Spring is officially coming and despite all that is going on around us, nature stays steady completing the tasks of instinctual behavior. Nesting is one such activity in the life cycle of birds that cannot be denied. Within their seasons of migration, courtship, nesting and maturing, a cyclic pattern is practiced, season after season, year after year.
How do birds know it is nesting season? Within birds, like humans, glands producing hormones stimulate the species to procreate. For birds, this instinct is tied to day length. When the hours of day light tip to a certain level, physiological changes stimulate breeding instincts.
Along with this urge comes the need to find suitable nesting territory. Birds seek regions which will provide safe nesting from predators and plenty of food for the young soon to hatch. Intriguingly, birds time breeding and nesting so appropriate food is abundant for the nestlings.
Chances are you’ve seen osprey around our region flying about with very large sticks in their talons or enjoyed watching them bring a fish back to the mate incubating eggs. Whether a nest is made of sticks, mud or palm fibers woven with shed snakeskins and Spanish moss rests solely on the species creating the build. Nests are characteristic of each, and some don’t create a nest at all, but simply use what is known as a “scrape,” laying eggs right onto the ground surface.
Providing a safe, comfortable place for young to develop is the purpose of every nest, regardless of its construction or lack thereof. Some adults either molt or pluck a section of feathers from their belly to create a “brood patch” prior to sitting on the eggs. This skin to egg incubation keeps the temperature just right until hatching time. Having a parent on the nest also shades eggs and resulting young from the harsh sun. Disturbing nesting birds, particularly wading birds, exposes nestlings to almost certain death from exposure. Due to this, it’s very important not to approach nesting areas on lake edges or in rookies along the water.
While the small, stick nests of songbirds is familiar, you might be surprised to know the nest of a Bald Eagle can be up to six feet across with a depth of about three feet. This is comparable to a king-sized bed. Imagine the energy required to build such a structure, stick by stick. It’s no surprise eagles reuse nest sites year after year, adding additional material each season.
Birds are remarkably adaptable and urban nests can be found just about anywhere including hanging planters, BBQ grills, building tops, power poles and the signage of big box stores. The urge to nest cannot be denied and while they sometimes nest in less than desirable locations, it’s important to note that nests and the birds inhabiting them are protected.