White-tailed Deer ( Odocoileus virginianus ) in Sifton Bog:   Reviewing non-lethal management options   Presented by  Eliz...
Outline <ul><li>General list of methods (past, present) </li></ul><ul><ul><ul><li>Brief discussion of what has not worked ...
General list of methods <ul><li>“ Do nothing”/”laissez-faire” </li></ul><ul><li>Supplemental feeding </li></ul><ul><li>Red...
What has not worked <ul><li>“ Do nothing”/”laissez-faire” </li></ul><ul><ul><li>Populations continue to cycle: if density ...
What has not worked (2) <ul><li>Reduction of deer impacts </li></ul><ul><ul><li>Efficacy is limited, short-lived,  impract...
Still questionable <ul><li>Hormonal contraception </li></ul><ul><ul><li>ie. Norgestomet, Levonogestral, MGA, MPA, Altrenog...
Options proven to work <ul><li>Surgical sterilization </li></ul><ul><li>Immunocontraception  </li></ul><ul><ul><li>PZP (Po...
Surgical Sterilization <ul><li>Males are captured, immobilized, and castrated or vasectomized. </li></ul><ul><li>Females a...
Surgical Sterilization (2) <ul><li>Disadvantages: </li></ul><ul><li>Animals must be captured, immobilized, operated on, th...
Immunocontraception I - PZP <ul><li>PZP vaccine induces strong immune response: produces antibodies to attack invading ant...
Immunocontraception I – PZP (2) <ul><li>Benefits: </li></ul><ul><li>Highly effective (80-100% in WTD), lasts 1-3 years, re...
Immunocontraception I – PZP (3) <ul><li>Disadvantages: </li></ul><ul><li>Estrus not inhibited:  ↑  # of cycles + extended ...
Immunocontraception II – GnRH <ul><li>GnRH is produced by the hypothalamus and  controls release of hormones that control ...
Immunocontraception II – GnRH (2) <ul><li>Benefits: </li></ul><ul><li>Highly effective ( 88% efficacy), reversible  </li><...
Conclusion:  Present status of methods <ul><li>There are many non-lethal methods that have had varied results when applied...
Conclusion (2) <ul><li>Fraker et al. (2002) and Locke et al. (2007):  </li></ul><ul><ul><li>SpayVac® administered once </l...
Conclusion (3) <ul><li>Miller et al. (2008):  </li></ul><ul><ul><li>GonaCon™ administered once </li></ul></ul><ul><ul><li>...
References Specific articles mentioned: Fraker et al. 2002. Long-lasting single-dose immunocontraception of feral fallow d...
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Sifton Bog Wtd Ppt Dec16

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Presentation to the Animal Welfare Advisory Committee of London, Ontario on December 16, 2008. Summarizes the related paper that looks specifically into the non-lethal methods that have been proposed to deal with white-tailed deer.

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Sifton Bog Wtd Ppt Dec16

  1. 1. White-tailed Deer ( Odocoileus virginianus ) in Sifton Bog: Reviewing non-lethal management options Presented by Elizabeth Gerrow on December 16, 2008 for the Animal Welfare Advisory Committee (AWAC), City of London, Ontario
  2. 2. Outline <ul><li>General list of methods (past, present) </li></ul><ul><ul><ul><li>Brief discussion of what has not worked </li></ul></ul></ul><ul><li>Options proven to work </li></ul><ul><ul><ul><li>Surgical sterilization , PZP , Anti-GnRH </li></ul></ul></ul><ul><li>Present status of non-lethal management options </li></ul>
  3. 3. General list of methods <ul><li>“ Do nothing”/”laissez-faire” </li></ul><ul><li>Supplemental feeding </li></ul><ul><li>Reduction of deer impacts </li></ul><ul><li>Live-capture and relocation </li></ul><ul><li>Surgical sterilization </li></ul><ul><li>Mechanical contraception </li></ul><ul><li>Hormonal contraception </li></ul><ul><li>Immunocontraception </li></ul>From http://en.wikipedia.org/wiki/White-tailed_deer
  4. 4. What has not worked <ul><li>“ Do nothing”/”laissez-faire” </li></ul><ul><ul><li>Populations continue to cycle: if density ↑ to “K”, deer may cause too much damage to ecosystem and/or die (starvation) </li></ul></ul><ul><li>Supplemental feeding </li></ul><ul><ul><li>↑ grouping, tolerance, and populations that skew densities </li></ul></ul><ul><ul><li>Possible food poisoning </li></ul></ul><ul><li>Mechanical contraception </li></ul><ul><ul><li>Not proven to be effective , especially for the effort that would be required, making it impractical </li></ul></ul>
