The least grebe (Tachybaptus dominicus), an aquatic bird, is the smallest member of the grebe family. It occurs in the New World from the southwestern United States and Mexico to Argentina, and also on Trinidad and Tobago, the Bahamas and the Greater Antilles.
The least grebe, while a species of least concern, experiences a number of predators, particularly early in life. Large fish species and turtles are reported to take young grebes, and bird-eating raptors, including the bat falcon and the golden eagle, have been observed taking adult birds.
The Least Grebe occurs from the south-central United States through South America including the West Indies, where it is uncommon on Puerto Rico (Raffaele and others 1998). It can usually be seen in the Caño Tiburones Natural Reserve (Oberle 2018). It also occurs on Culebra and Vieques Islands (Ventosa-Febles and others 2005), in the latter being an extremely rare visitor (Gemmill 2015). It is found locally in the lowlands, and it usually inhabits freshwater ponds, canals, temporary pools with thick fl oating vegetation (Oberle 2018), and freshwater cattail swamps (Raffaele and others 1998). The atlas fieldwork yielded a total of 72 records within 38 hexagons or 8 percent of the 479 total hexagons (see map). Of the 38 hexagons where this species was found, breeding met the atlas definition of confirmed in 26 percent (10) of the hexagons, probable in 21 percent (8), and possible in 50 percent (19), while the species was observed in 3 percent (1) of the hexagons but without evidence of breeding (see map).Least Grebe 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. 37Least Grebe/Tigua
Previously published reports indicate that the Least Grebe breeds through most of the year, but the breeding activity peaks from April to May and again from September to November (Raffaele and others 1998). The nest is built over water among emergent vegetation (Biaggi 1997, Raffaele and others 1998). Atlas results show that this species breeds throughout the year with the most breeding activity in May (see chart). Results (see table and map) show that this species breeds mostly in the lowlands within the subtropical moist forest life zone (62 percent of the hexagons) and less commonly within the subtropical dry forest life zone (35 percent of the hexagons).
The current population trend of the Least Grebe 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 Least Grebe has a protected habitat in land of 18 percent or 162 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (908 km2).