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Home , Bobcat, Cougar, Coyote, Red fox, Skunk, Striped Skunk

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Symposium Proceedings— in the Southwest: A Compendium of Our Knowledge Wildlife Damage Management, Internet Center (1995) for

April 1995

COYOTE INTERACTIONS WITH OTHER

Terry L. Blakenship Welder Wildlife Foundation, Sinton, TX

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Blakenship, Terry L., " INTERACTIONS WITH OTHER CARNIVORES" (1995). Symposium Proceedings—Coyotes in the Southwest: A Compendium of Our Knowledge (1995). 40. https://digitalcommons.unl.edu/coyotesw/40

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 Symposium Proceedings—Coyotes in the Southwest: A Compendium of Our Knowledge (1995) by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. COYOTE INTERACTIONS WITH OTHER CARNIVORES

TERRY L. BLANKENSHIP, Biologist, Welder Wildlife Foundation, P.O. Box 1400, Sinton, TX 78387

Abstracl: Coyotes ( latrans) occur sympatrically with several predators throughout their range. and food resources are similar, although the coyote typically utilizes a wider range of food items. Larger predators generally select larger prey, allowing predators of different sizes to coexist. Coyotes exhibit aggressive actions towasds smaller predators, but in most cases they avoid contact with other predator . Studies indicate that coyotes can exclude 01-displace ( vulpes, spp.), and an inverse relationship exists between abundance of coyotes and foxes. There is evidence suggesting that extensive reduction of coyote populations allows other predator populations to increase.

The coyote competes or coexists with several prefer specific habitat charactei-istics. Densities of predators thoughout its range. In , the each predator vary depending on area. Mountain mountain ( concolor), (Felis rujius) hons prefer the dense cover found in the thick brush and both and grey foxes (U. cinereoargenteus) of or the broken rough country are predators that share resources with the coyote. characterized by rirnrocks, boulder piles, cliffs and ( lotor) and striped of the Trans Pecos (McBride 1977). Foxes ( ~nephitis)are 2 other small carnivores that seem to prefer edges along brush and woodland are found in similar habitats and utilize the same areas where clearings have been created for pasture foods Research has identified the resources utilized or cropland. They also do well around by each of these species. However, dietary overlap habitations (Samuel and Nelson 1982) The alone does not imply is occurring. prefers habitats with larger trees and are usually Studies of competition for resources, and the effects found close to watel- However, they are a common of such competition, are fewer and inherently more predator in the blush habitats of South Texas and the difficult to detem~ine. semi- areas of West Texas (Davis and Schmidly 1994). Food resources or prey availability is a major factor in dete~min~ngan 's use of an area or The prey items utilized by each are habitat. Numbers of predators and use of the same also simllar, but the proportions are not similar. habitat and prey items can result in competition for Prey items taken are related to size of the predator, resources. The puspose of thls paper is to review habitat type, time of , and abundance of prey. cut-sent knowledge on. (1) resource use by, (2) McBride (1977) analyzed mountain lion stomach interspec~fic relations betweedamong, and (3) contents and scats fsom the Trans Pecos and population response to coyote control, in to reported the major foods were ( dete~minethe impacts of coyotes on the ca~nivores spp.), javelina (Tayassu tajacu), and listed above. Data included here illustrates how (Erethizon dorsat~cni). little has been done on interspecific relationships of predators in Tesas or the Southwest. Leopold and Krausman (1 986) documented the diets of mountain , , and coyotes in during 2 time periods. Their Resource use data indicate how 3 predators in the same area prefer certain prey items and how this can change when The coyote, mountain lion, bobcat, gray , prey abundance changes (Table 1). A significant raccoon, and are found throughout the decline in the desert mule dqer (Odocoileus state. The now ranges from the easteln past henzionl~scrook;) population occu~redduring the of the state to central Trans-Pecos region excluding second time period Mountain lions increased the south Texas (Davis and Schmidly 1994). These use ofjavelina when the deer population decreased. calnivores use sim~lal-habitats and can be found in close proximity to each other. However, each may Coyote and bobcat d~etsshowed greater Table 1. Average relative frequency of prey species in mountain lion, bobcat, and coyote scats for 2 time periods (1972-74 and 1980-81) in Big Bend National Park, Texas (after Leopold and Krausman 1986).

