The grasshopper sparrow (Ammodramus savannarum) is a small New World sparrow. The genus Ammodramus contains nine species that inhabit grasslands and prairies. These small sparrows measure 10–14 cm (3.9–5.5 in) in length, span about 17.5 cm (6.9 in) across the wings and weigh from 13.8 to 28.4 g (0.49 to 1.00 oz), with an average of 17 g (0.60 oz). Adults have upperparts streaked with brown, grey, black and white; they have a light brown breast, a white belly and a short brown tail. Their face is light brown with an eye ring and a dark brown crown with a central narrow light stripe. There are regional variations in the appearance of this bird.
This bird's song is a buzzy tik tuk zee, resembling the sound made by a grasshopper. Unlike some other members of the Ammodramus family of sparrows, they will readily sing from open and exposed perches.
The Grasshopper Sparrow is widespread from North America to northwestern South America including the West Indies, where it is a common year-round resident on Puerto Rico, Hispaniola, and Jamaica (Raffaele and others 1998). It is a common resident in grasslands of Puerto Rico (Oberle 2018), and it has also been reported on Vieques, where it is considered an extremely rare resident in winter, spring, and summer (Gemmill 2015). Habitat includes mostly weedy fields and pastures with tall grasses (Oberle 2018, Raffaele and others 1998). The atlas fieldwork yielded a total of 66 records within 42 hexagons or 9 percent of the 479 total hexagons (see map). Of the 42 hexagons where this species was found, breeding met the atlas definition of confirmed in 5 percent (2) of the hexagons, probable in 40 percent (17), and possible in 55 percent (23) (see map).Grasshopper Sparrow 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.
Previously published reports indicate that the Grasshopper Sparrow breeds primarily from May to August but also in other months (Raffaele and others 1998). The nest consists of a dome-shaped structure that is usually made of dry weeds, 257Grasshopper Sparrow/Gorrión Chicharrarootlets and hairs, and is built hidden in the grass or ground (Biaggi 1997). Atlas results show that this species basically breeds throughout the year with the most breeding activity from May to July (see chart). The breeding activity peaks in May, and it mostly takes place within the subtropical moist forest life zone (see chart). Results show that this species breeds mostly on the coastal plain and mostly within the subtropical moist forest life zone (57 percent of the hexagons), but it also breeds within the subtropical dry forest life zone (40 percent of the hexagons) and rarely in the subtropical wet and lower montane wet forest life zones at higher elevations (2 and 2 percent of the hexagons, respectively) (see table and map).
The current population trend for the Grasshopper Sparrow is described as decreasing in North America (Butcher and Niven 2007). Nonetheless, it is currently listed as a species of least concern by the IUCN (BirdLife International 2018). Locally, this species is not listed in any of the threatened categories of PRDNER and USFWS. In Puerto Rico, the Grasshopper Sparrow has a protected habitat in land of about 17 percent or 166 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (1004 km2).