° 1914 J Strong, Habits of the Herring Gull. 195 



maining in the nest when observed, though gulls of the same age 

 on the ground would never be found in the nest but would always 

 be hiding. That tree nesting juvenals do not leave their nest until 

 they are able to do so without injury, is probably due to a realiza- 

 tion of the danger involved in such an attempt. This remaining 

 in the nest under such circumstances may possibly be regarded 

 as intelligent behavior of perhaps a low order which prevails over 

 any blind instinct to leave the nest to hide when intruders appear. 

 Just how much this behavior is tied up with instinctive activity 

 is of course beyond our knowledge. 



The promiscuous feeding of juvenal gulls at Gravel Island ap- 

 peared to me to be a variation from the probably usual habit of 

 parents feeding their own offspring. Unfortunately we lack data 

 for establishing the extent of this variation. It could easily be the 

 consequence of the congested life on the island. I have noticed 

 that juvenal Wilson's Terns seek food of any adult that may happen 

 to come near them with food in its beak, but all of my observations 

 indicate that the parent tern probably feeds only its own offspring. 

 The gull must go through the somewhat complicated process of 

 regurgitation which seems far from voluntary. Large numbers of 

 juvenal gulls crowding about an adult who perhaps sees its own 

 offspring in the mob may be able to snatch the food regurgitated 

 without regard to parental relationships. 



A large number of so-called lower birds like ducks, coots, etc. 

 and the various species of gulls learn rather rapidly where they may 

 feed and breed without molestation by man. In the course of 

 only a week, wild ducks become far less shy on bodies of water in 

 or about cities than when they arrive, a matter of common observa- 

 tion. Gulls likewise recognize even more positively that they are 

 relatively safe in such places, but they are exceedingly wary wher- 

 ever shooting occurs. Such discrimination undoubtedly involves 

 at least the rudiments of intelligence even though the activities 

 in question may be largely instinctive. 



I had hoped to carry on some experiments on modifiability in 

 behavior with gulls, but my time was taken up so largely with the 

 general observations which I thought should come first that only a 

 single experiment was started. An entire nest was moved four 

 feet to one side at a distance of about one hundred feet from my 



