Grasshopper sparrows are small American sparrows that nest and feed mostly on the ground. 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.
Grasshopper sparrows breed across southern Canada, the United States, Mexico, and Central America, with a small endangered population in the Andes of Colombia and Ecuador. The northern populations migrate to the southern United States, Mexico, Central America, and the Caribbean. Grasshopper sparrows inhabit grasslands, shrubland, open fields, and prairies.
Grasshopper sparrows are secretive diurnal birds that spend much of their time foraging. They are not social and tend to stay hidden among vegetation. These birds walk or run on the ground while feeding and may sometimes hop. When flushed they fly a short distance and then dive back into the grass to escape threats on foot. Grasshopper sparrows communicate with the help of visual displays and vocally. They flutter with their wings, chase each other and use postures to indicate aggression. The song of these birds is a buzzy 'tik tuk zee', resembling the sound made by a grasshopper. Unlike some other members of their family, Grasshopper sparrows will readily sing from open and exposed perches.
Grasshopper sparrows are serially monogamous and pairs stay together only during one breeding season. The breeding season varies with location and males usually arrive on breeding grounds a few days before females. Once pairs are formed the birds start to build their nest. It is a well-concealed open cup located on the ground under vegetation. Pairs generally raise 2-3 broods per breeding season and each time construct a new nest. The female lays 3 to 6 eggs and incubates them 10-13 days alone; the male during this time protects the nest and the territory from intruders. The chicks hatch blind, helpless, and are covered with grayish-brown down. They leave the nest after 9-10 days but are unable to fly; the young walk or run on the ground in dense cover and are fed by both parents for a further 4-19 days. After that, they become fully independent and start to breed in their first year of age.
The main threats to Grasshopper sparrows include habitat loss, destruction of nests due to the mowing of fields, and the use of pesticides by farmers.
According to Partners in Flight resource the total breeding population size of the Grasshopper sparrow is 34,000,000 breeding birds. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.