European Wild Hogs Research Articles

The Benefits of Aerial Hunting for Feral Hog Management in Southeast Texas Pasture and Rangelands

The feral hog is an Old World species introduced to Texas by early Spanish explorers. Populations in Texas are descended from European wild hogs introduced for sporting purposes, and from escaped domestic swine that have established feral populations. Today, Texas has a feral hog population estimated at about 2 million animals, the most of any state. Feral hogs are considered a pest throughout much of their range. They are responsible for damaging crops, pasture, rangeland, livestock, and wildlife resources. Because of their reproductive capacity and their omnivorous eating habits, the feral hog population has rapidly increased across the state over the past 25 years. This increasing population, and resulting economic losses, have led resource managers to investigate alternative methods of managing feral hog populations. The uniqueness of the Texas Coastal Plains habitat lends itself to aerial hunting more often than a habitat type with a more densely formed overstory. We review the impacts of aerial hunting operations in Matagorda County in the Southeast Texas Coastal Plains.

A Serologic Survey of Selected Viral and Bacterial Diseases of European Wild Hogs, Great Smoky Mountains National Park, USA

Blood samples were collected from 108 wild hogs (Sus scrofa) from the Great Smoky Mountains National Park (GSMNP), USA, February to July 1990. We found no antibodies for swine brucellosis, pseudorabies, bovine virus diarrhea virus or porcine rotavirus infection. Antibody titers to porcine parvovirus were found in 15 (14%) samples and antibody to one or more leptospiral serovars was found in 48 (44%) samples. Thirty-nine (89%) of the 44 positive samples reacted to all five leptospiral serovars tested.

Freilanduntersuchungen zum Kampf‐ und Sexualverhalten des europäischen Wildschweines (Sus scrofa L.)

AbstractThis ethogram of the fighting and sexual behaviour of European wild hogs is supposed to serve as a basis for further research on the social behaviour of Sus scrofa L.The observations were recorded in writing respectively on cassette recorder as well as photographed and filmed. Behaviour patterns of the European wild hogs which were wrongly interpreted or not yet described could be documented. Being comparatively original, omnivorous social Artiodactyla, Suidae are well comparable with other Artiodactyla, with Perissodactyla, Carnivora and their domesticated types.There might also be references to the origin and development of behaviour patterns in various zoological categories or on reductions of social behaviour in domestication.

Radiotelemetry Studies of Feral Hogs in South Carolina

Movement patterns and behavior of feral hogs (Sus scrofa) were studied in the Upper Coastal Plain of South Carolina. Seven hogs (four boars and three sows) were radio-tracked for periods ranging from 1 to 10 months. One hundred fifty-two 24-hour tracking periods and 2,021 radio and visual locations were obtained on these individuals. Home ranges of the five hogs most intensively studied varied from 304 to 1,975 acres with a mean of 979 acres. Two sows that gave birth while being tracked had much smaller ranges (42 and 74 acres) during the farrowingfperiod. Seasonal shifts in range were exhibited by two boars and were apparently related to changes in food availability. Distances between extreme locations during 24-hour periods averaged 0.69 mile for boars and 0.38 mile for sows. No significant differences (P > 0.05) were found between daily movements of boars and sows except late in pregnancy when a highly significant reduction (P<0.01) in the sows' movements occurred. Hogs had diurnal activity cycles from October through May, but nocturnal movement significantly increased (P<0.0S) during the summer. There was also significantly more movement (P < 0.05) on moonlit nights than on dark nights. Bottomlands were the preferred habitat except during June when there was movement into pine plantations. No statistically significant relationships were evident between distances moved during 24-hour periods and temperature, relative humidity, and barometric pressure. Observations of breeding, prenatal and postnatal behavior, and of social organization are reported. Feral hogs are found in areas throughout the southeastern United States. In some locations, they are important game animals, and, in other areas, they are considered economically significant pests. Our study objectives were to use radio-location techniques to obtain detailed information on movement patterns, home ranges, activity cycles, habitat preference, and social behavior of feral hogs. Radio-location studies of feral hogs or of European wild hogs have not been reported previously. Some data on movements and behavior of feral swine have been obtained through observations and tag returns ( Pullar l9S0, Wodzicki 1950, Hanson and Karstad l9S9). European wild hogs have been more intensively studied ( Stegeman 1938, Lewis 1966, Matschke and Hardister l9B6), although their behavior is probably not direcdy comparable with that of feral swine. 1 Present address: Georgia Department of Natural Resources, Gaine and Fish Division, Fort Valley. 1240 The authors acknowledge the financial support of the Georgia Forest Research Council under Project No. S3-319; the University of Georgia, School of Forest Resources, and Savannah River Ecology Laloratory through contract AT(391)410 with the U. S. Atomic Energy Commissio1l; and the U. S. Forest Service. We also thank I. L. Brisbin, J. H. Jenkins, A. S. Johnson, F. E. Kellogg, and E. E. Provost for assistance throughout the study and in preparation of the manuscript.

