Reptile Conservation The Crisis Contributing Factors Halfway Technologies?
Conservation Biology Termed a crisis discipline Often the declines are occurring Ecological triage First steps Where is the species distributed? How many do we have? What habitats do they use? Is there anything we can feasibly do?
Reptile Conservation The Crisis Contributing Factors Halfway Technologies?
Crocodilians (23 Species) Least Concern 43% Extinct in the Wild 0% Extinct 0% Critically endangered 22% Endangered 9% Data Deficient 4% Near Threatened 0% Low Risk 9% Vulnerable 13%
Squamates (1,148 Species**) Critically endangered 4% Endangered 8% Vulnerable 12% Low Risk 0% Extinct 1% Near Threatened 7% Extinct in the Wild 0% Least Concern 53% Data Deficient 15%
Chelonians ( 212 Species) Data Deficient 5% Least Concern 9% Extinct 3% Extinct in the Wild 0% Critically endangered 12% Endangered 22% Near Threatened 20% Low Risk 0% Vulnerable 29%
Here At Home (60 Species) Endangered (11) Apalone mutica* Clemmys guttata Elaphe emoryi Emydoidea blandingii* Kinosternon flavescens Macrochelys temminckii Masticophis flagellum Necturus maculosus* Nerodia fasciata Pseudemys concinna Sistrurus catenatus *Denotes changes recommended for the next listing cycle Threatened (9) Clonophis kirtlandi Crotalus horridus Heterodon nasicus Nerodia cyclopion Nerodia erythrogaster neglecta* Tantilla gracilis Terrepene ornata* Thamnophis sauritus Tropidoclonion lineatum Need of Conservation (4) Farancia abacura Kinosternon subrubrum Opheodrys vernalis Ophisaurus attenuatus
Major Life History Traits Delayed maturity Long-lived Slow growth High adult survival Low juvenile survival Only ever known from four populations Two populations are extirpated Habitat destruction NE Illinois = urbanization Habitat degradation One population is large second is small Small population dynamics Both in the same watershed Clemmys guttata
Major Life History Traits Moderate maturity Moderately lived Moderate growth Unknown adult survival Unknown juvenile survival Restricted range On the western range limit Habitat destruction St. Louis = urbanization Cultivation Small population sizes??? Elaphe emoryi
Emydiodea blandingii Major Life History Traits Delayed maturity Long-lived Slow growth High adult survival Low juvenile survival Once common through out Illinois Habitat Destruction NE Illinois = urbanization Central Illinois = cultivation Many small fragmented populations High adult mortality Few populations are large
Kinosternon flavescens Major Life History Traits Delayed maturity Long-lived Slow growth High adult survival Low juvenile survival Specialized habitat sand ponds Relict populations Once widespread in west central Illinois Few populations and individuals remain Habitat Destruction Cultivation
Macrochelys temminckii Major Life History Traits Delayed maturity Long-lived Slow growth High adult survival Low juvenile survival Specialized habitat swamps and deep waters Northern range limit Never really common in Illinois No known populations
Masticophis flagellum Major Life History Traits Moderate maturity Moderately lived Moderate growth Unknown adult survival Unknown juvenile survival Restricted range On the western range limit Has not been found in Illinois in decades Only from one site
Major Life History Traits Moderate maturity Moderately lived Moderate growth Unknown adult survival Unknown juvenile survival Restricted range On the limit Has not been found in Illinois in decades Only from one site Nerodia fasciata
Pseudemys concinna Major Life History Traits Delayed maturity Long-lived Slow growth High adult survival Low juvenile survival Northern range limit Restricted to the southern collar counties New sites keep cropping up Habitat destruction Cultivation Levee construction Wetland drainage in floodplains
Sistrurus catenatus Major Life History Traits Moderate maturity Moderately lived Fast growth Low adult survival High juvenile survival?? Once wider distributed Wet prairie habitat 3 populations left Only one is large
Reptile Conservation The Crisis Contributing Factors Halfway Technologies?