  5. 5. What has not worked (2) <ul><li>Reduction of deer impacts </li></ul><ul><ul><li>Efficacy is limited, short-lived, impractical (fencing issues, etc.) </li></ul></ul><ul><ul><li>↑ grouping </li></ul></ul><ul><li>Live-capture and release </li></ul><ul><ul><li>Expensive, not effective, impractical </li></ul></ul><ul><ul><li>Difficult to capture a sufficient # of deer to ↓ populations </li></ul></ul><ul><ul><li>Stresses deer, with high pre- and post-release mortality rate </li></ul></ul><ul><ul><li>Difficult to find sites able and/or willing to accept relocated deer … especially as deer issue is so widespread. </li></ul></ul>From http://en.wikipedia.org/wiki/White-tailed_deer
  6. 6. Still questionable <ul><li>Hormonal contraception </li></ul><ul><ul><li>ie. Norgestomet, Levonogestral, MGA, MPA, Altrenogest, GnRH agonists </li></ul></ul><ul><ul><li>Natural, active in deer and work over long time periods </li></ul></ul><ul><ul><li>EXCEPT… </li></ul></ul><ul><ul><li>Varied results, unreliable, many concerns (food chain) </li></ul></ul><ul><ul><li>Requires large/frequent doses (ie. MGA - daily) </li></ul></ul><ul><ul><li>Changes behaviours, produces health concerns (ie. Levonogestral- reduced food intake in spring) </li></ul></ul>
  7. 7. Options proven to work <ul><li>Surgical sterilization </li></ul><ul><li>Immunocontraception </li></ul><ul><ul><li>PZP (Porcine zona pellucida) </li></ul></ul><ul><ul><li>Anti-GnRH (gonadotrophin-releasing hormone) </li></ul></ul>From http://en.wikipedia.org/wiki/White-tailed_deer
  8. 8. Surgical Sterilization <ul><li>Males are captured, immobilized, and castrated or vasectomized. </li></ul><ul><li>Females are captured, and have: </li></ul><ul><ul><ul><li>Ovariectomy (removal of gonads), or, </li></ul></ul></ul><ul><ul><ul><li>Ovariohysterectomy (removal of entire genital tract), or, </li></ul></ul></ul><ul><ul><ul><li>Clamping (tubule ligation). </li></ul></ul></ul><ul><li>Benefits: </li></ul><ul><li>Highly effective, irreversible, long-term/permanent, 1 treatment </li></ul><ul><li>May reduce overabundant populations </li></ul>
  9. 9. Surgical Sterilization (2) <ul><li>Disadvantages: </li></ul><ul><li>Animals must be captured, immobilized, operated on, then released – extremely stressful, with possible anesthetic risks </li></ul><ul><li>Requires equipment, stationary location, expertise </li></ul><ul><li>Can impact behaviour </li></ul><ul><li>Difficult if sterilized individuals are continuously captured-released while attempting to capture non-sterilized individuals </li></ul><ul><li>Emigration (sterile) opens space for immigration (fertile) </li></ul>
  10. 10. Immunocontraception I - PZP <ul><li>PZP vaccine induces strong immune response: produces antibodies to attack invading antigen and reproductive system </li></ul><ul><li>Antibodies attach to sperm receptors of ova, blocking fertilization (or, alters egg and/or embryo development by preventing implantation/development of fertilized egg) </li></ul><ul><li>Interferes with processes of proteins, hormones = infertility. </li></ul>Adapted from Muller et al. (1997)
  11. 11. Immunocontraception I – PZP (2) <ul><li>Benefits: </li></ul><ul><li>Highly effective (80-100% in WTD), lasts 1-3 years, reversible </li></ul><ul><li>Negative side effects rare/minor, </li></ul><ul><li>Cannot pass through food chain (biodegradable) </li></ul><ul><li>Species-specific, specific to ovary </li></ul><ul><li>Requires smaller volumes than steroid treatments </li></ul><ul><li>Can be remotely delivered, without capturing </li></ul><ul><li>If pregnant: does not interfere with pregnancy/offspring health; treated females produce fewer fawns </li></ul><ul><li>Pregnancy in Yr 1 does not affect effectiveness in following year </li></ul>
