Q Or. FERAL SWINE SURVEY - REGION 4 j t-• INTRODUCTION: •- : .-', :-,) \ In response to questions raised by Region 4 refuge managers conceriihgMe-impact ox feral swine on Southeastern refuges, a survey was developed to obtain the desired information. The survey form (Appendix A) included questions designed to assess the distribution, abundance and damage caused by feral swine on Region 4 refuges. Information was also requested on types and effectiveness of control methods. Survey forms were mailed to all Region 4 refuges with a two week response deadline. After two weeks, a second mailing was made to all refuges that had not responded. A total of 66 refuges from Region 4 responded to the survey. iGi- %r. 1TT0 •fi-Sst. K^ ~—=-A~««, Off. s. RESULTS AND DISCUSSION: Pile The raw data obtained from the questionnaire are shown on the summary sheet in Appendix A. Basically, approximately two-thirds of refuges reported feral swine populations on the refuge and/or on surrounding lands (61% and 70% respectively). Of those reporting swine present, 40 of 42 (95%) assessed the populations as stable or increasing while only 2 (5%) felt that populations were decreasing. Primary to the survey was the Managers' assessment of the extent of damage caused by feral swine. Twenty-five of 53 (47%) assessed hog damage as either significant or severe. Related damages included habitat/crop damage, competition with native wildlife, levee and road damage, erosion problems, threatened and endangered species depredation, diseases, and numerous other incidental impacts. These include reduction of oak regeneration, killing of trees by rubbing, and interference at bait sites for waterfowl banding. Most respondents reported some method of control based on the extent of the problem. Public hunts or incidental take during other hunts and opportunistic control by refuge staff were the most common. Refuges with more significant problems listed trapping (staff or contract) and night shooting over bait as more effective methods. Only one-third (33%) evaluated these control efforts effectiveness as good or excellent. Most felt that control efforts were only fair to poor in controlling swine populations. This was attributed to several problems combining lack of staff time to devote to control efforts plus high reproductive rates and difficulty of terrain or vegetation. Best control methods were listed as intensive baiting combined with large live traps or night shooting. This is restricted of course by the lack of staff time available for these time- intensive activities. An interesting aspect of the survey were the responses regarding public attitudes toward the presence of swine on a National Wildlife Refuge. Twenty-two of 31 (70%) reported that the local public opinion was favorable to the presence of swine on the refuge. Another 17 respondents felt that the surrounding population had no strong opinion either way. Only 9 of 48 (19%) felt that local public opinion was unfavorable to the presence of feral swine on the refuge. This indicates that strong swine control efforts could be potentially met with negative public pressure in many cases. It should be noted that intensive control efforts should take local public opinion into account prior to initiation. The map of Region 4 (Appendix B) shows the distribution of damage assessments among the refuges. Of particular note is the fact that all of the refuges reporting significant or severe swine damage are located in the Atlantic or Gulf coastal plains. Also virtually every coastal plain refuge with suitable habitats reported medium to high swine populations and significant damage. None of the refuges in the Piedmont or higher elevations reported any significant swine-related problems. It is obvious that in Region 4 significant problems with feral swine are related to coastal plain and lowland refuges. It appears that these lowland-bottomland habitat types are much more conducive to supporting high populations and perhaps are more sensitive to the types of damage caused by swine activity. Only three of the 66 respondents reported severe damage from feral swine and it is not surprising that all are coastal islands (St. Vincent Island NWR, Blackbeard Island NWR, Wassaw Island NWR). These relatively small areas support unique, highly sensitive habitats which are highly susceptible to the types of damage caused by large hog populations. They also tend to support proportionately higher numbers of threatened and endangered species, both plants and animals. Particularly sensitive to swine damage are sea turtle nests, ground-nesting birds and any threatened or endangered plants occurring where feral swine are prevalent. Every possible effort should be utilized to control feral swine on island refuges or prevent their introduction to areas where they are not established. A number of refuges reported "diseases" as a concern associated with feral swine but none mentioned a specific disease or problem. Significant diseases which may occur in feral swine populations