Todo della Giamaica

Identificazione

The Jamaican tody is a small, chunky bird that averages about 9 cm (or 4.25”) in size. The wing size for all tody species ranges between 42.8mm and 50.3mm. The Jamaican tody's wing size is intermediate between these sizes (about 46mm) compared to the Cuban and Puerto Rican todies, which tend to have smaller wings, and the broad-billed tody, which has the largest. The wing size of the Jamaican tody correlates with their average flight distance, which is about 1.5m, and their maximum flight distance, which is 26m. The average weight of the Jamaican tody is around 6.4 grams. They have a bright green head, red throat and a long, broad and flat red bill. They look very similar to the Puerto Rican tody (Todus mexicanus) but have a whitish breast that is blended with green, becoming even slightly yellow on the abdomen and under the tail-coverts. The Jamaican tody also has blue-gray subauricular feathers. Their legs and feet are reddish brown. Todies are generally a sexually monomorphic genus. However, some tody species have different eye colors between males and females, but in the Jamaican tody, this iris color is undistinguishable. Jamaican todies are very quiet birds during nonbreeding months but can be heard more frequently during the spring and summer. The vocalizations of the Jamaican tody are predominately a loud beep sound and a throat-rattle. (see external link below) The loud beep is a nasal sounding note that is similar in length to the loud beep of the Puerto Rican tody. The throat-rattling is a rapid, harsh-sounding noise that is produced often in territorial defense.

Tassonomia

It was thought that the genus Todus was established in 1760, after the split from the kingfisher from the genus Alcedo. However, the exact historical relationship between the genus Todus and other close relatives was not confirmed until around 2004 when a paper was published on the molecular phylogenic relationships for the tody species. Mitochondrial DNA and nuclear gene sequences were used to discover the heterogeneity among genes in these species. Genus Todus is monophyletic and a relatively old group based on divergence approximations. Todies are closer to the Baryphthengus and Hylomanes genera, from the family Momotidae, than the Ceryle and Chloroceryle genera, from the family Alcedinidae. The family Todidae likely derived from a motmot-like ancestor during the Oligocene period. Palaeotodus emryi is the only tody that is known to be from the late Pleistocene, and it is a close relative of the tody motmot (Hylomanes momotula), the primitive genus of the Momotidae and possibly the closest living relative to the todies. It is believed that the Todidae were once widespread across North America but when there was a decrease in tropical conditions there, it is thought that this led to the confinement of the motmot-tody group to the Neotropics.<p>The Jamaican tody is a member of the genus, Todus, which is composed of five species restricted to the Greater Antilles. All five species are very similar morphologically. The Cuban tody (Todus multicolor) is confined to the island of Cuba and can be found throughout the island, but tends to be more concentrated in shoreline habitats. The narrow-billed tody (Todus angustirostris) and the broad-billed tody (Todus subulatus) are both endemic to Hispaniola, composed of the Dominican Republic and Haiti. The narrow-billed tody is mainly found in very humid montane forest while the broad-billed tody generally inhabits very dry forest and sub-desert areas. However, both of these species can be found in either habitat and are most equally distributed in dry, lower montane forests. The Puerto Rican tody (Todus mexicanus) is only found on the island of Puerto Rico. Similar to other tody species, they can be found in a variety of habitats ranging from the moist, Luquillo Rainforest to the more dry, limestone forest.

Nome scientifico

Todus todus

Autorità

(Linnaeus, 1758)

Ordine

Coraciformi

Famiglia

Todidi

Genere

Todus

Areale e habitat

The Jamaican tody is endemic to Jamaica. They are found all around the island and can be seen near the semi-arid coast or in the humid mountains. They generally travel in pairs and can be found most commonly in forested areas, occurring in second-growth, untouched habitats, including mesic limestone forests, arid limestone forests, montane forest, shaded coffee plantations and even mangroves. The Jamaican tody is most visible during the spring and summer months, and are much more silent and easy to find during the fall and winter.

Migrazione

Resident species

Comportamento

Todies can be found generally performing two bathing techniques, bathing in flight after a dive and bathing in wet plant leaves or in light rain. They also perform bill-wiping, where they will clean both sides of their beak, from base to tip, especially after eating or preening and fluffing their feathers. To fluff their head feathers, they will shake their head back and forth in a fast, jerky movement. Todies also preen their feathers with their flat bills and this mainly occurs in their breast and wing areas on their body.<p>The Jamaican tody is a relatively quiet bird during the non-breeding season. However during the breeding season, they perform increased wing-rattling for both courtship and to show other todies that this is their territory. Courtship feeding has also been observed in the Jamaican tody where a dead insect is exchanged between two partners. In one observation of Jamaican tody copulation, the male chased the female a short distance and once she landed, he swooped down on her and held her crown while performing 29 cloacal contacts in the span of 35 seconds. Soon after, throat-rattles were heard and the two todies flew away in separate directions.<p>Jamaican todies can sometimes be found digging, in which they mainly use their rhamphotheca to create a nesting site. Their eggs are laid in unlined chambers near the end of their burrows, which are holes created in the soil on top of the hard, limestone habitats. The eggs are round, shiny and white, except when they are freshly laid and have a pinkish tint to them. They lay between 1 and 4 white eggs during their breeding season which lasts from December to July. The average size of a Jamaican tody egg is about 16.1 mm long and 13.3 mm wide. One egg is laid each night until the clutch is finished, and then eggs are incubated between 21 and 22 days before hatching asynchronously. Once the young emerge from the shell, the eggs are left in the chamber. While the burrows are generally occupied by todies, other species can sometimes be found inhabiting their homes such as spiders, field mice and lizards. <p>The Jamaican tody uses a sit-and-watch foraging strategy to capture its prey, which is similar to other todies in the genus Todus that can be found on nearby islands in the West Indies. They nearly entirely feed on insects and the larvae of insects but will occasionally eat fruit as well. The majority of their foraging is done below nine-tenths of the maximum canopy height of the forest, and is done in both dry and wet forests. From a perch, Jamaican todies scan the undersides and occasionally, uppersides of leaves for insects in which they will swoop down or up, respectively to catch insects. The smaller insects are swallowed in air while the larger ones are smashed against twigs before consuming. This insect consumption occurs almost continuously throughout the day, where they will eat around 1 to 2 insects per minute if available. The method of drinking for the Jamaican tody has not been observed but it is assumed that they get most of their water from leaf droplets and food they consume.

Conservazione

Tendenza della popolazione

declining