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Fencing has played a major role of the recovery of previously pig-damaged areas ... Forest being fenced to protect it from feral pigs in Hawaii ...
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Habitat • Grasslands • Forests • Dry woodlands • Tropical rainforests • Semi-arid and monsoonal floodplains • Swamps and other wetlands Hawaii Wetland Hawaii Tropical Rainforest
Introduction of Pig to Hawaii Polynesian Pig • The Polynesian race of pigs was brought with the first human inhabitants around 400 A.D. • The European race was brought to the islands by Captain James Cook in 1778. European Pig
Ecological Effect • They dig deep holes in the ground searching for soil invertebrates and the starchy centers of native plants. • They have been found to selectively seek out native species such as ferns, tree-ferns, lobeliads, and mints for food.
Ecological Effect Cont’d • With destruction of native vegetation comes the destruction of native bird and insect populations as well. • The pig facilitates the invasion of other introduced species. • Behaviors of uprooting vegetation and digging wallows leaves areas open allowing early successional invasive plants to become established 1. Native bog without pigs. 2. Three years after pigs found the bog. 3. Seven years after the bog was fenced.
Ecological Effects Cont’d • They dig holes in the ground, roto-till the earth, and strip the mountain-sides of vegetation. • So when the rain falls, nothing holds the soil and rocks from washing down the streams into the sea. Mud & freshwater washes into the ocean and kills reef
Health Effects • The wallows they dig fill with water allowing mosquitoes carrying avian malaria to breed. A native Apapane Bird native to Hawaii, with a mosquito on its beak.
More Health Effects • Classical swine fever (also known as hog cholera) is a highly contagious viral infection of swine that is often fatal. • The virus is most often transmitted through the ingestion of contaminated feed or garbage. • The virus may also be spread through: open wounds and mucous membranes, contact with bodily secretions or feces of an infected pig, physical transfer from a contaminated object, human or insect, sow to piglet transfer or inhalation in close quarters.
Why is Invasive Swine so Successful? • Plants have not evolved defenses against native browsing animals • Lack of native predators allows this species to flourish with no population regulators. Humans are basically a feral pigs only natural predator
Management Implications • Hunting is probably the number one control method. • Methods such as snaring have proven to be quite effective as well. • Fencing has played a major role of the recovery of previously pig-damaged areas • Trapping etc.
Controversial Issues with Mangement • The state of Hawaii has set hunting seasons for pigs as well as bag limits. In order to completely eradicate the pig it would seem advantageous to have a year-round season with no bag limits. • Although there is opposition against the eradication of Feral Pigs in Hawaii, Native Polynesian groups argue that by erasing the pig from the islands they are erasing a integral part their culture, and certain hunting outfits also oppose this idea, as there will be nothing left to hunt if the pigs are removed
Controversy Cont’d • Fencing has played a major role of the recovery of previously pig-damaged areas, however fencing only keeps the pigs out, it does not control the populations. • Even if the pigs are removed other measures must be utilized to remove the species that were brought in by the pig. Forest being fenced to protect it from feral pigs in Hawaii
Got To Love Natural Predators • http://www.youtube.com/watch?v=yrx-ohT9r1s