Fall Foods of European Wild Hogs in the Southern Appalachians

A study was conducted to determine fall food habits of European wild hogs (Sus scrof) in the southern Appalachian Mountains. Seventy-three hog stomachs were collected dunng big game hunts on the Tellico Wildlife Management Area, Cherokee National Forest. Principal plant foods were acorns ( Quers spp. ) and hickory nuts (Carys spp. ) and the principal imal food was invertebrates. Plant and animal foods constituted 89.4 and 6.4 percent respectively, in volume of total foods consumed. The degree of competition for mast between hogs and native wildlife nnay depend on the quantity and quality of the annual mast crop. The relationships of hogs with native fauna and flora should be investigated before hogs are transplanted into unoccupied habitat. A thorough food habits study is fundamental in delineating the life history and determining managemerst objectives for the European wild hog. Although this animal has been established in the southern Appalachian Mountains of southeastern Tennessee for approximately 50 years, little is known of its food habits. This study was undextaken to determine the seasonal utilization of plant and animal items by the European wild hog in the southem Appalachian Mountains. Only fall food habits are considered. Because of the interest in transplanting European wild hogs to other areasn information conceining its relationships with native fauna and flora is imperative. Appreciation is extended to Dr. G. H. Matschke former project leader, who collected most of the stomachsv to L. A. Hunt and J. D. Morris, Game and Fish Commission employees, for assistance with the analytical procedures; and to Judith D. Way, University of Tennessee, for identifying the invertebrates. We thank Dr. M. R. Peltonn University of Tennessee7 for reading the manuscript and offering suggestions, 1A contribution from Tennessee Federal Aid Project W-34-R, Game Management Division, Research Section. 2 Prewsent address: U.S.D.A., Forest Service, Federal Building, Lufldn) Texas. 854 and L. J. Korsehgen, Missouri Department of Conservationt for adviee in analyzing the data.