Mt. lion Bobcat Coyote

Prey

Deer 0.75 0.39 0.24 0.03 0.22 0.05

Javelina 0.15 0.38 0.06 0.02 0.10 0.02

Rodents 0.10 0.05 0.31 0.28 0.24 0.26

Rabbits 0.03 0.14 0.51 078 0.38 0.56

Birds, 0.04 0.03 0.14 0.18 0.17 0.22

Porcupine 007 001

Seeds, fruits 0.44 0 49

overlap. and were the primary items Duling winter, foods included 56% small in bobcat diets Deer were of secondary importance (cottontails, cotton rats, pocket (Geomys for both bobcats and coyotes, however when deer spp.), pocket mce (Perognathus spp.), 23% populations declined, bobcats and coyotes increased (mostly grasshoppers [Acrididae]), and 2 1% . their use of rabbits. Coyote diets were most diverse The late summer and fall diets included 30% and included seeds and fruits dui-ing the year. and , 26% insects, 16% small Leopold and Krausman (1 986) suggested deer use mammals, 14% birds, and 14% crayfish (Davis and decreased in the lion's diet because the deer Schmidly 1994). population had declined. They speculated that because mountain lions were not preying as much on Raccoons are considered to be 1 of the most deer, less deer cairion was available for coyotes or omnivorous ; their diet can include fruits, bobcats. small mammals, birds, insects, , garbage, grains, plant material, and most human foods Beasom and Moore (1977) studied the effects of (Sanderson 1987) Similar to raccoons, 78% of the a change in prey abundance on bobcat prey selection striped skunk's diet consist of insects during different in South Texas. Durlng one yeas 80% of the diet seasons of the year The I-emainder of their diet may consisted of cotton rats (Srgnzodon hrspidus), include small rodents, birds, reptiles, and vegetation cottontails (SvlvilagusJoridanus), and wh~te-tailed (Davis and Schmidly 1994). deer (0. vrrginianus). A total of 21 prey species was found in the diet. The following year there was an increase in and cottontail populations. Interspecific interactions The diet changed to 96% cottonsats and cottontails, and only 6 different species of prey were recorded. Interspecific interactions can result in the death of a competing predator, or merely the exclusion of The diet of the fox changes during the year. the subordinate species. Although aggressive inte~actionsoccur, most predators avoid contact. To capacity of bobcats by reducing prey availability and dete~mineif a predator is being excluded by another, suggested that bobcat numbers will decline and studies are conducted on the dietary overlap and stabilize at lower densities as a result of increasing habitat use durlng diffei-ent weather conditions, coyote densities. They also report one incident of seasons, or . coyotes preying on a bobcat. Under the right circumstances it is not impossible for a coyote or Mountam lions, bobcats, and coyotes in central gsoup of coyotes to kill a bobcat. utilized different habitat and topographic characteristics during summer. Mountaln lions and Coyotes are belleved to influence the bobcats were associated with habitats providing distribution and abundance of red foxes (Sargeant stalking cover, whereas coyotes used open areas 1982). Sargeant et. al (1 993) reported study areas more frequently. The bobcat's inability to move that had Increased coyote track counts had a through deep influenced use of areas in the cotresponding decrease in fox track counts. Major winter. A greater degsee of overlap of habitat and and Sherbure (1 987) reported simultaneous prey occurred during the winter as predators and locations of coyotes, bobcats, and foxes that shared prey moved to lower elevations ranges maintained distances between individuals. Avoidance is believed to be the principal motive for Dietary overlap in winter resulted in mountain this spatial segsegation. lions k~lling4 bobcats and 2 coyotes near feeding sites. These attacks involved mountain lions In areas where coyotes and red fox occur defending or usurping food caches (Koehler and sympatsically,fox tenitories are located on the edges Hornocker 1991) Boyd and O'Gara (1985) or outside of coyote territories. These data reposted that mountam l~onswere a major cause of supported the conclusion of interference competition moitality for bobcats and coyotes. Five of 8 bobcats between foxes and coyotes (Major and Sherburne and 3 of 7 coyote deaths were attributed to mountain 1987). Schmidt (1 956) suggested that red foxes are lions appasently protectmg food caches. Analysis of excluded or displaced from areas inhabited by mountain lion food habits have found trace amounts coyotes. The fox seems to do well around human of coyote, bobcat, and fox present in stomach habitations because of the lower number of coyotes contents (Robinette ct al. 1959, Krausman and (Samuel and Nelson 1 982) Ables 1981). Schmidt (1 986) cited references indicating that It has long been believed that coyotes out- coyotes kill red foxes, although he indicated that compete bobcats, I-esultingin reduced populat~onsof coyotes at-e an insignificant source of mortality. bobcats. Major and Sherbuine (I 987), conducting Sargeant and Allen ( 1 989) reported on coyotes' research in , ind~cated that coyotes and antagonlstlc behavior towards foxes and identified bobcats shared home ranges, habltat use, and diets, instances of coyotes kllling foxes. However, they but there was no data to support intei-ference also c~tedradio-telemetiy studies that found no competition. Coyote and bobcat diets and habitat mol-tality of foxes in al-eas inhabited by coyotes use overlapped in 01-egon,however there was l~ttle competition between the two because prey populations were hlgh (Witmer and deCalesta Population responses from coyote control 1986). Although there have been studies conducted on Litvaitis and Han- son (1989) studied bobcat- the overlap of diets and hab~tatuse betweenlamong coyote relationships during a period of coyote PI-edators, there have been few studies designed to expansion in Maine. Seasonal habitat use by study the response of predators to removal of coyotes vaned more than bobcats, perhaps because coyotes. If competition exists between coyotes and of the greater variety of food items In coyote diets. other predators, the reduct~onof coyotes should They also indicate that bobcat food hablts have reduce competition and allow other predator changed since the anival of coyotes to Maine. populations to increase.

