 2012, on the website of William and Mary College, researchers announced that they have begun to notice that eagles on occasion undertake the avian equivalent of “divorce.”
Bryan Watts, the director of the Center for Conservation Biology, was interviewed for the article. Watts noted that both males and female eagles will cheat. Getting away with cheating, however, favors the female. Watts explained that the male may be absent fishing when another male eagle visits the nest site and proceeds to mate with the female. Consequently, the unsuspecting mate returns and could end up raising eaglets that were fathered by the intruder instead of himself.
There are some male birds who are more steadfast once they mate. For instance, swans, cranes and albatrosses are known for sticking with a chosen mate over a lifetime. Two endangered species — the California condor and the whooping crane — are known to mate for life. Cranes typically choose a mate when they reach the age of two or three; condors, on the other hand, usually don’t mate until they are at least six to eight years old. Of course, both these birds live long lives. Whooping cranes may live to the age of 25 while condors can live for as long as six decades.
According to the Audubon website, we can look to a family of shorebirds for some examples that go against usual gender norms. Phalaropes reverse the usual sex roles in birds, with the females being larger and more colorful than males, In addition, females take the lead in courtship, while males are left to incubate the eggs and care for the young once the business of mating is done. Three species of phalaropes inhabit North America: Wilson’s phalarope, red-necked phalarope and red phalarope.
Many male birds lend a hand in building nests or raising young. There are some examples of “deadbeat dads,” however, with one of the most glaring being the beloved ruby-throated hummingbird. A male hummingbird is unlikely to ever lay eyes on his offspring. Once mating has been concluded, the female is left to build a nest on her own. She also incubates the eggs without any help from her mate, who has probably already skipped out and started to court other female hummingbirds in the vicinity. Once the two eggs hatch, the female hummingbird is solely responsible for feeding the hungry offspring. It’s the primary reason hummingbirds always lay two eggs. With her high metabolism, a female hummingbird would be hard pressed to feed herself and any more than two young.
Some male birds, like their human counterparts, approach romance by initiating courtship by bringing some shiny bling to the relationship. Bowerbirds, which are found mainly in New Guinea and Australia, are renowned for their unique courtship behavior. A male bowerbird will build a structure — the bower — and decorate it with sticks, flowers, shells or other brightly colored objects in an attempt to attract a mate. Alas, once he has won a mate with these “bribes,” he’s no better than male hummingbirds. The females are left to build the nest and raise the young without any assistance from the males.
Satin bowerbird males often decorate with blue, yellow or shiny objects, including berries, flowers or even plastic items such as ink pens, drinking straws and clothes pegs. As the males mature they use more blue objects than other colors. The decorated bower becomes a stage from which males carry out intense behavioral displays called dances to attract their mates.
The world’s largest flightless birds – ostriches, emus, rhea, cassowaries and a few others – would make good “father of the year” candidates. For instance, male ostriches share incubation duties with females. Once the eggs hatch, male ostriches are active in leading young to suitable foraging habitat and protecting them from predators. Some male ostriches can stand nine feet tall and weigh 320 pounds, so dad is an imposing obstacle for many predators. In the event of an attack, the male will try to draw off the predator while the chicks run for cover with their mother.
Fatherhood often means a dedicated effort on the part of some birds, while other basically make their genetic contribution to ensuring the survival of the species and are done with the concept. There’s a surprising variety to behold once one starts looking at the different avian approaches to fatherhood.