NESTING-SERIES OF BRITISH BIRDS. 153 
No. 46. WILLOW-WARBLER. 
(Phylloscopus trochilus.) 
This Warbler makes its appearance about the first week in April and 
is common throughout the British Islands till the end of September or 
even later. It frequents gardens and coppices, feeding principally on 
small insects, especially flies and aphides. The dome-shaped nest 
loosely constructed of dry grass and always lined with feathers, is usually 
placed among herbage on the ground. From six to eight white eggs, 
generally spotted with light red, are laid in the beginning of May, and 
two broods are often reared in the season. 
Norfolk, June. 
Presented by Lord Walsingham. 
No. 47. SAND-MARTIN. (Cotile riparia.) 
No other Passerine bird has so wide a range as the Sand-Martin, 
which occurs throughout the greater part of Europe, Asia, Africa, and 
America, extending in winter as far south as Brazil. It is one of our 
earliest spring visitors, arriving towards the end of March and depart- 
ing by the end of September. It is generally, though jocally, distributed 
in colonies all over the British Islands, wherever the steep banks of 
rivers or lakes, sand-pits, gravel-quarries, or railway-cuttings, etc., offer 
a suitable nesting-site. In such situations tunnels, varying from 
eighteen inches to six feet in length and slanting slightly upward, are 
bored by the birds, the nest of dried grass, lined with feathers, being 
placed in an enlarged chamber at the end. From four to six white eggs 
are laid in the middle of May, and two broods are generally reared in a 
season. 
The model exhibited is an exact representation of a portion of the 
side of a disused sand-pit occupied by a colony of Sand-Martins, and 
the dimensions of each tunnel were carefully measured. The two lateral 
tunnels have been opened to show their structure. 
The measurements are as follows :— 
Tunnel no. 1, 2 ft. long; nos. 2 & 3 run into a common passage, 2 ft. 
8 ins. ; nos. 4 & 6, 2ft.4 ms. ; no. 5 was abandoned, a stone preventing 
the birds from completing it; no. 8, 2 ft.7 ins. ; nos. 7 & 9,3 ft. 3ins., 
extended beyond the back of the model. 
Norfolk, July. 
Presented by Lord Walsingham. 
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