Rollin H. Baker

Nutritional Strategies of Myomorph Rodents in North American Grasslands

Grass-eating and seed-eating myomorphs associate in temperate North American grassland environments. These two groups have distinctive nutritional specializations as expressed by different morphological, physiological, and behavioral characteristics. There seems to be opportunity for many more species of seed-eaters than grass-eaters to occupy a single grassland community, at least in the American area discussed herein.

An Ecological Study of Tree Squirrels in Eastern Texas

Squirrels are an important game species in eastern Texas, being, according to Goodrum (1938), hunted more than any other game mammal or bird in the region. Much of the hunting is done in hardwood timber along the larger creeks and rivers where gray squirrels (Sciurus carolinensis carolinensis) are the dominant species. Fox squirrels (Sciurus niger ludovicianus) are more generally found along the smaller creeks and in upland pine and hardwood timber. Sportsmen consider the gray squirrel to be the more favored game. With the increase in the number of squirrel hunting clubs and the greater interest in the conservation and management of squirrels in eastern Texas, it has become necessary to learn more concerning squirrels and their habitat requirements in an effort to deal more effectively with problems relating to this important game species. Goodrum (1937a, 1937b, 1938, 1940) has presented a considerable amount of information on squirrels in eastern Texas, and the purpose of this study is to gain further data on certain phases of his original work. Field investigations were conducted during the period from August 1940 through August 1942, much of the work being done in connection with other field activities.

DISTRIBUTION OF RECENT MAMMALS ALONG THE PACIFIC COASTAL LOWLANDS OF THE WESTERN HEMISPHERE

Coastal lowlands on the western side of the Americas are irregularly narrow and squeezed between the shoreline and adjacent montane country. The 407 species belonging to 189 genera (marine and insular forms excluded) that are recorded as living on this coastal strip are best arranged in sectors north to south as follows: in Nearctica, the Tundran (67?N to 61?N) with 25 species; the Coniferan (61?N to 38?N) with 92 species; the North Eremian (38?N to 260N) with 114 species; and in Neotropica, the North Subtropical (26?N to 160N), a temperate-tropical transition with 109, species; the Tropical (16?N to 70S) with 267 species; the South Eremian (70S to 290S) with a minimum of 18 species; the Nothofagian (290S to 550S) with 35 species; and the Patagonian (500S to 550S) with a minimum of 10 species. Northern sectors in Nearctica, somewhat comparable ecologically to southern sectors of Neotropica, are endowed with from two to six times as many species as the latter. Factors accounting for the paucity of species in southern sectors include (a) the progressive reduction of species as living space in continental South America dwindles in a southward direction, (b) the extreme narrowness of lowlands along much of the South American coast and (c) the abrupt insertion of sparsely-inhabited deserts (South Eremian Sector) in an otherwise latitudinally favorable environment of South America blocking north-south movements and preventing intermingling of tropical and temperate species, as has occurred in coastal North America. Holarctic species are conspicuous in the Tundran Sector but diminish rapidly to the southward, although 5 Holarctic genera are represented in Southern Chile. Our current knowledge of the distribution of Pacific coastal mammals indicates that their lowland habitats must be beset with assorted kinds of barriers to deter north-south dispersal of most mammals so that more than one-half (62 per cent) of the species are known only from single sectors. Consequently, mammalian affinities may be with inland faunas, in the Cordillera or the Atlantic coastal lowlands, rather than to sectors either north or south along the Pacific coast.

Daytime Roost of the Yellow Bat in Veracruz

On July 22, 1955, a field party from the University of Kansas found yellow bats, Dasypterus intermedius (H. Allen), concealed among dried corn stalks hanging from the sides of a large, open tobacco shed, one mile southwest of Catemaco, Veracruz. This shed, approximately 60 feet long, 40 feet wide, and 25 feet high, was constructed of vertical poles that supported a corrugated metal roof. The shed was braced …

May Food Habits of Armadillos in Eastern Texas

conclusions concerning the question of the armadillo pr?dation on quail eggs, which is a popular acknowledged fact among the residents of eastern Texas. However, only 25 stomachs were taken, too few to offer any solution to this question but because little has been recorded regarding the food habits of the armadillo, the results of the examination of the material appear worthy of being listed. The stomach contents were examined by the author.

Eumops underwoodi sonoriensis in Arizona

On May 5, 1954, William J. Schaldach, Jr., shot a mastiff bat at 7:25 pm over a pond two miles east of Sasabe, Pima County, Arizona. This specimen (59092 KU), identified as Eumops underwoodi sonoriensis Benson, is, to my knowledge, the first record ot …