The birds had been partially driven away from the spot where we landed and had been working, but we found them in prodigious numbers a little way on.  Cousin Silas insisted on our tying up old Surley, to prevent the unnecessary destruction which he dealt among them.  Before committing any great slaughter among them, Cousin Silas advised us to kill only a few of each description, to ascertain which were the most palatable for present consumption, and which were likely to preserve best for future store.  Sitting on nests roughly constructed of sticks among the shrubs, were a number of frigate birds (the _Tachypetes Aquila_).  He is a magnificent fellow, allied in some respect to the cormorant, but with shorter legs, and having a forked tail.  His plumage is a rich empurpled black, and the beak, both mandibles of which are curved at the tips, is red.  His wings are of immense length, and his power of flight is wonderful.  He can fish perfectly well for himself, but he is a most irreclaimable pirate, and likes to watch till other birds have seized their prey, and then he drops down upon them and carries it away.  Sailors also call them men-of-war birds, but I think they ought to be called pirates.  We looked into their nests, and found only one egg in each.