Forms a species group with L. scotica and L. pytyopsittacus, and all have sometimes been considered conspecific (see under those two species). Has apparently hybridized too with Spinus pinus. In W Palearctic, geographical variation rather slight and clinal (nominate race becomes paler, brighter and larger W–E, and within Europe brighter N–S), also with considerable individual variation; some accepted races possibly synonyms, e.g. guillemardi of nominate; several named races, e.g. hispana (SE Spain), mariae (from Crimea), vasvarii (NW Turkey), caucasia (Caucasus) and ermaki (N Altai), proposed on basis of very slight differences or show intermediate characters; conversely, some populations (e.g. in S Iberia)#R may merit subspecific recognition; race balearica restricted to Balearic Is based on evidence of genetic study#R. Situation in E Palearctic and S Asia not yet investigated. In North America, numerous attempts made to assign populations N of Mexican border to discrete races, with distinct breeding ranges; described races reai (from Idaho) and vividior (from Colorado) may merit recognition, whereas sitkensis and benti sometimes merged into race bendirei#R, but position complicated by identification of ten discrete types of flight call (across USA and W Canada)#R allied to other vocal characteristics (detectable using sonograms) and differences in bill size or shape (allied to specialization on particular species of conifer) and plumage colour, which, if driving reproductive isolation, may be considered “cryptic species”; in 2009, a newly discovered form from Idaho was proposed as a species, “L. sinesciuris”, on basis of small morphological and vocal differences attributed to absence of competition for pine (Pinus) cones from squirrels (Sciuridae)#R. Similar work in W Europe identified six vocal types, with some degree of assortative breeding and considerable overlap in area; in more recent study in W Mediterranean, however, a further six vocal types were described, thus placing some doubt on their taxonomic value. Further research required, especially as multiple vocal types now known to exist within crossbill populations, and adaptation to respective resource may be more appropriate explanation (see L. scotica). Race pusilla (also believed to be vocally distinct)#R sometimes listed as “percna”. Nineteen subspecies recognized.
Food and feeding
Status and conservation
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