Aims: The aim of this work is to discover a) the existence of specimens of southern grey shrike with two, three or 2+3 tandem repeats in areas further away within the Iberian Peninsula, b) what proportion of specimens with this genetic character exist in any one population, and c) if there is genetic flow between neighboring populations.
Location: Four populations in Iberian Peninsula (three populations from Navarre and one population from Cáceres).
Methods: A small blood sample was obtained from 242 captured shrikes. An analysis has been carried out of the control region for the mitrocondrial DNA. The DNA was extracted and a fragment was amplified using primers DLL2 and FTPH2. The results were analysed by means of the Arlequin program for haplotype frequencies.
Results: Birds with two, three and 2+3 tandem repeats were recorded. The percentage of shrikes with two or three repeats did not differ either between populations or sexes. The presence of heteroplastic shrikes in two of the four populations was few frequent (1.6 % of the 242 birds studied).
Conclusions: Data suggest the existence of a genetic flow between populations, so they maintain the equilibrium conditions for this characteristic.
