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Housekeeping. Issues portfolios: 3 issues Due December 2. When Humans and Wildlife Collide Part I: Damage. Problems with white-tailed deer. Case Example: Whitetail Deer Potential Solutions. Fencing and repellents. Case Example: Whitetail Deer Potential Solutions.
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Housekeeping Issues portfolios: • 3 issues • Due December 2
Case Example: Whitetail Deer Potential Solutions Fencing and repellents
Case Example: Whitetail Deer Potential Solutions Fertility control agents: immunocontraception
Case Example: Whitetail Deer Potential Solutions Food supplementation
Case Example: Whitetail Deer Potential Solutions Sharpshooters --Cost effective --Safer than open season --Socially acceptable?
Case Example: Whitetail Deer Potential Solutions Reintroduce predators
When Humans and Wildlife Collide Part II: Disease Principles of Fisheries & Wildlife Management FiW 2114 Lecture 25
Objectives of Lecture 1. To explore different outcomes of human/wildlife interactions (in this context, disease) 2. To explore selected case studies involving white-tailed deer, bison, and mice 3. To evaluate feasible alternatives for control of disease transmission
Negative interactions: Disease Wildlife populations are vulnerable to diseases and parasites, some communicable to humans and agricultural species • deer - chronic wasting disease, bovine tuberculosis, Lyme disease • bison - brucellosis • raccoon, bobcat, fox, skunk, … - rabies • rodents - hantavirus, bubonic plague • crows, jays, other birds - West Nile virus
Animal-to-animal transmission • Chronic wasting disease of cervids • Bovine tuberculosis • Brucellosis of bison
Background: Prions • Prions = Proteinaceous infectious particles • Cause transmissible spongiform encephalopathies • Interact with normal protein, cause it to misfold • Stanley Prusiner won Nobel Prize for showing this • Ex: scrapie of sheep, mad cow disease, Creutzfeld-Jakob disease of humans, and…
Chronic Wasting Disease • Affects cervids • Contagious and fatal in (deer and elk populations • Humans, livestock may be immune
Chronic Wasting Disease • Prevention and management • Aggressive testing of cervids • Reductions of density in CWD areas • Restrictions on transport of deer, elk meat • Some states have banned importation of live cervids • Warnings to hunters about consumption of some parts of deer, notably CNS
CWD – Actions taken • In 2001, USDA declared an animal emergency because of the epidemic of CWD in captive elk in Nebraska • In 2002, wild deer in Wisconsin were diagnosed with CWD • In Virginia in 2002, of 1114 deer tested, all were negative for CWD
Bovine tuberculosis • Tuberculosis is a disease of the respiratory system caused by Mycobacterium bovis • Three types: human, avian, and bovine • Bovine TB transmissible to other mammals • Transmission to humans only through raw milk or respiratory exposure to infected cattle or carcasses
Bovine tuberculosis • Bovine TB was once common in cattle in the U.S., but rare in deer • Concern regarding deer is transmission to livestock • Before 1994, only 8 cases in deer in North America
Bovine tuberculosis in Michigan • 1994: Found in a white-tailed deer • To date, found in 228 deer of 30,000 tested • Also in 5 coyotes, 2 raccoons, one black bear, and one bobcat • Predators presumably contracted TB by eating lungs and lymph of infected deer
Bovine tuberculosis: Management • 1997: Multi-agency committee recommended: • Survey of wildlife populations • Testing of livestock • Ban supplemental feeding of deer • Ban new deer or elk enclosures • Reduce deer density through hunting • Educate the public
Bison in Yellowstone What is the value of a buffalo? • biological
Bison in Yellowstone What is the value of a buffalo? • biological • ecological
Bison in Yellowstone What is the value of a buffalo? • biological • ecological • cultural
Bison in Yellowstone What is the value of a buffalo? • biological • ecological • cultural • aesthetic
History of Bison in Yellowstone • Yellowstone - only place in lower 48 states where buffalo were not extirpated • In 1902, 23 wild bison left in Yellowstone on bison ranch • Intensive management kept herd size down • Highest reported herd size was 1,477 (1954) • 397 bison in 1967
Brucellosis and bison in Yellowstone • Bison a reservoir for bacterium, Brucella abortus • Contagious, caused by exposure to reproductive tissues or fluids (only females are infectious) • Causes spontaneous abortion in ~5th month • Hence, economic implications for cattle producers
