A DESCRIPTION OF THE BIRD ROCK GROUP ON 

 EXHIBITION IN THE AMERICAN MUSE! M OF 

 \\llk\l HISTORY, REPRESENTING A POR- 

 TION OF A " BIRD ISLAND M OF THE NORTH AT- 

 LANTIC AND THE NESTING-HABITS OF ITS 

 CI PANTS. 



r.\ i-'k \nk m. Chapm \n. 



I tir.it. T of ilir I )cp.irtincnt «>f Mammalogy .m<l < )rniili ! 



[SLAM DS a- Bird 1'r<> i i ( i ORS. 



To the preserving influence of island-life we owe the continued 



existence of many birds which have long ceased to live, or, at 

 :. to nest, on the mainland. This is true of the great oceanic 

 islands as well as of the sand-bars, reefs, and rocks on which sea- 

 birds rear their young, and even of the tiny islet of reeds or 

 vegetable mould which forms the nest of the Grebes (see Group 

 of Pied-billed Grebes in the Main Bird-Hall). In every instance, 

 however, whether the island be a thousand square miles or one 

 square foot in extent, it owes the preservation of its bird-life to 

 the same cause, and this cause is the entire or comparative ab- 

 sence of bird enemies. 



Oceanic islands, or those which have had no connection with 

 the mainland. rule, without terrestrial mammals, and con- 



sequently destructive animals such as wolves, foxes, cats, both 

 wild and domesticated, minks, weasels, etc., are wanting, even 

 when the conditions are favorable to their existence, while the 

 barren rocky islets, reefs, and sand-bars are uninhabited, not 

 only by these predaceous species, but also by the birds' worst 

 enemy — man. 



Thousands of instances could be cited to illustrate the im- 



thc part played by islands in protecting birds, but we 



need go no farther than our Atlanti< < oast to be i onvinced that 



• it not for islands we should long ago have lost a number 



of birds which now never nest on the adjoining mainland. I >r 



example, illy all our remaining I 



now breed only on islands, the remaining large COl< 

 birds off the Men Vork and Mass.u lni 



5 



