Quick Answer
The aquatic bird being described is likely a cormorant. Cormorants are medium-to-large sized waterbirds that have predominantly dark plumage, long necks and bodies, and slender hooked beaks. They are expert swimmers and divers, and use their hooked beaks to catch fish and other prey underwater.
More Detailed Answer
Cormorants are a group of about 40 species of aquatic birds that belong to the Phalacrocoracidae family. They have a cosmopolitan distribution, meaning they are found nearly worldwide in coastal areas and inland waterways. Some of the most widespread and commonly encountered species include the Great Cormorant, Double-crested Cormorant, and Great Cormorant.
Cormorants are medium-to-large sized birds, ranging from around 70 cm to 100 cm in body length. Their most distinctive feature is their long, slender, hooked beak. The beaks are serrated which helps them hold onto slippery prey. Their necks are also relatively long, allowing them to reach down to catch prey. Cormorants have compact bodies that are adapted for diving and swimming underwater. Their feet are fully webbed and their legs set far back on their bodies to provide optimal propulsion in the water.
True to their aquatic lifestyle, cormorants have dense, waterproof plumage. Their feathers are predominately black or very dark brown in color. Some species may show white patches on their cheeks, throat, or belly. The black plumage is an adaptation to hunting underwater, as it provides camouflage against dark water backgrounds when viewed from above. The dark coloration also discourages water-logging, as melanin strengthens and waterproofs feathers.
Cormorants are piscivorous, meaning fish make up the bulk of their diet. They hunt by diving from the surface and pursuing prey underwater. Powerful feet and webbed toes propel them through the water as they chase after fish. When they spy a target, they seize it in their hooked beak. The serrated edges help them maintain a firm grip on slippery, wriggling prey. Cormorants are capable of diving to depths of up to 45 meters in search of food. They are voracious predators, and can eat around 1 pound of fish per day.
Habitat and Distribution
Cormorants occupy a wide range of aquatic habitats across most of the world’s continents. They are found along rocky coasts, in estuaries, lakes, rivers, and wetlands. Most species utilize both saltwater and freshwater ecosystems. They require areas with ample fish to prey on.
Some of the key places worldwide where cormorants can be found include:
- Coastal regions of North America, South America, Europe, Africa, Asia, and Australia
- Lakes and inland waterways of North America, Europe, Asia, and Africa
- Islands including Greenland, Iceland, Japan, and New Zealand
Many species are at least partially migratory, traveling to warmer climates during the winter months. Cormorants often gather and nest in large colonies. They build nests near the water, in trees, on cliffs, or on the ground on secluded islands.
Species Examples
Some of the most widespread and familiar cormorant species include:
- Great Cormorant – Common in Europe, Asia, Africa, and Australia. Entirely black plumage with bright orange facial skin.
- Double-crested Cormorant – Abundant in North America. Black with orange facial skin and paired head tufts.
- Neotropic Cormorant – Found in Central and South America. Smaller with a square tail and yellowish throat pouch.
- Pelagic Cormorant – Occupies western North America. Small with a slender bill and white thigh patches.
- Red-faced Cormorant – Endemic to New Zealand. White cheeks and throat; blue eye ring.
Comparison to Other Waterbirds
While the overall description clearly points to a cormorant, there are some other types of dark-colored aquatic birds that have some similar characteristics. Comparing cormorants to these related species highlights some of their distinctive features:
Cormorants vs. Anhingas
- Anhingas are very closely related to cormorants. They occupy similar habitats worldwide.
- Anhingas have longer, more slender beaks and longer tails than cormorants.
- Male anhingas have black and brown plumage; females have light tan neck and chest.
Cormorants vs. Herons and Egrets
- Herons and egrets have long legs and more upright postures suited to wading.
- Most herons have longer necks and legs relative to body length.
- Plumage patterns are varied, often with white and grey coloration.
Cormorants vs. Loons
- Loons are unrelated to cormorants, but occupy similar aquatic habitats.
- Loons are bulkier, with short necks and thick, pointed bills.
- Plumage tends to be black and white checkered patterns.
Cormorants vs. Grebes
- Grebes are small to medium-sized diving waterbirds.
- They have short necks and bills, and lobed feet set far back on the body.
- Usually have black, brown, and white striped or mottled plumage.
The slender hooked bill, dark plumage, long neck and body adapted for diving sets cormorants apart from these other types of aquatic birds. Their unique adaptations make them highly efficient at pursuing and catching fish underwater.
Cormorant Behaviors
Beyond their physical traits, cormorants exhibit some interesting behaviors and traits:
- Drying their wings – After fishing, cormorants will often perch with their wings outstretched. This allows their non-waterproof feathers to dry out to regain the ability to fly.
- Plunging dives – Cormorants dive straight down from the surface when hunting, like an arrow. Their streamlined shape and dense bones help them plunge below.
- Swimming low – They swim very low in the water with just their neck and head sticking out. This reduces drag for efficient underwater propulsion.
- Nostril flap – A small flap of skin covers their nostrils to prevent water entry when diving.
- Colonial nesters – They tend to gather in colonies or groups during breeding season for nesting and raising young.
Observing cormorants in their habitat reveals much about their specialized adaptations for a fast-paced aquatic lifestyle hunting fish.
Conclusion
Based on the description given of a dark aquatic bird with a long neck and body and slender hooked beak, the bird in question clearly matches the traits of a cormorant. Cormorants comprise a diverse family of fishing waterbirds distributed widely across coastal regions, lakes, and waterways. Their dense, dark plumage aids underwater camouflage, while a long coiled neck and beak allow them to snatch up passing fish. While similar to some other diving waterbirds, the unique adaptations of the cormorant make it unmistakable. Watching cormorants swiftly and seamlessly pursuing prey underwater gives a glimpse into their specialized fishing abilities.