NESTING-SERIES OF BRITISH BIRDS. 153 



No. 46. WILLOW- W ARBLER. 



(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 locally, 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, 2 ft. 4 ins. ; no. 5 was abandoned, a stone preventing 

 the birds from completing it ; no. 8, 2 ft. 7 ins. ; nos. 7 & 9, 3 ft. 3 ins., 

 extended beyond the back of the model. 



Norfolk, July. 



Presented by Lord Walsingham. 



M 



