The spotted turtle (<i>Clemmys guttata</i>)
and Blanding’s turtle (<i>Emydoidea
blandingii</i>) are two state-endangered species in Indiana whose populations
are in decline. Historically, both species were found across the northern
portion of Indiana in various wetland habitats. There are multiple causes of
population decline for both species, including habitat fragmentation, habitat
loss and degradation, urban development and encroachment, poaching, and road
mortality. Despite efforts to record these species across the state, there has been
no intensive population assessments. Based on this need, I conducted both
visual encounter surveys across the state and used Maximum Entropy (MaxEnt)
modeling to facilitate understanding the current distribution of both species
in Indiana. Twenty-three locations were visited and surveyed in Indiana, with
trapping being conducted at an additional four locations where populations were
known to be larger. Surveys aided in delineation of six populations of
Blanding’s turtles and five populations of spotted turtles. A total of 69
Blanding’s turtles and 70 spotted turtles were observed between surveying and
trapping. Delineated populations were mainly found in the northern third of
Indiana. This data and other occurrences were used to predict suitable habitat
across Indiana. The Blanding’s turtle models were sufficiently resolved to
predict potential localities or potential sites for focused management or
repatriation. Spotted turtle model performance reflected the need for more
samples, but also the likelihood of fewer numbers due to declining habitat
availability. Both Blanding’s turtle and spotted turtle models argue for the
need of more intense survey efforts based on historical occurrences, as well as
restoration efforts across the state. Most models for both species were
observed to have a trend towards suitable habitat in the northern third of the
state, correlating with the results of the survey efforts. The results of this
project indicate that Blanding’s turtle and spotted turtle populations are
still in decline likely due to limited habitat availability.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/7406633 |
| Date | 04 January 2019 |
| Creators | Jessica Hinson (5931170) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Distribution_of_Populations_and_Suitable_Habitat_for_Spotted_Turtles_Clemmys_guttata_and_Blanding_s_Turtles_Emydoidea_blandingii_in_Indiana/7406633 |
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