Birds of Gran Canaria. 595 



a,b. c? ? . Barrauco below Santa Brigida. 1st April '09- 



c. ? . Between Maspalomas and Juan Grande. 2nd 

 March '12. 



Iris brown ; bill black ; feet black. Wing-measurements 

 167-172 mm. 



C. m. hrehmorum is paler and more brownish grey than 

 C. apus, the white on the throat extends lower, and the 

 forehead is decidedly paler. 



From C. niurinus it is distinguished by its darker colour- 

 ing throughout. 



This Swift is almost entirely confined to the north of the 

 island ; Herr von Thanuer never met with it in the south, 

 and I have only done so on one occasion, near Juan Grande, 

 where about ten birds were hawking over the plain. Very 

 few are to be seen in the winter months. 



In April (1910) when passing through the town of 

 Aguimes, I was very much struck with the thousands of 

 Swifts which were hawking over the houses — the air was 

 literally full of them, but in about four days' time they had 

 totally disappeared. This is the only occasion on which 

 I have seen this Swift in any numbers. Earlier in the year 

 a few occasionally make their appearance in the neighbour- 

 hood of Las Palmas and Santa Brigida. Canon Tristram 

 believed them to be resident, but in this, I think, he was 

 mistaken ; by far the greater number observed are summer 

 migrants. 



On the 18th of August (1908) I observed a few Swifts in 

 the Monte, and in May and June (1912) I noticed several 

 hawking over the Port Road. 



Polatzek found these Swifts in the Barranco Guiniguada. In 

 August and September he mentions that they went regularly 

 every morning along the Barranco past San Mateo towards 

 the heights, and returned about five o'clock in the afternoon. 



Cypselus unicolor. Madeiran Black Swift. 

 Cypselus unicolor Tristram, Ibis, 1889, p. 23. 

 A2ms unicolor Hartert, Nov. Zool. 1901, p. 327 : Polatzek, 

 Cm. Jahrb. 1908, p. 164. 



