Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Massasauga Recovery Team. 2006. Third International Symposium and Workshop on Conservation of the Eastern Massasauga, Sistrurus catenatus: Population Viability and Outreach. 2005 October 12-14, Toronto Zoo, Ontario, Canada. www.brocku.ca/massasauga Andrew Lentini Captive Massasauga Populations and Conservation Captive Massasauga Populations and Conservation Andrew Lentini, Toronto Zoo Captive Massasauga Populations and Conservation • Conservation of threatened species and habitats requires multifaceted approaches to be successful. • Preservation of what already exists in situ is important but cannot be considered the only, or even an adequate, strategy for preserving biodiversity (Ayyad, 2003). Captive Massasauga Populations and Conservation • In many cases, particularly with massasaugas in southern Ontario, we are faced with altered and depleted habitats and there is a need to mitigate losses and detrimental changes. • What roles can captive populations play in species conservation? Captive Massasauga Populations and Conservation • American Zoo and Aquarium Association (AZA) recognises that captive populations of threatened species should be managed to complement and improve the success of conservation initiatives. Captive Massasauga Populations and Conservation • There are currently 62 captive massasaugas in twelve AZA zoos (ISIS). • Many of them have well established public education programs and participate in and support field conservation and research. Buffalo: 1.0 Detroit: 3.2 John Ball: 1.1 Philadelphia: 1.0 Rochester: 2.0 Toledo: 3.2 Columbus: 0.0.2 Fort Wayne: 0.1 Milwaukee: 1.1 Racine: 0.1 St. Louis: 1.0 Toronto: 21.17 Captive Massasauga Populations and Conservation Weise et al. (1994) defined four general conservation roles for captive populations in AZA institutions: 2. Support for field conservation projects 3. Local and international education 4. Basic and applied research 5. Long term maintenance of genetic variation for future supplementation of wild populations Captive Massasauga Populations and Conservation • Research using captive populations can guide and help develop recovery actions and adaptive management strategies. • Contributes to the development of technologies and research techniques that will benefit wild populations. • A valuable opportunity to study threatened wildlife without placing wild populations at risk. Captive Massasauga Populations and Conservation AZA Research • Weise et al. (1996): In a four year period AZA institutions and their collaborators published over 1,300 research articles involving a variety of taxa. • Card et al. (1998) reviewed research within the zoo herpetology community over a ten year period – 164 refereed technical papers – 101 non-technical papers – 16 field studies. Captive Massasauga Populations and Conservation Research with captive massasaugas in AZA institutions: • Cooperative project between Milwaukee County Zoo, Wisconsin DNR and USFWS, King et al. (2004). • Used captive born and raised massasaugas. • Developing a repatriation method for this species. Captive Massasauga Populations and Conservation Toronto Zoo’s Massasaugas • Two captive populations of massasauga rattlesnakes that are maintained separately for the recovery of this species. • One is the zoo’s permanent population of snakes (long term captives for exhibit, public outreach/education, etc.) • The other is a population of rescued snakes from Windsor, Ontario. These animals are from a small population threatened with imminent destruction as the result of a residential development project Captive Massasauga Populations and Conservation •Ojibway: Remnant tall grass prairie in Ontario •Threats: Loss of habitat, road traffic and indiscriminate killing Tallgrass Prairie Heritage Park. Ojibway Prairie Provincial Nature Reserve. Captive Massasauga Populations and Conservation •Habitat fragmented by residential development •New roads and fences isolating populations Captive Massasauga Populations and Conservation •New residential development destroyed known hibernacula •Resident snakes were rescue by Ojibway Nature Centre, OMNR, and Recovery Team in 2004 •Transferred to Toronto Zoo Captive Massasauga Populations and Conservation • Two of the rescued rattlesnakes were gravid females and they gave birth soon after arrival. • Commitment of substantial resources (time, space, supplies, $10K/year) to maintain this large group of snakes in isolation. Captive Massasauga Populations and Conservation • This population of rescued massasaugas provides a tremendous opportunity for research. • Two research projects, one in captivity and one in the field, have been proposed for this population. • The first is a proposal to determine the feasibility of head starting (raising rattlesnakes