800 MR. w. bickerton's exhibition of [Kov. 23, 



Dr. F. D. Welch, F Z.S., exhibited photographs of a male 

 Gayal [Bihos frontalis) living in the Society's Gardens, in which 

 the lower halves of both foi-e and hind legs were almost entirely 

 black instead of pure white as in the normal adult. 



British Nesting Terns. 



Mr. William Bickerton, F.Z.S., M.B.O.U., gave a lecture 

 illustrated with about 120 lantern-slides showing the nesting 

 haunts and habits of the five species of Terns which nested in 

 the British Islands. These, given in the order in which they 

 arrive during the Spring migration, are: — Sandwich Tern [Sterna 

 cantiaca), end of Mai-ch ; Common Tern (S. Jluviatilis) and 

 Ai-ctic Tern [S. macrura), latter part of April ; Roseate Tern 

 (aS'. dougalli), very end of April ; Little Tern [S. minuta), early in 

 May. He contributed the following notes on these Terns, 

 arranged in the order in which the birds were photogi-aphed — 

 Sandwich Tern, Common Tern, Little Tern, Roseate Tern, 

 Arctic Tern. The three first-named he had photographed in a 

 haunt where they all nested in the same locality, namely an 

 area of sand-hills on the coast at Ravenglass in Cumberland. 



Sandwich Tern {Sterna cantiaca). — This is the earliest to arrive 

 in spring, and the first to nest. The Sandwich Terns at Raven- 

 glass did not all nest in one area, but chose four or five different 

 areas in different portions of the Sand-hills District. Some of 

 these nesting areas were on quite bare sand ; others amongst the 

 long marram grass, and others in intermediate areas partly sandy 

 and partly grass-covered. They are probably the most social of 

 all the five species in that the nests ai-e more concentrated in any 

 pai-ticular nesting area. The eggs were always either one or two 

 in number. On no occasion were three eggs found in any one 

 nest, although the colonies were visited in thi'ee successive nesting- 

 seasons — 1905, 1906, and 1907. The young birds began to hatch 

 out during the last week in May. The Sandwich Tern is the 

 most insanitary of all the five species, inasmuch as the droppings 

 of the birds always seemed to be deposited immediately round 

 the outside of the nest — a point that had not been noticed with 

 regard to any other species. In fact the condition of the sur- 

 I'oundings of the nest was, i-oughly speaking, a test of the length 

 of time that had elapsed since incubation commenced. 



Common Tern [Sterna flu.viatilis). — This was the latest of the 

 three species to nest at Ravenglass — very few eggs being found 

 before the end of the first week in June, at which date large 

 numbers of the Sandwich Terns were hatched out. He had been 

 on the nesting area as late as July 7th and failed to find a single 

 young bird hatched out. At that time the Sandwich Terns had 

 absolutely completed their nesting season. There were probably 

 1000 to 1500 pairs of Common Terns nesting, and the following 



