Grebes and cormorants of Puerto Rico

Pied-billed Grebe: the ringed bill

Pied-billed Grebe is compact and short-necked with a thick, chicken-like bill. In breeding season the bill is whitish with a black ring and the throat turns black; outside that season the bill is dull and pale and the plumage brown. When threatened it does not fly off: it sinks slowly until only its head shows above water.

In Puerto Rico it is a common resident of wetlands, ponds, and reservoirs on the coastal plain, and it also occurs on Culebra and Vieques. The Atlas found it in 89 hexagons and documented breeding year-round, with the most activity from March to June. It builds a floating nest of plants anchored to vegetation. In breeding season it gives hollow, cuckoo-like notes.

Least Grebe: the yellow-eyed grebe

Least Grebe is the smallest grebe in the Americas, 8 to 10 inches long, dark gray, with a thin bill and a bright yellow eye that shows even at a distance. In breeding season its throat darkens. It flies more readily than other grebes, and pairs give metallic trills as a duet.

In Puerto Rico it is uncommon and local in the lowlands, favoring freshwater ponds, canals, and temporary pools with thick floating vegetation, plus cattail marshes. It is usually seen at Caño Tiburones Natural Reserve, and the Cabo Rojo and Laguna Cartagena refuge checklist rates it common in all four seasons. It nests over water among emergent vegetation.

Grebe, duck, or gallinule?

Many people call a grebe a "diving duck," but it is not a duck. Ducks have flat bills; grebes have short pointed or thick chicken-like bills and almost no visible tail. A grebe also vanishes underwater without warning and resurfaces far away, while dabbling ducks tip up with their tails in the air. Resident diving ducks such as Ruddy Duck have stiff tails and broad bills.

Common Gallinule swims on the same ponds but has a red shield and bill and a white flank stripe. If the bird is brown, round-profiled, shows no red on the face, and sinks instead of flying, it is almost certainly a grebe.

Cormorants: rare visitors

Cormorants are large, dark, hook-billed waterbirds that swim low in the water and perch upright with wings half-spread to dry. In our catalog, both Double-crested Cormorant (Nannopterum auritum) and Neotropic Cormorant (Nannopterum brasilianum) are listed as accidental in Puerto Rico: they do not breed here, and every record is news.

Double-crested Cormorant is North America's most widespread cormorant, blackish with orange skin on the face and throat, and it flies with a slight kink in the neck. Neotropic Cormorant lives in warm waters, mostly fresh or brackish, from the southern United States to South America and in Cuba and the Bahamas, and it sometimes fishes in groups driving fish into shallows.

Neotropic or Double-crested: the key marks

Neotropic Cormorant is about 20 percent smaller, with a slimmer head, shorter bill, and a noticeably longer tail: in flight the tail extends behind the wings almost as far as the neck and head extend in front. The most reliable mark is the lores, the skin between eye and bill: dull gray to blackish on Neotropic and almost always orange on Double-crested.

Check the throat skin too. On Neotropic it is duller yellow-orange and comes to a point behind the eye; on Double-crested it is bright orange with a rounded rear edge. In breeding plumage, Neotropic has a border of white feathers forming a "V" on the face. Photograph the head in profile and the bird in flight to document the record.

Where to find grebes and how to report a cormorant

For both grebes, the best bets are Laguna Cartagena, Caño Tiburones Natural Reserve, and vegetated lowland ponds; Pied-billed Grebe also uses reservoirs. Watch patiently from shore: after each dive, wait and scan, because they often resurface several yards from where they went down.

If you see a large, black, hook-billed bird drying its spread wings on a lagoon or pier, first rule out Magnificent Frigatebird and boobies. If it looks like a cormorant, photograph the head, throat, and tail, note the exact date, time, and place, and submit it to eBird: a well-documented record is the only way to confirm an accidental species.

What is a zaramago?

Zaramago is the Puerto Rican name for grebes (family Podicipedidae). The Zaramago proper is the Pied-billed Grebe, a common resident of ponds and reservoirs that dives for food and sinks when threatened.

What is the tigua?

The Tigua is the Least Grebe (Tachybaptus dominicus), the smallest grebe in the Americas. It is dark gray with a yellow eye and thin bill, and in Puerto Rico it is uncommon and local on freshwater ponds with floating vegetation.

Are there cormorants in Puerto Rico?

Only as rare visitors. Double-crested and Neotropic Cormorants are recorded as accidental and do not breed in Puerto Rico. A large dark bird drying its spread wings deserves photos and an eBird report.

How do I tell a Neotropic Cormorant from a Double-crested?

Neotropic is about 20 percent smaller, with a longer tail, gray to blackish lores, and yellowish throat skin that ends in a point. Double-crested has orange lores and throat skin with a rounded rear edge.

Is a grebe a duck?

No. Grebes form their own family. Unlike ducks, they lack flat bills, show almost no tail, and build floating nests. That is why people sometimes call them diving ducks even though they are not.

Why does a grebe sink in the water?

It is how it escapes. Instead of flying, the Pied-billed Grebe sinks slowly until only its head shows, or dives and resurfaces far away. It also dives to catch fish, insects, and other prey, driven by its feet.