GENETIC-ANALYSIS OF BROWN-HEADED COWBIRDS MOLOTHRUS ATER RAISED BY DIFFERENT HOSTS - DATA FROM MTDNA AND MICROSATELLITE DNA MARKERS

Ecological and behavioural data suggest that female brood parasitic br own-headed cowbirds Molothrus ater are host generalists; this predicts that there should be no genetically differentiated host races within cowbird populations. We tested this hypothesis by comparing differenti ation in two rapidly evolving DNA markers (mtDNA control region sequen ce and nuclear DNA microsatellite loci) among unrelated cowbird chicks raised by two ecologically distinct hosts. No differentiation was obs erved in either marker supporting the absence of host race hypothesis.