Fauna and Flora of the Region
The Morrison area as a floral biome is characterized by its transitional nature, from the plains to the east and the mountains to the west. Harrington (1954) has designated the environment as the Mountain Shrub Subdivision of the Mountain and Plateau Area.
Especially characteristic of the zone are the following plants:
- Quercus Gambelli—scrub oak
- Prunus Virginianus melanocarpa—wild plum
- Crataegus spp. (Probably succulenta)—hawthorn
- Amelanchier spp.—service berry
- Crysothamus Lanceolata—rabbit brush
- Rhus trilobata—poison ivy
- Rosa Woodsi—wood rose
From the Ponderosa Pine-Douglas Fir Subdivision the following characteristic plants overlap:
- Pseudotsuga taxifolia—douglas fir
- Pinus Ponderosa—Ponderosa pine
- Mahonia Berberis aquifoliam—Oregon grape
- Arctosaphylos uva-ursi—kinnikinick
- Rubus occidentalis—blackberry
- Rubus stigosus—raspberry
- Populus tremuloides—quaking aspen
These distinctive plants have invaded from the prairie fringe:
- Stipa cometa—needle grass
- Agropyron smithii—wheat grain
- Boutelorea grasilis—grama grass
- Boutelorea curtipendula—grama grass
- Poa fendleriana—bluegrass
- Sphaeralcea ceccinea—globe mallow
- Helianthus petiolaris—sunflower
- Chrysopsis rillosa—golden aster
- Muhlenbergia montana—muhly
- Yucca glauca—yucca
- understory of sedges and broad-leaf herbs
The nature of the faunal belt characteristic of the Transition Zone is varied. Both boreal and austral mammals are represented. Only six species appear restricted to it, two squirrels of the Sciurus aberti group, three pocket gophers of genus Thomomys and a small brown bat. The following mammals are not restricted to the Transition Zone but are characteristic of it in the eastern foothills:
- Eutamias quadrivitratus—Say chipmunk
- Peromyscus nastus—Estes Park cliffmouse
- Neotoma fallax—Gale wood rat
- Lepus campestris—White-tailed jack rabbit
- Sylvilagus nuttalli pinetis—Rocky Mountain cottontail
- Canis lestis—Mountain coyote
- Lynx uinta—Mountain wildcat
- Mephitis hudsonica—Northern plains skunk
Mammals common to the Transition and Upper Sonoran Zones include:
- Antilocapra americana—Antelope
- Odocoileus virginianus—Macrourus white-tailed deer
- Onychomys brevicaudus—Grasshopper mouse
- Castor canadensis frondator—broad-tailed beaver
- Canis Occidentalis—Grey wolf
- Spilogale tenuis—Rocky Mountain spotted skunk
- Eptesicus fuscus—Brown bat
The following are common to the Transition and Canadian (mountain) Zones:
- Cervus canadensis—Elk
- Callospermophilus lateralis—Say ground squirrel
- Eutamias amvenus operarius—Colorado chipmunk
- Erethiron epixanthum—Yellow haired porcupine
- Eutamias mihumus consobrinus—Least chipmunk
- Microtus nanas—dwarf field mouse
- Microtus pennsylvanicus—Saguache meadow mouse
- Zapus princeps—Rocky Mountain jumping mouse
- Vulpus macrourus—Western fox
- Ursus americanus—Black bear
Common to the Transition, Canadian and Upper Sonoran Zones are:
- Odocoileus hemionus—Mule deer
- Cynomys gunnisoni—Gunnison prairie dog
- Cynomys leucurus—White-tailed prairie dog
- Felis oregonensis hippolestes—Mountain lion
- Lutreola vison energunenos—Mink
- Putorius arizonensis—Mountain weasel
- Taxidea taxus—badger
The above lists were drawn mainly from Meritt Cary’s Biological Survey of Colorado (1911). Though this is the most complete work available, it is somewhat out of date and contains certain species names that have been superseded. An effort was made to check this with more modern works, such as Warren’s Mammals of Colorado (1942), but this was not always possible.