Status of Feral Pigs in Kansas and Nebraska
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University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln USGS Staff -- Published Research US Geological Survey 2006 Status of Feral Pigs in Kansas and Nebraska Philip S. Gipson Kansas State University Charles D. Lee Kansas State University, [email protected] Sam Wilson Nebraska Game and Parks Commission James R. Thiele Nebraska Game and Parks Commission Deke Hobbick Kansas Department of Wildlife and Parks Follow this and additional works at: https://digitalcommons.unl.edu/usgsstaffpub Part of the Earth Sciences Commons Gipson, Philip S.; Lee, Charles D.; Wilson, Sam; Thiele, James R.; and Hobbick, Deke, "Status of Feral Pigs in Kansas and Nebraska" (2006). USGS Staff -- Published Research. 195. https://digitalcommons.unl.edu/usgsstaffpub/195 This Article is brought to you for free and open access by the US Geological Survey at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in USGS Staff -- Published Research by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Published in PRAIRIE INVADERS: PROCEEDINGS OF THE 20TH NORTH AMERICAN PRAIRIE CONFERENCE, UNIVERSITY OF NEBRASKA AT KEARNEY, July 23–26, 2006, edited by Joseph T. Springer and Elaine C. Springer. Kearney, Nebraska : University of Nebraska at Kearney, 2006. Pages 19-24. STATUS OF FERAL PIGS IN KANSAS AND NEBRASKA PHILIP S. GIPSON1, Kansas Cooperative Fish and Wildlife Research Unit, U. S. Geological Survey, Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA CHARLES D. LEE, Department of Animal Science and Industry, Kansas State University, Manhattan, Kansas 66506, USA SAM WILSON, Nebraska Game and Parks Commission, 2200 North 33rd Street, Lincoln, Nebraska 68503, USA JAMES R. THIELE, Nebraska Game and Parks Commission, 2200 North 33rd Street, Lincoln, Nebraska 68503, USA DEKE HOBBICK, Kansas Department of Wildlife and Parks, 206 North 1600 Road, Lecompton, Kansas 66050, USA Abstract: Wild pigs have expanded their range markedly during the last 30 years. In Kansas feral pigs from domestic stock were first reported in 1994 on Fort Riley Army Base. During 2005, 2006, and 2007 the occurrence of reproducing wild pigs was confirmed on 18 sites throughout Kansas and 4 sites in Nebraska. One Nebraska population is in a county neighboring Kansas. Estimated numbers of pigs ranged from 8-10 individuals at each of 2 sites in Kansas to more than 30 on each of 3 other sites. The wild pig population in Kansas appears to be changing from 1 predominantly of domestic stock to 1 of Eurasian wild boar descent and hybrids of the 2. Ninety-one percent of wild pigs examined from Kansas between 1993-1997 were classified as coming from domestic stock. However, only 34% of wild pigs examined in 2003-2006 were classified as being from domestic stock. Sixty-six percent were classified as wild boar or hybrids. On 1 site in Nebraska, 1 sow and a litter of 6 piglets were classified as hybrids with wild boar; wild pigs killed on 3 additional sites appeared to be from domestic stock. Proceedings of the North American Prairie Conference 20:19-24. Key words: domestic stock, Eurasian wild boar, feral pig hybrid, wild pig Wild pigs (Sus scrofa) have expanded their LaFond and Salwey (2005) found wild pigs in range markedly in North America during the last counties in Wisconsin. Sweeney et al. (2003) 30 years. In 1979 wild pigs were reported in the indicated that wild pigs were established in Canada southeastern United States as far west as Texas and as well. in California (Wood and Barrett 1979).1 By 1998 Reproducing populations of wild pigs are wild pigs were found in all of the southern states common on the southern Great Plains of Texas and from Florida to California and north through the Oklahoma (Stevens 1996), with some populations central tier of states from Colorado and Kansas to dating to the 1700s (Taylor 1993). At least 3 Ohio and West Virginia (Gipson et al.1998). releases of Eurasian wild boar occurred in Texas 1 Current Address: Department of Natural Resources Management, Texas Tech University, Lubbock, Texas 79409-2125, USA 20 Feral Pigs in Kansas and Nebraska • Gipson et al. during the 1930s and 1940. Wild boar are a native They are almost never red or light brown and wild species in Europe and Asia. These wild boar seldom have white belts or spots. Feral pigs from released in Texas bred with local feral pigs of domestic stock are most often all black, black and domestic ancestry (Taylor 1993). The occur-rence red with brown spots, or black with white spots. of wild pigs on the central Great Plains of Kansas Occasionally individuals with white shoulder belts and Nebraska appears to be relatively recent, with occur. The wild/grizzled color of wild boars has the first published account in 1994 (Gipson et al. not been observed among feral pigs. 1994). Our goal in this paper is to provide an overview of the status of wild pigs in Kansas and Juvenile Coat Color.