36 BIRDS OF TUNISIA 



CAPRIMULGUS vEGYPTIUS ISABELLINUS (Temminck). 



ISABELLINE DESERT-NIGHTJAR. 



Caprimulgus aegyptius, LicM. Verz. Doubl. p. 59 (1823). Hartert 

 Cat. Birds Brit. Mus. xvi, p. 562 ; Malherbe, Faune Orn. de I'Alg. p. 9 

 (1855) ; Eoenig, J. f. 0. 1888, p. 165 ; id. J. f. 0. 1892, p. 360 ; 

 Whitaker. Ibis, 1895, p. 102. 



C isabellinus, Temm. PL Col. 379 (1825) ; Malherbe, Faune Om. de 

 I'Ahj. p. 9 (1855) ; Loclie, Expl. Sci. Alg. Gis. ii, p. 105 (1867). 



C. aegyptius saharae, Erlanger, J. f. 0. 1899, p. 525. 



Description. — Adult male, spring, fiom Tozer, South Tunisia. 



General colour of plumage above bright sandy-isabelHue, finely pencilled, 

 and vermiculated with pale grey ; a few narrow black streaks on the crown 

 and sides of the head ; some black marking on the scapulars and upper wing- 

 coverts ; wings and tail irregularly barred with blackish-brown ; greater 

 portion of the inner webs of the quills white ; underparts sandy-isabelline, 

 finely barred and vermiculated with light brown ; a patch ou the throat 

 white ; sides, flanks, and under wing-coverts with the barring almost 

 obsolete. 



Iris black; bill dark brown ; feet light brown. 



Total length 10-50 inches, wing 7'70, culmen from gape 1-10, tarsus 

 0-80. 



Adult female similar to the male, but slightly larger. 



There are apparently two fairly separable forms of pale-coloured or 

 what inir;ht be called Desert-Nightjars, one being grey, the other 

 isabolline. In Egypt botli forms seem to occur, and Captain Shelley, 

 as far back as 1872, pointed out this fact, although he did not consider 

 the difference between the two of sufficient importance to call for 

 their separation. 



In Tunisia, apparently the isabelline form alone occurs, and to 

 this Baron v. Erlanger has given the name of C. a.gijptius Sahara 

 (J. f. 0. 1899, p. 525). 



If Lichtenstein's description of his C. cegyptius (Verz. Doubl. 

 p. 59) be applicable to the grey form, this must no doubt bear his 

 name; but Temminck's name of C. isahdUnus, if we are to judge by 

 the plate and desscription given of the bird (Temm. et Lang., PI. Col. 

 879), undoubtedly appears more applicable to an isabelline-coloured 

 form . 



Tennuinck, it is true, does not seem to have recognised the differ- 



