paid no attention to the fresh supply I left. They were very restless and they were almost constantly flying about their quarters, often rising to the top of the enclosure, the most unusual feature of their activities. They went to the swimming tank which appears in Plate XX, frequently, though one of them prevented the others from spending much time on the water by driving them away. The gulls alighted frequently on the edge of the tank as shown in Plate XX, and they often remained there two or three minutes except when the belligerent gull drove the others away. I have never seen so much activity by these birds as at that time except possibly on two or three other occasions which were also at the time of gull migrations. Unfortunately, it has not been practicable for me to watch the birds carefully during periods when migrations occur. The performances just described suggested to me the possible existence of a migration impulse as the cause. This suspicion is strengthened by the observations of others on the behavior of other captive wild birds at migration times, but it must be admitted that my notes on these performances of my gulls have only suggestive value. SUMMARY.1 1. The Herring Gull is gregarious in habit, but it is also quarrelsome. Some of the fights are undoubtedly the consequence of invasions upon nesting precincts as stated by Herrick, but many are probably due to simple belligerency. This bird is often a great coward and may be routed by smaller birds, the crow for instance. The fights between adults have always been harmless, in my experience. Herring Gulls will fight fiercely for food when very hungry. 2. Herrick's conclusion that the frequent killing of the young by adults is the consequence of the instinct to guard a nesting precinct probably holds true in many cases. There is, however, some evidence that this is not always the explanation. Juvenals sometimes attack younger birds just as savagely as the adults do and in the same manner. 3. Other birds often nest safely even on a small island densely populated by breeding gulls. 1 This section is not complete. It includes principally the more important conclusions of this paper. 4. The Herring Gull nests usually in places the most inacces The breeding place is usually on When seeking food or aside from sible to man that are available. an island not inhabited by man. the breeding season, this bird is frequently to be seen near human habitations on the coast or following vessels. 5. This gull is practically omnivorous in its habits according to the observations of various writers. Animal food is preferred, but other food may be eaten if the bird is hungry enough. 6. The Herring Gull does not dive for its food to any extent, and it never plunges vertically into the water as Terns do. 7. Breeding begins later in Green Bay and on Lake Michigan than at points on the Atlantic coast much farther north. This difference is very likely due to the accumulation of ice in the northern portions of the Great Lakes, which does not disappear until after the beginning of spring. 8. The nests are made of such material as is available, but fine materials are preferred. 9. The offspring are shaded by the parents on a hot day until they are strong enough to leave their nest and seek a shaded spot. 10. The young are given food which is first regurgitated upon the ground. There may be promiscuous feeding of young birds by adults not their parents. 11. Young Herring Gulls not yet old enough to fly usually hide when human intruders appear as is the case with other members of the order. Sometimes only the head may be hidden but the bird sits perfectly still. If removed from its hiding place, the hiding instinct is replaced by the instinct to run away. The juvenals able to fly join the adults at such a time, in the general panic, overhead, or they fly away some distance, usually to water. 12. Herring Gulls which I have had in my possession since they were in the nestling-down plumage were less mature in plumage at two years than is indicated by Dwight for birds of that age. It is my judgment that Herring Gulls rarely breed before they are three years old. All of the breeding Herring Gulls which I have seen were adults, so far as I could determine. 13. It has been my experience that the young are at least two months old before they begin to fly well. 14. I have given especial attention to the voice of the Herring Gull. The most frequent sounds are the "challenge" and the "alarm" cry. A "mewing" sound is fairly common. These cries all involve characteristic positions, especially the "challenge" and "mew." The "challenge" seems to represent a variety of emotional states but, in general, excitement. The young have a characteristic squeal or chatter which is high pitched. It is used in calling for food or with a little modification when frightened. My captive gulls began to use what appeared to be a rudimentary "challenge" cry in September of their first year. I have heard this only a few times. 15. Both vision and hearing are keen in the Herring Gull, as appears to be the case with most birds. 16. It has been my experience that the Herring Gull has nearly as good darkness vision as man at least. During the breeding season or when food is best obtained at night, this bird is very active at night. My captive gulls will eat, if very hungry, when there is barely light enough for me to distinguish their food. 17. Food which is wet with solutions of either table salt or acids is rejected. My birds detect the presence of these solutions even when they are very weak to my taste. 