Common cuckoo of two years. More than 100 host species have been recorded: meadow pipit, dunnock and Eurasian reed warbler are the most common hosts in northern Europe; garden warbler, meadow pipit, pied wagtail and European robin in central Europe; brambling and common redstart in Finland; and great reed warbler in Hungary. Female common cuckoos are divided into gentes – groups of females favouring a particular host species' nest and laying eggs that match those of that species in color and pattern. Evidence from mitochondrial DNA analyses suggest that each gene may have multiple independent origins due to parasitism of specific hosts
Common house martin Common house martin The common house martin ("Delichon urbicum"), sometimes called the northern house martin or, particularly in Europe, just house martin, is a migratory passerine bird of the swallow family which breeds in Europe, north Africa and temperate Asia; and winters in sub-Saharan Africa and tropical Asia. It feeds on insects which are caught in flight, and it migrates to climates where flying insects are plentiful. It has a blue head and upperparts, white rump and pure white underparts, and is found in both open country and near human habitation. It is similar in appearance to the two other