Sardinia, where I am on a criminally brief trip, has a lot of interesting wildlife. The most famous are endemic cave salamaders, but I am also enjoying observing local Curruca warblers. There are 5 of them here, and interactions between them are fascinating. They all have different, but overlapping, habitat preferences, and all can be found in shrubland that covers much of the island. That type of vegetation is very common in places with Mediterranean climate; it is called macchia in Italy, maquis in France, and chapparal in Spain and California. They are also difficult to observe because they are adept at hiding from view in their dense shrubs. During the mating season they sing a lot and some perform display flights, but now they are done breeding or are feeding fledglings, so seeing them all took me some effort.
The most common here is Sardinian warbler (C. melanocephala). Almost every patch of large shrubs has a pair. Large and aggressive, these warblers respond to playbacks of all other Curruca species, and not to huddle with them. It looks like all other Curruca have adapted by living in places that Sardinian warblers find suboptimal.
Common whitethroat (C. communis) lives in isolated shrub patches surrounded by open fields or forest. Spectacled warbler (C. conspicillata) hides in small shrubs scattered on particularly dry slopes and salt flats. Marmora’s warbler (C. sarda) also nests in small shrubs, mostly on tops of limestone cliffs or at higher elevations. Dartford warbler (C. undata) breeds in very dense groves of tall shrubs and small trees, mostly along streams. And all four can occasionally be found in “classical” macchia, with tall, well-spaced shrubs, but there they have to survive the persecution by Sardinian warblers.
On the Italian mainland, where Sardinian warblers are not found, all four smaller species are much easier to see. I wonder what prevents Sardinian warblers from expanding there.
Naturalist on Earth 