Martin pescatore inanellato

Identificazione

Megaceryle torquata is a Neotropical kingfisher that lives in habitats ranging between the US and Mexico. In 1888, the species was first discovered in the US, while the first ringed kingfisher nest was found in 1970. They are commonly seen along the Rio Grande and in water bodies in southern Texas. Their distribution is increasing and expanding northwards.<p>The wings of adult males range between 184.9 and 211.1 mm (7.28 and 8.31 in), with an average of 196.3 mm (7.73 in).  Their tails range from 110.0–129.0 mm (4.33–5.08 in), and their bills measure 74.9–94 mm (2.95–3.70 in). Female wings are from 185.0-210.1 mm, and their tails measure 111.5–132.1 mm (4.39–5.20 in) and possess bills measuring 75.9–90.9 mm (2.99–3.58 in). Individuals can weigh between 305 and 341 g (10.8 and 12.0 oz). Such measurements prove that the species do not differ sexually in terms of size.<p>Ringed kingfishers have dark-brown irises that are consistent among all age groups. They have straight bills that are longer than their heads, along with curved culmens and tomial serrations. The lower mandible appears to have some yellowish colorations. They possess syndactyl feet with olive-green or yellowish toes and black claws. A large crest appears between the base of their bills and necks. Several individuals have a white collar located around the neck.<p>Each ringed kingfisher possesses 10 primary wings, 15 secondaries, three tertials, and 12 rectrices. They are rounded, and the tail is squared. Subspecies can be found in Texas, Mexico, Central America, and South America, due to slight plumage differences. Individuals themselves vary slightly as a result of variable environmental constraints and day-length regimes.<p>Ringed kingfishers can be identified by sex due to differences in coloration. The males possess rusty-brown underparts with white undertail coverts and a white throat. Females have a bluish-gray band seen on the upper breast and a whitish band.<p>A ringed kingfisher's clutch size is typically three to six eggs, which are incubated for about 22 days.

Tassonomia

The ringed kingfisher is from the family Alcedinidae in the order Coraciiformes. The ringed kingfisher is related to the belted kingfisher. Overall, the species appears much larger than its counterpart, while possessing a rufous belly, a massive bill, and a blue back.<p>Three subspecies are identified by size and color, as well as location.

Nome scientifico

Megaceryle torquata

Autorità

(Linnaeus, 1766)

Ordine

Coraciformi

Famiglia

Alcedinidae

Genere

Megaceryle

Areale e habitat

Ringed kingfishers are seen in freshwater habitats, tropical and temperate marine shorelines, and several islands, such as Coiba Island. Breeding occurs in aquatic regions with the support of aquatic animals, including fish-populated areas for nesting burrows. Nests can be found farther away from water. Habitats are near waterbodies that include streams, rivers, ponds, lakes, estuaries, and marine habitats. Habitats with clear water and less vegetation are preferred to easily access prey.<p>Ringed kingfishers are found in broad areas between Texas, USA and South America. The ranges of ringed and belted kingfishers overlap from Central America and above for 6–8 months. Ringed kingfishers also have ranges that overlap with other kingfisher species in Central and South America. Breeding ranges of ringed kingfishers vary in the Neotropics in Mexico, the Caribbean, and South America. Their preference for mangrove habitats has been observed in the tropics. Foraging occurs offshore as far as 1 km (.7 mi). Overwintering ringed kingfishers are indifferent to breeding ranges, but are able to forage farther than during their breeding periods. Large irrigation canals in Rio Grande, Texas, have been used as wintering grounds by such species. They are usually found in areas with high fish densities during the dry season.

Migrazione

Complete migrants

Comportamento

The anatomy of ringed kingfishers prevents efficient terrestrial movements. Individuals shuffle into and out of nesting burrows, so displacing between branches is difficult for this species. They possess strong wings that beat very slowly as a result of their size. They are able to fly over land for long periods of time in comparison to other species of kingfishers.<p>A mating ritual involves the male ringed kingfisher offering fish to the female before copulation. The pair performs, wherein the male creates calls circling above the water, while dropping into the water. This process lasts for a short time.<p>Female and male ringed kingfishers incubate their eggs while performing other duties equally. Short foraging breaks are taken during late afternoon since incubation periods are long. Each individual takes turns during the morning. Incubating birds are capable of finding prey by regurgitating their undigested food to attract flies in their burrows.<p>Ringed kingfishers have louder and lower-pitched calls compared to the belted kingfishers. Captured Juveniles have been heard screaming, giving a klek or kek call. The same call is heard during human intervention or other disturbances. A softer klek is produced by the adult to signal its incubating partner. Its common vocalizations are described as rattles.<p>Ringed kingfishers can perch for several hours on trees while watching for prey in fresh water. Belted kingfishers perch for only a few moments. Ringed kingfishers have also been observed to forage in marine water. They catch their prey by diving from a perch.

Conservazione

The IUCN considers the ringed kingfisher to be of least concern. Increasing population trends indicate that the species is not vulnerable, as it is widespread and has a large habitat distribution and breeding ranges.

Tendenza della popolazione

stable