SANDWICH TERN. 301 



places for the purpose of nesting every season. This 

 Tern is gregarious, but the colonies vary a good deal in 

 extent, that on the Farnc Islands being by far the most 

 important and time-honoured. It will be remarked, how- 

 ever, that the same patch of ground is not invariably 

 used, the birds selecting certain sites in succession. 

 But little nest is made, merely a hollow lined with a few 

 bits of withered marine herbage ; whilst in many cases 

 a nest of any kind is dispensed with altogether. Many 

 nests are placed near to each other, in some cases not 

 more than a foot apart. These are made either amongst 

 the sand, shingle, and drift near the water, amongst short 

 grass and campion, and more frequently further away 

 from the sea, on a bare patch of elevated ground. The 

 birds rise in clouds as soon as their haunt is invaded, 

 and fluttering and screaming hover above the intruder's 

 head as he walks amongst the nests. The eggs resemble 

 the surroundings so closely in tint that great care is 

 needed in walking not to tread upon them. 



Range of egg colouration and measurement : 

 The eggs of the Sandwich Tern are usually two in 

 number, more rarely three, and vary considerably in 

 colour. In ground colour they vary from white or 

 creamy-white to buff, spotted and blotched with dark 

 brown and orange-brown, and with underlying markings 

 of violet-gray. It is impossible adequately to describe 

 these exceedingly handsome and richly-marked eggs. 

 Some varieties are covered with large bold blotches and 

 washes of colour, others are splashed here and there 

 with brown or gray ; some are evenly spotted over the 

 entire surface, others zoned, others covered with short, 

 streaky lines. Average measurement, 2"i inches in 

 length, by 1*4 inch in breadth. Incubation, performed 

 by both sexes, lasts from twenty-one to twenty-four 

 days. If the first lot of eggs be taken or washed away 