Litva~tisand Hallson (1 989) found that coyotes Toxicants, such as strychnine and compound did not displace or exclude bobcats. They 1080, were used In coyote control programs until speculated that coyotes have reduced the cartying their uses were banned in 1972. Compound 1080 was used extensively in western states (including foxes, and there is an Inverse relationship between Texas) as an effective and selective predacide for abundance of coyotes and foxes. No studies show coyote management (Nunley 1977). Nunley (1 977) that coyotes exclude bobcats, raccoons, or . and Schrmdt (1 986) indicated that coyote population There is evidence to indicate that extensive reduction trends decreased in western states with the initial use of coyote populations allows other predators to of compound 1080. Nunley (1 977, 1978) reviewed increase. This response is probably related to the & Wildlife Service catch records increase in food availability. from New to look at coyote control efforts on non-target species. He indicated that the use of Literature Cited Compound 1080, which increased substantially in 1950, resulted in a decrease in coyote numbers and Beasom, S.L. and R A. Moore. 1977. Bobcat food a subsequent increase in bobcat, (Ta.urdea habit response to a change in prey abundance ramrs), skunk, and fox numbers. This response was Southwest. Nat. 21 :45 1-457. believed to be a result of reduced competition for food and not a reduction in by coyotes. Boyd, D and B.O'Gara. 1985. predation Similar trends occurred in other western states, on coyotes. The Mui-relet 66.17. therefore Nunley (1 978) deemed it unlikely that the population responses among other predators was Davis, W.B. and D.J. Schmidly. 1994. The caused by natural cycles In prey abundance. mammals of Texas. Texas Parks & Wildlife Dept., Austin. 338pp Robinson (1 961) and Linhart and Robinson (1 972) reported on the densities of bobcat, skunk, Henke, S.E. 1992. Effect of coyote removal on the badger, raccoon, and fox in areas under sustained faunal community ecology of a short-grass coyote control Trapper catch records in New prair~e Ph D. Thesis, Texas Tech Univ., Mexico, and were used as an Lubbock. index to determine fluctuations in densities. Thus high densities of various carnivore species would be Koehler, G.M. and M G. Homocker. 1991 reflected by high catch records. They concluded that Seasonal resource use among mountain lions, coyote control was having little effect on carnivore bobcats, and coyotes. J. Marnm. 72:391-396. populations. Data kom Wyoming showed that fewer coyotes were caught, but an increase in captures of Krausman, P.R and E.D. Ables 198 1. Ecology of bobcats, badges, raccoons, and red fox were noted. the Carmen Mountains white-tailed deer. U.S Natl. Park Seiv. Sci. Monogr. Ser. 15. 114pp. A year-round intensive coyote control program was conducted in Andrews County, Texas to study Leopold, B D and P R. Krausman. 1986. Diets of the population response of selected marnmallan 3 predators in Big Bend Nat~onalPark, Texas. predators (Henke 1992). The relative abundance of J. Wlldi. Manage. 50:290-295 bobcats, , and increased on controlled areas after initiation of coyote removal. Linhart, S.B and W.B. Robinson. 1972. Some No change was detected in skunk populatrons relative carnivore densit~esin areas under sustained coyote control. J. Marnrn. 53:880- 883. Conclusions Lrtvaltrs, J.A. and D.J. Hall-ison 1989. Bobcat- Sympatric predators often share habitats and coyote niche relationships dur~nga period of utilize similar foods depending on location, season, coyote population increase. Can. J. Zool. and prey availabilrty Decreases in prey abundance 67.1180-1 188. can result in increased competrtion and increase interspecific ~nteractions.Differences in size allow Major, J.T. and J.A. Sherburne. 1987. Interspecific similar predator species to coexist in the same area I-elationshipsof coyotes, bobcats, and red foxes (Rosenzweig 1966). No studies have identified in western Maine. J. Wildl. Manage. 5 1:606- coyote predation as a cause for limiting or 616. decreasing other predator populations. Studies do indicate that coyotes can and do exclude or displace McBr~de,R.T. 1977. The status of the mountain Samuel, D.E. and B. B. Nelson. 1982. Foxes. Pages lion (Felis concolor stattleyana) of the Texas- 475-490 in J.A Chapman and G.A. Feldhamer, Mexico border. M S Thesis, Sul Ross State (Eds.) Wild Mammals of . Johns Univ., Alpme, TX. I6Opp. EIopkins Univ. Press, Baltimore, MD 1 147pp.

