Chiffchaff, WMids, April 2011
On April 15th 2011, near Meriden, West Midlands, this Chiffchaff - a standard nominate collybita - gave a so-called 'alternative call' persistently. Every one or two seconds for several minutes it delivered a call with a rising-and-falling pitch, with an abrupt downward inflection. The call could be transcribed as 'sweeoo'. It was one of 14 employing this call observed on that date, with many others heard during April elsewhere in the West Midlands region (90+ during the month). Smaller numbers were still to be heard through May, into the post-migration period, confirming that some individuals were locally breeding nominate collybita (see also 'Mixed pair, call-wise' below). Such 'alternative' calls are well-known from autumn juveniles but it has often been claimed that they are rarely heard after mid-October (see Article on 'Siberian Chiffchaff'). In fact, 'alternative' calls can also be heard at times in the Winter (see for example Copete & Armada 2004) and on occasions from adults d