Badger Movement Ecology in Colorado Agricultural Areas After a Fire
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University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Wildlife Damage Management Conferences -- Wildlife Damage Management, Internet Center Proceedings for 2005 Badger Movement Ecology in Colorado Agricultural Areas After a Fire Craig Ramey USDA, APHIS, Wildlife Services, National Wildlife Research Center, Fort Collins, CO, USA Jean Bourassa USDA/APHIS/WS, National Wildlife Research Center, Fort Collins, CO, USA Follow this and additional works at: https://digitalcommons.unl.edu/icwdm_wdmconfproc Part of the Environmental Sciences Commons Ramey, Craig and Bourassa, Jean, "Badger Movement Ecology in Colorado Agricultural Areas After a Fire" (2005). Wildlife Damage Management Conferences -- Proceedings. 124. https://digitalcommons.unl.edu/icwdm_wdmconfproc/124 This Article is brought to you for free and open access by the Wildlife Damage Management, Internet Center for at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Wildlife Damage Management Conferences -- Proceedings by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. BADGER MOVEMENT ECOLOGY IN COLORADO AGRICULTURAL AREAS AFTER A FIRE CRAIG A. RAMEY, USDA, APHIS, Wildlife Services, National Wildlife Research Center, Fort Collins, CO, USA. JEAN B. BOURASSA, USDA/APHIS/WS, National Wildlife Research Center, Fort Collins, CO, USA Abstract: While investigating the American badger (Taxidea taxus) in eastern Colorado’s wheatlands, we studied 3 badgers which were affected by a 2.1 km2 man-made fire and compared them to 2 adjacent badgers unaffected by the fire. All badgers were equipped with radio-telemetry collars and generally located day and night for approximately 1 month pre-fire and 3 weeks post-fire. Three point triangulation locations were converted into a global information system database. Adaptive kernel analyses compared pre- and post-fire horizontal: home ranges (i.e. 95% utilization areas, UAs), core activity areas (50% UAs), movements, den and habitat use patterns. Mean (¯x) locations pre-fire (43.7) and post-fire (32.0) provided home ranges for affected badgers that averaged 8.3 km2 and 9.2 km2, respectively. While 2 badgers maintained one core area which was outside the burn, the third used 2 core activity areas, one remained the same after the fire and second changed. Diurnal to nocturnal movements (measured in 24 hrs cycles) were pre-fire ¯x = 1.2 km and post-fire ¯x = 1.3 km. Den use remained approximately 5, but some locations changed after the fire. Mean home ranges included 74% winter wheat or wheat stubble. Habitat use for all 5 badgers averaged: 81.4% wheat, 8% riparian, 7.2% sagebrush, and 3.4% burned. Unaffected badgers averaged 7.7 km2 home ranges, 1 core area, 1.0 km diurnal-nocturnal movements, 4 dens, and 93% wheat crops and 7% riparian habitats. After the fire burned 10% of badger 4's home range, 1 of 3 core areas, and 3 of 5 dens, it moved > 3km northwest into another tributary and established 1 new den. However, it frequently revisited the northern portion of its home range and associated core area. After approximately1 month, it consolidated this UA into a new core area 1.7 km northwest and maintained 1 of 3 pre-fire core areas. The fire consumed 6% of Badger 2 home range, and post-fire it moved into the unoccupied southern portion of badger 4’s pre-fire home range. It also moved slowly west into sagebrush probably in partial response to the tilling of approximately 1/3 of its home range which was completed on April 16. Only 1.0% of Badger 1’s home range and its core area were not affected by the fire. However, it slowly moved its home range southeast approximately 1.0 km into the unoccupied area assumed to have been the home range of an un-collared badger found dead in early April. Its core area moved approximately 0.5 km southwest. In summary the movement ecology of affected badgers illustrated three themes: (1) home ranges and core areas moved initially away from the fire, (2) then adjustments were made by each badger in response to other badgers, the burned area, and habitat requirements, and (3) finally a new equilibrium of home ranges was established among these badgers post fire including the use of the burned areas after a few weeks. Key words: badger, fire, movements, radio-telemetry, Taxidea taxus, utilization areas, wheat Proceedings of the 11th Wildlife Damage Management Conference. (D.L. Nolte, K.A. Fagerstone, Eds). 