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Blanding’s Turtle (Emydoidea blandingii) Conservation and Educational Efforts in a Portion of Wisconsin Affected by Suburbanization.
Jonathan Zellmer ; 808 West Blodgett Street ; Marshfield, WI 54449
60 to 90 DAYS
EGG INCUBATION.
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Slow Growth = Slow Recovery.
Blanding’s turtle populations that lose adult females can expect a slow recovery or continued population declines because of slow growth rate of juveniles and reduced number of reproductive females.
Introduction Blanding’s turtles have been studied at McMillan Marsh Wildlife Area (MMWA) during past 20 years through voluntary effort and
funding. The most notable feature affecting MMWA and its
Blanding‘s turtle population is the close proximity to city of Marshfield, WI. Suburbanization has been occurring adjacent
to MMWA and its Blanding’s turtle population.
The perimeter of this poster depicts a flowing cycle of
Blanding’s turtle life - through time – from procreation toward
the repeating of this process, in order to reproduce another
generation of Blanding’s turtles. Embedded in this depicted cycle around perimeter of poster are hazards that can have a
devastating affect on a Blanding’s turtle population – namely
loss of adult turtles and loss of neonates. The loss of adult
Blanding’s turtles combined with slow growth rate of young Blanding’s turtles can cause population declines to be much more drastic than declines in other faster reproducing wildlife
populations.
MMWA provided good habitat for Blanding’s turtles in the distant past. However, during recent years the suburban
development of lands adjacent to MMWA’s public lands grew rapidly, during the 1980s and 1990s. Suburban development
has produced a partially positive impact by providing nesting
habitat through introduction of road shoulders in an area that
has poor soil type for turtle nesting success - too much clay
content in this area’s soil. However, this one positive impact of additional nesting habitat through new road construction brings
many negative consequences. The fragmentation of land with
roads and improvement of road surfaces caused traffic speed
and frequency to increase adjacent to MMWA, which has
contributed to the road mortality of many adult female
Blanding’s turtles during nesting season. Throughout this period of increased suburbanization of lands adjacent MMWA
Blanding’s turtles were protected in writings of WI Threatened and Endangered Species Law, but habitat that Blanding’s Turtles need to survive is not protected by writings in this law.
One of the most regularly used nesting habitats at MMWA was
an abandoned railroad grade. The railroad grade was formally
converted to a bicycle trail with little consideration for protecting
this important Blanding’s turtle nesting habitat. After railroad grade was converted to bicycle trail, and bicycle trail surface
was heavily compacted, Blanding’s turtle nesting activity declined on this railroad grade. This loss of nesting habitat
caused Blanding’s turtles to wander further from wetlands and increased nesting along road shoulders of suburbia adjacent
MMWA. The road shoulders provided positive benefit of
needed nesting habitat with fatal consequence of motor
vehicles destroying many adult female turtles during nesting
seasons.
The protection of habitat should be a legal responsibility of
public agencies, especially for protection of threatened or
endangered species.
Methods An intensive search effort to locate and identify adult female
Blanding’s turtles and nesting sites was conducted in 1995 and 1996.
In June of 1999, eggs were collected for a Blanding’s turtle headstarting program at MMWA.
Blanding’s turtle nests were protected with wire mesh protection devices from 2008 - 2011. This effort was accomplished with
assistance from trained volunteers, all of whom lived in
suburban areas adjacent MMWA. Blanding’s turtle nests that were protected from 2008 - 2011, were each carefully
excavated and nest contents examined after incubation time
period was completed.
In only 2010 and 2011, failed eggs were collected and
dissected to examine for signs of embryo development. The
eggs that failed to hatch and any dead neonates were
collected. This investigation of nests was done to determine
success of egg development in various habitats at MMWA,
which were primarily trail corridors, old railroad grade and road
shoulders.
Turtle crossing signs were installed along busy roads to warn
motorists of turtle crossing activity.
Public Agencies
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? ?
Acknowledgements Special Thanks, go to Thomas Prebble, Elisa Prebble and family
for their many efforts with protecting Blanding’s turtles and turtle nests. Thanks also go to McMillan Township and volunteers who
helped to protect Blanding’s turtles. Bob Hay, et al. for technical support.