Attempts to Identify Meat of Game Animals by Starch-Gel Electrophoresis

Total protein, esterase, and lactic dehydrogenase patterns of muscle extracts from domestic cow (Bos taurus), pig (Sus scrofa), and sheep (Ovis aries), and from moose (Alces alces), deer (Odocoileus virginianus), and caribou (Rangifer tarandus) were compared. The electrophoretic patterns were genera specific. Electrophoretic analysis shows promise as a method for identification of meat for game law enforcement. IDENTIFICATION OF NIUSCLE TISSUE BY ELECTROPHORESIS * Dila;oawth and McKentie 917 MATSCHKE, G. H. 1962. Trapping and handling European wild hogs. Proc. 16th Annual Conf., Southeastem Assoc. Game and Fish Commissioners, Charleston, South Carolina. 21-24pp. MORGAN, B. B., AND P. A. HAWKINS. 1949. Veterinary helminthology. Burgess Publishing Co., Minneapolis. 400pp. SEVERINGHAUS, C. W., AND E. L. CHEAT. 1956. Life and times of the white-tailed deer. Pp. 57-186. In W. P. Taylor (Editor), The deer of North America. The Wildlife Management Institute, Washington, D. C. 668pp. SOULSBY, E. J. L. 1965. Textbook of veterinary clinical parasitology. Vol. I Helminths. F. A. Davis Co., Philadelphia. 1120pp. SPINDLER, L. A. 1934. The incidence of worm parasites in snvine in the southern United States. Proc. Helminthol. Soc. Washington. 1(2) :4042. AMAGUTI, S. 1961. Systema helminthum. Vol. III. The nematodes of vertebrates. Part I. Interscience Publishers, Inc., Neur York. 679pp. Received for publication May 16, 1968. An enforcement problem of wildlife agencies is the positive identification of game species which may have been taken illegally. Jackson ( 1962 ) described a method for identifying muscle tissue of game animals using paper chromatography. He stated that electrophoresis probably could be used for identification of tissue samples, but that the paper chromatography method was simpler. This met-hod has proven unreliable in Atlantic Canada, and the precipitin reaction is now used to identify meat samples of game and domestic animals (J. Berkan, personal communication). Unfortunately, the precipitin reaction is not genera specific, the taxonomic level required for game law enforcement. The comparison of the composition of skeletal muscle has been the subject of many studies. Hamoir (1955) found that skeletal muscle proteins varied biochemically both qualitatively and quantitatively even between elosely related fish speeies. Starch-gel electrophoresis has been demonstrated to be suited for sueh eomparative ss-ork ( Giles 1962, Tsuyuki et al. 1965, Baker 1966, Scopes 1968, Jaeobson et al. 1969 ) . Wilson et al. ( 1967 ) found that some commereial samples of frozen fish fillets whieh were labeled haddock contained eod ( Gadus morrhua) lactate dehydrogenase ( LDH ) when subjected to starch-gel electrophoresis and the gel stained for LDH. They suggested that many enzymes, besides LDH, exhibit species specifieity and that mislabeling of naeat products should easily be detectable using

Some Parasites of European Wild Hogs in the Southern Appalachians

Some Parasites of European Wild Hogs in the Southern Appalachians

Immobilizing European Wild Hogs with Succinylcholine Chloride

Sixty-three pen-reared European wild hogs (Sus scrofa) were injected one or several times for a total of 92 injections with succinylcholine chloride at doses ranging from 0.1 to 6.7 mg/lb. Thirtyeight hogs (41 percent) died from overdosages; at the lowest effective level, 0.3 mg/lb, 3 of 13 animals died (23 percent). In only 32 (35 percent) of the observations were the hogs successfully immobilized. The time elapsed from injection to immobilization averaged 97 + 10 seconds (range 3s250 seconds) and that from injection to recovery averaged 25.6 + 7.4 minutes (range 3.S134 minutes). In most casesn hogs that survived the first dose could be immobilized at a wider range of dose levels without mortality. Two animals were unaffected at doses of over 3 mg/lb. An anesthetic index of only 2.6 indicates that succinylcholine chloride has a very narrow safety margin for European wild hogs. Several immobilizing drugs have been tested on the European wild hog in Tennessee. Cap-Chur-Barb3 (pentobarbital scopolamine ) has the advantage of a wide safety margin but has the disadvantage of long preand postimmobilization periods (Henry and Matschke 1968). These were undesirable characteristics in our studies because of the time spent tending the traps, the distance between traps, and the necessity of replacing the hog in the trap overnight to prevent predation by feral dogs or bears, thus rendering the trap inoperative for that night. In this study, succinylcholine chloride, a muscle-relaxant, was evaluated because of its short preand postimmobilization period. Thanks are extended to J. C. Lewis, Research Supervisor, and B. H. Erickson7 UTAEC Agricultural Research Laboratory, Oak Ridge, Tennessee, for reviewing the manuscript. R. H. Conley, L. A. Hunt, J. D. Morris, and D. J. Williams assisted in the collection of data. 1A contribution from Tennessee Federal Aid Project W-34-R, Game Division, Research Section. 2 Present address: Bureau of Sport Fisheries and Wildlife, Wildlife Research Center, Federal Center, Denver, Colorado. 3Palmer Chemical Company, Douglasville, Georgia. PROCEDURES Pen-reared hogs ( progeny of trapped and confined wild hogs) were used in this study. Succinylcholine chloride was injected into the muscles of the hindquarters by a hand syringe. Time at injection and the length of preand postimmobilization periods were recorded for most hogs. When a hog regained its footing, it was considered recovered. Statistical estimates of the dose necessary to immobilize (ED50) or kill (LD50) onehalf of the population were computed by the technique outlined by Litchfield and Wilcoxon (1949). RESULTS AND DISCUSSION Sixty-three hogs were injected at doses ranging from 0.1 to 6.7 mg/lb (Table 1). Some were injected several times, for a total of 92 observations. Action of the drug was similar to that described by Zurowski and Sakowicz (1965), in that the preimmobilization period was very short, averaging 100.0 + 9.4 seconds and ranging from 30 to 250 seconds, and was characterized by tremors over the whole body and bristling of the dorsal guard hairs. The front feet of the animal usually

