To learn the incubation pattern of these kingfishers was one of the most challenging and perplexing ornithological problems that I ever tried to solve…The great difficulty was to keep my attention so firmly fixed on a hole where for long hours nothing happened--a sort of yogic exercise in the contemplation of nothingness--that I did not miss the sudden, unannounced exit of a kingfisher…I soon discovered that there was a single changeover each day, in the early morning.
Alexander F. Skutch, Studies in Tropical American Birds, 1972
The Ringed Kingfisher (Megaceryle torquata) is a large, crested Neotropical kingfisher that has expanded its range into the USA from Mexico within the last 40 years. Although first recorded in the USA in 1888, the first Ringed Kingfisher nest was not discovered until 1970. Seen regularly only along the Rio Grande and adjacent water-bodies in southern Texas, Ringed Kingfishers are continuing to expand their distribution and breeding range northward in Texas. Populations from Central America northward share their range with Belted Kingfishers (Megaceryle alcyon) for 6-8 months. Amazon Kingfishers (Chloroceryle amazona) and smaller species co-occur with Ringed Kingfishers year-round over broad areas of Central and South America ( Remsen 1991a , American Ornithologists' Union 1998a ).
Like all American kingfishers, the Ringed typically perches in riverside or lakeside trees where it watches for its prey in clear water. Its large size and habit of perching high up in dead trees or other open perches makes it a conspicuous bird within its tropical range. Sometimes perched for up to two hours while foraging, the species' patience has impressed several observers ( Skutch 1976 , Remsen 1991a ). Ringed Kingfishers seldom hover for more than a few seconds, unlike their North American relative, the Belted Kingfisher. Mainly a freshwater species, the Ringed Kingfisher will forage along saltwater shorelines if perches and prey are available. The species mainly eats fish captured by plunge-diving from a waterside perch. Remsen's ( Remsen 1978b , Remsen 1991a ) intensive studies in Colombia and Bolivia provide much-needed data on habitat use, foraging behavior, and diet, as well as ecological relations with other kingfishers.
Solitary except while breeding, both male and female kingfishers vigorously defend their territories along shorelines of lakes or rivers throughout the year. They do this with loud, low-pitched calls and sometimes aerial chasing. Loud calls are given when birds are disturbed by conspecifics or human intruders. Except for a small amount of data gathered by Skutch ( Skutch 1976 ) and others, little is known of their nesting habits. As with Belted Kingfishers, the availability of suitable nesting sites—high dirt banks where nesting burrows can be excavated—appears critical for the distribution and local abundance of this species. Human impacts have not been studied much, but changes in water levels caused by dams and water withdrawal can impact habitat availability and suitability. Due to low population density, the species' wariness, and the distance of the largest Ringed Kingfisher populations from major research centers, focused studies of environmental contamination and population density remain to be done.