152 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



Behavior. — I have never noticed anything peculiar or distinctive in 

 the flight of this species, which is very much like that of the larger 

 gulls; nor can I find anything of interest in regard to it in print. 

 The species is, of course, easily recognized in life by its very distinc- 

 tive colors in all plumages. 



Mr. Anthony (1906) refers to its voice as a " whining catlike cry" 

 while attacking the pelicans to rob them of their food. Mr. Osburn 

 (1909) says: 



Their cry was an oft-repeated "Cow-auk," "cow-eek," given wlien high In 

 the air, and a rapid guttural " caw-ca-ca-ca " when hovering near the nest. 



Mr. W. L. DaWson (1909) writes that, if disturbed in their sum- 

 mer loafing places, " they suddenly take to wing and fill the air with 

 low-pitched mellow cries of strange quality and sweetness, as they 

 make off to some distant rendezvous." 



Though not so much of an egg thief as some other gulls, it is some- 

 what of a pilferer of food and quite bold in attacking species larger 

 than itself which are too stupid to resist its persecution. Mr. 

 Anthony (1906) has given us the following interesting account of 

 its method of robbing the pelicans : 



Heermann's gull is by far the most active and successful in catching small 

 fish from the surface ; but as a rule will seldom attempt to catch his own din- 

 ner if there are any pelicans among the delegates to the convention. There 

 are times when the herring are so thick and so driven from below by the 

 large fish that the pelicans will sit on the surface and snap them up without 

 plunging, as is their normal method, from a height of from 10 to 30 feet in the 

 air. If the fish are swimming the deep plunge often carries the bird com- 

 pletely under the surface, and when a second later he bobs up like, a cork he 

 is sure of finding at least one, often two Heermann's gulls expectantly await- 

 ing the result. If there are two they will usually take up stations on each 

 side and but a foot in front of the pelican, which still holds its huge bill and 

 pouch under the water. It may be that the pelican does not yet know the 

 result of his efforts, for In plunging the pouch is used as a dip net and, if 

 nothing else, it is full of water, which is allowed to escape past the loosely 

 closed mandibles until, perhaps 5 or 10 seconds after the bird made his plunge, 

 a flutter is seen In the pouch, announcing one or more struggling victims. It 

 is still an open question, however, whether they will be eaten by the gull or 

 the pelican, and the latter is seemingly well aware that a herring in the gullet 

 is worth two in the pouch, for it will often wait several seconds for a favor- 

 able opportunity for disposing of the catch; the gulls meantime constantly 

 uttering their nasal whining note and keeping well within reaching distance 

 of the pouch. When the critical moment arrives the pelican throws the bill up 

 and attempts to swallow the fish, but, with cat-like quickness, one or both gulls 

 make a similar effort, and should the fish in its struggles have thrust its tail 

 or head past the edges of the mandibles, as very often happens, it is an even 

 chance that the gull gets the prize ; in fact, I have often seen a Heermann gull 

 reach well into the pouch and get away with a fish in the very act of slipping 

 down the throat of the pelican. 



I remember a very amusing incident of this nature I once witnessed on the 

 coast of Lower California. The pelican, after securing a herring; "backed 



