Today we meet the anhinga, a long-necked bird who’s adept at swimming and spearing fish and is sometimes confused with being a snake. The anhinga’s scientific name, (Anhinga anhinga), gets right to the point. Twice. It’s Spanish name, pato aguja, which translates to needle duck, comments on the physical appearance of this waterbird.
Anhingas are fairly large birds coming in at around 34 inches long and over two and half pounds. They appear mostly black at a distance. If you’re able to get a nice up-close look at them, you’ll notice white streaks across the back on their wings. Females and juveniles have buffy-brown heads and necks but can appear all black from a distance. These birds have webbed feet, very long necks, often held in an ‘s’ shape, and long, sharp beaks (thus the Spanish name).
Anhingas inhabit wetland habitats like lakes, lagoons, slow moving rivers, and mangroves. Some birds that they share these environments with dive into the water from far above for their prey, while others stalk the shores and shallows seeking their meals. The anhinga takes a different approach. It dives right in. They are the submersibles of the bird world. While searching for prey, the anhinga completely submerges below the surface of the water. It uses a quick thrust of its long neck to spear its prey with its sharp bill. They use this method to lance a wide variety of fish, reptiles, amphibians, and aquatic invertebrates.
If you encounter an anhinga in the wild, it will most likely be doing one of these three things, swimming around looking like a snake, sunbathing with its wings spread, or soaring high in the sky. Frequently, while swimming in search of prey, the only visible part of the anhinga is the neck and head, giving the viewer the impression that they’re looking at some sort of serpent zooming around in the water. They enjoy a good sunbath because they, unlike many other species of waterbird, do not have an oil-producing gland that allows them to be waterproof. After a swim, they’re reliant on the sun’s rays to dry their feathers. Anhingas can also be spotted soaring high on thermal updrafts with their wings and necks fully extended, often in the company of other birds like vultures.
Anhingas are present throughout Costa Rica in suitable wetland habitat. While their range is large, they aren’t extremely common within that range, so it’s always a nice treat to see one. While reviewing camera traps I’ll occasionally stumble upon them, more often than not, doing one of the three activities listed above. I record them with my camera traps most frequently when I place my cameras in trees overhanging a body of water. You can see a few of my favorite anhinga clips in the video below.
