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without feeding. In other words, a toad refuses food on 36.9 per cent. of the days. Therefore instead of a toad filling its stomach four times in twenty-four hours, according to Kirkland, it may eat (probably fill its stomach) once in a day and a half. The average amount eaten per toad per day in these 260 days is 1.12 g. The average weight of the toads is 36.6 grams, which is about the weight of the largest males or of a medium-sized female. These feeding tests show that the amount eaten at one feeding compares very closely with the stomach contents as recorded by Garmann, Hartman, and Kirkland. Furthermore they demonstrate: (1) That the stomach of a toad is not a rubber bag with an unlimited capacity as commonly supposed; (2) that the toad when feeding, if food is abundant, soon fills its stomach; (3) that toads do not feed every day. This was suspected, since toads are seen in greater numbers on rainy nights.

Usually as soon as the toads fed they buried themselves and remained so from one to ten days. Sometimes their eyes and nostrils were left exposed. Even so, insects placed in their cages usually failed to tempt them to leave their burrows.

If we take the mean, 36.6 grams, as an average sized toad, we find that it eats on an average, 26 insects or 1.12 grams per day. Counting May, June, July and August as a toad's feeding months, it will eat in this time some 3,200 insects, or 134.4 grams.

To estimate the value of a toad's work in dollars and cents is rather difficult, since the toad eats beneficial as well as harmful insects. Garman from his data does not hesitate to class the toad with useful animals, yet he would not have us overlook the number of beneficial insects eaten. According to Kirkland eleven per cent. of its food consists of insects directly or indirectly valuable to man and eighty per cent. is either directly injurious or obnoxious. He computes on the data previously given of a stomach content that a toad is worth $19.88 per year for the cutworms alone which it destroys. He assumes that a toad fills its stomach four times a day with 6 cut

worms and other insects for three months and that the cutworms do damage to the amount of one cent each. Granting that cutworms are injurious to the amount of one cent each and that they work four months instead of three, still Kirkland's estimate is about four times too large, for a toad can not fill its stomach more than once in twenty-four hours. Furthermore, my experiments show that it eats, on an average, only once in one and a half days. These factors give the toad a value of about $5 per year on the basis of Kirkland's estimate. Such figures may be approximately correct for greenhouses, gardens or truck farms, but on the whole I am inclined to think they are too large for farming districts. (To be concluded)

NOTES ON THE BEHAVIOR OF THE DOMESTIC

FOWL1

PHILIP B. HADLEY

RHODE ISLAND AGRICULTURAL EXPERIMENT STATION

DURING the month of February, 1909, the writer's attention was called to an interesting feature of the behavior of a buff rock cockerel kept in the poultry department of the Rhode Island State College at Kingston, Rhode Island. Having briefly described the facts of the case to Dr. Robert M. Yerkes of the Department of Psychology of Harvard University, and having been informed by him that the behavior in question was somewhat noteworthy, the writer has collected data, secured photographs, and desires to present the following description, believing it may be of interest to students of animal behavior. The point of behavior under consideration consists in the acquired habit of an adult barred rock cockerel of "working" an automatic feeder, containing bran and grain, located in one of the colony houses of the poultry department, and by this action of securing a larger amount of the grain constituent than the feeder, working by itself, would naturally be able to supply.

The automatic feeder in question is of a type manufactured by John Anderson, of Slocums, Rhode Island, and involves mainly a box (Fig. 1, B) containing feed, and a tray (T) suspended beneath it. The dimensions of the box are roughly sixteen by eleven by eight inches. The food material escapes from the box through a narrow opening at the back and bottom of the feeder, and is caught in the tray, which is thirteen inches long by seven and one half inches broad, and is suspended eleven inches form the floor. The supply of food material falling on the tray is regulated by a balance system. The tray is so

1

1 Papers from the Division of Biology, No. 5. Published August, 1909.

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suspended from the point F that, when it is lightened (consequent to feeding), it rises and simultaneously admits a new supply of food material from the box. As soon as a sufficient amount to increase the weight of the tray has fallen, the latter drops again and automatically shuts off the supply. This process of filling and empty

ing continues as long as there is material left in the box and there are fowls to eat from the tray.

The material contained in the automatic feeder is usually a mixture of bran, wheat, and whole corn. While both the hens and the cockerel eat a fair amount of the bran constituent, they like the grain, especially the whole corn, much better. This predilection is exhibited especially by the cockerel, which attempts to obtain a minimum amount of the bran and a maximum amount of the corn. Usually there are from four to eight hens, together with the cockerel, attempting to feed from the tray at the same time. As a consequence, the grain, which is mixed with the bran, is in the tray but a short time before it is eaten, and nothing but the bran remains. When this condition has come about the cockerel proceeds to "work" the feeder. This is accomplished in the following

manner.

As shown in Fig. 1, the cockerel while eating almost invariably stands at the left-hand corner of the feeder. At this point he usually feeds from the corner of the tray, while the hens feed from both sides or from the ends, some of them standing between the feed-tray and the wall, where there is a free space of ten and one half inches. As soon as the corn has all been eaten the cockerel steps back sufficiently to clear the corner of the tray, takes a few steps forward around the corner, raises its head high and gives a vigorous push or peck to the beam designated (a) in Fig. 1. The force of this blow usually serves to throw out the board slat which holds the food back in the box; and, as a result, fresh material falls upon the tray, the increased weight of which immediately closes this outlet from the box. As soon as more corn has fallen on the tray the cockerel hastily returns to his former position at the corner of the tray and devours as many of the kernels as possible before the hens have again cleared the receptacle of grain; whereupon the cockerel again leaves the tray and pecks the beam. The final result of this continuous performance is that the tray be

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