Dear Bird Folks,
I’ve read that baby eagles can’t fly until they are ten weeks old. I assume it’s because they are so large. With that in mind, I’d like to know which bird is able to fly in the shortest amount of time after hatching. I’m betting on hummingbirds because they are so small. Right?
– Karla, Wilmington, DE.
While your size-to-flight theory does have some merit, hummingbirds, like many birds, are born naked. That’s a problem. The law clearly states that they can’t leave the nest until they are completely feathered. Ever since Janet Jackson’s infamous “wardrobe malfunction” at the 2004 Super Bowl, the federal government has forbidden nudism, even in birds. (This wouldn’t be a problem if Bill Clinton were still president.) Now the only people who can see us naked are doctors and the perverts at airport security.
It takes a baby Ruby-throated Hummingbird about eighteen days before it grows enough feathers to support flight. That’s actually longer than some larger birds. For example, the House Finch is typically flying in sixteen days and the Song Sparrow’s first flight takes only twelve days. Birds that are born with very few feathers are called “altricial.” In addition to not having feathers, altricial birds are often blind at birth. (According to the law, birds that are born naked must also be blind, so they can’t see each other’s nakedness.) Other birds, like ducks and quail, hatch out fully feathered and with perfect vision. These birds are called “precosial.” Precosial birds have the ability to be up and on the move the day they are born. There is also one other group of birds that not only can see and walk right away, but they can also fly from day one. These birds are called “superprecocial.” I know superprecocial sounds like a name for one of the X-Men, but they are real birds. But, being able to fly the day they are born is not what makes these birds interesting. What is interesting is how they are born.
In far away Australia there are three species of birds known as “mound-builders.” Mound-builders have finally solved the age-old problem of raising children. They simply don’t do it, not one bit. In America we have our own avian slackers, the cowbirds. Cowbirds don’t raise their own kids either; they trick some other sucker bird into doing it for them. However, these Aussie birds would never do that. Being Australian makes them far too polite to do something so devious. Instead, they produce baby birds that are ready to go the day they pop out of the eggs. There is no parental incubating, no feeding, no flying lessons and no lectures about running with scissors. Once the female lays her eggs, she is done with the entire process and never knowingly sees her own offspring. The rest of the work is done by the mound, with just a little help from the old man.
Here’s how it works. The male mound-builder scrapes up a large pile of organic material that contains mostly soil and leaves. As the soil and leaves decay they produce heat. The male senses this heat with his beak. The mound must be just the right temperature in order for him to breed. He won’t mate if he has a cold mound, and who can blame him? If a female arrives before the mound is the correct temperature, she is driven away…but is told to wait by the phone. Things can change. When the internal temperature of the mound reaches around ninety-four degrees, he’s ready for her. The female lays about eighteen eggs, which she buries deep inside the mound. After that she is done. The male stays behind to monitor the temperature. If the mound gets too hot, he digs away some material. If it starts to cool off, he adds a bit more. After about fifty days of mound incubation, the chicks hatch, dig themselves out of the mulch pile and head off on their own, with no assistanance from the male. There is no welcome-to-the-world high-five from the kids or no “thanks for all the hot compost, dad.” The young birds just up and go. It all seems a little cold, but at least the kids don’t ask him for money. So I’m sure he’s fine with it all.
One of the most common mound-builders in Australia is the brush-turkey. Brush-turkeys are not closely related to North America’s Wild Turkeys, although both birds are principally ground dwellers and both have freakish naked heads. However, our turkey has the customary fanned tail, while the brush-turkey’s tail fans laterally. It sticks up like a tail of a fish or a rudder on a plane. Traditionally, brush-turkeys were birds of the rainforests, but in recent years many of them have been moving into suburbia. Most Australians don’t seem to mind sharing their yards with these interesting birds, unless they happen to have a garden. Occasionally, a homeowner will wake up and discover that what used to be a beautiful flowerbed has been turned into a jumbo incubation mound. (And some of you think chipmunks are a pain.)
Because mound-builder chicks get no support from their parents, Karla, they have to be born ready to walk, run and even fly if necessary. This same process takes quite a bit longer for the naked little hummingbirds to achieve. As for that Janet Jackson fiasco back in 2004, I was away from the TV when that happened, so I missed the whole rude and disgusting event. Thank goodness for instant replay.