44 BIRDS OF TUNISIA 



Dresser (Man. Palaearctic Birds, p. 41) includes this Chat as a sub- 

 species of S. xantJioprymna , but the point of difference between the 

 two species is so well marked and clearly defined as to warrant full 

 specific distinction. 



In North Africa S. inoesta occurs more or less abundantly through- 

 out the Algerian and Tunisian Sahara, and in corresponding districts 

 in Tripoli and Cyrenaica. In the last-named country Mr. Dodson 

 found it plentiful along the coast line of the Gulf of Syrtis, south 

 of Benghazi, and obtained numerous examples of it in those 

 districts. 



"Whether the western range of S. mcesta in Africa, extends into 

 Marocco, seems to be at present unknown, but it is quite possible that 

 it does so, and that the species occurs in some of the inland semi- 

 desert districts of the Empire. It is true that Mr. Dodson, when 

 collecting for me in Marocco, never came across the bird, but 

 apparently none of the districts visited by him were suited to the 

 requirements of this Chat, or likely to attract it. For the same 

 reason, many other desert forms of birds, which are common in the 

 Tunisian and Algerian Sahara, are entirely unrepresented in my 

 Maroccan collection. 



In Algeria, as already mentioned, S. mcesta is not uncommon, and 

 I have met with the species in considerable numbers on the plains 

 lying to the east of Biskra, which run into the semi-desert country of 

 the Tunisian Sahara, and like it, are mostly of a stony, or sandy 

 gravel description, scantily clothed with a scrub-vegetation. Loche, 

 writing of Algerian birds, refers to this Chat under the name of 

 Dromolcea isabtUina (Expl. Scient. Alg. Ois. i. p. 201). 



In the Tunisian Regency the present species is resident and not 

 uncommon in the more southern districts, but it appears never to 

 stray north of the Atlas Mountains, and may therefore be looked upon 

 as being strictly a desert bird. I have found the species particularly 

 abundant on the stony plains lying to the west of Gafsa, where, in the 

 late spring, when most of the migrants have passed northwards, 

 S. mcesta and S. deserti are the two species most often met with. It 

 must not be supposed, however, that these two species of Chat are 

 always to be found together in the same localities, as in certain 

 districts the one may be most plentiful, while the other is scarce, 

 or even totally wanting. 



Although the sandy gravel plains of the Upper Sahara may be 



