Tristrams Warbler (Sylvia deserticola)

[order] PASSERIFORMES | [family] Sylviidae | [latin] Sylvia deserticola | [UK] Tristrams Warbler | [FR] Fauvette du desert | [DE] Atlas-Grasmucke | [ES] | [NL] Atlasgrasmus

Close in size to Subalpine Warbler (but with 15% shorter wings) and Spectacled Warbler (but with 10% longer tail); less attenuated than Dartford Warbler, with 15% shorter tail. Small warbler, with small bill, rather high crown, short wings, and slim tail. ( mainly grey above, with bright orange-brown edges to black-centred inner wing-feathers; pink-buff to vinous-brown below. ) and juvenile grey-brown above and paler buff below, with whitish chin and moustachial stripe. Eye yellow to brown, set in whitish eye-ring.

Africa : Northwest

Breeds in lower middle latitudes in Mediterranean and steppe-desert zones, in hilly areas covered with scrub and in poorest forests of holm oak where more bushy conditions occur. In Atlas mountains of Morocco, inhabits bushes between large well-spaced cedars which occur above 1600 m; also in relatively dense shrub cover of juniper, Cistus, Buxus, Pistacia, etc. Winters in Morocco in lower and more open bushy habitats, even to desert fringes, including oases, saline areas, and river beds.

In bush, 1-1.5 m above ground. Nest: deep cup of coarse grasses lined with finer grasses and plant down and sometimes horse hair. Clutch: 3-5. (No information on incubation and fledging periods.)

Chiefly insects. Habits similar to Dartford Warbler: explores bushes, daintily hopping from twig to twig, and also forages among clumps of grass.

This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Partial migrant, making altitudinal and mainly short-distance movements, occasionally reaching southern edge of Sahara. Some birds present mid-winter in breeding range.