My apologies for the late posting this week. I believed I ought to press on with this text and catch up, particularly because it’s related to what’s taking place within the hen world within the Iberian Peninsula in the intervening time. Final Saturday we had some early rains down right here within the south, the primary in over three months, however not sufficient to start out the inexperienced flush. A number of birds are heading south now they usually have to deal with extraordinarily dry circumstances.
Wetlands are dry and water restricted to some small swimming pools right here and there. The Avocets (Recurvirostra avosetta) and Black-winged Stilts (Himantopus himantopus) have now completed breeding and are gathering in flocks. Bearded Reedlings (Panurus biarmicus), Penduline Tits (Remiz pendulinus) and Moustached Warblers (Acrocephalus melanopogon) are actually readjusting to the place there’s standing water.
Normally, these are post-breeding dispersals however some might carry out restricted migrations. That is the case of the Zitting Cisticola (Cisticola juncidis) which carry out every day flights excessive into the sky, noisily saying their place to others and making the soar throughout the Strait of Gibraltar into Morocco. It’s fairly superb that such a tiny hen is able to doing this. It’s not dispersal however precise migration. A few years in the past, I studied this phenomenon and located that the southward passage was then matched by a spring return of the identical people.
Different species, thought of to be primarily resident, additionally carry out restricted migrations. That is the case of Dartford Warbler (Curruca undata). The Sardinian Warbler (Curruca melanocephala) truly crosses the Sahara Desert in small numbers. How a hen with such brief, rounded, wings manages it’s a thriller to me.
The Moustached Warblers might not go far however two different congeners are on the transfer in direction of tropical Africa. Many Reed Warblers (Acrocephalus scirpaceus) drop in to relaxation and feed, even within the dry olive maquis which might not in any other case be occupied by these birds. Sedge Warblers (Acrocephalus schoebaenus) are a lot scarcer, showing to have a cease over additional north after which overflying us in a direct flight throughout the desert. These are actually marvelous feats.
Among the many biggest is that of the Greenland Wheatear (Oenanthe oenanthe leucorhoa) that makes a trans-Atlantic crossing earlier than making landfall alongside the western coasts of Iberia. Now could be the time to see these maginficent birds on the transfer.
Different birds comply with this western route, presumably to catch the little bit of inexperienced alongside the coasts of north-western Spain to then migrate south alongside the western fringe of the Sahara, avoiding the worst components of the desert. That is notably the case with Pied Flycatcher (Ficedula hypoleuca), which collect in giant numbers down the Atlantic coast, but additionally different species, comparable to Frequent Redstart (Phoenicurus phoenicurus).
Many migrants are opportunists and exploit domestically considerable assets. The migration of Backyard Warblers (Sylvia borin) and Golden Orioles (Oriolus oriolus) coincides with the September manufacturing of figs. Discover a fig tree right now of 12 months and you’ll quickly discover one or the opposite of those birds gorging on the figs. So, there are numerous options to the issue of the dry season, because the examples I’ve chosen clearly show. Even inside intently associated species – Moustached, Reed, Sedge Warblers – the options to the identical downside of lack of water, have adopted very totally different trajectories.
Autor Clive Finlayson
