voL xI1.}) NOTES ON ZONAL DISTRIBUTION. 75 
Rook ; while others remain to breed only on certain types of 
ground—Blackbird, Robin, Wren, Chaffinch, Wood-Lark— 
showing that they are nearing their climatic limit. Again, 
four of our summer visitors are here resident: Blackcap, 
Chiffchaff, Wryneck, Kentish Plover ; while a larger number 
occur only on migration: Wheatear, Whinchat, Redstart, 
Garden-Warbler, Willow-Wren, Wood-Wren, Tree-Pipit (once 
met with in winter), Pied Flycatcher. 
Consideration of the breeding-grounds of the local species 
just mentioned suggests that dryness in summer is the factor 
which, directly or indirectly, makes this zone unsuitable for 
the breeding of a number of species. In this connection 
it is interesting to note that the Wheatear does not breed 
below:about 1,000 metres, hardly reaching below the limits 
of the montane zone, where the grass remains more or less 
fresh all the summer; yet about the middle of August, 
Wheatears appear in numbers on the parched Campagna 
on their way southwards ; hence we may suppose that it is 
only for the nestlings that this zone cannot produce the 
right kind of food. 
Several of the species belonging to the Mediterranean 
fauna are nearly or quite confined to this zone. These are: 
Calandra Lark, Short-toed Lark, Lesser Grey Shrike, Penduline 
Tit, Cetti’s Warbler, Fan-tailed Warbler and Bee-eater, 
and probably Black-eared Wheatear and Spectacled Warbler 
(very local species). 
The arrival of the migratory breeding species in this zone 
is naturally earlier than in the south of England, but the 
divergence is not the same in different species. Thus the 
Swift, of which the first few arrive in Rome about the 21st of 
March, while some numbers are present by the Ist of April 
and nearly all by the 10th, may be said to be thirty-five or 
forty days ahead; while the Nightingale, arriving about 
the Ist of April, and the Spotted Flycatcher, about the 
20th, are some fifteen days ahead. Most species arrive in 
this zone when vegetation (and insect life also, to judge by 
the butterflies) is more advanced than on their arrival in 
the south of England. 
_ The departure of several species is also earlier than in 
England, a fact which much surprised me. Swifts leave 
between the 15th and 25th July, except for a few stragglers ; 
though passing flocks, presumably from north of the Alps, 
are to be seen almost throughout August. Whitethroat, 
Spotted Flycatcher, Swallow and Martin all leave a little 
earlier than with us; but the Nightingale seems to be an 
exception, not leaving till the second half of September : 