2005 337 INTRODUCTION Killingley 1983); therefore, such activities can Very little data has been published damage rangeland pastures (USDA 1990). about the movement ecology of the North Badgers may also negatively impact farm America badger (Taxidea taxus), a fossorial equipment and water systems (Minta and member of the weasel family. This medium Marsh 1988), because they may cause an sized carnivore is stocky and shaggy in increased need for maintenance. These appearance, and its activities are mainly sporadic negative interactions with humans nocturnal. Its head is shaped as a stout cone make the badger economically a minor that facilitates digging (Long and Killingley vertebrate pest to agricultural interests, but 1983). It has an extensive history in the they may cause serious losses to individual prairie grasslands associated with their prey farmers or ranchers (Minta and Marsh 1988). species (Messick 1987). Although badgers Even though badgers in agricultural primarily consume prairie dogs (Cynomys habitats have not been the focus of North spp.) (Clark 1977), they are also opportunistic American research, in Europe the Eurasian predators that eat deer mice (Peromyscus badger (Meles meles) has been involved in maniculatus), ground squirrels (Spermophilus many studies in cultivated landscapes, spp.), pocket gophers (Thomomys spp. and particularly control measures (Kowalczyk et Geomys spp.), and voles (Microtus spp.) al. 2003, Fischer 2003, Rosalino and Santos- (Fagerstone and Ramey 1995). Reis 2004). For example, badger damage to Because they are primarily nocturnal, field crops such as maize (Zea mais) has been badger studies have been greatly facilitated by studied in southwestern England with crop the use of radio–telemetry. One such study depredations decreasing after using an electric was done by Sargeant and Warner (1964), and fence for exclusion purposes (Poole et al. it described the extensive movements of a 2002). In contrast, Eurasian badger removal single badger. Later, Lindzey (1971) studied in agricultural areas have had mixed results as 7 badgers in pre-dominantly non-crop a control measure. Initially, their spatial sagebrush in Utah and Idaho. More recent organization was severely perturbed during studies have viewed their population trends in the first year; however, re-colonization relation to other prairie pothole carnivores occurred rapidly mainly by females thereafter (Greenwood and Sovada 1998) or studied (Tuyttens et al. 2000). In China, the constant their risk to dieldrin at the Rocky Mountain harvest of the hog badger (Arctonyx collaris) Arsenal National Wildlife Refuge in Colorado has decreased their numbers to very low (Henriques 1997, Hoff 1998). One conclusion levels (Wang 1999) which are maintained from these and other studies is that little is year after year. known about the badgers of the Great Plains Natural fires from summer lightening especially in agriculture areas. storms on the Great Plains have long posed a Badgers are considered occasional danger to prairie residents both human and pests in North American agricultural habitats animal. More recently, man-made fires set for (Minta and Marsh 1988). Their interactions weed control have become a part of the prairie with humans, occur because their fossorial environment. Some rangeland fire niche creates mounds from either digging investigators in the central Great Plains have deep burrows for dens or seeking rodent prey shown fire suppression whether natural or (Lindzey 1971, 1982). These activities man-made resulted in increased growth of sometimes have been hazardous to livestock herbaceous plants and woody vegetation. that step into them and may fracture a leg (Kaufman and Fleharty 1974, Kaufman et al. (Burt and Grossenheider 1964, Long and 1988) Some investigators have speculated 338 that as a result of fire there may have been occurred and were due to leg fractures caused increased habitat for badger prey and/or by stepping in badger’s holes in pastures. In possible their transitory movements. In addition, a recent development at the study summary, the effect of fire whether natural or site had been the conversion of some of the man-made on badger movement ecology has prairies from livestock grazing to dry-land not been previously studied in agricultural farming particularly for alfalfa or winter habitats of the North American Great Plains. wheat. During harvest, the machinery is in The Wildlife Services (WS) program need of frequent repair because they hit many of the U.S. Department of Agriculture earthen mounds and burrows that they strike (USDA), Animal and Plant Health Inspection that result from badger activities such as den Service (APHIS) has identified the badger as excavation and foraging. For over 50 years one of 17 species that it needs to control in private trappers and more recently WS certain instances as an agricultural pest personnel have intermittently controlled (USDA 1990). A two-ingredient gas cartridge badgers in this area, but they remained a (sodium nitrate and charcoal) producing high problem. concentrations of carbon monoxide gas when The study site was along both sides of burned has been suggested by Savarie et al. Badger Creek (T 4 S, R 58 W, Sec. 1, 2) (1980) to be an effective pyrotechnic fumigant which flows from south to north at for vertebrate pests that live in burrows or approximately 1,600 m above sea level. The dens. This predacide while undergoing re- area was comprised mainly of gentle hills and registration with the EPA, was shown to be an with some shallow canyons, sandy loam soil ineffective tool to control problem badgers (Nunn Association), and semi-arid conditions.