PARENTAGE WITHOUT PARENTAL CARE: WHAT TO LOOK FOR IN GENETIC STUDIES OF OBLIGATE BROOD-PARASITIC MATING SYSTEMS

Abstract

AS IN PREVIOUS decades (King and West 1977, Payne 1977, Brooke and Davies 1989), avian obligate brood parasitism-a reproductive strategy defined by laying and not caring for eggs in nests of other species-has continued to feature prominently in the general scientific literature (e.g. Lotem 1993, Sherry et al. 1993, Reboreda et al. 1996, Marchetti et al. 1998, Kilner et al. 1999, Gibbs et al. 2000, Tewksbury et al. 2002). Because obligate brood parasitic birds constitute only -1% of all avian species (Ortega 1998, Davies 2000), why are they clearly over-represented in terms of publication? This question seems to have three answers. First, the prominence of parasitic Old World cuckoos (e.g. Cuculus canorus, Clamator glandarius), cowbirds (Molothrus spp.), indigobirds (Vidua spp.), and, to a much lesser extent, the parasitic Black-headed Duck (Heterocephalus atricapillus), some New World cuckoos, and honeyguides, is partly due to fascination of researchers with the remarkable array of traits that are tied to unusual and successful reproductive habits of those parasites. These adaptations include behavioral strategies (e.g. nest search-