Six Significant Threats Habitat Loss and Degradation Introduced Invasive Species Environmental Pollution Disease Unsustainable Use Global Climate change
Habitat Loss in the US Alteration of Coastal Plain Carolina bay wetlands has reduced essential habitat Black swamp snakes (Seminatrix pygaea) Eastern green water snakes (Nerodia floridana) Chicken turtles (Deirochelys reticularia) Bogs in the eastern United States Bog turtles (Clemmys muhlenbergii), Dammed or channelized rivers Map turtles (Graptemys) For most wetland species many habitats are used Must protected wetlands and surrounding habitat
Invasive Species Cats and mongooses extirpated insular lizard species Tuataras are declining because of introduced rats Feral pigs have caused a decline in Galapagos tortoise Brown Anoles caused declines of native anoles Brown Tree Snakes caused declines and extirpations of lizards Fire ants caused the extirpation of the Texas Horned lizard The Desert and Gopher tortoises threatened by nonnative plant species
Environmental Pollution Genetic damage in Slider Turtles exposed to metal and radioisotopes At contaminated sites turtles accumulate contaminants Sex reversal and abnormal gonads found in turtles due to PCBs Male American Alligators in contaminated lake had significantly reduced plasma testosterone levels and permanent gonadal alterations Water snakes (Nerodia fasciata) from coal ash polluted wetlands have high level of metal contaminates and thus higher metabolic rates
Disease Upper respiratory tract disease Contagious respiratory ailment Caused by the bacterium Mycoplasma agassizii Potential cause of population declines in Desert and Gopher tortoises Shell diseases Cutaneous dyskeratosis affects the shell and thickened forelimb scutes of Desert Tortoises Emaciation and lesions of the plastron of the Flattened Musk Turtle Viral fibropapillomas impair vision, locomotion, and feeding ability in seas turtles Ophidian Paramyxovirus Caused near total losses in some zoo populations Unknown how the virus effects wild populations
Unsustainable Use Asian Turtle Crisis Used a a food resource Exported to Chinese markets for medicinal remedies Turtles can no longer be found in the wild in Vietnam Records indicate China receives thousands of tons of turtles per year Turtles from some US states are now exported to China Sea Turtles Global population of nesting Leatherback Sea turtles declined from 115,000 in 1980 to 34,500 in 1995 Illegal harvesting of adults and eggs Over-collecting of Snakes The Ocellated Montane Viper has been removed from the wild for the pet trade in large numbers Several boa and python species have declined because of harvest Rattlesnake roundups have caused devastating effects on all species of rattlesnakes in the US as well as desert tortoises
Global Climate Change Climatic changes could reduce or eliminate specialized ecosystems and their suites of species Effects on freshwater turtle species are enhanced juvenile growth rates, earlier ages at maturity, and shifts in functional sex ratios Greatest impact on species with TDSD
Reptile Conservation The Crisis Contributing Factors Halfway Technologies?
Approaches to Conserving Biodiversity Resource Management Approach Associated with game and fisheries management Relies on high-tech solutions Heavy reliance on manipulation of species and habitats Establishing food plots Herbicides for controlling vegetation Increase targets population sizes via RRTs, captive rearing, headstarting Goal is to increase the numbers of the target species regardless of the direct or indirect effects on non-targets
Approaches to Conserving Biodiversity Conservation Biology Approach Largely non-manipulative Relies minimally on high tech solutions Emphasizes Ecosystem functionality Monitoring ecosystem and population processes Maintaining viable populations Data is gathered to make informed decisions Manipulation may be considered but the goal is to restore natural processes
The Halfway Technologies Traditional manipulative programs work for game species Debatable for non-game species A halfway technology is one that addresses the symptoms of the problem and gives the appearance of success Costly and largely ineffective
RRT Programs Release, Repatriation, Translocation Concept: Moving organisms from one place to another where they occur Problems: Moving an organism out of its home range results in an increased mortality rate Adults that have established patterns of space use should never be moved Distance is an issue Unknown if it will work with naïve individuals No monitoring of success!!!
RRT Programs in Turtles Herman s Tortoises 850 individuals repatriated in France From 1985 1988 No monitoring Radiated Tortoises 165 individuals Moved to a different reserve in Madagascar Early 1990 s No Monitoring
You guessed it Sauga RRT Wisconsin Release snakes in the Summer and Fall Fall 7 adult 8 subadult Summer 16 subadult Monitored via radiotelemetry Summer snakes Greater movement Larger home ranges Increased Mass Mortality 0 before hibernation 7 during hibernation Fall Snakes Lesser movement Smaller home ranges No mass gain Mortality 5 before hibernation 8 during hibernation 1 shortly after hibernation 93% Mortality Mortality comparison Through hibernation Fall 87% Summer 50%
Species Introductions Not very common but may be looked toward as species become locally extirpated Concept: Release the species back into a site from which it was extirpated or a new area that has similar habitat Problems: We may not know what the cause of the decline was thus we are releasing them back into the vortex Unknown if the habitat we chose is correct To work requires a sustained effort
Introductions in Turtles Aldabra Tortoise Sychelles Islands 1978 1982 250 moved to start a new colony By 1990 117 remained New colony not established Alligator Snapping Turtle Illinois Early phases Initially planned to just release 20 30 turtles across five sites Initial monitoring was going to be done by CREEL survey
Headstarting Common practice for turtle conservation Concept: Raise turtle to larger sizes to escape size specific mortality Release them back into the wild Problems: Turtle life histories are built for high juvenile mortality Best bet is to maintain protection of mature adults Unknown if survival is actually enhanced Unknown if there are behavioral problems Will not work with all herp life histories or if it does will need to be long-term
Head-starting Programs in Turtles Blanding s turtles DuPage County Last decade Gravid females are injected with oxytocin and eggs incubated Scant information on followup Populations are still declining No measure of success Hawksbill Sea Turtle Palau Islands 1982 1991 2,364 released 7 recaptured Project failed
Consider the Life History Turtles Longevity High adult survival Low juvenile survival Delayed sexual maturity Study Kemp s Ridley and Yellow Mud Turtle Head-starting actions are unlikely to help When subadult and adult mortality is increased headstarting is ineffective Action focused on the first year are not treating the symptom
Head-starting Programs in Snakes Plains Gartersnake Ohio Two groups of head started snakes 1995-1996 and 1999 Worst case scenario was no worse than natural situations Best case scenario offered a 5-6 time increase in survival Suffered from small sample sizes of wild snakes from comparison One head-start year was bad one was good