EXAMINATION OF POPULATION STRUCTURE IN RED-COCKADED WOODPECKERS USING DNA PROFILES

The degree to which DNA similarity is related to kinship and population structure in natural populations was investigated for a small population of cooperatively-breeding Red-cockaded Woodpeckers (Picoides borealis) in the western Piedmont region of South Carolina. An independent pedigree was established from records of color-banded individuals. Results of DNA profiles were then examined relative to this pedigree. DNA similarity among unrelated woodpeckers averaged 0.55 ± 0.01 (SE). The mean number of DNA bands scored and similarity did not significantly differ between founders and the current population. Examination of parentage in 10 families indicated that multiple paternity did not occur when band by band comparisons or similarity values were compared among parents, helpers, and offspring. Thus, Red-cockaded Woodpeckers were monogamous in this population. DNA similarity among all individuals ranged from 0.32-0.78. Distribution of these similarity values by kinship resulted in some overlap with other kin values. Therefore, specific similarity values could not be assigned a kinship value without knowledge of the pedigree. However, least-squares linear regression indicated that similarity was significantly related to kinship (P < 0.05). These results indicate that use of DNA profiles may be important in quantifying population structure, however, they must be used in conjunction with a known pedigree before any assessment of kinship among individuals is made. Band by band comparisons remain a viable technique for examination of parentage when all putative parents have been sampled.