Biometric data of North African Blackbird Turdus merula: are there many subspecies?

During the past two centuries, few studies have been conducted on biometrics of North African Blackbirds. Several of these studies were carried out during the latter part of the 19^th and in the early 20^th centuries. As a result, two subspecies were recognized namely Turdus merula algira inhabiting northern regions of North Africa and some localities in southwestern continental Europe and T. m. mauritanicus inhabiting central western Morocco and southern Algeria and Tunisia (to the end of arid climatic regions). In this study we provide morphological data from the northeastern Algerian population of Blackbird. Results reveal no differences between sexes in any of the measurements (small sample size). Comparison of morphological data of specimens collected in the northern region of North Africa and from the southern region of Maghreb countries (Algeria, Tunisia and Morocco) show morphometric differences only in wing length. These results are consistent with the existence of multiple subspecies in North African populations of Blackbird. Our findings support the assumptions of previous researchers in considering T. m. algira as typical of northern areas of Maghreb countries and T. m. mauritanicus typical of southern areas of the region.