in captivity to maximise growth) as a repatriation strategy, and to assess the utility of repatriation as a conservation management tool in Ontario. Captive Massasauga Populations and Conservation • The goal of this in situ proposal is to return some of the captive born rescued juveniles into a protected area that can support a population of rattlesnakes near Windsor where their progress can be monitored. Captive Massasauga Populations and Conservation • Protected habitat exists in the Ojibway Prairie Provincial Nature Reserve (OPPNR) which had a population of massasauga rattlesnake until the 1970’s. Captive Massasauga Populations and Conservation • The conditions that led to the initial extirpation of rattlesnakes (human persecution, road mortality, and development) in the OPPNR release site have been reversed or mitigated. Captive Massasauga Populations and Conservation • Plans for this repatriation were developed in 2004 and were being implemented in the first few months of 2005. • Included the development of a detailed research project and securing funds to pay for the repatriation, monitoring of the snakes post release, and costs associated with any habitat modifications required. Captive Massasauga Populations and Conservation • Unfortunately, shortly before the planned release in the spring of 2005, the OMNR rescinded the permit for this proposal because of political concerns regarding the impact on public safety of releasing venomous animals in an urban area. Captive Massasauga Populations and Conservation • The proposal is being re-evaluated by OMNR in light of the following specifics provided by the Recovery Team: • Thanks to years of outreach and education work by Ojibway Nature Centre, the public are aware of and mostly supportive of snakes. Captive Massasauga Populations and Conservation • Snakes are already in Windsor and LaSalle neighborhoods. The rescued snakes came from a residential area (one rescued male was 10 meters from existing housing). • Snakes will be returned to an area within the OPPNR (approx 2km from the rescue site) and away from existing houses. Captive Massasauga Populations and Conservation • The release site in the OPPNR is protected and is large enough to support a population of rattlesnakes • Recent surveys show that there are suitable hibernation sites available. • A small mammal survey also shows that there is a prey base present to support released snakes. Captive Massasauga Populations and Conservation • Adaptive management options are available for the method used to return these rehab snakes to Ojibway. • Will monitor released animals and intervene if necessary. Captive Massasauga Populations and Conservation • The second research question that can be investigated using this captive population of rescued snakes relates to the surgically implanted radio telemetry transmitters that will be employed to monitor this group when released. Captive Massasauga Populations and Conservation • Radiotelemetry has proven to be one of the most versatile and important tools in wildlife research in the past 30 years (Millspaugh and Marzluff,2001). Captive Massasauga Populations and Conservation • The surgical implantation of transmitters requires invasive manipulation that may affect the behaviour and health of snakes. • Animal Care Committees and welfare concerns require assessment. • Properly evaluating potential transmitter effects requires the use of control and treatment animals. Captive Massasauga Populations and Conservation • Due to the cryptic nature of massasaugas, a free range group of controls is difficult to find. Captive snakes provide an ideal study group. • To investigate transmitter effects, a lab study has been initiated at Toronto Zoo in collaboration with York University. Captive Massasauga Populations and Conservation • Twenty-four snakes have been randomly assigned to three treatment groups. – Twelve snakes received surgically implanted transmitters in Feb. 2005 (as part of the planned spring repatriation). – Six received a sham operation to separate the effects of the anaesthesia and surgery from the effects of the transmitter. – Six serve as a control. Captive Massasauga Populations and Conservation Behavioral and physiological parameters • Inflammatory processes as a result of infection or the presence of a foreign body • Increased stress which may be reflected in elevated stress hormone metabolite levels in faeces (Young, 2004). Captive Massasauga Populations and Conservation • Activity patterns and position in a thermal gradient chamber are being studied to determine temperature selection. • Potential effects on nutrition are being studied by examining feeding behaviour, growth (weight and length), and bone density. Captive Massasauga Populations and Conservation Assurance Colonies • The fourth