434 
Rev. H. B. Tristram on the 
a special object of dislike to the Willow Wren, whose clamours 
frequently disturb its noontide siesta. 
No other Shrike came under my observation in the winter, 
nor did any appear to halt in the Desert on their vernal migra¬ 
tion, though on our return to the coast we found that at least 
five species had arrived from the south. 
90. Hirundo rustica. (Chimney Swallow.) 
A few pairs of Swallows remained all the winter in each oasis; 
but none of those observed were in mature plumage, and I there¬ 
fore presume that it is only the younger and weaker birds who stay 
behind. The Arabs informed me that for one swallow they have 
in winter they have twenty in summer, and that they usually retire 
about the end of November, returning in February. Certainly very 
few had arrived by the end of February, though in the beginning 
of that month I saw myriads on the wing at Biskra, which must 
have remained for some time in that neighbourhood, as they 
did not reappear in any considerable numbers in Tunis till the 
beginning of March. But throughout the whole winter a few 
were to be seen wherever there was water or marsh. The natives 
are perfectly familiar with the fact of the migration of vast flocks 
to the south, which all go, as they say, to Tirabuctoo, the El 
Dorado of Arab and Swallow. 
91. Cotyle rupestris. (Rock Swallow.) 
I saw two of these birds in December in a ravine in the M*zab 
country. 
92. Cotyle riparia. (Sand Martin.) 
A few at El Aghouat in November. They did not appear to 
winter in the Sahara, and can only, I imagine, be stragglers 
there at any time, as the weds and oases afford them but few 
conveniences for nidification. 
93. Chelidon tjrbica. (House Martin.) 
Exactly the same remarks will apply to this bird as to the 
Chimney Swallow. A few pairs may everywhere be seen through¬ 
out the winter, while in summer, I am told, there is not a hovel 
without several building in the corners of the doorways, where 
their nests may generally be seen. Those I shot were in im¬ 
mature plumage. 
