spectators as though the hawk would actually succeed in disposing of this troublesome quarry, since it continued to rise easily with its burden to a height of about twenty-five feet. By this time however the fully aroused victim was stirred to a desperate effort, and it became clear that the audacious hawk had 'bitten off more than it could chew.' In Mr. Sullivan's words the tabby "twisted around, gave a terrible splutter and scream and clawed the hawk with a vengeance." The latter, flapping wildly, at once relaxed its grip, while pussy nothing loath, withdrew her claws, fell to the ground, and dashed under the posts. Numerous downy feathers, floating gently to the ground convinced the onlookers that the chagrined hawk had none the best of the encounter. Temporarily tired of cats, it now soared to a great height and returned with empty talons to the chalk cliffs. The cat in question was a very small one, and Montana cats are notably thin in summer; but, allowing for these facts, the victim must have weighed six pounds at least. Nevertheless, Mr. Sullivan feels sure that, had the cat behaved like the rabbit for which she was mistaken, the hawk would successfully have conveyed the quarry to its eyrie in the rocks. As the nest was two miles distant this would seem an extraordinary feat, and presumably transcend any hitherto published records of the kind. I quite admit that under favorable conditions of wind the female hawk might transport a five or six pound jack-rabbit to the eyrie; but that any cat-lifting hawk should ever surpass what this one achieved seems to me improbable. The dexterous application of the cat's raking claws would not fail to prevent it, as in the above remarkable instance.

Where a rabbit succumbs to the shock of the hawk's constricting grip, the agile and wiry feline, on the other hand, is stimulated to offer a desperate resistance, and like Mr. Sullivan's protégé is little the worse for the encounter. It cannot be told whether the hawk was mistrustful of rabbits after this event, but the cat became so suspicious of a flying object that she would race for the wood-pile if Mr. Sullivan threw his hat into the air.

BIRDS AS DESTROYERS OF GRASSHOPPERS IN CALI

FORNIA.

BY HAROLD C. BRYANT.

CONSIDERABLE evidence of the interrelations existing between bird and insect life has come to light in connection with investigations into the economic status of certain birds carried on under the auspices of the California State Fish and Game Commission and the University of California. Some of the best evidence came from an investigation of a grasshopper outbreak in the vicinity of Los Banos, Merced County, California. A part of the results of this investigation was published in the University of California 'Publications in Zoology,' volume 11, pages 1-20. In the present paper additional matter is combined with a part of that previously presented, the whole being now offered with a special view to the problem of insect destruction by birds in California.

Certain sections of California are annually troubled with grasshoppers, and there is seldom a year when they do not cause considerable damage to crops in some part of the state. Reports of damage caused by grasshoppers in 1912 first began to be received in June. The western part of Merced County, and parts of Kings and Kern Counties were most affected. In the vicinity of Los Banos, Merced County, where the investigation was carried on, grasshoppers give some trouble each year but their depredations in 1912 were more extensive than usual. On many of the ranches the entire summer crop of alfalfa was destroyed. The only control measure resorted to was burning over of pasture and alfalfa land. As most of the grasshoppers already had wings when the burning was done, the majority escaped unharmed. Garden truck and small trees in the infested areas were attacked by the pests. Corn, tomatoes, and even onions were stripped of every leaf. In many instances small shade trees, even including eucalyptus, were completely defoliated.

The species of grasshopper causing the damage was the differential grasshopper, Melanoplus differentialis. The only other species noted at the time were Camnula pellucida, Conozoa behrensi, and Parapomala calamus.

An estimate of the numbers per square yard in the infested areas was obtained by counting the numbers disturbed by the observer at each step. Little damage could be noted where grasshoppers were less than fifteen to the square yard. Where damage was greatest alfalfa fields averaged about twenty-five to the square yard. In some pasture land along the irrigation canals the number was estimated at thirty per square yard.

This will give the reader an idea of the conditions existing at the time observations hereafter recorded were made.

The neighborhood of Los Banos, largely due to the great irrigation system and to the large amount of land which has been 'swamped,' supports a very large bird population. Water birds and shore birds are very abundant along the canals and in the marshes, whereas the pasture lands, the alfalfa, and the trees, furnish food and cover for many land birds. During a week's stay, July 10 to 17, 1912, twenty-two species of water and shore birds were recorded and forty species of land birds. Censuses taken indicated that the Bicolored Redwing was the most abundant bird and that the Cliff Swallow, Barn Swallow, Western Meadowlark, Linnet, Western Kingbird, and California Shrike, listed in the order of their abundance, were also common.

Observation showed that the following species of birds were feeding on grasshoppers. Only those birds actually seen with grasshoppers in their bills were recorded.

Western Meadowlark, Sturnella neglecta.

Bicolored Red-wing, Agelaius phoeniceus californicus.

Brewer's Blackbird, Euphagus cyanocephalus.

Bullock's Oriole, Icterus bullocki.

Arkansas Kingbird, Tyrannus verticalis.

California Shrike, Lanius ludovicianus gambeli.

English Sparrow, Passer domesticus.

Although observation in the field furnishes some evidence as to the kinds of birds feeding on an insect and the quantity consumed, yet it is on stomach examination that we must depend for accurate evidence as to the numbers of insects taken. In this instance a determination of the numbers of grasshoppers taken by the bird was made easy because of the presence of the mandibles of the insects hard parts which remained undigested. Experiments

by other investigators as well as some performed by the writer show that insects such as grasshoppers are digested by birds in from three to four hours. Consequently the number of grasshoppers destroyed each day must be at least three times the number found in a stomach.

The following table gives the results of the stomach examinations. In spite of the comparatively few stomachs of each species examined the results should give a fairly accurate idea of the extent to which birds in the infested areas were feeding on grasshoppers.

Considering the capacity of the bird, the Burrowing Owl (Speotyto cunicularia hypogaa) must be considered the most efficient destroyer, twenty-eight grasshoppers having been found in the one stomach examined. Blackbirds and Meadowlarks however, exceeding in numbers of individuals, were probably doing the most effective work.

The comparative destruction of grasshoppers per day by single individuals and by the total number of each species is crudely