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MASKED DUCK Nomonyx (Oxyura) dominicus 33–38cm. Rarely encountered
denizen of freshwater wetlands with emergent vegetation, from lake edges and
small ponds to roadside ditches. Found as singles or small groups, usually not
associated with other species. Often mostly hidden in vegetation, at least during
daytime; emerges at night on more open water to feed. Feeds by diving; rarely
seen in flight (mainly dawn and dusk) but can spring into air, like a teal.
Breeding male distinctive; female/imm. and nonbr. male have distinctive
buff face cut by 2 horizontal dark stripes (beware similarity to ducklings of
Black-bellied Whistling Duck, often found in same areas). Usually silent.
STATUS: Scarce and local (nomadic?) on both slopes, mainly nw. lowlands, Central Valley, and s. Pacific
slope; might show up anywhere, mainly below 1500m. (Tropical Americas.)
GREBES (PODICIPEDIDAE; 2+ SPECIES) Cosmopolitan family of small to fairly
large diving waterbirds; rarely seen in flight. Ages differ; like adult in 1st year; sexes similar in
plumage, but male averages bigger bill.
LEAST GREBE Tachybaptus dominicus 21–24cm. Small, dark grayish grebe of
varied fresh and brackish habitats, from ponds and roadside ditches to fairly
open lakes and mangroves; favors areas with emergent vegetation for cover, but
sometimes out on open water. Found as singles or small groups, at times
associating with appreciably bulkier Pied-billed Grebe. Note slender dark bill,
golden eyes; broad white wingstripe rarely seen. SOUNDS: ‘Song’ a rapid, slightly
pulsating, purring trill, recalling White-throated Crake but slightly lower,
burrier; also a quacking kwrek, and bleating eirhk! Juv. has high, insistent,
piping whistles. STATUS: Uncommon to fairly common but rather local on both
slopes, to 1500m. (Tropical Americas.)
PIED-BILLED GREBE Podilymbus podiceps 28–33cm. Distinctive, chunky
small grebe with stout pale bill. Found in varied wetland habitats, from roadside
ditches and ponds to slow-moving rivers. Singles or small groups, at times
associating loosely with other waterbirds, especially American Coot, Least
Grebe. Breeding adult has ivory bill with black band; juv. bill appreciably more
slender, dull pinkish overall. Narrow white trailing edge to wings rarely seen.
SOUNDS: Complex ‘song’ a variable series of hollow clucks, coos, and grunts
(can be given at night); also a rapid-paced, bleating chatter in greeting, and
single quiet clucks. STATUS: Uncommon to scarce and local on both slopes, to
1500m; more widespread Sep–Apr. (Americas.)
FINFOOTS (HELIORNITHIDAE; 1 SPECIES) Distinctive, small pantropical
family. Despite the name, Sungrebes favor shady areas, are not closely related to grebes, and do
not dive to feed. Ages/sexes differ slightly (male cares for young); attains adult appearance in
1st year.
SUNGREBE Heliornis fulica 27–29cm. Small, easily overlooked swimming
bird of unpolluted, typically slow-moving waterways with overhanging vege
tation, including mangroves; can disperse to isolated lakes and ponds. Found as
singles or pairs, usually swimming near shady cover. Picks for food on emergent
and hanging vegetation and makes brief skittering dashes to snatch food near
water surface. Flies readily when disturbed, pattering along the surface for
takeoff; flight strong and low over water, when broad rounded tail conspicuous.
Roosts on branches over water. Cheeks tawny on adult female, white on male;
female bill and eyering flush red in breeding season. Juv. has whitish cheeks
(tinged buff on female), duller bill than adult, pinkish-banded feet (yellowish on adult). SOUNDS: Often
quiet, but at times utters a sharp clucking wek! and (in territorial interactions?) a short series of (usually
4) barking clucks, kwek! kwek! kwek! kw’eh. ‘Song’ a series of far-carrying, hollow hoots, ook, ook,...,
usually 1 about every 4 secs, sometimes faster paced. STATUS: Uncommon to fairly common on Caribbean
slope, scarce in s. Pacific lowlands; locally to 800m. (Tropical Americas.)