Bonelli's warbler

Latin name: Phylloscopus bonelli

Morphological description
A fairly dull bird. Gray-brown back and head, light-colored belly. The rump and wings are yellowish green.

Habitat
This warbler mainly inhabits the dry, sunny slopes of Valais and Graubünden, where it favors areas with sparse forests or scrubland dotted with sparse vegetation. In the Alps, it readily inhabits pine, larch, and Swiss stone pine forests up to the tree line. Its distribution thus mainly covers altitudes between 700 and 1,700 m.

Behavior
Although it is mostly hidden in the foliage, sometimes even in the treetops, it rarely remains inactive and can then be spotted, hopping and flitting constantly from branch to branch in search of food.  The male's song (a high-pitched trill “si-si-si-si-si-si”), emitted from the top of a tree, is the best way to spot the bird. Migratory bird spending the winter in the Sahel (south of the Sahara).

Reproduction
Nests on the ground, in a small depression, a tuft of grass, or at the foot of a shrub.

Diet
Insects (aphids, caterpillars, diptera, etc.) and spiders taken from foliage.

Observation period: May to August