THERE ARE VERY few warbler songs which the vast majority of birdwatchers can instantly recognise. The Chiffchaff is the most obvious exception, with the Cetti’s Warbler having a reasonable case for second place, at least for birdwatchers in the southern half of the country. The distinctiveness of the shouted song is just as well, otherwise we would hardly be aware of this most elusive of birds. Unlike a Victorian child, the Cetti’s Warbler is to be heard and not seen. This is a bit of a shame, as Cetti’s Warblers are really quite handsome for little brown jobs, looking like a bit of a large, long-tailed, unstreaked Wren, with pleasingly rufous plumage tones. But skulkers they are, hiding within tangles as well as reed fringes, usually at a site near water. These tough, year-round resident warblers have made a remarkable expansion in recent decades. They were unheard of (and unheard) as a breeding bird until the late 1960s, with breeding confirmed for the first time in 1973. There were nearly 100 probable breeding pairs before a massive crash after severe winters in the mid-1980s. But, by 1996, there were as many as 600 territories in the UK and the Channel Islands. Since that time, the population has doubled every four to seven years, and there is now a population of about 2,000 singing, in a disjointed population from the south coast of England up to the Midlands and Wales, and even up into Yorkshire and Lancashire. It is a success story worth celebrating. So, raise a glass each time you hear one, even if raising your binoculars will probably be a waste of time.