|At Cordillera de Talamanca, Costa Rica|
This American sparrow is a common bird in humid lowlands and foothills up to 1,500 metres (4,900 ft) altitude, in semi-open habitats such as thickets, young second growth, overgrown fields and shady plantations and gardens.
The large domed nest, built by the female, is made of coarse plant material and has a wide side entrance. It is normally placed less than 1 metre (3 ft 3 in) up in dense growth, but may be as high as 1.8 metres (5 ft 11 in). The clutch is two, rarely three, unmarked white eggs, which are incubated by the female alone for 12–14 days to hatching.
The Black-striped Sparrow is a mainly terrestrial species, 16.5 centimetres (6.5 in) long and weighing 37.5 g. The adult is distinctive, with a grey head which has broad black stripes each side of the crown and narrower black stripes through each eye. The upperparts are olive, with yellow on the bend of the wing. The underparts are dull white shading to grey on the breast sides and to olive on the lower belly. Young birds have brown stripes on a yellower head, brownish-olive upperparts and yellow-olive underparts.
This species resembles the Olive Sparrow, but is larger, and the ranges do not overlap. There are a number of subspecies:
- A. c. conirostris breeds in most of northern South America.
- A. c. richmondii breeds in Central America south to western Panama. It is smaller and brighter than nominate conirostris.
- A. c. striaticeps breeds from central Panama to western Ecuador. It is whiter below than nominate conirostris or richmondii.
- A. c. viridicatus breeds on Isla de Coiba, Panama. It is greyer on the head, breast and flanks than striaticeps.
- A. c. inexpectatus breeds in part of western Colombia. It is small, dull, and brownish-olive above
- A. c. umbrinus breeds in the Maracaibo basin of northern Colombia and Venezuela. It is another small, dull race, but brighter above and slightly larger than inexpectatus
The Black-striped Sparrow has a metallic churk call. The male’s song, given from the ground or a low perch, consists of a whistles and slurred notes, tsweet-tsweet tsweet-tswee ti-ti-ti, followed by a trill, but varies geographically.
The Black-striped Sparrow feeds on insects, spiders and seeds taken on the ground, and also picks berries and invertebrate prey from low bushes. It is seen in pairs, never in flocks, and is a shy and retiring species.
- Byers, Olsson and Curson, Buntings and Sparrows ISBN 1-873403-19-4
- Hilty, Birds of Venezuela, ISBN 0-7136-6418-5
- Stiles and Skutch, A guide to the birds of Costa Rica, ISBN 0-8014-9600-4