—A stripped pattern is Nebraska. We review recent range expansions and visible on the back and upper sides of wild boar present evidence that suggests wild pig populations piglets and on about half of hybrids. These strips in Kansas, and possibly in Nebraska, are changing are clearly visible on near term fetal pigs and on from predominately pigs of domestic stock to wild juveniles less than two months old. Very few feral boar and hybrids. pigs from domestic breeds exhibit a stripped pattern. When it is present, it is often extremely METHODS faint and difficult to see. Feral pigs were collected with live traps and shooting by the study team, personnel from Bristle Color.—Eurasia wild boar and hybrids resource management agencies, private have primarily banded bristles, with white to dark landowners, and hunters. Locations of breeding tan distal tips. This gives them their characteristic populations of wild pigs were confirmed by grizzled color pattern. A few solid black bristles examination of pregnant or lactating sows killed on are present on wild boar and hybrids may have a site, observations of adult and juvenile pigs, and some solid black or red/brown bristles. Feral pigs from tracks of piglets and adults. Efforts were from domestic breeds do not have banded bristles; made to have a member of our study team visit they exhibit only solid coloration on bristle shafts. sites where hunters, farmers, and outdoor enthusiasts reported seeing pigs or their sign, Depth of Facial Profile.—Mayer and Brisbin including wallows, rooting, rubs on trees and posts, (1991) referred to depth of facial profile as “dorsal feces, and tracks. profile”. Eurasian wild boar and their hybrids Following criteria described by Mayer and have a distinctly flattened and straight facial profile Brisbin (1991), we classified wild pigs into 1 of 3 from the muzzle through the supraorbital area and categories: 1) pigs from domestic stock, 2) hybrids along the crest of the brain case, giving an between domestic stock and Eurasian wild boar, appearance similar to the facial profile of a collie and 3) predominantly Eurasian wild boar. To dog. Domestic and wild pigs from domestic stock assure consistency in applying the criteria, only the typically have a more cupped forehead angled first author classified wild pigs into categories. upward in the interorbital area, similar to a pointer or boxer dog. Criteria Used To Classify a Pigs Origin Adult Coat Color.—Eurasian wild boar over Head to Body Length Ratio.—Wild boar and four to six months of age consistently have a wild hybrids tend to have have shorter bodies and type color pattern of grizzled dark brown or black. proportionally longer heads than domestic or wild The grizzled appearance is caused by banded, pigs from domestic ancestry. light-tipped bristles, especially in the facial region and along the top of the shoulders; some have light RESULTS AND DISCUSSION tipped bristles covering most of the body except for Reproducing populations of wild pigs occurred distal limbs, ears, tail and snout. Hybrids in 18 locations in Kansas and 4 in Nebraska commonly have the wild/grizzled color pattern of (Fig. 1). Estimated sizes of local populations wild boar, sometimes with a distinct light gray cast. ranged from 8-10 individuals at 2 sites in Kansas to All black is another common color of hybrids. more than 30 individuals. Our records indicate that Feral Pigs in Kansas and Nebraska • Gipson et al. 21 more than 400 feral pigs have been killed in of Nance and Platte Counties (Fig. 1). Wild pigs Kansas since they were first reported in 1993. In along the border of Valley and Sherman Counties each of 3 Kansas counties (Morton, Kiowa, and and those along the border of Nance and Platte Bourbon), populations of wild pigs were located Counties were first detected in winter 2006/2007. <30 km from each other. Pigs in these neighboring Approximately 20 feral pigs were killed in Harlan populations were physically similar and we suspect County from 2003-2005. At least 32 individuals that movement of individuals between the from the population first observed in Seward populations has occurred. A similar situation County in May 2004 have been killed. A mini- existed in Phillips County, Kansas and Harlan mum of 90 feral pigs have been killed in Nebraska. County, Nebraska where populations in the In addition to the 2 existing populations of wild respective counties were about 30 km apart. Wild pigs in Nebraska, 2 other populations were noted. pigs were known to occur in Phillips County before But both populations only survived briefly in a being observed near Harlan County Reservoir in wild state. The first population was reported in 2003. The Harlan County population is likely the northeastern Nebraska near the Winnebago Indian result of pigs dispersing out of Phillips County.