If you’re a raptor, your decision to choose a mate and begin raising offspring means a sudden increase to the demands of your day. Suddenly it is no longer enough to find food for yourself; instead, you and your mate, previously two solitary hunters, must take on challenges beyond anything you’ve faced before, and even though you’re being driven by instinct, that doesn’t make the task any less daunting. The fact that so few young birds survive their first year of life makes the dedication of their parents that much more admirable, even if it’s also tragic.
Mating age for a raptor varies per species, but regardless, birds that are old enough to mate are those who have at least made it through that first shaky year. They’ve learned the techniques needed to survive, and they’ve earned the right to try to pass on their own legacy to future generations of hawks, eagles, or owls. The most significant and lasting impact of choosing a mate is that raptors are generally monogamous. Most raptors choose a single mate, and depending upon the species, many of these couples will stay together whether it is mating season or not. In 2005, the New York Times detailed scientific efforts to determine whether raptors truly are faithful spouses by testing subsequent broods coming from the same pair over multiple breeding seasons. Similar testing of small birds had shown that egg clutches sometimes featured contributions from multiple fathers; in raptors, however, every offspring from every nesting cycle contained the genetic material of only the same two mated raptors. Coming together, they really are in it for the long haul.
In a general sense, having a mate is advantageous, particularly if the species in question forms these lifetime pair bonds. They can hunt together, and for birds that are typically solitary, having a partner gives them a wealth of new tactics to further aid in procuring food. During nesting season, however, both birds are pushed to their limits for the evolutionary greater good. First, they need a nesting site. Some raptors steal or occupy old nests; others build theirs from scratch, or return to ones they’ve used before. Females require extra energy prior to egg laying, which puts additional pressure on her to hunt like the wind before it’s time to clutch. The more she can feed herself, the larger the stores of energy her body will have to get her through the process. Once she begins laying, it’s the male’s turn: he takes on double duty, hunting to feed both himself and his mate. And you thought it was hard just trying to survive on your own? Try having two mouths to feed. When the eggs hatch, that means two or three more little mouths demanding food as well. And while it may sound like a lot of work for the father to be hunting for an entire family, someone has to worry about defending the nest and their helpless young. Some species will cede ground more readily than others; some, like red-tailed hawks, are capable of laying a second set of eggs if something terrible happens to the first batch. Others, though, will defend their unborn or newborn babies with savage ferocity. Female goshawks, for instance, are legendary for being incredibly aggressive nest defenders, attacking just about anything that gets even close to their nesting site – including people. The size of the threat doesn’t matter; what matters is defending their young.
If all goes well, the babies develop. They get old enough and bold enough to leave the immediate confines of the nest, maybe going so far as to perch on a neighboring limb. Then, if things progress as they should, it will be their turn to go out and make a go of it; eventually they have to survive without their parents feeding them. They have to learn the hard way what to do, and what not to do, in order to live another day. Every failed hunt is a missed meal, and every missed meal is a growing hunger in their belly. But every success is a lesson reinforced. Every time they make a kill, they are learning. Hopefully, they can learn enough to survive the first year. Hopefully, they can last long enough so that one day it will be their turn to choose a mate, build a nest, and sacrifice their all to give their own babies a fighting chance in the world.