Florida’s Underwater Fishing Experts
If you’ve ever walked near a lake, marsh, canal, or coastal shoreline in Florida, chances are you’ve seen a dark waterbird perched with its wings stretched wide in the sun. You were probably looking at either an Anhinga or a Cormorant, two native Florida birds that are highly skilled underwater hunters. Anhingas and Cormorants are often mistaken for one another, but they are different species with unique traits, behaviors, and appearances. Though both are native, most Anhingas are a year-round resident, whereas Cormorants are more of a seasonal-resident with some birds migrating south in the winter.
Meet the Anhinga
The Anhinga (Anhinga anhinga), also referred to as the “snakebird”, is a large water bird. They can grow to be 34 to 36 inches in length with a wingspan of almost four feet. They have earned their nickname due to their distinctive swimming behavior and physical appearance. When swimming, Anhingas often keep most of their body underwater, leaving only their long neck above the surface, making them look like a snake gliding though the surface of the water.
Anhingas prefer to reside in shallow, slow-moving, sheltered, freshwater wetlands for hunting, with access to nearby perches and banks for drying and sunning themselves. They are commonly found in habitats such as lakes, ponds, marshes, swamps, and rivers. With the exception of periods of severe drought, Anhingas are rarely found outside of a freshwater habitat.
Anhingas have very long, slender necks along with a sharp, pointed bill that they use like a spear to catch fish. Male Anhingas are mostly black with silvery wing markings, while females have a lighter tan or buff-colored neck and head. Unlike pelicans or gulls, they don’t scoop up prey. Instead, they dart forward quickly underwater and stab fish with precision. Once they spear their prey, they surface, toss their prized catch up into the air and swallow it headfirst. Anhingas consume about one-quarter to one-third of their body weight in fish each day. That’s pretty impressive for a bird with an average weight of 2.7 pounds!
There are at least 40 different species of Cormorants, but the most commonly found species in Florida is the Double-Crested Cormorant (Nannonpterum auritum). Double-Crested Cormorants are chunkier birds with thicker black bodies, averaging a weight of 4-6 pounds. That’s almost double the average weight of an Anhinga! They also have shorter necks, crystal blue eyes, yellow-orange facial skin, hooked bills designed for gripping slippery prey, and an orange throat pouch similar to their pelican relatives. Mature adults have fully black bodies, while juveniles have paler feathers on their head and breast. Unlike Anhingas, males and females look alike at both ages.
These birds are often seen in both freshwater and saltwater environments, including lakes, bays, estuaries, canals, and coastlines. Cormorants are strong swimmers like Anhingas. They use their webbed feet to propel themselves underwater in pursuit of their prey. But rather than spearing their prey like Anhingas, Cormorants use their hooked bills to chase and grab fish. This species of Cormorant eats more than 250 species of fish!
There are a lot of similarities between the Anhinga and the Cormorant. Anhingas (pictured on left) and Double-crested Cormorants (pictured on right) share a spread-winged behavior that is almost identical. They both have lengthy, snake-like necks and are often seen perched along the shore, in rivers, lakes, ponds and other bodies of water. Their ability to swim with their body completely underwater is due to the unique shape of their feathers and lack of preen oil on them, which birds use to waterproof their feathers. Unlike many waterbirds, the Anhinga and Cormorant's feathers are not waterproof due to the lack of preen oil. They become waterlogged when submerged in water, making it easy for them to dive into the water and stay submerged in order to hunt underwater prey, such as fish and amphibians. This adaptation to their buoyancy has equipped Anhingas and Cormorants with the ability to stay underwater for substantial periods of time. Because their feathers absorb so much water, Anhingas and Cormorants cannot take flight directly after being submerged. Instead, they find a perch and spread their wings wide open to dry in the sun. Wing-spreading is one of the most recognizable behaviors shared by both birds. That dramatic sunbathing pose helps dry their wings and warm their bodies before the next fishing trip.
Differences
Though Anhingas and Cormorants are both water birds with long necks and strong swimming abilities, their physical characteristics differ in many ways. Anhingas (pictured on left) rely on their long, pointed beaks to spear fish. Whereas Double-crested Cormorants (pictured on right) have thin, strongly hooked bills that they use to grab their prey. Cormorants are generally stockier and denser than Anhingas, which are longer and slimmer in stature. Cormorants also have a hooked shaped bill, shorter neck and tail, distinctive crystal blue eyes, and no markings on their back. Anhingas have blue green to reddish colored eyes, white markings on their back, and a straight pointed bill. Anhingas also often ride low in the water with only their neck visible, while cormorants float higher and show more of their body. An easy way to remember the differece is that the pointed beak of an Anhinga resembles the letter "A", and the curved beack of the Cormorant resembles the letter "C".
Along with physical differences, there are many other important differences between the two species. Anhingas much prefer to reside in freshwaters whereas Cormorants inhabit mostly coastal waters. Other behavioral differences include migration patterns, hunting techniques, social behaviors, and calls. Anhingas travel a short distance when migrating, make a loud raptor-like clicking sound, and prefer to hunt independently (except during breeding season). Cormorants, on the other hand, migrate a longer distance, produce deep guttural sounds, and are highly social creatures that prefer to hunt and nest in groups.
Both of these birds are apex predators within their aquatic environments. Their diet mainly consists of fish and other small aquatic animals. This helps maintain balance in aquatic ecosystems by regulating populations of various prey species. This type of natural regulation prevents any single fish species from becoming overly dominant in a particular ecosystem, indirectly promoting biodiversity. Anhingas and Cormorants also serve as indicators of wetland health. Healthy lakes, rivers, and marshes with good fish populations can support birds like Anhingas and Cormorants. These birds are specialized hunters, efficient divers, and excellent examples of how animals adapt to their environment. Next time you see a dark bird perched, drying its wings by the water, take a closer look. Is it the sleek, snake-necked anhinga or the sturdy, hooked-billed cormorant? Either way, you got to witness one of Florida’s most skilled anglers at work!
