Yellow-crowned Night-Heron (Nyctanassa violacea)

Yellow-crowned Night-Heron

Description

The yellow-crowned night heron (Nyctanassa violacea), is one of two species of night herons found in the Americas, the other one being the black-crowned night heron. It is known as the "bihoreau violacé" in French and the "pedrete corona clara" in Spanish.

Threats

The yellow-crowned night heron has no real competition for food. The adults have virtually no predators, but the nests are vulnerable to other animals. Both the eggs and the young are an appealing meal to American crows and some mammals such as raccoons. Crows are also known to harass adult yellow-crowned night heron out of their nest, or displace the eggs in order to use the nest themselves. The importance of the impact of such predation varies geographically, Virginia being the state where it matters the most.[citation needed]

Distribution And Habitat

The Yellow-crowned Night-Heron occurs from the Eastern and Central United States south into coastal areas of South America including the West Indies, where it is common in The Bahamas, Greater Antilles, northern Lesser Antilles, Virgin Islands, and Cayman Islands (Raffaele and others 1998). It occurs throughout Puerto Rico and satellite islands such as Desecheo, Culebra, and Vieques (Raffaele 1989a, Sorrié 1975), in the latter being an uncommon resident from spring to fall and a rare resident in winter (Gemmill 2015). This species habitat includes mostly mangrove swamps but also coastal mudfl ats and sometimes dry thickets far from water (Raffaele and others 1998), as well as shores, lagoons, and estuaries (Oberle 2018). The atlas fieldwork yielded a total of 176 records within 123 hexagons or 26 percent of the 479 total hexagons (see map). Of the 123 hexagons where this species was found, breeding met the atlas definition of confirmed in 13 percent (16) of the hexagons, probable in 2 percent (2), and possible in 38 percent (47), while the species was observed in 47 percent (58) of the hexagons but without evidence of breeding (see map). Yellow-crowned Night-Heron distribution. The map shows the highest breeding code by hexagon and overlaying the ecological life zones in Puerto Rico. Note: percentages may not total 100 due to rounding. 161Yellow-crowned Night-Heron/Yaboa Común

Breeding Habits

The Yellow-crowned Night-Heron feeds heavily on crabs and builds a bulky platform nest made of twigs, usually near water in a tree but sometimes far from water (Raffaele and others 1998). Previously published reports indicate that breeding occurs from March to July (Raffaele and others 1998). Nevertheless, atlas results show that this species breeding season extends throughout the year, with the most breeding activity in May and June (see chart). The overall breeding activity mostly takes place in the subtropical moist forest life zone. Atlas results show that this species breeds mostly within the subtropical moist (52 percent of the hexagons) and subtropical dry forest life zones (35 percent of the hexagons) (see table and map). However, results also indicate that at higher elevations it breeds in subtropical wet forest life zones as well (12 percent of the hexagons) (see table and map).

Conservation

The current global population trend for the Yellow-crowned Night-Heron is described as stable (Wetlands International 2012). This species is currently listed as a species of least concern by the IUCN (BirdLife International 2016). Locally, this species is not listed in any of the threatened categories of PRDNER and USFWS. In Puerto Rico, the Yellow-crowned Night- Heron has a protected habitat in land of 11 percent or 177 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (1553 km2).