18. Meat is eaten much more readily when it is fresh. The extent to which spoiled meat is tolerated varies directly with the degree of hunger. 19. It is a common practice of these birds to rinse food of uncertain palatableness or when it is dirty, in water. 20. Some evidence was obtained concerning the use of nerves of general sensation in testing food. 21. A positive reaction is shown to air currents. In a severe storm, gulls leave the ground and indulge in flight manœuvres. 22. The Herring Gull is sensitive to extremes in temperature. In very cold weather, the feet are kept protected by the plumage a large portion of the time. 23. There is a large amount of bathing, especially in hot weather. In very cold weather, no water seems to be required beyond that present in the food obtained. AN ECOLOGICAL STUDY OF THE BREEDING BIRDS OF AN AREA NEAR CHOTEAU, MONT. BY ARETAS A. SAUNDERS. THE subject of the ecological associations of various forms of life has recently been given considerable attention. Most of the studies that have been made along this line, however, have been of plant life. Such studies of animal life, and particularly of bird life, have been comparatively few. This is probably because animals, and particularly birds, can move about from place to place, and are consequently less closely related to any one ecological association. In the breeding season, however, birds are fairly stationary, remaining in the vicinity of their nests. At this time they are confined to certain associations, which evidently depend on the character of their food and the locality chosen for their nesting sites. Sometimes a given species is confined to a single association and makes up a component part of its life. At other times a species may be found in several different associations, and may be less common in one than another. Occasionally a species nests in one association, but obtains its food largely in another. The study of these associations and the proportionate abundance of the different species of each is not only of great scientific interest, but also has an important bearing on the problem of obtaining an accurate census of our birds, and on the problems of the preservation of wild life. In forestry, the study of the forest types, which is merely a simpler name for an ecological association of forest trees, is of great importance. In my work with the United States Forest Service in Montana, I was frequently called upon to study and map these types. Through this work I obtained a closer insight into these associations and their relations to other forms of life. In the local lists of birds which I have published for the different parts of Montana where my work has been located, I have attempted to describe the more important associations and list the species breeding in each. I have always hoped, however, for an opportunity to make a deeper study of these associations, showing the proportions of the different species in each association, and the actual abundance of each species figured on an acreage basis. In the nesting season of 1912, I found such an opportunity. It was not in the mountain forests as I had hoped it would be, but in the vicinity of the little prairie town of Choteau, in Teton County, Montana. Here, with the exception of a short period from May 28 to June 5, I was confined to office work all through the spring and early summer, until August 5, when I finally left for a trip to the mountains. During this time I had my early mornings, evenings, Sundays and holidays free to explore the country in the immediate vicinity of Choteau, in search of birds and birds' nests. On the southeast side of Choteau was an area, watered by a small stream known as Spring Creek, which I found to be an excellent place for birds. While I often explored other areas in the vicinity, I found this one to be the most accessible, and was on it almost daily throughout the spring and summer. Early in June, after most of the migration was over and when the nesting season for most species was just beginning, I decided to make an ecological study here. I blocked out, roughly, a rectangular area, which by later measurements I found to be about 1400 by 8250 feet, and to contain about 265 acres. On this area I started to determine as closely as I could, the actual number of birds of each species, breeding in each association. I could not very well hope to find all the nests, particularly of the ground nesting birds, but I found that I could get my numbers accurately by noting the number of male birds of a species in song. I found that during the period of early morning song, practically ever male bird was participating. By going over the area carefully each morning, and noting the numbers of birds of each species that were in song I soon had my census of the singing birds. The non-singing birds were most of them conspicuous for other reasons and easily found. It is possible that I may have missed a few birds that nested on the area. A Sharptailed Grouse might have had its nest in the cinquefoil brush, as several did in similar places outside the area. A Sora could have nested in one of the cattail sloughs and escaped my notice. It is also possible that there were more nests of the Mallard on the area than I found. With these exceptions I am quite certain that I counted all the nesting birds on the area. Of course I repeatedly |