About Curruca cantillans (Pallas, 1764)
The eastern subalpine warbler, with the scientific name Curruca cantillans, is a small warbler in the Sylviidae family that breeds in the southernmost regions of Europe. It was first described by German naturalist Peter Simon Pallas in 1764, and originally given the binomial name Motacilla cantillans. Its specific epithet cantillans means "warbling" in Latin, derived from canere meaning "to sing". Like most species in the Curruca genus, it has distinct plumage for adult males and adult females. Adult males have a grey back and head, brick-red underparts, and white malar streaks referred to as "moustaches". Females are mostly brown on their upper body, with a greyer head, and whitish underparts with a pink flush. The song of the eastern subalpine warbler is fast and rattling, similar to the song of the lesser whitethroat. This species appears to be part of the Sardinian warbler-Menetries' warbler superspecies. All three species in this group have white malar areas, dark upper heads in adult males, and naked eye-rings. These three species are in turn related to another superspecies made up of Rüppell's warbler and the Cyprus warbler, which also share the trait of a white malar area with blackish upper plumage, per research from Shirihai et al. 2001 and Jønsson & Fjeldså 2006. The eastern subalpine warbler was previously split into two distinct subspecies groups, which some research (Shirihai et al. 2001) suggested were divergent enough to qualify as separate species. The two groups had different male plumages, distinct calls, and were allopatric, and further study was needed to confirm this potential split. In May 2020, the IOC World Bird List formally recognized the split of the original subalpine warbler into two separate species: the western subalpine warbler and the now separate eastern subalpine warbler. Moltoni's warbler was formerly considered the same species as this group. The eastern subalpine warbler differs from the western subalpine warbler by its deeper blue-grey upperparts, a blackish mask on the lores and ear-coverts, brick reddish-brown coloration limited to the throat and breast that is sharply separated from a mostly white belly, paler flanks, and a wider white submoustachial stripe. This species inhabits dry open country, often on hill slopes, with bushes available for nesting. The nest is built in low shrub or gorse, and clutches contain 3 to 5 eggs. Like most warblers, it is primarily insectivorous, but will also eat berries. The species prefers tall, dense heterogeneous maquis with sparse tree cover in dry Mediterranean areas, particularly holm oak (Quercus ilex) maquis, and maquis dominated by strawberry tree (Arbutus) and tree-heath (Erica). It is also frequently found in young cork oak (Quercus suber) forest and in dense, treeless bushy areas. It uses bushy formations dominated by brambles (Rubus fruticosus) along sunny ravines and valley bottoms, and favors intermediate stages of post-wildfire succession. Breeding takes place from late March to late June, and the species is monogamous. Males build multiple "cock nests", but both sexes work together to build the breeding nest. The breeding nest is a deep, robust cup made from grasses, thin roots and leaves, lined with finer grasses, small rootlets and hair. It is placed in low scrub, a bush or small tree, approximately 30 to 130 centimeters above the ground. Clutches contain three to five eggs. The diet consists mostly of small insects and their larvae, but berries and fruits are also eaten outside of the breeding season.
