Yesou, P., Buchheim, A., & Bermejo, A. 2005. Which subspecies of Shag occurs in Galicia?. British Birds, 98: 369-370.

Juvenile Shags Phalacrocorax aristotelis with whitish underparts and pale legs, characteristics typically attributed to the Mediterranean subspecies P. a. desmarestii, may occur within the range of nominate aristotelis (BWP). Such pale individuals are extremely rare in Britain, however, and account for only a small proportion of the Shags breeding in Brittany, western France…