Download Andrew Lentini Captive Massasauga Populations

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.