It just so happens that yesterday, 19 March 2012, the first Iberian Chiffchaff was recorded in Extremadura. Recently I was also approached about a future book on this species. So it now seems a good time to take stock of its Extremadura status ...
Iberian Chiffchaff (Phylloscopus ibericus) was hived off of as a separate species from Chiffchaff (Phylloscopus collybita) in 1996. The first certain Extremadura record of the brand new species then came in Plasencia (Cáceres) in April 1997, most likely a passage bird (Javier Prieta). The first probable breeding of the species was recorded in Piornal, Valle del Jerte, Cáceres, where a pair held territory in a mixed Scots Pine / Sweet Chestnut copse in 2001 and 2002 (J. Prieta). Also in May 2001 another male was heard singing in Torremenga, La Vera, Cáceres (Jesús Calle). In 2002 a small breeding population was found in Sierra de Tentudía, Badajoz (Javier Salcedo), after which there were more one-off observations of males singing in May and June in Toril (J. Prieta), Puerto de Miravete (Godfried Schreur) and La Garganta (Ricardo Montero), all in the province of Cáceres. The known breeding population, therefore, is restricted to a small nucleus in the Sierra Morena of Badajoz (Monesterio, Calera de León and Cabeza la Vaca) and isolated cases of singing males in May and June on the Cáceres side of the Gredos mountain range and in Monfragüe, without apparently forming stable populations. The Badajoz breeders, part of a population that spreads further south into northern Huelva, occupy mainly mixed pine populations and riparian copses (J. Salcedo). In view of their scarcity, however, and the difficulty of identifying them in the field (except by voice), a more widespread breeding population in Extremadura can by no means be ruled out.
In general, there is little information on Iberian Chiffchaff in Extremadura. By now a total of 142 birds has been recorded (Prieta et al., 2000; Prieta 2002 and 2007; Prieta and Mayordomo, 2011; monthly summaries of this blog); the pattern of these observations is plotted in the above graph. Breeding birds are shown in red while those recorded outside the breeding areas, assumed to be migrants, are plotted in blue. These show a bimodal pattern, with spring passage in March and April, almost always males singing, and return passage in August-October, on the basis of field identification, calls and some residual song. Some years, however, calls attributed to Iberian Chiffchaff are head until mid November (Sergio Mayordomo). The breeding areas, basically Tentudía, are occupied from March to September, numbers peaking in April, probably due to topping up by migrants (as also occurs in northern Huelva; Rafael Romero, pers. comm.). The much higher spring peaks shown in the graph are probably at least partly due to the greater likelihood of song-based detection in spring than in autumn.
- Prieta, J. 2002. Aves de Extremadura, Vol. 2. 1999-2000. ADENEX. Mérida.
- Prieta, J. 2007. Aves de Extremadura, Vol. 3. 2001-2003. ADENEX. Mérida.
- Prieta, J., y Mayordomo, S. 2011. Aves de Extremadura, vol. 4. 2004-2008. SEO-Cáceres. Plasencia.
- Prieta, J.; Valiente, J. y Benítez, J. M. 2000. Aves de Extremadura, vol. 1, 1998. Adenex, Mérida.