Can Brucellosis be transmitted from bison to livestock? • Originally transmitted from livestock to bison • No documented case of transmission in wild from bison to livestock; only occurred under confined conditions • Antibody-based test;buffalo can test positive w/no incidence of disease • Testing revealed that <1% of buffalo were infected
Brucellosis and Bison in Yellowstone Bison tend to leave from north or west edges of park
Brucellosis and Bison in Yellowstone: Management or Massacre? • 3,500 buffalo in 1996 • Severe winter (1996-97) • 1,084 buffalo shot while exiting the park • 2,000 total dead; others starved in park • Huge outcry by range of stakeholders
Bringing Science to bear on the controversy • USDI called for scientific study • Released report: Brucellosis in the Greater Yellowstone Area in 1997 • Recommendations: • Establish disease surveillance and quarantine areas around Park • Vaccinate cattle around park and monitor frequently • Develop vaccine for bison (currently none exists) • Test and slaughter infected bison, elk, cattle • Collect better data on infected animals and risk of transmission
Brucellosis and Bison in Yellowstone: Management planning • Interagency group organized to develop management plan: NPS, USFS, State of Montana, APHIS • June 1998: Interagency group proposed 7 alternatives in a draft Environmental Impact Statement:
Bison in YellowstoneManagement Alternatives • 1: “No” action: continued capture/slaughter of bison leaving N or W boundaries of park • 2: Minimal management: changes in cattle operations; allow bison to range • 3: Management w/public hunting • 4: Interim plan, limited public hunting/quarantine • 5: Aggressive brucellosis control: 10 years of vaccination, then capture-test-removal • 6: Aggressive brucellosis control through vaccination • 7: Preferred alternative: manage for specific population range (1,700-2,500)
Mediated negotiation among the parties….Final EIS and bison management plan for Yellowstone National Park • (December 2000) • National Park Service will: • Capture, test and possibly hold bison • Vaccinate wildlife • Limit population of bison to manage risk of disease • APHIS and Montana will: • Accept disease management, as opposed to disease eradication • All parties will participate in adaptive management program
Today in Yellowstone • 1,100 bison killed in winter-spring 2003 • No testing for brucellosis • USFS transferred some grazing allotments to Idaho • Reduces risk of livestock contacting buffalo leaving park
Bison in Yellowstone Management Alternatives Do we view the bison issue the same as the white-tailed deer issues? What features are similar and which different?
Animal-to-human transmission • Bubonic plague • Rabies • Lyme disease • Hantavirus pulmonary syndrome
Bubonic plague • Bacterial illness transmitted by fleas on rats and other rodents and by contact with infected blood or tissue • Active in 15 states, mostly in the West • NM: two cases in 2002, 1 in 2001, one in 2000, six in 1999, nine in 1998, … • Last plague-related death in U.S. was in 1994
Bubonic plague, historically • Plague outbreaks have killed about 200 million people in the past 1500 years • “Black Death” started in 1347 and killed 25 million people in Europe and 13 million in the Middle East and China within 5 years
Rabies • Acute, contagious infection of central nervous system • Caused by virus, entry by animal bite • Incubation 21-120 days, virtually always fatal • Many different species variants • Currently epizootic in raccoons here in VA, throughout East • Nearly all human cases are bat rabies
Ticks • Ticks are vectors of: • Lyme disease • Babesiosis and Ehrlichiosis • Rocky Mountain spotted fever • How does this relate to how wildlife and humans collide??
Lyme disease • Lyme spirochete enters ticks with blood meal • As deer and mice forage, they brush against plants, and ticks attach to them • Humans also brush against plants • Ticks, mice and deer don’t get Lyme disease; humans (and some domesticated animals) do
How can managers minimize transmission of Lyme disease? • ? • ? • ? • ?
How can managers minimize transmission of Lyme disease? • Promote awareness and change in human behavior: • Keep clothing tightly fastened • inspect yourself for ticks • recognize symptoms • vaccine for those likely to be exposed • Control deer (and mouse) populations
Hantavirus Pulmonary Syndrome • Etiological agent - a hantavirus • Sin nombre virus (in East) • Family Bunyaviridae (ssRNA) • Vertebrate hosts
Vectors Deer mouse, Peromyscus maniculatus Cotton rat, Sigmodon hispidus
Transmission of hantavirus • Chonically infected rodent • Horizontal transmission by intraspecific aggressive behavior • Virus present in aerosolized excreta • Transmission to humans by bite or by contact of aerosolized virus with mucus membranes