  12. 12. Immunocontraception I – PZP (3) <ul><li>Disadvantages: </li></ul><ul><li>Estrus not inhibited: ↑ # of cycles + extended mating season </li></ul><ul><li>Question of long-term treatment effects - more studies needed </li></ul><ul><li>Forms using multiple inoculation system are difficult/impractical </li></ul><ul><li>Substantial ↓ in population may need high (50-90%) proportion of sterilized females </li></ul><ul><li>Concern for fawns born later due to the extended breeding season: survival rate compromised by winter season? </li></ul>
  13. 13. Immunocontraception II – GnRH <ul><li>GnRH is produced by the hypothalamus and controls release of hormones that control ovary function (females) and testes (male). </li></ul><ul><li>Critical to normal function of fertility systems </li></ul><ul><li>Anti-GnRH vaccine induces antibodies that prevent GnRH from binding with its receptors on the pituitary </li></ul><ul><li>Reduces active GnRH levels circulating in blood = ↓ released of reproductive hormones, FSH and LH = infertility. </li></ul>From https://secure.pharmacytimes.com/ lessons/images/200410-03/20041003f2.jpg
  14. 14. Immunocontraception II – GnRH (2) <ul><li>Benefits: </li></ul><ul><li>Highly effective ( 88% efficacy), reversible </li></ul><ul><li>Lack of adverse side-effects </li></ul><ul><li>Inhibits estrus cycles and testicular function </li></ul><ul><li>Treated females produce fewer fawns </li></ul><ul><li>Disadvantages: </li></ul><ul><li>May alter health and/or behaviour </li></ul><ul><li>Variability (efficacy < 100%) likely due to individual variation (immunocompetence) </li></ul><ul><li>If oral vaccine is developed, must be species-specific </li></ul>
  15. 15. Conclusion: Present status of methods <ul><li>There are many non-lethal methods that have had varied results when applied to wild WTD </li></ul><ul><li>PZP , GnRH vaccines have shown the most promise and are being actively developed and tested </li></ul><ul><li>Specific vaccines produced: </li></ul><ul><ul><ul><ul><li>SpayVac® (PZP) </li></ul></ul></ul></ul><ul><ul><ul><ul><li>GonaCon™ (GnRH) </li></ul></ul></ul></ul>From http://en.wikipedia.org/wiki/White-tailed_deer
  16. 16. Conclusion (2) <ul><li>Fraker et al. (2002) and Locke et al. (2007): </li></ul><ul><ul><li>SpayVac® administered once </li></ul></ul><ul><ul><li>100% contraceptive efficiency </li></ul></ul><ul><ul><li>2 to 3 year period </li></ul></ul><ul><li>BUT SpayVac® is no longer available despite its success, leaving attention to other vaccines </li></ul>From http://terramar.bc.ca/
  17. 17. Conclusion (3) <ul><li>Miller et al. (2008): </li></ul><ul><ul><li>GonaCon™ administered once </li></ul></ul><ul><ul><li>>79% contraceptive efficiency over 5-year period </li></ul></ul><ul><ul><li>Note: it is a project of the U.S. Department of Agriculture’s Wildlife Services’ National Wildlife Research Center </li></ul></ul><ul><ul><li>For more information and the factsheet: </li></ul></ul><ul><ul><li>http://www.aphis.usda.gov/wildlife_damage/nwrc/research/reproductive_control/gonacon.shtml </li></ul></ul>
  18. 18. References Specific articles mentioned: Fraker et al. 2002. Long-lasting single-dose immunocontraception of feral fallow deer in British Columbia. Journal of Wildlife Management 66(4) : 1141-1147. Locke et al. 2007. Effectiveness of Spayvac ® for reducing white-tailed deer fertility. Journal of Wildlife Diseases 43(4): 726-730. Miller et al. 2008. The single-shot GnRH immunocontraceptive vaccine (GonaCon™) in white-tailed deer: comparison of several GnRH preparations. American Journal of Reproductive Immunology 60(3) : 214-223. Muller, L.I., R.J. Warren, and D.L. Evans. 1997. Theory and practice of immunocontraception in wild mammals. Wildlife Society Bulletin 25(2) : 504-414. Information was extracted from the report, “White-tailed deer ( Odocoileus virginianus ) in the Sifton Bog of London, Ontario, Canada: A preliminary report reviewing non-lethal management methods and common (mis)perceptions”, written by E. Gerrow and submitted to AWAC on December 8, 2008.

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