Little Blue Heron (Egretta caerulea)

Little Blue Heron


The little blue heron (Egretta caerulea) is a small heron belonging to the family Ardeidae.

Distribution And Habitat

The Little Blue Heron occurs from most of the United States through Central and South America including the West Indies (Biaggi 1997), where it is generally a common resident on most of the islands (Raffaele and others 1998). It is a common resident in Puerto Rico and can be seen regularly at the Parque Centrals boardwalk along the Caño Martin Peña in the municipality of San Juan (Oberle 2018). It also occurs on satellite islands such as Vieques (Sorrié 1975) and Culebra (Kapan 2003), in the latter being common in fall, winter, and spring, and uncommon in summer (Gemmill 2015). Habitat includes mostly calm and shallow freshwater and saltwater areas (Raffaele and others 1998) including ponds, wetlands, canals, mangrove swamps, estuaries, and lagoons (Oberle 2018). The atlas fieldwork yielded a total of 199 records within 118 hexagons or 25 percent of the 479 total hexagons (see map). Of the 118 hexagons where this species was found, breeding met the atlas definition of confirmed in 8 percent (10) of the hexagons, probable in 1 percent (1), and possible in 2 percent (2), while the species was observed in 89 percent (105) of the hexagons but without evidence of breeding (see map).Little Blue 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. 151Little Blue Heron/Garza Azul

Little Blue Heron Distribution

Breeding Habits

Previously published reports indicate that the Little Blue Heron breeds from April to July, and it is usually colonial with other heron species (Raffaele and others 1998). The nest consists of a platform made mostly of twigs, which is usually constructed high in trees (Raffaele and others 1998) or in bushes near water (Biaggi 1997). Atlas results indicate that this species breeds from March to June and sometimes in August, with the most breeding activity during March and June (see chart). Overall, the breeding activity mostly takes place within the subtropical moist forest life zone (see chart). Results show that this species breeds mostly within subtropical moist (62 percent of the hexagons) and subtropical dry forest life zones (23 percent of hexagons) (see table). It also breeds within subtropical wet and lower montane wet forest life zones at higher elevations (15 percent of the hexagons) (see table and map).


The current overall population trend of the Little Blue Heron is described as decreasing, although some populations have unknown trends (Wetlands International 2012). However, this species is currently listed as a species of least concern by the IUCN (BirdLife International 2017). Locally, this species is not listed in any of the threatened categories of PRDNER and USFWS. In Puerto Rico, the Little Blue Heron has a protected habitat in land of 11 percent or 33 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (311 km2).