of the roles for captive populations identified by Weise et al. (1994), the long term maintenance of genetic variation, comes into play when standard conservation practices are not enough to prevent the extinction of vulnerable populations. • This is particularly true in cases such as the Ojibway rescue where immediate threats could not be mitigated in a timely manner. Captive Massasauga Populations and Conservation • An assurance colony, or any other captive population of threatened wildlife, should not be allowed to become an irrelevant collection of individuals; rather it must be responsibly managed in order to fulfill its conservation mission • AZA uses a systematic and scientific approach to animal breeding programs and population management . Captive Massasauga Populations and Conservation Captive population management can help retain genetic diversity • Strategies – Breeding to increase the carrying capacity of the captive population – Maintaining a balanced sex ratio – Increasing generation time. • In some cases, a well managed captive population contains more genetic diversity than remaining wild population Captive Massasauga Populations and Conservation • Captive breeding for reintroduction may not be an appropriate conservation strategy for all species (Hutchins et al., 1995; Snyder et al., 1997). • Limited space, human and financial resources available for captive breeding programs, mean that it is possible to manage only a small percentage of the number of wildlife species at risk in this manner. Captive Massasauga Populations and Conservation • May be most appropriate to select “flagship” species for captive breeding programmes. • High profile species that will attract public attention and help preserve habitat and other taxa as well as preserve genetic diversity of the target species. Captive Massasauga Populations and Conservation • Due to the limited space available for managed captive breeding populations, a co-operative strategy for managing captive populations needs to be used • There are two strategies employed by AZA members: the Population Management Plan (PMP) and the Species Survival Plan (SSP). Captive Massasauga Populations and Conservation • Both management options provide full scientific analysis and result in recommendations that will benefit the captive population (long term survival and fitness of individual animals). • SSPs have a more comprehensive approach that ensures that captive populations have the best chance of fulfilling their conservation potential. Captive Massasauga Populations and Conservation • SSPs also facilitate recovery of threatened species by collaborating with many partners in situ. • Example: Puerto Rican Crested Toad SSP: cooperation between the USFWS, PRDNR, NGOs and the AZA. • Have published a joint recovery plan for this species. • Combines both captive and in situ actions; a prominent part of the plan is captive propagation for reintroduction. Captive Massasauga Populations and Conservation Politics and conservation • It appears that the setbacks this repatriation has experienced are due to political pressures and not based on scientific or conservation principles. • Communication, outreach, public consultation and support, and diplomacy will all be needed to make the experimental translocation a reality. • We hope that the repatriation will be approved for 2006 and we continue to house these rescued snakes in a quarantine facility at Toronto Zoo. • We also monitor their health status so that the risk of exposing resident wildlife to novel pathogens is minimized. Captive Massasauga Populations and Conservation Politics and conservation • Despite the conservation and scientific merits of an experimental repatriation, the proposed 2006 release might yet be cancelled by the OMNR. • Research into the effects of transmitters was initiated opportunistically since these snakes received the transmitters in preparation for a 2005 release that was later cancelled. This research project with the captive population will be completed. Captive Massasauga Populations and Conservation Politics and conservation • Regrettably however, the opportunity to return rescued wildlife to protected natural habitat where individual animals can contribute to the recovery of this species will have been lost. • Valuable research into repatriation methodology and the value of this technique will not take place. Captive Massasauga Populations and Conservation Conclusion: • Thanks to mechanisms set up by professional zoo associations such as the AZA, captive populations in modern zoos are in a position to assist in recovery of wild populations if given the opportunity. • We hope that the rescued Ojibway massasaugas can play a role in species conservation and serve as a viable and important instrument for species recovery.