Neotropical Cormoran
Quick Facts
- Scientific Name: Nannopterum brasilianum
- Spanish Name: Cormorán neotropical
- Family: Phalacrocoracidae
- Known Nicknames: Neotropic cormorant, Olivaceous cormorant, Bigua cormorant
- Average Length: 58–73 cm / 23–29 in
- Average Weight: 1.0–1.5 kg / 2.2–3.3 lb
- Wingspan: 91–102 cm / 36–40 in
- Key Feature: Long, slender, hooked bill and a distinct white border to the gular pouch (throat patch)
- Primary Diet: Piscivore (primarily fish, also crustaceans and amphibians)
- Range: Southern United States (Texas, Louisiana) through Central America and South America to Tierra del Fuego
- Habitat: Freshwater and coastal wetlands: rivers, lakes, mangroves, estuaries, and lagoons
- Social Structure: Colonial (nests in large mixed-species colonies; often roosts in groups)
- Nesting/Breeding: Cliff ledges, tree branches, or man-made structures (e.g., bridges, pylons) near water
- Statut de conservation : Préoccupation mineure (LC)
- Population Trend: Increasing
The Neotropical Cormorant (*Nannopterum brasilianum*), often seen drying its outstretched wings in a characteristic “heraldic” pose, is a sleek, dark waterbird found from the southern United States through South America. Unlike many cormorants, it has a notably long, slender bill with a distinct hook at the tip, perfectly adapted for spearing fish. Its general appearance is glossy black with a subtle bronze sheen on the back, while breeding adults develop white tufts on the sides of the head and a patch of white feathers on the throat. A unique special feature is its reduced uropygial gland, which produces less waterproofing oil—hence the sunning posture, which is essential for drying its partially wettable plumage and allowing it to dive deeper for prey. Highly social and often seen in large flocks, this cormorant is a masterful underwater hunter, propelling itself with powerful webbed feet.
Faits amusants
Unlike most cormorants, the Neotropic Cormorant has a unique "sky-pointing" display where it tilts its head back and points its bill straight up—a posture thought to aid in swallowing large fish or to signal during courtship. It is one of the few cormorant species that regularly perches on power lines and fence posts far from water, using its sharp, hooked bill to grip slippery prey like eels and catfish. A quirky adaptation: it often dries its wings by spreading them wide in a "heraldic" pose, but unlike other cormorants, it can also stay submerged for over a minute while hunting, using webbed feet and a rudder-like tail to chase fish through murky shallows.
Habitats et répartition
The Neotropical Cormorant is highly adaptable and inhabits a wide variety of freshwater and coastal environments. It is commonly found in lakes, rivers, marshes, estuaries, mangrove swamps, and sheltered bays, preferring areas with calm or slow-moving water where it can forage for fish. This species also frequents artificial habitats such as reservoirs, irrigation canals, and sewage ponds. Its geographical range is extensive, stretching from the southern tip of Texas in the United States and coastal Mexico, through Central America, and across most of South America east of the Andes. The distribution continues south through Brazil, Bolivia, Paraguay, Uruguay, and Argentina, reaching as far as Tierra del Fuego. It is absent from the high Andes and the western coastal deserts of Peru and Chile.
Comportements & Reproduction
Neotropical cormorants are highly social, nesting in dense colonies often mixed with other waterbirds. They are monogamous during a breeding season, with pairs forming through elaborate courtship displays that include wing-waving, bill-touching, and mutual preening. Males typically select a nest site and then attract a female by presenting nesting material. Both parents share incubation duties for about 25–30 days, and after hatching, they cooperatively feed the chicks by regurgitation. A unique reproductive strategy is their ability to breed opportunistically in response to water levels; in fluctuating wetlands, they may initiate nesting shortly after rains or floods to ensure food availability, sometimes raising two broods in a single season if conditions remain favorable.
Alimentation
The Neotropical Cormorant is an exclusively piscivorous bird, meaning its diet consists almost entirely of fish. It primarily hunts small, slow-moving, schooling species found in shallow coastal waters, estuaries, lakes, and rivers, such as tilapia, mullet, and killifish. Unlike many other cormorants, it rarely eats crustaceans or amphibians, focusing strictly on fish. An interesting fact about its feeding behavior is that it forages in large, synchronized flocks, often working with other fish-eating birds like pelicans to corral prey into dense balls. Another notable trait is that, because its feathers lack full waterproofing (which helps it dive deeper by reducing buoyancy), the Neotropical Cormorant must spend significant time after each feeding session perched with its wings spread open to dry them, a process essential for maintaining its ability to hunt efficiently.
Couleurs
The Neotropical Cormorant is predominantly glossy black overall, with a slight greenish or bluish iridescence on the back and wings during breeding season. It has a bright yellow-orange throat pouch and a distinctive white border along the rear edge of the gular pouch. Non-breeding adults may show a small white patch on the throat. Juveniles are brownish with a pale whitish belly and breast. Its dark plumage aids in thermoregulation and provides camouflage against dark water and rocky shorelines.
