LIFE HISTORIES OF NORTH AMERICAN GULLS AND TERNS. 19 



On cloudy days or in the dusky twilight, these birds have a habit of uttering 

 loud wailing cries, interspersed with harsh shrieks, which are among the most 

 peculiar notes heard in the northern breeding grounds. 



Mr. W. Elmer Ekblaw says of the habits of this jaeger in Green- 

 land: 



The jaeger not only steals the food away from the other birds, but also preys 

 upon their eggs and young. In 1914 I found in one day's tramp two eider nests 

 and one nest of the ring-necked plover that had been despoiled by this ravager. 

 The pierced egg shells were scattered about the nests, as if the jaeger had de- 

 lighted in the destruction he had wrought. The knots and sandpipers of the land 

 birds and the kittiwakes and terns of the sea birds cordially hate the jaeger. In 

 protection of their nests and young these birds often valiantly attack and drive 

 off the greedy jaeger, but usually he pursues them vindictively until they yield 

 to him. He is the particular enemy of the kittiwakes, and whenever he dashes 

 into a flock of them his vicious screams scatter them panic stricken. He then 

 singles out one for his victim and pursues him relentlessly with buteonine 

 tenacity of purpose. 



Disliked, as parasitic jaegers must be by their victims, they are 

 well able to take care of themselves and have few destructive enemies. 

 Even man, although eagerly taking the eggs for food on the breed- 

 ing grounds, disdains to eat the robber bird. It may, like the 

 strongest of sea birds, at times succumb to the tempest. King (1836) 

 records that one in a storm " sought refuge from the raging elements 

 under the lee of our tent." 



Fall. — The fall migration of the young of the year begins in 

 Alaska, according to Nelson (1887), after the 20th of September and 

 the birds keep out to sea on the New England coast. I have seen 

 adults at Ipswich as early as July. Here they pursue their calling 

 among the terns until these birds leave for the south, whither they 

 follow them by September, and continue the same methods of mak- 

 ing a living during the winter. 



DISTRIBUTION. 



Breedifig range. — Arctic and subarctic regions of both hemispheres. 

 In North America east to Greenland (Disco Bay arid Baffins Bay and 

 probably north to Thank God Harbor. South to northern Labrador 

 (Killinek) , and northern Hudson Bay (Southampton Island) , cen- 

 tral Keewatin (near York Factory), southern Mackenzie (Great 

 Slave Lake), southwestern Alaska (Alaska Peninsula and Kodiak 

 Island), arid the Aleutian Islands. West to Bering Sea coast of 

 Alaska. North to the Arctic coast of Alaska and Mackenzie, also 

 Banks Land (Mercy Bay)', Melville Island (Winter Harbor), and 

 other Arctic Islands to about 80° north latitude. Has been recorded 

 in summer in southeastern Alaska (Glacier Bay) and inay occa- 



