PLANT LIFE IN OKLAHOMA. 45 



south-easterly, and while they doubtless contribute to the distribution 

 of some of our western species, they cannot assist those migrating west- 

 ward. 



Oklahoma is far enough south (33° 38' to 37°) so that many birds 

 which are only summer residents farther northward, such as Robins, Blue- 

 birds, and Waxwings are common here in the winter, and subsist largely 

 or partly upon various kinds of dried fruits. In summer many species 

 of berry-eating and drupe-eating birds assist in the distribution, and as 

 a result one or more species of hackberry {C&Uis), plum {Prunis), 

 grape {Vitis), Virginia creeper (Parthenocissus) , soapberry {Sa-pindus) , 

 sumac {Rhus), greenbrier {Smilax), pokeweed {Phytolacca), Cedar 

 {Juniperus) , oak {Qu&rcus), prickly pear {Opuntia), and cactus {Mam- 

 mUlariaq have found their way up valleys, into tributary and adjacent 

 valleys or far out on the prairies. 



The examination of numerous stomachs of cedar waxwings, robins, 

 bluebirds, blackbirds, tanagers, orioles, mockingbirds, brown thrashers, 

 catbirds, and thrushes reveals seeds and nuts of fruits that help' make 

 up the birds diet. The red cedar high on the canyon bank, the soap- 

 'berry tree at the head of a tributary canyon or on a hillside above other 

 trees, the solitary grape vine or sand plum in a grassy valley far re- 

 moved from others of its kind, the skunk-bush {Rhtis canadensis var. 

 trilolata) perched on the brow of a gypsum-capped butte, the Missouri 

 currant among the rocks on the rough side of a glass mountain, the 

 lone hackberry in a prairie draw, the rock-grape growing in a cleft in a 

 sandstone or granite ledge, are monuments to the services of birds as 

 distributors of plants. 



The writer has been much interested in the relation of the wild 

 turkey to the distribution of the black- jack {Quercus marilandica) and 

 Texas oak {Q. undulata). In years when these oaks bear fruit, their 

 acorns have supplied a large proportion of the food of the wild turkeys 

 in the vicinity, and the forests of the former species (black-jack oak) 

 have been most favorable places for the hunter of these birds in winter. 

 Examination of their crops in winter reveals surprisingly large numbers 

 of acorns, often more than a hundred being found in a single bird. 



The turkey is a ground-li\dng bird and often travels in flocks for 

 several miles on foot, passing frequently across divides; between valleys. 

 Until 20 or 25 years ago this bird was abundant in the semi-timbered 

 and prairie regions of Oklahoma and Texas. The accidental death of 

 one of them often resulted in leaving dozens or seoresi of acoims on the 

 ground miles from oak trees. Some of these acorns must have been in 

 condition for germination and grown into trees, and the oaks' range 

 was thus extended. In the sandhill region along the north side of 

 Cimarron River in Woods County the black-jack oak reaches its north- 

 western limit in the State. A similar region along the Iforth Canadian 

 has this tree reaching its last station 30 or 40 miles farther southwestward. 

 Along the borders of the wooded regions in these sections and especially 