Literature Cited Partners in Amphibian and Reptile Conservation, http://parcplace.org/ . International Union for Conservation of Nature, http://www.iucn.org/ . Turtles of the United States and Canada. Carl H. Ernst et al. Blanding’s Turtle ( Emydoidea blandingii ): A Technical Conservation Assessment, Congdon, J.D. and D.A. Keinath (2006, July 20). U.S Fish and Wildlife Service http://www.fws.gov/ . WI DNR, http://dnr.wi.gov/topic/EndangeredResources/ .
Discussion The development of a conservation program should have been
started by public agencies prior to any noticeable decline in
adult Blanding’s turtles. The Blanding’s turtle is not a species to be managed through reactionary management tactics. The
loss of adults, juveniles and neonates is much more
devastating to Blanding’s turtle populations than to wildlife populations with rapid reproduction and physical growth.
Public agencies were not acting in the best interest of the public
in allowing development that was detrimental to long-term
health of both the Blanding’s turtle population and MMWA. The long-term security of these publicly entrusted natural resources
was given lower status than the short-term gains of a small
segment of society.
Land use decisions within or adjacent to MMWA should be
guided with respect to long-term security of publicly entrusted
natural resources.
Conclusion Turtles, chelonians as a whole, are currently considered the
world’s most endangered group of vertebrates, with over half of the 300 chelonian species being threatened with extinction.
Turtles have population traits and physical characteristics that
place them at more risk of population declines than birds,
mammals, amphibians and other reptiles.
The Blanding’s turtle population at MMWA is currently threatened with habitat fragmentation/loss, road mortality,
agricultural mortality, nest destruction, reduced wetland
protections, pet trade, diseases and climate related changes –
these could all have a combined detrimental effect on
endangerment of long-term existence.
Blanding’s turtles are a flagship species for use in wetland conservation and educational efforts. The ecological needs of
Blanding’s turtles are a living educational tool for protecting healthy connections between wetlands and surrounding
habitats, but only if people are willing to accept their value to
society.
The Blanding’s turtle is an excellent wildlife species for proving and improving competency of natural resource management
agencies.
Hopefully, Blanding’s turtles will receive the respect and attention that will provide the most possible benefits to future
generations of people and wildlife.
Results There were 94 adult female turtles identified through a carapace
notching method during 1995 and 1996 nesting seasons.
In June of 1999, 148 eggs were collected for a Blanding’s turtle headstarting program at MMWA. There were 111 hatchlings
produced from eggs by artificial incubation efforts conducted by
WI-DNR, Bob Hay. These Blanding’s turtle hatchlings were released by 5th Graders and Cub Scouts at locations near original
nest sites.
There were 84 Blanding’s turtle nest sites protected in and adjacent MMWA by volunteers, from 2008 - 2011. These nests
were each investigated and contents recorded after 100 days of
incubation. The failed eggs found during 2010 and 2011 were
dissected and egg contents recorded. Hatchlings found fully
developed but trapped in nest contents were released into
adjacent habitat.
PROCREATION. AQUATIC HABITAT. UPLAND HABITAT. SUBURBAN HABITAT. HUMAN INTERACTION. ROAD MORTALITY.
NESTING.
NEST PREDATORS.
NEST PROTECTION.
HATCHLING EMERGENCE. LOSS of PROTECTION. HATCHLING STRUGGLES. JUVENILE STRUGGLES.
Unsuitable nesting habitat. Egg collection.
Headstarting hatchlings. Nest investigation.
Abnormally shaped eggs.
Infertile egg. Failed embryo development.
Deceased neonate and roots.
Road Mortality. Soil Compaction. Nest Predators.
Turtle crossing signs that were installed to help protect
Blanding’s turtles on roads from motorists - were stolen shortly
after being installed.
Healthy hatchling. Healthy adult.
Proactive conservation effort should be required of public
agencies to ensure continued existence of MMWA’s Blanding’s turtle population.
Blanding’s turtles are connected to the habitats in and adjacent MMWA, but the language of WI threatened and endangered
species law lacks connection between habitat and habitat’s role in maintaining species health. The foreseeable future of
Blanding’s turtles shows a need for protection because of slow recovery characteristic of this slow growing species and
worldwide declines in turtle populations.
Tarred nest on road shoulder. Real Estate map.
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