Imagine the human population dwindling because pregnant women are unable find a hospital suitable to deliver their babies; and when they finally do find such a hospital, it requires lengthy travel and the mothers run the likelihood of being run over or eaten along the way. This is what Blanding’s turtles are experiencing. Their traditional nesting habitats are becoming frequently unsuitable and the female turtles crawl great distances to nest, risking death at the hands of predators and motor vehicles (American Forests). As natural wetlands undergo more and more suffering, habitat management and restoration become more and more essential for the survival of this rare species. Zara Dowling, Tanessa Hartwig, Erik Kiviat, and Felicia Keesing conducted research on this necessary habitat management in New York, where Blanding’s turtles are listed as “threatened” (Hudsonia Ltd.). Of the three management methods that were studied for success and cost-effectiveness, tilling the nest plots proved to be more favorable than mowing or weeding.
Blanding’s turtles spend the majority of their time in wetlands, but require loamy soil with sparse vegetation for nesting. Breeding females are put in excessive danger when they are required to make long travels, often across highways, from their living habitat to their nesting habitat (American Forests). Habitat fragmentation and degradation, along with wetland loss, force this danger upon the female turtles. Having appropriate nesting sites adjacent to wetlands would eliminate much of the Blanding’s turtles’ risks.
In 1996 and ’97 in LaGrange, New York, a Blanding’s turtle habitat site was constructed by Hudsonia Limited. This artificial habitat was used to make up for habitat and nesting areas that were lost during the expansion of Arlington High School (Hudsonia Ltd.). Dowling, Hartwig, Kiviat, and Keesing chose this to be the site of their research. They implemented their treatment techniques on eight different breeding sites where turtles were known to have successfully nested in the past. Three plots, one 5 m x 7 m area for each management method, were created at each site. The researchers studied treatment costs along with the preferences of ten female turtles in 2006 and in 2008.
The nesting sites had all been treated with hand-weeding in the past. 90% of vegetation was removed, creating usable nesting ground. Weeding created successful nest sites in previous years, but the plots were susceptible to overgrowth and required large amounts of costly labor and management, making it the most expensive of the three techniques (Ecological Restoration). Weeded plots were implemented in the study to determine whether the turtles truly prefer this treatment or if they only nested in those plots because no mowed or tilled areas were available. During the two years of study, only one turtle nested in a weeded plot. Researchers were undoubtedly thrilled to discover that Blanding’s turtles do not have expensive taste.
Mowing was found to be the most efficient management method; however, equipment expenses make it less cost-effective than tilling (Ecological Restoration). In the eight mowed plots, a high brush mower was used to cut all vegetation to a height of 5 cm. Research showed that only two turtles out of both years chose to nest in mowed plots.
The remaining plots were tilled completely to the typical nest depth of 15 cm. Twelve females of the twenty studied in 2006 and 2008 nested in tilled plots. This indicates a strong preference of Blanding’s turtles for tilled nest sites. Because of the small sample size and consequential risk of error, it is hard to say whether the difference in turtles that chose tilled plots vs. other managed sites is significant (Ecological Restoration). However, the cost-effectiveness of tilling would make it the best technique even if the turtles’ preference isn’t significant.
Three techniques of nesting management were studied, but only one stands out among the rest. Plot tilling seems to have earned the favor of female Blanding’s turtles and researchers alike. The tilled areas were not only the most popular nesting sites, but also the least expensive to maintain. The turtles have a pressing problem, and scientists have found a suitable solution with a win-win outcome: safe nests for Blanding’s turtles and full wallets for plot management teams.
Blanding’s turtles spend the majority of their time in wetlands, but require loamy soil with sparse vegetation for nesting. Breeding females are put in excessive danger when they are required to make long travels, often across highways, from their living habitat to their nesting habitat (American Forests). Habitat fragmentation and degradation, along with wetland loss, force this danger upon the female turtles. Having appropriate nesting sites adjacent to wetlands would eliminate much of the Blanding’s turtles’ risks.
In 1996 and ’97 in LaGrange, New York, a Blanding’s turtle habitat site was constructed by Hudsonia Limited. This artificial habitat was used to make up for habitat and nesting areas that were lost during the expansion of Arlington High School (Hudsonia Ltd.). Dowling, Hartwig, Kiviat, and Keesing chose this to be the site of their research. They implemented their treatment techniques on eight different breeding sites where turtles were known to have successfully nested in the past. Three plots, one 5 m x 7 m area for each management method, were created at each site. The researchers studied treatment costs along with the preferences of ten female turtles in 2006 and in 2008.
The nesting sites had all been treated with hand-weeding in the past. 90% of vegetation was removed, creating usable nesting ground. Weeding created successful nest sites in previous years, but the plots were susceptible to overgrowth and required large amounts of costly labor and management, making it the most expensive of the three techniques (Ecological Restoration). Weeded plots were implemented in the study to determine whether the turtles truly prefer this treatment or if they only nested in those plots because no mowed or tilled areas were available. During the two years of study, only one turtle nested in a weeded plot. Researchers were undoubtedly thrilled to discover that Blanding’s turtles do not have expensive taste.
Mowing was found to be the most efficient management method; however, equipment expenses make it less cost-effective than tilling (Ecological Restoration). In the eight mowed plots, a high brush mower was used to cut all vegetation to a height of 5 cm. Research showed that only two turtles out of both years chose to nest in mowed plots.
The remaining plots were tilled completely to the typical nest depth of 15 cm. Twelve females of the twenty studied in 2006 and 2008 nested in tilled plots. This indicates a strong preference of Blanding’s turtles for tilled nest sites. Because of the small sample size and consequential risk of error, it is hard to say whether the difference in turtles that chose tilled plots vs. other managed sites is significant (Ecological Restoration). However, the cost-effectiveness of tilling would make it the best technique even if the turtles’ preference isn’t significant.
Three techniques of nesting management were studied, but only one stands out among the rest. Plot tilling seems to have earned the favor of female Blanding’s turtles and researchers alike. The tilled areas were not only the most popular nesting sites, but also the least expensive to maintain. The turtles have a pressing problem, and scientists have found a suitable solution with a win-win outcome: safe nests for Blanding’s turtles and full wallets for plot management teams.
Sources:
“Experimental Management of Nesting Habitat for the Blanding's Turtle”
Zara Dowling, Tanessa Hartwig, Erik Kiviat, and Felicia Keesing
Ecological Restoration, June 2010
http://ehis.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=4&hid=101&sid=56c3e71e-f809-4e14-85f2-e7bb95c63410%40sessionmgr111
“The Turtle Trackers”
American Forests, March 2006
http://ehis.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=4&hid=101&sid=60596bed-c9a0-43e0-aaee-1ff04f70f0e8%40sessionmgr113
“Blanding’s Turtle”
Hudsonia Ltd.
http://hudsonia.org/programs/conservation-ecology/blandings-turtle/
Image:
Dan Thompson
http://chicagowildernessmag.org/issues/summer2005/blandingsturtle.html
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