Estimating Whole Weights from Dressed Weights for European Wild Hogs

Estimating Whole Weights from Dressed Weights for European Wild Hogs

Immobilizing Trapped European Wild Hogs with Cap-Chur-Barb

Wild-trapped European wild hogs (Sus scrofa) were injected intramuscularly with Cap- Chur-Barb (pentobarbital scopolamine). Only 1 of 130 hogs was killed, and complete immobilization occurred in 115 hogs at dosages ranging from 1 cc/8.6 to 1 cc/53.9 lb of body weight. Time required for immobilization ranged from 12 to 281 minutes and averaged 55.5 minutes. Immobilization usually lasted at least 3 hours; in eight cases it lasted from 154 to 327 minutes and averaged 251.9 minutes. The recommended dosage is 1 cc/15 lb body weight. Cap-Chur-Barb is highly satisfactory for handling European wild hogs and is the best immobilizing drug tested to date. Abstract: Wild-trapped European wild hogs (Sus scrofa) were injected intramuscularly with Cap- Chur-Barb (pentobarbital scopolamine). Only 1 of 130 hogs was killed, and complete immobilization occurred in 115 hogs at dosages ranging from 1 cc/8.6 to 1 cc/53.9 lb of body weight. Time required for immobilization ranged from 12 to 281 minutes and averaged 55.5 minutes. Immobilization usually lasted at least 3 hours; in eight cases it lasted from 154 to 327 minutes and averaged 251.9 minutes. The recommended dosage is 1 cc/15 lb body weight. Cap-Chur-Barb is highly satisfactory for handling European wild hogs and is the best immobilizing drug tested to date.

Fetal Development in European Wild Hogs

Fetal Development in European Wild Hogs

Length of Estrous Cycle and Gestation in European Wild Hogs

Length of Estrous Cycle and Gestation in European Wild Hogs

Aging European Wild Hogs by Dentition

A method of aging pen-reared European wild hogs (Sus scrofa) was developed by using the time and order of tooth eruption and replacement. Wild hogs are born with incisors three (i-) and canines (cl-). All deciduous incisors and premolars erupt by 120 days. Molars one (MI) and premolars (P1), the first permanent teeth, erupt at about 5 months. At 7 months permanent incisors three (L!) 1'3 canines (C ) replace their deciduous counterparts. Molars two (MI) and permanent incisors one (IU) are present in igs aged 12-15 m nths. Temporary premolars are replaced at 14-18 months, a d m e t lower incisors two (I-) erupt at 18-22 months. Upper incisors two (II.) d lower molars t ee (M--) erupt at 21-26 months. Permanent dentition is complete with the eruption of upper molar r A at 26 months or later. Since molars th ee (M-1) c ntinue to grow as the upper and lower jaws elongat this may possibly be used s a agi g c nique fo hogs over 26 months f age. T oth eruptio data ob ai ed fro wild trapped hogs correspo ded cl sely with the penn d h g d ta. Re earch on the Eur pean wild hog in T nnessee has be n handicapped by the lack of an aging technique. Although techniques are v ila l for agi g do estic species a d wild hogs in Euro e, it was ot known whether these methods could be applied reliably to the European wild hogs in Tennessee. I wish to thank James C. Lewis, Supervisor of Game Research, and Vernon Henry, European wild hog project leader, for reading the manuscript and offering suggestions. I am grateful to the following Game and Fish employees for assistance in handling the hogs: L. A. Hunt, E. Mountain, H. E. Rice, G. B. Peaden, R. R. Pugh, and D. J. Williams.