Saturday, 6 January 2018
27-3-2017 VILLA LAPAS, COSTA RICA - TROPICAL KINGBIRD (Tyrannus melancholicus)
The tropical kingbird (Tyrannus melancholicus) is a large tyrant flycatcher. This bird breeds from southern Arizona and the lower Rio Grande Valley of Texas in the United States through Central America, South America as far as south as central Argentina and eastern Peru, and on Trinidad and Tobago. Birds from the northernmost and southern breeding areas migrate to warmer parts of the range after breeding.
An adult tropical kingbird is 22 cm (8.7 in) long, weighs 39 g (1.4 oz) and has a wingspan range of 38–41 cm. The head is pale gray, with a darker eye mask, an orange crown stripe, and a heavy gray bill. The back is grayish-green, and the wing and forked tail are brown. The throat is pale gray, becoming olive on the breast, with the rest of the underparts being yellow. The sexes are similar, but young birds have pale buff edges on the wing coverts.
27-3-2017 VILLA LAPAS, COSTA RICA - BARE THROATED TIGER HERON (Tigrisoma mexicanum)
The Bare-throated Tiger-Heron is a bird of tropical swamps. Along the coast, it is typically a mangrove species. It is found, however, in a variety of coastal and freshwater situations, typically characterized as forest edged aquatic habitats. It feeds in coastal lagoons, mangrove swamps, fresh water marshes, swamps, gallery forests along rivers and streams, and wet meadows. It feeds more in the open and in larger habitats than other tiger herons. It is primarily a coastal species occurring below 1,000 m. It avoids human habitats.
The primary foraging behavior of this cryptic heron is Standing in shallow water or on the edge of the water, with neck stretched out diagonally, waiting motionless for long periods. It also Walks slowly, often in situations away from cover. It is a solitary species, usually foraging alone. However a dozen have been seen in a loose group when food is readily available. It is primarily crepuscular but also partially nocturnal. When disturbed it takes flight and perches in a nearby tree. It eats fish, frogs, crabs, and flies.
Courtship is little understood in this species, and the displays reported have little context to them (Dickey and van Rossem 1938 Sutton et al. 1950, Wetmore 1965). The primary display appears to be a version of the Stretch—a pair faced each other, necks and bodies crouched horizontally, feathers fluffed up; the birds raise their bills and neck vertically, depressing the neck and body feathers, and emitting two or three hoarse booms or roars. They may sway the neck at the vertical. This may be repeated, and one bird may move toward the other. Mutual Bittern posture has also been described.
Eggs are dull white with a green tinge, rarely flecked with brown or buff. The usually unspotted eggs are not typical of the tiger herons (Dawn 1964). Two measured 56.6 x 43.5 mm and 58.1 x 45.3 mm. Clutches are 1-3 eggs. There is no information on incubation, chick development or fledging and little is known about the nesting success of this species. Nestlings are at risk to hawk (Buteogallus) predation (Lewis and Timm 1991).
The bare throat of this species was recognized for years as being highly distinctive. It is now placed in the same genus as the other two South American tiger herons. The tiger herons are a distinctive lineage of the Ardeidae, adapted to a forest existence. The five species constitute a sister group to all the other herons and bitterns and to the Boat Billed Heron (Sheldon et al. 1995).
The Bare-throated Tiger-Heron occurs in coastal Mexico, Central America, and northern South America.
Breeding range: In Mexico, it occurs as far north as south Tamaulipas and south Sonora, along both coasts, across the Isthmus of Tehuantepec, in all of the Yucatan, coastal in Central America through Panama, including Coida Island and Perles Archipelago but of limited distribution on the Caribbean slope, into extreme north west Colombia from Gulf of Urabá to the lower Atrato River valley.
Friday, 5 January 2018
Thursday, 4 January 2018
Wednesday, 3 January 2018
Tuesday, 2 January 2018
21-3-2017 HOTEL BOUGANVILLEA, COSTA RICA - TROPICAL KINGBIRD (Tyrannus melancholicus)
Tropical kingbirds appear to be monogamous. In most parts of the species' range, they are permanent residents and remain together in pairs year-round.(Sibley 2014)[page needed] The call is a high-pitched twittering trill, tree-e-e-e-e-e-e, with a more complex version sung by the male at dawn.
Their breeding habitat is semi-open areas with trees and shrubs, including gardens and roadsides. Tropical kingbirds like to observe their surroundings from a prominent open perch, usually high in a tree, undertaking long flights to acrobatically catch insects in mid-air (hawking), sometimes hovering to pick food off vegetation (gleaning). The insects preyed upon include beetles, bees, wasps, termites, butterflies, moths, dragonflies and grasshoppers. They also eat some berries and fruit from such diverse species as tamanqueiro (Alchornea glandulosa), common guava (Psidium guajava), the Annonaceae, Cymbopetalum mayanum and gumbo-limbo (Bursera simaruba); foraging for these even in disturbed habitat. As they keep mainly to the upper levels of trees, they find little profit in following mixed-species feeding flocks in the understory.
Aplomado falcons have been known to prey on adult tropical kingbirds, while eggs and young have been attacked by swallow-tailed kites and chestnut-mandibled toucans. These birds aggressively defend their territory against intruders, even much larger birds such as magnificent frigatebirds, toucans, caracaras or hawks. In a study in Parque Nacional de La Macarena of Colombia, parasitism by microfilariae and trypanosomas (presumably T. everetti) was infrequently recorded in tropical kingbirds.
The male and female inspect potential sites together before selecting a site, typically a fork or crotch high in a tree (up to 20 m (66 ft) high) but sometimes just a few metres above water.(Sibley 2014)[page needed] The female builds a bulky, sloppy-looking, shallow nest of vines, rootlets, twigs, weeds, and grasses; it is unlined or lined with hair. Nests average about 13.2 cm (5.2 in) across and 7.6 cm (3.0 in) tall, with interior cup about 7.6 cm (3.0 in) across and 4.1 cm (1.6 in) deep.
The female incubates the typical clutch of two to four eggs for approximately 16 days, and the nestlings fledge in another 18 or 19 days. The eggs are whitish or pale pink with variable amounts of dark blotching.
21-3-2017 HOTEL BOUGANVILLEA, COSTA RICA - CLAY COLOURED THRUSH (Turdus grayi)
The clay-colored thrush (Turdus grayi) is a common Middle American bird of the thrush family (Turdidae). It is the national bird of Costa Rica, where it is well known as the yigüirro (Spanish: [ʝi'ɣwiro]). Other common names include clay-colored robin.
It ranges from South Texas (where it is rapidly expanding its range) to northern Colombia. West and north of the Isthmus of Tehuantepec, it is limited to the Atlantic slope, except for a population around Oaxaca City, Mexico that probably originates from escaped cage birds. In much of its range it is familiar in yards and gardens, similar to some other thrushes such as the American robin, the Eurasian blackbird, and the song thrush.
In general appearance and habits it resembles other Turdus thrushes such as the American robin. It is about the same length or slightly smaller: 23–27 cm (9.1–10.6 in), and weighs 74–76 g (2.6–2.7 oz) on average. The plumage is brownish, somewhat lighter below than above, lightest on the flanks. Birds from humid regions are darker than those from dry regions. The throat is faintly streaked. Immature birds have faint mottling on the back and underparts. The bill is greenish-yellow with a dark base, the legs are pinkish or flesh-colored, and the irises are reddish—all useful identification points.
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