SEA-BIRD NUMBERS AND MAN 85 



in a day, and one of the residents who had taken part in the slaughter 

 himself told me that as many as 100,000 terns were sometimes killed 

 in a season." 



By 1902 the little tern had gone. Fortunately this island and other 

 places were shortly afterwards recolonised, possibly as a result of the 

 election of Theodore Roosevelt as President of the United States in 

 1901! As Roger Peterson (1951) writes, "During his term of office, 

 which meant so much to the wild creatures, his pen created 38 federal 

 refuges. Ten years later, when he visited one of these on the coast 

 of Louisiana, he remarked, as a cloud of royal terns arose from their 

 eggs, that this sight alone was worth all the effort." 



Of all sea-birds, terns are the most unpredictable in their social 

 breeding habits. The numbers of occupied nest sites, even at ancient 

 and traditional colonies, fluctuate very much more than the numbers 

 at traditional colonies of other sea-birds such as gulls, auks or gannets. 

 Sometimes a very large colony with some thousands of nests may 

 desert in mid-season; sometimes it may establish its headquarters 

 some miles away from the place where it did so in the previous season. 

 A glance at the table will show the reader the fluctuations in occupied 

 nests at the principal Sandwich and common tern colonies in Norfolk. 

 These colonies have been since the early 'twenties under the strictest 

 protection, and it is almost certain that the changes are due to factors 

 outside human control. They are certainly not due to human predation 

 and disturbance, but some of them may be due to fluctuation in food 

 supplies, others to weather; of course, changes in food supplies can 

 be a consequence of weather. Terns appear to be very sensitive to 

 changes in the environment; more so than any other family of sea-birds. 

 Nevertheless, it seems perfectly clear that there has been a really 

 important recovery in the conditions of these sea-birds of the North 

 Atlantic during the present century and that this recovery is due to 

 protection. It is one of the many indications that the bird protection 

 movement which has been active on both sides for more than half a 

 century, has now won appreciable results. We can, for the first time 

 in human history, say that we have improved the number and variety 

 of our wild birds for the aesthetic satisfaction that they give us and for 

 no reason whatsoever connected with commerce or profit. 



It is worth giving details of these changes in the fortunes of the 

 terns. The gull-billed tern, for instance, has colonised Florida in the 

 last twenty years, and on the Old World side of the Atlantic has spread 

 from its ancient isolated nucleus in Denmark to Germany and Holland 



