más intenso que permite identificar con facilidad la especie
Nikon D300 +Tamron 90mm +flash anular
Early migration of Philloscopus bonelli
Philloscopus bonelli is a characteristic bird of supra-mediterranean forests, preferably occupying formations of the genus Quercus (oak, melojares, quijigares and oak), pine forests and beech or juniper. It shows a marked altitudinal range in its distribution, coinciding with the distribution of forests where nests, although they bird prefer sunny slopes and more heat.
This is a bird with a relatively restricted area of reproduction compared with other species of the same gender (Philloscopus trochilus, Philloscopus collybita, Philloscopus silibatrix) and their populations have a distribution largely confined to countries surrounding the Mediterranean Sea (Spain, Portugal, France, Italy, Yugoslavia, Greece, Turkey, North Africa, etc. ..) and is not as wide as the distribution of their congeners, spread widely throughout Europe and part of Eurasia.
Leaving aside the uncertainties that still exist in the distribution and taxonomy of Philloscopus ibericus, Philloscopus bonelli would undoubtedly reach the largest populations in Spain (close to 3 million pairs) and a distribution more extensive. However, estimates of the combined population of Philloscopus ibericus and Philloscopus collybita breeding in our country do not exceed of 600,000 pairs.
During an inventory and census of breeding birds in the Natural Park of Cornalvo (Badajoz), a member of Fotonatura and blogger, José María Benítez Cidoncha has detected a notable presence of Philloscopus bonelli since the first week of July and increasing progressively over the following weeks. Out the possibility that they were breeding populations, because in Extremadura only nest in the woods of the highest mountains (oak and pine forests of the Villuercas, Sierra de Gredos and Tentudía, mostly), they could be only exemplary in migration. Their presence in the meadows of holm and cork oaks and in open bushes and rivers also confirmed that they were not in their usual nesting habitats.
The migration of Philloscopus bonelli is usually very discreet and less noticeable, although the latter observations suggest that we don’t know so much about their migratory pattern. This migration so early is very surprising. On the one hand, this species usually reach their breeding grounds between late April and mid May, in part because it requires that the forests where nests awaken from their winter slumber (usually deciduous forest and uplands of the mountains). Moreover, the references confirm that during the months of July and July are still bringing in most of its distribution range.
The migration of Philloscopus sp. often occur more frequently in early August, with the massive arrival of Philloscopus trochilus and, later, Philloscopus collybita. For this reason I think it is worth commenting on, because I have not found any similar reference consulting ornithological yearbooks and other sources of information.
It would be interesting to know if someone has early observations of Philloscopus bonelli during the first half of July that could clarify the migration phenology of this species.
In the Natural Park of Cornalvo we carried out a short time ringing in a little ponund frequented by this species. In less than two hours we caught 5 birds, being in all cases adults with significant accumulations of fat in the chest and flanks, as usual in migratory birds.