Recently, on a Jay's Bird Barn (now The Lookout)-sponsored guided bird walk, I discovered a hummingbird nest under construction. Our group was birding in Watson Woods, and I was lucky enough to see a hummingbird fly by, and I visually followed it and saw her land on her nest.
Finding a hummingbird nest in nature is usually totally accidental, with a little bit of luck thrown in. For starters, their nests are small, and they typically use natural materials that blend in with the tree or shrub where they build their nest.
However, when a female is actively building her nest, her flight patterns are predictable and can lead you to a delightsome discovery when you locate a nest. The nest is usually made with soft, downy plant materials, spider cobwebs and pieces of bark or lichen to match the exterior color of the nest with the color of the branches to which the nest is attached.
Interestingly, other than the act of mating, the male plays no roll in nest-building, incubation or rearing the young. When I share this tidbit of information with bird watchers, invariably someone makes a comment that they have known a lot of men like that! But all kidding aside, the females are busy when they are building their nest.
Female hummingbirds typically lay two eggs, which are about the size and shape of Tic-Tac breath mints, if you are familiar with those. Since the female does all of the incubating, she has to leave the nest unattended from time to time throughout the day to go forage for food, as the male does not bring any food to her when she is on the nest.
This brief foray to find food is necessary since she doesn't have a mate sharing this duty, and she couldn't possibly survive the 21-day period it takes for the eggs to hatch. Once the babies have hatched, the female will gently remove all eggshell fragments to keep the nest tidy.
When the babies hatch out, their type of development (that which occurs in the egg) is referred to as 'altricial.' Baby hummingbirds are completely helpless - their eyes are closed, they are basically featherless, and they are not capable of feeding themselves. On the other hand, baby bird species such as quail, ducks and geese are covered with a downy coat of feathers, with eyes open and they are totally ambulatory. This type of development is referred to as precocial.
Depending upon the weather, a mother hummingbird continues to sit on the nest after the babies have hatched to provide themoregulation, since the babies really don't have the ability to maintain their body temperature. Gradually, as the babies' feathers fill in, the mom spends less and less time on the nest, and she will be out foraging for food to feed them.
The fledging process - the time between hatching and when they are ready to leave the nest - takes another 21 days. For several days, prior to leaving the nest, the babies will sit on the edge of the nest and practice flying by vigorously flapping their wings. Adult hummingbirds, in flight, flap their wings about 60 times per second, so the babies really have to build their muscles before their first flight!
Even after fledging, the mother will continue to care for her babies for a week or two until the youngsters are capable of gathering enough food on their own. I hope you are enjoying the hummingbirds in your yard this spring - they are truly a marvel!
Birding tip for the week: Be on the lookout for lazuli buntings this week. Their preferred diet at feeders is white-proso millet.
Until next week, Happy Birding!