Focusing on the physiological and behavioral factors that enable a species to live in a harsh seasonal environment, this book places the social biology of marmots in an environmental context. It draws on the results of a forty-year empirical study of the population biology of the yellow-bellied marm

From preface: The following review of one of the Upper Cretaceous faunas as developed in the interior region of the United States has grown out of the study of a collection of fossils found by me in Huerfano park and adjacent localities in southern Colorado. This collection, the greater part of whic

of new species here presented, although large, must be small compared with the forms yet unknown.

Resolution of the controversy about the origin of this evaporitic limestone and gypsum unit is possible only if the position that the Todilto is exclusively marine or exclusively nonmarine is abandoned. The Todilto Formation was deposited in a coastal body of saline water (a salina) adjacent to the

An overview of both past research and significant new findings and interpretations of archaeological work conducted in Colorado's Upper Gunnison Basin, including a massive body of data from the author's eight years of work at the Tenderfoot lithic-scatter site. This important new contribution to arc

On the 15th September, IS.")!), we forded the San Juan, opposite Canon Largo, with no little danger, the strong current and deep water sweeping down some of the mules, which were recovered with difficulty.We were fortunate in passing through Cation Largo just after heavy rains, as 1 learned afterwar

Sufficient evidence has accumulated over the last six years to show that the leopard frogs (Rana pipiens, sensu lato) of North America actually include several forms that merit recognition as distinct species.Littlejohn and Oldham (1968) showed that four essentially allopatric forms, recognizable on

ANTIARCHIThe peculiar armored placoderm, Bothriolepis, is a characteristic element of Late Devonian fresh-water faunas throughout much of the world.It is common in the western United States, but its remains are usually fragmentary or poorly preserved, so that identi- fication is difficult.Two specie

This study is

This report is concerned primarily with the timber resource.However, because practically none of the forest area is managed for timber alone, the report also briefly describes demands for associated forest valueswater, recreation, wildlife, and forage.

Precambrian metasedimentary and metaigneous rocks, Paleozoic sedimentary rocks, and Cenozoic sedimentary deposits and igneous rocks are exposed in the Tesuque-Velarde-Tres Ritos-Cowles thirty-minute quadrangle. The mapped area includes the main central and western parts of the southern Sangre de Cri

A vegetation classification based on a combination of concepts and methods developed by Braun-Blanquet and Daubenmire was used to identify 37 tentative forest habitat types on the Gunnison National Forest. Woodland habitat types comprised two series with a total of 3 habitat types, and forest habita

In previous reports on the Cretaceous rocks of NM, writers have followed the nomenclature established by Cross, and have described all the rocks between the Dakota Sandstone and the Mesaverde coal measures as Mancos Shale. Lee and Darton, in describing the rocks of central and northeastern NM, recog

necessary for the appear- ance of a new American Bird-book.Mine must be that the only complete work on Colorado Birds is that of Cooke, which, though brought up-to-date by successive supplements, is now out of print and very difficult to obtain.Moreover, Cooke gives no descriptions or keys, so that

the total precipitation falls as snow from October through May. As spring advances, snow disappears progressively from lower to higher elevations, and from south slopes first. The varied topography of the Forest is typical of the southern Rocky Mountains. The western portion of the Forest is charact

As you are aware, I have been engaged for some time past in work, under your direction, on the control of rodents