Two types of species radiation in avian feather lice. (a) Convergent adaptive radiation. After colonizing a new host, feather lice diversify to exploit the same niche via similar morphotypes. In this example from Johnson et al. , body lice on Tinamous diversify into head and wing ecotypes and wing lice on Parrots diversify into head and body lice. (b) Non-adaptive radiation. In this example from Johnson et al., a head lice lineage appears to have colonized several orders of birds (Cuculiformes, yellow; Falcinoformes, blue; Piciformes, red). This could also represent an adaptive radiation as species would still be entering a novel environment - a new host.
Lapoint and Whiteman BMC Biology 2012 10:53 doi:10.1186/1741-7007-10-53