TIIIUD ANMAL .MKKTI.Nc; 05 



canons to the north. Some of the breedin<>- birds are: Bartramian 

 Sandpiper, Long-billed Curlew, Ferruginous Itough-legged Hawk, West- 

 ern Xighthawk, McC'own's Longspur, Western Vesper and (irasshopper 

 Sparrows. Desert Horned Lark, Western :Mea<low-lark. and Kock Wren, 

 the last nesting in holes in the chalk buttes. 



While there are no mammals restricted to this table-land, yet it is 

 characterized by the absence of a number of prairie forms which occur 

 in the Hat Creek Basin at a much lo\vci- level, among Ihera being 

 Leitiis iiuhmotis, Ci/noiiii/s hi(lorici<iinis. I'crodiinix rirhdnlsoni, Perof/nathus 

 h. paradoxus, P. flacescennC!), and OuuvhomyH Icuaxjaxter. The omnijn-esent 

 Coyote {Canis nehroHcenHiH) is abundant here as elsewhere. An occasional 

 antelope is seen, but the species is fast becoming- rare. A single species 

 of rabbit {Leirua bailcyi) is found around the buttes, and makes its 

 home in crevices of the rock. Badgers and a spermophile {Hpennnphilus 

 t. paUidu.s) are common. A white-footed mouse {Peromi/scus t. nebras- 

 ceiisift) occurs sparingly in rocky places, \\hile Hayden's Vole (Microtus 

 a. haydeui) has its small runways ramifjnng through the matted grass. 



KeiJtiles are poorly represented. Blue racers, bull-snakes, and the 

 Prairie Rattlesnake, together with a .species of horned toad 

 {PUrynoHoma douylassi) were noted. 



Wooded Canon Reyion. — The northern escarpment of Pine Ridge is a 

 region of extremely rugged and. in manj' cases, perpendicularly walled 

 canons which vary in length from one to three miles, the majority of 

 them giving off numerous side canons also of varying lengths. A few 

 carions, however, descend from the plateau to Hat Creek Basin between 

 unbroken walls, these being shortest and having a much more abrupt 

 descent. Cold streams, fed by numerous springs along the first mile 

 or so of their course, flow through the larger canons, and these, in 

 addition to the heavy tree growth and north exposure, cause a cooler 

 and moister atmosphere than in surrounding regions, thus accounting 

 for the presence of a groat many northern plants and breeding birds 

 generally found in this latitude at a much greater altitude. 



The prevailing tree of the region is the Yellow Pine (Piiius poudernsa) 

 which clothes the canon sides and frequently forms a fringe around 

 the upper walls. A sparse growth of Red Cedar {JumpcruH viryhiianus) 

 is sometimes mixed in with the pine near the rim rock, while near the 

 heads of streams in the deepest canons thickets of Quaking Aspen and 

 Poplars (Populus tremuloides and P. halsamifera) are found. Among 

 other trees and shrubs in the canons are the Juniper (Juniper us com- 

 munis), the Creeping Barberry (Berberis nquifoViuni), the Mountain Maple 

 {Acer ylabrum),the Small Service-berrj' (A/He^/»(7//V/- alnifoHa), ihe Hairy 

 Dogwood {Cornus amomum), and the Black Jiirch (Bctula occidentalis). 

 Smaller plants much in evidence are AstrayaUts hypoglottis, Symphoricarpus 

 paucifforus, Galium borealc,TioIa canadensis, Limnorchis hyperborea, Penstemon 

 yhtber, and Campanuhi rotundifoliii. The majority of trees and plants just 

 listed are characteristic of the Transition Zone throughout the Rocky 



