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TIGER HERONS (GENUS TIGRISOMA)

(3 species). Large, heavyset tropical herons with very

long necks, relatively short legs. Usually close to wooded cover and perch readily in trees; hunt by waiting

and slow stalking. Flight heavy, with stiff wingbeats emphasizing upstroke; note broad wings, very short

foot projection relative to other herons. Ages differ: 1st-years of all species similar and boldly ‘tiger-

barred’ with tawny and dark brown; 2nd-year resembles adult but with coarser barring, duller pattern;

like adult in 3rd year. Deep throaty ‘songs’ (may suggest large owl or mammal) often given at night.

BARE-THROATED TIGER HERON  Tigrisoma mexicanum 71–82cm. Lowland

wetlands with slow-moving water, ponds, mangroves, wooded swamps, damp

pastures; locally also rocky streams and rivers in foothills. See genus note. Singles

or locally loose concentrations up to 10 or so birds may hunt in fairly open

situations along with other herons, storks, ibises. All ages have diagnostic naked

yellow throat skin, but can be difficult to see (pale yellowish on imm., orange-

yellow on displaying adult). Adult distinctive: gray face contrasts with black cap,

warm brownish neck has fine barring. Imm. plumages much like other tiger

herons, differs from Fasciated Tiger Heron in longer bill, habitat (but both can

occur in fast-flowing rocky streams); averages duller rusty than Rufescent Tiger Heron, but plumage tones

and patterning of both species variable, not known to be reliable for ID; note habitat differences (Bare-

throated in mangroves, semi-open habitats, Rufescent in rainforest; but can occur together in some areas).

Also cf. Pinnated Bittern. SOUNDS: Flushed birds often give low, guttural grunts. In breeding season,

especially at dusk or during night, ‘song’ is a far-carrying, steadily repeated, throaty grunt or roar, at times

with paired cadence from dueting or countersinging birds, rrohr, rrohr..., 10/10–15 secs. STATUS: Fairly

common to uncommon on both slopes, mainly below 1000m. (Mexico to nw. Colombia.)

FASCIATED TIGER HERON  Tigrisoma fasciatum 61–66cm. Relatively small

and compact tiger heron of fast-flowing rocky streams and rivers in forested

foothills. See genus note. Usually singles, stalking or standing quietly along

banks near cover, or out on rocks in mid-flow; relatively agile, hopping readily

from rock to rock. Usually identified readily by habitat, but locally Bare-

throated Tiger Heron can be in similar habitat. Note relatively short bill and

legs of Fasciated; adult has overall gray neck, white median throat stripe, cf.

Bare-throated Tiger Heron (some imms. similar in plumage to adult Fasciated

but throat naked, yellow). Imm. very similar to imm. Rufescent Tiger Heron,

note habitat, slightly shorter bill (but young juv. Rufescent has relatively short bill); plumage tones and

patterning of both species variable, not known to be reliable for ID. SOUNDS: May give low guttural

croaks when disturbed. STATUS: Uncommon and local on both slopes, mainly 100–1000m, locally to

2500m. (Costa Rica to S America.)

RUFESCENT TIGER HERON  Tigrisoma lineatum 65–75cm. Humid lowland

forest and adjacent second growth, along quiet streams, at small ponds, in

swampy understory, sometimes in more open situations at edges of lakes and

larger rivers; not in fast-flowing open situations of Fasciated Tiger Heron, or

more open, often second-growth habitats of Bare-throated. See genus note.

Usually rather retiring, heard more often than seen. Adult handsome and

distinctive, with deep rusty head and neck; 1st-year very similar to other tiger

herons, note habitat, also feathered white median throat (can be difficult to see

clearly) vs. Bare-throated. SOUNDS: Flushed birds often give a low, guttural

grunts. ‘Song’ mainly at night in breeding season comprises low, slightly roaring moans in varied

arrangement, often fairly rapid series of 10 or more shorter notes, whoh whoh..., 2–3/sec, final notes

longer; may suggest large owl. Also low, drawn-out moans of 2–3 secs duration, every few secs or in short

series; at times with an introduction of 2–15 shorter moans, ooah ooah ooah oooaaaahhh.…STATUS: Scarce

on Caribbean slope, to 500m. (Honduras to S America.)