African Desert Warbler Curruca deserti Scientific name definitions

11·5 cm. Small, compact, rather short-tailed warbler with relatively short wings. Adult breeding has crown to back pale sandy-rufous, rump and uppertail-coverts more rufous-orange; remiges sandy-brown with narrow sandier fringes, inner tertials lacking (or having very small and indistinct) blackish centres, upperwing-coverts light sandy-brown with narrow paler fringes, alula feathers blackish with narrow pale sandy fringes; tail mostly light sandy-rufous, outermost rectrix mostly white, central pair unmarked or with very restricted (barely visible) blackish centres, other rectrices (T2–T4) with small blackish centres; chin, throat and underparts white, breast side and flanks suffused with pale yellowish-buff; iris pale yellow, blackish orbital ring, white eyering; upper mandible blackish with pale pinkish-yellow cutting edges, lower mandible pale pinkish-yellow, sometimes with small black tip; legs yellow to greyish-yellow. Adult non-breeding is very like breeding adult, perhaps purer white below. Sexes similar. Juvenile resembles adult, but plumage less pure white below and outermost tail feather has more sandy-coloured edges and tip.

Until recently considered conspecific with C. nana, but differs in its sandier-rufous (less greyish) crown to back (2); greatly reduced blackish centres of inner tertials and central rectrices (2); whiter underparts (1); slightly longer bill (effect size 1.58, score 1); but slightly shorter wing, indicating non-migratory habit (effect size –1.48, score 1). Claims of “very different” voices (1 Shirihai, H., Gargallo, G. and Helbig, A.J. (2001). Sylvia Warblers. Identification, Taxonomy and Phylogeny of the Genus Sylvia. Christopher Helm, London. Close ) (apparently responsible for near-universal acceptance of split) could not, however, be confirmed in independent analysis of available recordings (2 Boesman, P. (2016). Notes on the vocalizations of Desert Warbler (Sylvia nana). HBW Alive Ornithological Note 260. In: Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. Close ), although variable level of divergence may exist. Form described as Sylvia ticehursti on basis of single specimen from S Morocco (near Ouarzazate), and treated either as a separate species or as a race of C. deserticola, is probably aberrant individual of race maroccana of latter (which it resembles in general structure and in tail and tertial patterns), or hybrid between it and present species (which it resembles in having pale sandy-brown upperparts). Monotypic.

Prefers sandy deserts with sparse scrub and grass and, especially, areas with dense clumps of Aristida pungens; occurs also on steppe beside alluvial flats and, less frequently, in more stony areas with scattered vegetation of e.g. Nucularia (Chenopodiaceae). Ascends to 2000 m in SE Algeria (Hoggar).

Resident to partially migratory. Probably largely sedentary or undertaking erratic movements within desert range; in N, however, present only during breeding season, Tafilalt area of S Morocco being largely vacated mid-Jul to late Dec. Vagrants have been recorded in Cape Verde Is, Canary Is, Madeira, mainland Spain, Italy, Malta and the Netherlands (3 van den Berg, A.B. (2014). WP reports. Dutch Birding. 36(6): 402–420. Close , 4 Zaal, H. and Ottens, G. (2015). Afrikaanse Woestijngrasmus bij Alphen aan den Rijn in november-december 2014. [African Desert Warbler near Alphen aan den Rijn in November-December 2014.] Dutch Birding. 37: 320–326. In Dutch with English summary. Close ).

Appears to feed mostly on small insects and spiders, supplemented with some berries and seeds when available. Insects eaten include butterflies and moths (both adults and caterpillars), beetles (Coleoptera), bugs (Hemiptera) and ants (Formicidae). Forages on ground or low (up to 1 m above ground) in vegetation, by picking items from substrate or gleaning them from bushes, grass and the like. Associates commonly with wheatears (Oenanthe) and, less so, with bee-eaters (Merops) and shrikes (Lanius), seizing insects disturbed by those birds.

Song , delivered from cover or from top of tree, occasionally in flight or from ground, a very brief but rich rattle followed by a rich short warble, the whole c. 1–2 seconds long, given at rather long intervals of c. 4–10 seconds; generally sounds more rich, less clean and fluting, than song of C. nana. Contact call a short rattle; also gives rasping “djjj-djjj-djjj” call, reminiscent of call of C. undata. Calls much as those of C. nana.

Not globally threatened (Least Concern). Fairly common but rather locally distributed. There is no evidence of any declines in this species’ numbers nor of any significant threats to its survival. Further study of its ecology and breeding would be beneficial.