include pseudorabies, swine brucellosis, vesicular stomatitis., and hog cholera. In addition, feral swine host a wide variety of internal parasites including lungworms, stomach worms, and kidney worms. All the above primarily pose a threat only to domestic swine, but the parasitic trichina worm can be transmitted to humans through undercooked meat. Some research projects are or have been conducted regarding potential methods of chemical birth control in swine. To date practical methods of achieving birth control in free- ranging swine populations are not available. REFUGE MANAGEMENT IMPLICATIONS: None of the literature searches revealed vaccines or oral baits that could feasibly be used to deliver a "swine specific" virus., disease, or reproductive inhibitor—without repeated hands-on injections. However, it appears that more research along these lines could be productive. For example., the paper by Fletcher., et. al., 1990, demonstrated that over 95% of the hogs exposed to oral baits (spread aerially) had actually consumed the marked baits. The next step is to be able to attach a swine specific reproductive inhibitor., etc. to such baits. There is little doubt that introduction of hog-cholera to just a few swine (say on isolated islands) could indeed be very effective; however, such a technique would most likely not be acceptable to the Department of Agriculture (States/Federal) or to the pubKc. It appears that box/pen trapping, snaring, fencing., incidental shooting, or hunting programs are the major tools now available to managers. In trapping and shooting, intensive baiting greatly enhances such removal techniques. Incidental take of pigs by hunters (especially deer hunters) seems to be effective and should be considered. In some cases,, hunts focused on hogs can also be successful for control, but this could become a doubled-edged sword if dogs are used. Several states have found that dog/hog hunting becomes so popular that some faction of hunters tend to move pigs to Wildlife Management Areas to improve such hunts. In conclusion, use of baits with pens/traps, snares, and possibly hog-only hunting (without dogs) appears to be the preferred control techniques. However, incidental take of hogs during other hunts (i.e., deer hunting) or having hog specific hunts (dogs excluded) can also provide good/effective control on refuges. If you would like more specific information on trap designs, snares, baiting, etc.—contact Ron Freeman at 334-844-4796 (Auburn, Alabama). SUMMARY: — Feral swine occur on nearly two-thirds of Region 4 National Wildlife Refuges. — Highest populations and significant damage are concentrated almost entirely in the lowland/bottomland refuges of the coastal plain. — Seventy percent of refuges with swine populations reported that local public opinion was favorable toward the presence of swine on the refuge. — Island refuges are the areas of most concern. Depredation of sea turtle nests, ground nesting birds, and destruction of fragile island habitats are the primary problems. — Two-thirds of refuge respondents evaluated their control efforts as only fair or poor. — Intensive live-trapt)ing is still by far the most effective method of controlling swine populations. Shooting over bait is the next best alternative. A combination of methods I is needed in areas where damage is severe. — Disease potential remains an ever-present but relatively low level danger in feral swine populations. Appendix A United States Department of the Interior WSK AND WILDLIFE SERVICE WILDLIFE MANAGEMENT BIOLOGIST OFFICE ROOM 302 FUNCHESS HALL ATJBUSNTJMVERSrrY,AL 36849-5414 Phone: 334/844-4796 Fax: 334/887-4509 Email: r<[email protected] karen fiizzdl^fvvs.sov FERAL SWINE SURVEY Refuge Supervisors Ingram, Grabill and Jerome have authorized this short survey of all Region 4 National Wildlife Refuges to assess the distribution, abundance, and damage caused bjr feral swine. This is a result of a refuge needs assessment conducted at the project leaders meeting in Orlando. Please take a few minutes to complete me survey form and list your special concerns or needs at the bottom. Ron Freeman (Auburn. AL WHM Office) will also be gathering intbrmatiott on current research regarding population control and reduction. Once such information is assembled, it will be suppled to all refuges indicating problems with feral swine. Please return your information by June 25,2001 in the pre-addressed envelope enclosed for your use. Thank you for your cooperation. REFUGE: SUMMARY OF SURVEY STATE AND COUNTY: R4 NATIONAL WILDLIFE REFUGES 1. Are feral swine present on refuge: Yes 40 No 26 2. Do feral swine occur on surrounding lands Yes 43 No 18 Unk 1 3. Assessment of current population: Low 20 Medium 18 High 10 None 2 4. Is population currently: Stable 26 Increasing 14 Decreasing 2 Unk 4 5. What is your assessment of damage caused by feral swine on your refuge? None 14 Insignificant 14 Significant 22 Severe 3 6. What do you consider the main problems (if any) caused by feral swine on your refuge (ie.