Speaking of Nature: the anhinga
Bill Danielson photo
The gorgeous eyes of a male anhinga in breeding plumage are a splendid display of color.
Bill Danielson photo
This flyover by an adult female anhinga shows the characteristic shape of the bird in flight.
Bill Danielson photo
An immature anhinga dries its wings on a piling with decorative lights.
When I looked at the calendar on my office desk, I was absolutely floored by how quickly time has gone by. January is more than half over, midterms are already under way and winter break is just around the corner. And with the winter weather shifting from rain in the 50s to snow in the 10s, I think everyone is getting a little mixed up. Our last bout of rain had everyone thinking it was spring and lamenting the fact that it wasn’t.
Spring is still months off, but summer is a simple airplane flight away and many people are planning to visit summer in February by flying south to Florida. I just returned from such a trip and I know the delightful weather that is waiting for any of you who are Florida-bound. I wish I could go again, but that’s just not in the cards this year.
Florida may represent many different things to many different people, but if you’re like me, then nature is on your mind. It doesn’t matter how many times I visit, I simply want to immerse myself in a subtropical landscape filled with all sorts of strange and wonderful plants and animals. Even familiar faces, like those of the northern cardinal or the blue jay, seem new and mysterious in forests that contain palm trees.
But the one bird I most look forward to seeing is the anhinga (Anhinga anhinga). It is so wildly different from any bird we have here in the Northeast that it is simply a joy to be in their presence and observe their strange ways. And strange they are!
By northern standards, the anhinga is huge. With a body length of 3 feet from the tip of the beak to the tip of the tail, the anhinga is larger than the majority of northern birds. Its wings are just about 4 feet across and are extremely broad. The bird’s tail is just about as long as its neck and in flight these characteristics give the bird the appearance of a large “X” with one thick leg and one narrow leg.
When you get close to an anhinga, however, you realize that all of this size hides the fact that the bird is actually quite delicate. The anhinga’s beak is long, slender and tapers to a fine point. The anhinga’s neck is long, slender and serpentine in appearance, which clearly contributes to one of the bird’s folk names — the snakebird. But appearance alone may not explain this name. Behavior probably played a role as well.
The anhinga is a fishing bird that pursues its prey underwater. Many birds make a living in this way, but the anhinga is rare among water birds because it spends so much time in the water, but its feathers are not waterproof. So, when the anhinga enters the water to hunt, it becomes waterlogged almost instantly.
Only a tropical bird could take an approach to an aquatic life such as this because only a tropical bird could rely on the consistent warmth of both water and air to keep it from dying of exposure. And the waterlogged condition is very helpful for the anhinga as it hunts underwater. No energy is lost trying to fight one’s own buoyancy if one has no buoyancy to fight.
So when the anhinga gets into the water, it can sink with great ease and it is often seen swimming along with nothing but its snake-like head and neck visible above the surface. This must surely have been a contributing factor to the name “snakebird.”
The slender neck with the long tapered beak allows the anhinga to poke and probe into every conceivable hiding place where a fish might try to avoid capture. The shape of the beak is also essential for the anhinga’s capture of prey because unlike almost every other bird that fishes for a living, the anhinga actually impales its victims with its rapier beak rather than simply grasping them.
This does present the successful hunter with a bit of a problem once a fish has been captured in this way. How does a bird with no hands manage to get the fish off its beak and down its throat? The answer — carefully! I imagine there is a steep learning curve for young anhingas as they try to manage the technique.
First, the fish must be stunned. That way the fish will not be able to escape in the event that it is accidentally dropped. So the anhinga will swim to a favorite log, or other hard perch, and commence bludgeoning the fish into incoherence. It is also possible that this serves the purpose of loosening the wound around the beak, which facilitates the next step.
Once the fish is sufficiently stunned, the anhinga must then go about the process of a careful series of shakes that send the fish closer and closer to the tip of the beak. Forcing the fish against a log and slowly pulling backward with the head may also help in this endeavor. The trick is to loosen the grip without dropping the fish altogether.
Finally, once the bird is ready, an expert flip of the beak will toss the fish into the air where it can be caught with the beak. This has to be the most difficult maneuver for young anhingas to master, but adults make it look easy. I suppose it is fair to say that any anhinga that can’t do this with grace and finesse probably doesn’t live long enough to become an adult.
Once the meal is consumed, the bird will either resume its hunting, or head for a favorite perch out of the water where it can dry its wings. This is accomplished by simply spreading its wings out and putting its back to the sun, the way a turkey vulture might dry its wings after a heavy rain. Anhingas spend a lot of their time drying and preening their feathers and this is a great time to see the differences between the sexes.
The male is jet black with white highlights on the feathers of the back and wings. In the breeding season, the males will also develop a crest of feathers on top of their heads. But to my mind, the most beautiful feature of a male anhinga is his eyes. Scarlet irises surrounded by blue-green skin are located right next to a goldenrod beak in an almost duck-like display of color.
The body of a female anhinga will look quite similar to that of the male, but the feathers of the neck are a dull, coffee-brown. Immature birds have even more brown in their feathers, but as they age, they can approach the appearance of a female. The only way to distinguish an older immature bird from an adult female is those red eyes. The young birds have brown eyes.
So if you find yourself headed to Florida in the next few weeks, be sure to keep your eyes open for anhingas. They will be found near calm, fresh water and can surprise you by popping up almost anywhere from drainage canals, to golf courses, to large amusement parks with water features. February is the beginning of the breeding season, so the males will be at their most spectacular.
Bill Danielson has worked as a naturalist for 16 years. In that time, he has been a national park ranger, a wildlife biologist and a field researcher. He currently works as a high school chemistry and biology teacher. To contact Bill, or to learn more about his writing, visit www.speakingofnature.com