If you haven’t noticed this small, dark, long-tailed warbler you will almost certainly have heard it. The harsh, scolding chatter is one of the most familiar bird sounds in Portugal at any time of the year. The species occupies a wide range of habitats, from woodland and scrub in open country to gardens in towns, but is naturally skulking. It is most likely to be seen in the breeding season when the males perform short song flights. The rapid, ‘scratchy’ jingle is also delivered from the cover of vegetation.

The Sardinian Warbler is by far the commonest and most widespread of several close relatives occurring in Iberia and the Mediterranean region. In Portugal it shares scrubland with the resident Dartford Warbler, which is even longer-tailed and has vinous-red underparts, and with the migratory Subalpine Warbler, which spends the winter in West Africa. This sports a diagnostic white moustachial stripe and has a sweeter song.

The population of Sardinian Warblers in Portugal numbers hundreds of thousands of pairs and may even exceed a million. In the colder winters of the Spanish highlands it is vulnerable to high mortality but there are no obvious threats in Portugal other than from cats and nest robbers like weasels, snakes and lizards.

Although considered mainly sedentary, some migratory movements occur, mainly as a result of post-juvenile dispersion. I was fortunate to find only the third for the British Isles on Tresco in the Isles of Scilly in late September 1980. This particularly shy individual led the ‘twitchers’ a merry dance until it settled down into a patch of gorse, where it remained for the whole of the following winter.

Being colourless (apart from its red eye-ring) and lacking a beautiful song, the Sardinian Warbler hasn’t stirred the imaginations of poets or composers. Yet it almost received an honourable mention in Louis de Bernière’s brilliant novel ‘Captain Corelli’s Mandolin’. Set on the Ionian island of Kefallinia (Cephalonia), his researches included the literature in the museum in Argostoli. Unfortunately, he didn’t discover (or misread) the bird list I left there after my ornithological studies on the island, erroneously naming it ‘Sicilian Warbler’!