372 BIRDS OF PENNSYLVANIA. 



times in large numbers. In one case one hundred and fifty-three seeds of poison 

 ivy were found in a single stomach ; in several cases the number was more than one 

 hundred, and the" average in nineteen stomachs exceeded fifty. 



At a large crow-roost on the Virginia side of the Potomac, near Washington, the 

 droppings of the crows are literally full of these seeds, usually accompanied by 

 many seeds of the harmless (red-berried) sumachs, arid a still smaller number of 

 those of the flowering dogwood (Cornus florida) and the sour gum (Nyssa). The 

 same is true of the large roost near Baltimore, Md., whence Mr.' C. L. Edwards, of 

 the Johns Hopkins University, sent to the department seeds of all the above species 

 more than a year ago. The seeds of poison ivy and poison sumach had been found 

 previously in crow stomachs collected near Washington, but for lack of a good ref- 

 erence collection of seeds they remained unrecognized until December, 1888, when 

 they were identified by the writer. 



In order to give some idea of the number of these seeds consumed by the crow it 

 may be stated that a single pound of the dried excrement taken from the roost in 

 the National Cemetery at Arlington, February 8, 1889, contained, by actual count, 

 1,041 seeds of poison ivy, and 341 seeds of poison sumach, in addition to 3,271 seeds 

 of other sumachs, 95 seeds of Virginia juniper, 10 seeds of flowering dogwood, and 

 6 seeds of sour gum. The material, which covered about four square feet, was taken 

 at random from above the layer of leaves, and represents the average deposit on the 

 roost. As the roost covers upward of fifteen acres, some idea may be formed of the 

 number of those seeds deposited there. 



It is a well-known fact that the germination of many kinds of seeds is hastened 

 by their passage through the digestive organs of birds and other animals, and hence 

 it was believed at once that the crow was aiding in the distribution of these poison- 

 ous plants. In order to place the matter beyond question, however, seeds taken 

 from the Arlington roost were tested in several ways, and not only was their vitality 

 found to be unimpaired, but they were found to germinate more quickly than seeds 

 taken from the vine. Of one hundred seeds of Rhus venenata from the roost, moist- 

 ened and kept warm, ten sprouted within forty-eight hours, and twenty more within 

 the next five days. One hundred and fifty seeds of the same kind and from the 

 same source were planted in a flower pot in the greenhouse, and at the end of four- 

 teen days one hundred and thirty of them had become vigorous seedlings from one 

 to two inches high, and several more were breaking the ground. Similar results 

 were obtained with seeds of Rhus toxicodendron from the roost, while seeds takon 

 from the vine had not sprouted at the end of fourteen days. Thus it becomes certain 

 that these seeds are improved rather than impaired by their passage through the 

 digestive organs of the crow, and this bird therefore is doing incalculable harm by 

 sowing broadcast the seeds of a poisonous vine and a more poisonous shrub, both of 

 which unfortunately are far too abundant already. 



THE GROW AS A DESTROYER OF THE EGGS AND YOUNG OP POULTRY AND WILD 



BIRDS. 



More than three hundred and fifty of our correspondents have contributed notes 

 relating to the crow as a robber of the nests of domesticated fowls and wild birds. 

 About seventy of these state simply that "no damage of this kind has been ob- 

 served," but with this exception the evidence is almost wholly unfavorable to the 

 crow. Two hundred and seventy-eight observers state distinctly that they know of 

 more or less mischief of this kind committed by crows. One hundred and forty- 

 seven have personal knowledge of its carrying off young chickens, and one hun- 

 dred and seventy -four report damage to domesticated fowls. There are twenty-five 

 complaints of injury to the eggs and young of turkeys, and about a dozen instances 

 of similar damage to ducks and geese. 



Rather more than ten per cent, of the reports on domesticated fowls state that the 

 damage is slight or occasional, but on the other hand upward of fifty observers re- 

 port frequent and serious depredations, many of them stating that the crows do 

 much more damage than hawks. It is significant that out of more than three hun- 