Nunley, G.L. 1977. The effects of coyote control Sargeant, A. B. 1982. A case history of a dynamic operations on non-target species in New resource-the red fox. Pages 12 1 - 137 in G. C. Mexico. Great Pla~nsWildl. Damage Sanderson, (Ed.) Midwest furbearer Workshop 3:88-110 management. Midwest F~shand Wildl. Conf., Wichita, Kans

, 1978. Present and h~storicalbobcat population trends in and the west. , and S. H Allen. 1989 Observed interac- Proc. Ve~tebrPest Co~lf.8: 1 77- 1 84. tions between coyotes and red foxes. J. Mamm. 70:63 1-633. Robinette, W.L., J.S. Gashwiler, and O.W. Monis. 1959. Food habits of the cougar in and , R.J. Greenwood, M.A. Sovada, and T.L. J Wildl. Manage. 23:253-273. Shaffer. 1993. Distribution and abundance of predators that affect duck production-prairie Robinson, W.B 196 1. Population changes of pothole region. U.S Fish and W~ldl.Serv. ca~nivoresin some coyote-controlled areas J. Resour. Pub. 194. 96pp. Mamm. 42 5 10-5 15 Schmidt, R.H. 1986. Community-level effects of Rosenzwe~g,M L. 1966 Community structure in coyote population reduction. Pages 49-65 in J. sympatric J Marnrn 47:602-612. Cains, Jr. (Ed.) Comrnun~tytoxicity test~ng. Arner Soc. for Testing and Mat. STP 920.1 Sanderson, G.C 1987. Raccoon. Pages 487 - 499 in M Novak, J.A. Baker, M.E. Obbard, and Witrner, G.W. and D.S deCalesta. 1986. Resource B Malloch (Eds.) W~ldfurbearer management use by unesploited sympatric bobcats and and conservation In North America coyotes in Can J. Zool. 64:2333- Trappers Assoc., Toronto 1 150pp.. 2338.