be virtually unknown as a host of the common cuckoo, a widespread European brood parasite. The invasive Argentine ant (Linepithema humile) is common in the Mediterranean area, and reduces arthropod numbers by removing most native ant species. The reduction in prey items is greatest in the tree canopy, and has a greater effect on species like the firecrest that feed high in the foliage. Less food is available for chicks, and parents have to spend more time foraging. Data on specific parasites of the firecrest is lacking, but the widespread moorhen flea, Dasypsyllus gallinulae has been recorded in a related Regulus species. A number of feather mites have been recorded in the genus, including Proctophyllodes glandarinus on firecrest. These mites live on fungi growing on the feathers. The fungi found on the plumage may feed on the keratin of the outer feathers or on feather oil. Status The common firecrest expanded its range in the nineteenth and twentieth centuries, colonising northern France, followed by first breeding in the Netherlands in 1928 and Denmark in 1961. In Britain, it had only been recorded a handful of times by 1839, but first bred in 1962, and is now widespread as a breeding bird in much of southern England. Milder winters have meant that more birds can winter further north, and therefore the breeding range can expand without incurring the risks involved in lengthy migrations. A population was found in northern Morocco in 1986. Population growth may be limited by lack of suitable habitat, and there may be local declines due to loss of conifers through storms or replacement by plantations of native deciduous trees. There may also be localised losses in areas of high heavy metal pollution, which particularly affects ground feeders like thrushes and conifer foliage gleaners, including both European Regulus species. Conifer specialists suffer from the loss and poor quality of needles, and the consequent decrease in abundance of their invertebrate food. The common firecrest has a large range and a population estimated at 10–15 million individuals, most in Europe. The population is believed to be stable in the absence of evidence for any declines or serious threats, and it is therefore classed as least concern on the IUCN Red List. In culture Aristotle and Pliny relate the legend of a contest amongst the birds to see who should be their king, the title to be awarded to the one