86 



THE COMMON CROW. 



are plumper and much richer in nutriment. 1 Crows eat all species of 

 Rhus, and at all seasons, thus insuring the spread of these plants. 

 The berries of the poisonous species are much preferred, and it is only 

 as these become scarce that the harmless ones are much eaten. The 

 average quantity of poisonous and harmless sumac berries consumed 

 during the year is almost exactly the same, but most of the poisonous 

 berries are eaten during late summer, autumn, and early winter, while 

 most of the harmless berries are eaten during midwinter and toward 

 spring, as shown by the following table: 



Table showing percentages of sumac berries in Crow stomachs from August to April. 





Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Jan. 



Feb. 



Mar. 



Apr. 



Average 

 for the 

 year. 











4 

 6 



5 

 4 



6.58 

 3.89 



9.96 

 .56 



0.89 



0.74 



2.27 





0.5 



3.4 



8.46 



2.24 











After eating these berries the Crow rapidly digests the nutritious 

 pulp and ejects from the mouth the seeds, together with the sand swal- 

 lowed to aid in digestion (see hg. 1). The subject of the winter food of 

 Crows, as shown by the material found at the roosts, has already been 

 discussed (see pages 21-24). It is only necessary to add that the seeds 

 are not at all harmed by digestion of the surrounding pulp, and after" 

 expulsion from the stomach are in good condition to grow. By actual 

 experiment it was found that more than 90 percent of such seeds ger- 

 minated when planted. 



In one case 153 seeds of poison Rhus were taken from a single Crow 

 stomach in addition to much other food, and in numerous instances 

 stomachs were found to contain from 90 to 130 of these poisonous seeds. 



A caged Crow, well fed on grain and some animal food, ate poison- 

 ivy berries whenever offered, although he refused berries of the smilax 

 and those of the harmless red-berried sumacs unless very hungry. 

 After eating 50 or more berries of the poison Rhus this Crow ejected 

 the seeds, perfectly clean and devoid of pulp, in rather less than forty 

 minutes, after which he was willing to eat more berries. These facts 

 indicate that under ordinary circumstances a single Crow might dis- 

 tribute several hundred seeds of poison Rhus in the course of a day, 

 with a fair prospect that many, if not most of the seeds, would germi- 

 nate and live. 



The bayberry or wax myrtle (Myrica cerifera) is an abundant shrub 

 along the Atlantic Coast from Maine to Florida, but its range does not 

 extend inland very far, except m the neighborhood of the St. Lawrence 

 Eiver and lakes Ontario and Erie. The berries or fruits have a waxy 



1 Ehu8 venenata, the most poisonous species, is known as poison' sumac, poison 

 elder, poison dogwood, and swamp dogwood, while Rhus toxicodendron is variously 

 known as poison ivy, poison oak, poison creeper, and poison vine. 



