BUBO ASCALAPHUS DESERTORUM 81 



aud retiring habits. Erlanger met with the species on the Djebel 

 Sidi-Ah-ben-Aoun, where he obtained a pair, with their eggs, and 

 a third specimen was given to him by a gentleman at Gabes (J. f. 0. 

 1898, p. 495). 



The Eagle-Owls mentioned by Dr. Koenig as having been obtained 

 by him in the Algerian Sahara and in Tripoli, wej'e presumably of the 

 present form. 



Of the habits of B. a. desertorum we know but little, but they 

 probably do not differ from those of the preceding form. According 

 to Messrs. Rothschild and Wollaston, the species lives in isolated 

 pairs on rocky hills, and may be as often found on the sunny as on the 

 shady side of a hill, its breeding-quarters being at times exposed to 

 the full heat of the sun. The birds are very much on the alert, and 

 when disturbed, fly off without hesitation. 



Respecting the breeding of this species, Erlanger states that the 

 site selected for that purpose by the pair he obtained in South Tunisia 

 was at the entrance to a cavern in a cliff-side ; three eggs were found 

 deposited in a hollow in the sand, surrounded by the castings of the 

 birds, and the refuse of their food. The eggs were white, two of 

 them measuring each 53 x 42"5 mm., and the third 565 x 42 mm. 



VOL. u. 



