A new technique to identify and assess the dispersion of eggs of individual brood parasites

摘要: A new technique for identifying eggs of brood parasites to individual females is presented. Twenty-six undeveloped brown-headed cowbird were removed from nests on a small study area in eastern Kansas. Proteins their yolks subjected starch gel electrophoresis. Electromorphs are completely maternal origin, and results separate sample California showed that electromorphs do not differ among an cowbird. Combinations at four polymorphic “loci” identified seven hypothetical females. The binomial probability two or more eight (fieldwork suggested no than 7–8 laying the site) share particular combination was calculated off-site, independent eggs. Six these probabilities below 5%. Eggs collected directly matched electromorph combinations. Discriminant function analyses 11 egg variables correctly classified 95.7% group which they placed by combination. Patterns dispersion individuals over host species, time space assessed. Despite sizes, it clear host-specific overlap considerably areas.