 Several other subspecies have been named , but are generally no longer considered valid . Most are intergrades that occur where the ranges of various subspecies meet . These include : S. v. <unk> <unk> , 1891 and S. v. <unk> <unk> , 1904 , which are intergrades between vulgaris and <unk> from western Russia ; S. v. <unk> <unk> , 1905 and S. v. <unk> <unk> and <unk> , 1909 , intergrades between vulgaris and <unk> from the southern Balkans to central Ukraine and throughout Greece to the <unk> ; and S. v. <unk> <unk> , 1928 , an <unk> between <unk> and <unk> in northern Iran . S. v. <unk> <unk> , 1928 from southern Iran 's ( <unk> Province ) is very similar to S. v. vulgaris , and it is not clear whether it is a distinct resident population or simply migrants from southeastern Europe . 
