Monogamy is natural in bird kingdom

Father's Day celebrates the contributions that dads make to family life -- paternity, resource provision, defense and companionship, to name just a few. Among humans, this role is expected because we are among the relatively few monogamous species of all types of animals. Families thrive when dads take an active role in family life.
But in nature monogamy is unusual, except among birds. More than 90 percent of bird species practice monogamy where one male pairs and mates with one female. The length of the pair bond varies from one breeding season to many years.
One reason male birds take on such an important role in family life is that they can do everything a female can except lay eggs. Male mammals, for example, cannot produce milk so they can't feed their young. Male birds, however, can defend a territory, help build nests, and provide food for both females and young.
The best dads
If faithfulness is the standard, the best dads are those that form life time bonds with their mates. Typically these are long-lived species. Geese, swans, cranes, albatrosses, penguins, ravens, many parrots, roadrunners, and even tufted titmice and white-breasted nuthatches maintain the same mate from year to year. The value of faithfulness is that long term partners needn't spend time finding mates and courting each spring and can begin the nesting process sooner. Young that leave the nest earlier in the season can gain valuable experience that prepares them for what lies ahead. Plus experienced parents are better parents.
If this is true, removing the father from a monogamous family unit should significantly reduce the number of young that leave the nest. In one such field experiment with snow buntings, 11 control nests tended by both parents fledged an average of 4.5 young. At 13 other nests, the male was removed, and the & quot;widowed & quot; female fledged an average of only 2.7 young per nest. Clearly fatherhood has measurable value.
Among northern mockingbirds, a familiar backyard bird, males take over the care of young after they leave the nest. For several days he plays Mister Mom while his mate builds a new nest for a second brood.
The parental role of male Australian malleefowl, a turkey-like bird, is even more impressive. Males build a huge nest mound consisting of thousands of pounds of soil, sand, and decaying vegetation. When the female comes to the mound to lay an egg, the male opens a spot so she can drop the egg deep inside the pile. Then he covers the egg. The heat produced by the compost pile warms the eggs; the male regulates the temperature by moving organic matter closer or farther from the eggs. Call it incubation by proxy.
Nature's Dutch Dating
And then there's the spotted sandpiper and several species of phalarope, a type of shorebird, where the sexes swap roles. This is called a polyandrous mating system.
Female spotted sandpipers, which can be seen bobbing along the edges of streams and wetlands, establish and defend territories rich in food and nesting sites. Males enter these territories, build nests, incubate the clutch of eggs the females lay, and then raise the young without the female's help. That because she's busy laying another clutch of eggs in another male's nest. Spotted sandpiper females collect males like male red-winged blackbirds collect females.
And then there are the phalaropes, where brightly colored females pair and defend a series of drably colored males. She lays the eggs, but he assumes all the remaining parental duties.
But not all bird dads are paragons of perfect parenthood. Many grouse, manakins, and bowerbirds assemble at mating grounds called leks where males put on elaborate displays to attract females. Dominant males mate with many females who are left to nest with no help from the male. And some males engage in brief (e.g., ruby-throated hummingbirds) or extended (ducks) courtships before abandoning females.
The moral of this story: There's more than one way to raise a family. Happy Father's Day.
Send questions and comments to Dr. Scott Shalaway, R.D. 5, Cameron, W.Va. 26033 or via e-mail to sshalaway@aol.com