32
CORMORANTS (PHALACROCORACIDAE; 1 SPECIES) Worldwide family of
rather large diving birds with long, hook-tipped bills, fully webbed feet. Ages differ, sexes
similar; adult appearance attained in 2–3 years.
NEOTROPIC CORMORANT Phalacrocorax brasilianus 64–70cm. Only cor
morant in Costa Rica, but cf. slightly larger and longer-tailed Anhinga, which
has sharply pointed bill, very long and pale-tipped tail. Widespread in varied
wetland habitats, from ponds and rivers to mangroves and inshore coastal
waters. Roosts on trees, rocky islets, sandbars; often perches with wings
outstretched. Flies with fairly quick wingbeats, brief glides, often in lines and
Vs like waterfowl or ibises. Locally in flocks of 100s. Imm. can fade to mostly
whitish below. SOUNDS: Guttural grunts and croaks in interactions and when
nesting. STATUS: Fairly common to common locally in lowlands, smaller
numbers inland along rivers and at lakes; mostly below 1500m. (Americas.)
ANHINGAS (ANHINGIDAE; 1 SPECIES) Small pantropical family of long-necked,
long-tailed diving waterbirds with sharply pointed bills, fully webbed feet. Ages/sexes differ;
adult appearance attained in about 3 years. Wing molt synchronous, unlike gradual wing molt
of cormorants.
ANHINGA Anhinga anhinga 84–94cm, WS 109–119cm. Varied wetland
habitats, from small wooded ponds to lakes, rivers, mangroves. Distinctive, but
cf. Neotropic Cormorant, which is often in the same areas. Perches on trees over
water, often with wings outstretched, and soars readily on thermals. Flies with
deep strong wingbeats, alternated with glides on flattish wings, the long tail
usually spread slightly. Often swims with only neck above the surface, jerking
along, hence a local name ‘snakebird’ (cormorants can also do this, however).
Juv. has dirty buff head and neck, brown belly, duller upperwing panels than
adult; 2nd-year like duller adult. Breeding male develops pale puffy plumes on
head and neck, bright blue eyering. SOUNDS: Rasping and creaky short croaks, often in slightly stuttering
or descending series. STATUS: Fairly common to uncommon locally on both slopes to 1000m, rarely
wandering higher. (Tropical Americas.)
DUCKS (ANATIDAE; 12+ SPECIES) Familiar worldwide family usually associated
with water. Ages differ slightly to distinctly; most species attain adult appearance within 1st
year. Sexes similar in whistling ducks, different in other ducks (nonbr. males resemble females in
late summer, but this plumage not typically seen in Costa Rica). A few other northern migrant
ducks occur as irregular and rare winter visitors as far south as Costa Rica (Appendix B).
MUSCOVY DUCK Cairina moschata 66–87cm male>female. Large, very
heavy-bodied duck of wetlands with adjacent cover, from forest streams to
mangroves; perches readily in trees. Feeds by dabbling, often while wading in
shallows. Distinctive, but widely domesticated; wild birds usually wary, mainly
seen in flight. Signs of feral origin include extensively pink face (vs. mostly dark
on wild birds) and variable white patches on head and body; black-bodied feral
birds typically distinguished by mixed black-and-white on the largest upperwing
and underwing coverts (vs. solidly white on wild birds). Male appreciably larger
than female, obvious when together; juv. dark overall, usually with white spot
on forewing. SOUNDS: Low quacks and hisses, rarely heard. STATUS: Scarce (mostly) to locally fairly
common (in more remote and protected areas) on both slopes, mainly below 1200m; feral birds possible
anywhere. (Tropical Americas.)
