CONCEALED OR COVERED NESTS 105 



generally taken advantage of for this work, but 

 instances have occurred where the collectors have 

 been overtaken by a storm, their boats smashed up 

 and lost, and they themselves placed in rather an 

 awkward position. The birds take their time about 

 commencing to build, and if there has been a wet 

 December the first crop of nests is generally a poor 

 one, being soiled by the damp and drippings from 

 the roofs of the caves. However, about the last 

 week in January, the collectors go round the islands 

 to the different caves, a journey which takes about 

 three weeks in an open boat, and bring in all the 

 nests that have been built. The best quality, re- 

 sembling pure isinglass, and worth their weight in 

 silver, are found in caves in limestone and volcanic 

 rock, the nests built in sandstone and serpentine 

 being inferior. The birds now build much faster, 

 and at the end of February a second collection is 

 made, which is usually the best of the season. The 

 third collection is made in April, when the nests, 

 though of good quality, are thin and dry. The birds 

 are then left to build and hatch out their young. 

 They leave the islands soon after the south-west 

 monsoon sets in. The nests are very carefully 

 removed from the rock by an iron trident, and are 

 kept in clean linen bags, as it is important that they 

 should not be crushed, soiled, or wetted by the sea- 

 water. When brought into Port Blair they are 

 cleaned from all feathers and impurities, and then 



