The ability to observe animals at leisure is not common in nature. Very few animals spend a large portion of their time in view of an interested observer. Nesting birds are a conspicuous counterpoint to this fact. By being able to see an animal at all times, its entire life is made observable. It’s a bit like being able to watch a reality show that is focused on the struggle for life with none of the drama increasing edits needed. The details of this were made obvious to me this spring when I was assigned the task of monitoring an active red-tailed hawk nest and recording the behavior of its inhabitants with the goal of ensuring that nearby construction activity did not force the hawks to abandon the nest, something that can happen if they experience novel disturbances.
Hawks display behavior that many people might find surprising. For instance, male and female hawks share the duties of raising their young, from incubating the eggs to feeding the nestlings; the hawks are a sublime example of egalitarianism in parenting. When it is time for the parents to switch the role of incubator, there is usually a brief moment when the two hawks move close to one another and seem to exchange some subtle form of communication about their time with the eggs, before the hawk whose shift is up flies off, and the other hawk takes its place as incubator. The length of time as incubator varies widely and is typically between one and three hours but sometimes much less or much longer. Often the shift ends when the hawk who is not incubating decides to return to the nest. Sometimes this is clearly too long, or the hawks just want a moment away from parental duties since it can happen that if the weather is warm enough, the nest will be left alone, and the two parents can be seen soaring overhead.
The not needing contrived drama that I alluded to earlier was made apparent when a hapless great blue heron that was likely foraging in a nearby creek happened to fly past the hawk nest, which contained nestlings. The heron likely posed no threat to the young hawks, but the parents had no way of knowing this and responded with a ferocity equal to the months of time and energy that they had invested in their offspring. With a loud, surprised squawk, and two hawks swarming it, the heron beat a hasty retreat and probably found a new spot to forage in the future.
To compliment my own observations, here are a few facts about an animal that can make even the busiest person take a moment to look up, and observe, when they happen to notice one flying overhead with red tail aglow.
Red-tailed hawks are one of the most common raptors in North America, and their distinctive call is widely recognized even by people who don’t own a pair of binoculars or walk around looking up at tree branches as a hobby. Strangely enough people who recognize the call may not connect it with the red-tailed hawk. The reason for this is that the call has been dubbed over the call of many other birds in films and commercials. The National bird of the U.S., the bald eagle, has frequently been subject to having its less majestic call replaced with the soaring sound of the red-tailed hawk.
Red-tailed hawks are also one of the largest birds in North America. The females, which are larger than the males by up to 25%, can be slightly over two feet tall. Despite this size, the heaviest red-tail will weigh just barely over 3 pounds.
Audio Source: Walter A. Thurber/Macaulay Library at the Cornell Lab of Ornithology
Photo Credit: By William Roberts