Habitat Preferences of Feral Hogs, Deer, and Cattle on a Sierra Foothill Range

摘要: The relative habitat preferences of feral hogs (Sus scrofa), blacktailed deer (Odocoileus hemionus columbianus), and cattle were assessed for 17 types by sampling the distribution abundance fecal sign on a northern California annual range. Hogs preferred oak thickets irrigated pastures; brushland woodland; level topography sites with relatively high herbage production including pastures, upland plains, savanna-woodland. Deer used study area during winter only, whereas permanent residents. An association analysis indicated greatest potential interspeciflc competition would be between foothill ridge tops pastures. As part life history ecology hog in (Barrett 1978) preliminary was made three ungulates (hogs, deer, cattle) living Dye Creek Ranch situated 15 km south Red Bluff, Tehama County, California. results to delineate those habitats (range sites) which there is conflict livestock game preserve enterprises utilizing same land. Information available Sierra rangelands (Leopold et al. 1951, Wagnon 1968), but little (Pine Gerdes 1973). No studies have considered all species simultaneously. Study Area Methods included portion eastern plains Sacramento Valley stretched eastward into lower foothills Mt. Lassen. climate Mediterranean rainfall averaging 450-650 mm (Barbour Major 1977). rise 400 m above valley floor are dissected east-west draiinages. Available subjectively classified aerial photos using topographic vegetation criteria. Topographic categories included: (I) floor, (2) flat ridge-tops river canyons slopes under 10%, (3) north, (4) canyons. Vegetation ( 1) pasture, plain, boulder wash, rock-grass, (5) buckbrush, (6) savanna, (7) woodland, (8) thicket (includes riparian forest). first 3 author assistant professor, Department Forestry Resource Management, University California, Berkeley 94720. Funds this supplied National Science Foundation Graduate Fellowship, Field Station, Union Wildlife Fund, Zoology, Agricultural Experiment Station. I thank W. Long W.S. Keeler instigating supporting study, Drs. A.S. Leopold, M. White, H.F. Heady, L.A. Jaechel, J. Patton, their counsel support throughout project. particularly want Kathy Barrett who helped aspects study. Scientific common names follow Storer Usinger (1963). Manuscript received May 29, 1980. (Fig. I) located exclusively below 100 elevation old floodplains terraces (U.S. Agriculture 1967). remaining five 2) found only 1978). A total combinations mapped as types. Mapping units varied 50 200 width, thus small ungulate home ranges. Two resident sub-populations recognized 1978), stratified accordingly edge (2327 ha) 1562 ha). utilized range had free access both strata, exception that restricted fences North-south belt transects positioned systematically at intervals 0.8 km. In 1968, 448 plots (1.5 X 32 m) sampled (0.06% sample), 291 1969 (0.04% sample). proportion each type an indicator availability type. Sampling accumulated scats, pellet groups (1968 only), cow pats plot completed within 2 weeks September year just prior influx cattle. This season selected after pilot samples density scats end dry season. Most droppings from previous also remained identifiable through Thus data representative deposition pattern over 2-year period. Data pooled compared years strata. frequency occurrence animal calculated Chi-square test distributions not significantly different (P<0.05) years, therefore, pooled. There minor statistically significant differences However, since rank order preference various was, exception, Results Discussion Topography apparently important environmental variable except its correlation water (Table 1). Of Valley, pasture evidenced rooting. summer commonly saw 160 ha. plain dropped along trails crossed reach pastures washes. difficult observe because they hidden tall grass or trampled soft ground cattle, likely underestimated. Boulder washes intensively rooted brodiaea (Brodiaea sp.) bulbs low acorn production. 342 JOURNAL OF RANGE MANAGEMENT 35(3), 1982 content downloaded 157.55.39.253 Sat, 11 Jun 2016 06:34:32 UTC All use subject http://about.jstor.org/terms strongly vegetation. Other than caves, live oaks (Quercus wislizenii) associated provided major bedding cover hogs. true when blue douglasii) leafless. Live thickets, mainly north slopes, forests coolest locations