Writing 20: Conservation of Biodiversity
Dr. Stephanie Jeffries
Cracking the Shell
One of the smallest species of turtle in the world, the bog turtle faces severe
population declines throughout the eastern United States. As a result, in 1997 the U.S.
Fish and Wildlife Service added the bog turtle to its list of threatened species (Morrow
and others 2001). According to the Endangered Species Act of 1973, the bog turtle’s
status as a threatened species indicates that it will most likely become endangered in the
“foreseeable future” (Introduction…2001). The fact that bog turtle populations in
Maryland exhibited a 43% slump over a 15-year period legitimizes this claim (Morrow
and others 2001). The article “Habitat Selection and Habitat Use by the Bog Turtle
(Clemmys muhlenbergii) in Maryland” describes an extensive study conducted by Jessica
L. Morrow, James H. Howard, Scott A. Smith, and Deborah K. Poppel to gather more
information on this dwindling creature. By analyzing the bog turtle’s habitat, the study
has further identified potential causes of the species’ endangerment and also has proposed
methods for conservation. Although the investigation did not test the decline of the bog
turtle population, the information gathered reveals the ideal living conditions necessary to
maintain a steady bog turtle population.
Even if extinction is not an imminent threat, endangerment looms in the bog
turtle’s future. The article specifies numerous threats that account for the depletion of
populations in Maryland and elsewhere in the United States. Among the most harmful
include increased plant succession in the habitat and a lack of animal grazing (Morrow
and others 2001). The advent of harmful plants to the environment has had obvious
effects on the bog turtle’s habitat. Taller plants have reduced open areas vital for bog
turtle nesting and basking. In addition, these plants absorb moisture from the ground, thus
affecting the damp environment necessary for a bog turtle’s habitat. The purpose of this
study is to differentiate those aspects of the habitat the bog turtle employs from those that
are detrimental. Consequently, more effective conservation practices can be determined.
The scientists observed the habitats of 54 bog turtles in two different sites from
April 1996 to August 1997. The two privately owned sites in Harford County varied
greatly in size and vegetation (Morrow and others 2001). Site A was about ten times
larger than Site B, encompassing a 2.0-hectare (20,000 m2) area. After recording the size,
sex, and age of each turtle, the scientists fashioned transmitters to each turtle’s shell for
monitoring movement. By dividing the year into mating, nesting, postnesting, and
hibernation seasons, the researchers were able to evaluate habitat use over time.
The results of the study revealed vital information about suitable living conditions
for the bog turtle. As for ground cover components, the bog turtles in both sites preferred
water, arrowhead, and sedges (Morrow and others 2001). Also, composed of a mat of
grass and dry vegetation, tussock-like plants provided an ideal setting for turtle nesting,
basking, and protection. However, turtles avoided berries, vines, woody plants, and
exotic plants such as the Japanese honeysuckle. Florae in this category were too tall or
sparse, leaving the bog turtles susceptible to predators and the environment as a whole.
Researchers in both sites found that exotic and woody vegetation had a consistently low
impact on the bog turtles’ lives and even detracted from the viability of the habitat. Not
only unused, these plants reduce groundwater through absorption, affecting the muddy
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environment vital for turtle survival. In addition, the canopy created by taller vegetation
minimizes sunlight, making the crucial process of thermoregulation in these cold-blooded
creatures much harder. Having differentiated between the beneficial and detrimental, the
researchers now understand which plants must be removed as well as those whose growth
should be stimulated in the bog turtle’s habitat.
Possessing a greater knowledge of the ideal bog turtle environment, the scientists
expanded upon four existing conservation strategies proposed by Lee and Norden in 1996
(Morrow and others 2001). Included among these methods are breeding programs,
private land acquisition, population monitoring, and the physical manipulation of the
turtle’s habitat. The information gathered by Jessica Morrow and her team of researchers
reveals strengths and weaknesses to these proposals. The article does not address
breeding as a means for stimulating population growth, but there is clear potential in this
strategy if the correct conditions can be achieved. Private land acquisition will be
difficult, however, because 97% of bog turtle sites occur on private plots. There are
simply not enough turtle populations on protected public sites to support the species.
Without the consent of private landowners, bog turtles will continue to die off. Other
techniques such as relocation of existing populations can be researched, but the success
of such a strategy is questionable. The researchers in this article support the strategy of
population monitoring by use of transmitters. Nevertheless, this strategy only provides a
passive glimpse at the demise of the bog turtle. Instead, concrete steps need to be taken
before this species can comfortably exist in large numbers. The manipulation of the
turtle’s habitat is an example of active conservation tactics. The study has shown that
exotic and woody plants are detrimental to the bog turtle’s existence. As a result,
“practices such as prescribed burns, selective removal of [these] plants, and moderate
animal grazing” can be employed (Morrow and others 2001). However, further research
is necessary to test the effects of fires on the turtles’ wellbeing. Also, it is difficult to
control those plants the livestock choose to eat. Clearly, an explicit plan for bog turtle
conservation remains to be found.
Although this species remains largely unimportant in the public eye, measures
must be taken to reverse the depletion of bog turtle populations. An ecosystem is a
delicate, living entity, and each organism is vital for its survival. Losing bog turtles seems
insignificant, but these reptiles contribute to the stability of their habitat. This study has
definitely contributed to the conservation of the bog turtle, but further studies need to be
conducted in additional populations to assess a definite plan for the survival of this
threatened species.
Reference List
[1] Bog Turtle, Clemmys Muhlenbergii. 2001 [cited 2008 Sept 7] . In: Guide to
Federally Listed Endangered and Threatened Species of North Carolina [publication
on Internet]. Raleigh (NC): The North Carolina Natural Heritage Program. Pp. 35.
Available from: http://www.ncnhp.org/Pages/guide.htm
[2] Introduction: Definition of Legal Status. 2001 [cited 2008 Sept 7]. In: Guide to
Federally Listed Endangered and Threatened Species of North Carolina [publication
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on Internet]. Raleigh (NC): The North Carolina Natural Heritage Program. Pp. 1-2.
Available from: http://www.ncnhp.org/Pages/guide.htm
[3] Morrow JL, Howard JH, Smith SA, Poppel DK. 2001. Habitat Selection and Habitat
Use by the Bog Turtle (Clemmys muhlenbergii) in Maryland. Journal of
Herpetology 35(4): 545-552.
Dear S,
I thought you did a great job explaining what the researchers did and connecting the
study to the conservation of the species. There are a few places I pointed out that are
unclear or contradictory. In your writing, you want to make every sentence count, and
strive for absolute clarity. You may not have needed to discuss the four conservation
strategies at the end, only those that were relevant to the point you were going to make. I
liked this section though, too, because your own voice was evident.
Overall, I think that this review breaks the paper down effectively for your journal club
and will be helpful in evaluating some of the conservation strategies.
If you have questions about your assignment or my comments, please let me know.
Cheers,
SBJ
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