Bog turtle
Bog turtle Temporal range: Pleistocene – Recent
Middle | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Testudines |
Suborder: | Cryptodira |
Superfamily: | Testudinoidea |
Family: | Emydidae |
Genus: | Glyptemys |
Species: | G. muhlenbergii
|
Binomial name | |
Glyptemys muhlenbergii (
Schoepff , 1801) | |
Distribution. The range does not extend beyond the Canada–US border.[3][4][5] | |
Synonyms[6] | |
List
|
The bog turtle (Glyptemys muhlenbergii) is a critically endangered
An adult bog turtle weighs 110 grams (3.9 oz) on average. Its skin and shell are typically dark brown, with a distinctive orange spot on each side of the neck. Considered
The bog turtle has a low reproduction rate; females lay one
Taxonomy
The bog turtle was noted in the 18th century by
In 1829,
The genus name was changed to Glyptemys in 2001. The bog turtle and the wood turtle, Glyptemys insculpta, had until then been included in the genus Clemmys, which also included spotted turtles (C. guttata) and western pond turtles (C. marmorata).[13] Nucleotide sequencing and ribosomal DNA analyses suggested that bog turtles and wood turtles are closely related, but neither is directly related to spotted turtles, hence the separation of the genus Glyptemys.[14]
Description
The bog turtle is the smallest species of turtle in North America.
The spotted turtle and painted turtle are similar in appearance to the bog turtle.[20] The bog turtle is distinguishable from any other species of turtle by the distinctively colored blotch on its neck. A major difference between it and the spotted turtle is that the bog turtle has no coloration on the upper shell, unlike the latter species.[21]
Mature male bog turtles have an average length of 9.4 centimeters (3.7 in) while the average female length is 8.9 centimeters (3.5 in) (straight carapace measurement).[19] The males have a larger average body size than females,[22] likely due to sexual selection for larger males in winning and performing the act of mating.[23] The female has a wider and higher shell than the male, but the male's head is squared and larger than a female's of the same age. The plastron of the male looks slightly concave while the female's is flat. The male's tail is longer and thicker than the female's.[24] The cloaca is further towards the end of the tail of the male bog turtle, while the female's cloaca is positioned inside the plastron.[16] Juveniles are very difficult to sex.[25]
Distribution and habitat
The bog turtle is native only to the eastern United States,[nb 1] congregating in colonies that often consist of fewer than 20 individuals.[28] They prefer calcareous wetlands (areas containing lime), including meadows, bogs, marshes, and spring seeps, that have both wet and dry regions.[24][29] Their habitat is often on the edge of woods.[30] Bog turtles have sometimes been seen in cow pastures and near beaver dams.[15]
The bog turtles' preferred habitat, sometimes called a fen, is slightly acidic with a high water table year-round.[31] The constant saturation leads to the depletion of oxygen, subsequently resulting in anaerobic conditions.[32] The bog turtle uses soft, deep mud to shelter from predators and the weather. Spring seeps and groundwater springs provide optimum locations for hibernation during winter. Home range size is sex dependent, averaging about 0.17 to 1.33 hectares (0.42 to 3.29 acres) for males and 0.065 to 1.26 hectares (0.16 to 3.11 acres) for females.[29] However, research has shown that densities can range from 5 to 125 individuals per 0.81 hectares (2.0 acres).[33] The range of the bog turtle extensively overlaps that of its relative, the wood turtle.[23]
Northern and southern populations
The northern and southern bog turtle populations are separated by a 400-kilometer (250 mi) gap over much of Virginia, which lacks bog turtle colonies.[16][34] In both areas, the bog turtle colonies tend to occupy widely scattered ranges.[28]
The northern population is the larger of the two. These individuals make their home in states as far north as Connecticut and Massachusetts, and as far south as Maryland. These turtles are known to have fewer than 200 habitable sites left, a number that is decreasing.[35]
The southern population is much smaller in number (only about 96 colonies have been located),[36] living in the states of North Carolina, South Carolina, Georgia, Virginia, and Tennessee.[16] This area in particular has seen about 90 percent of its mountainous wetlands dry up.[37] The turtles in this population are even more scattered than in the northern population and live at higher elevations, up to 1,373 meters (4,505 ft).[36]
Evolutionary history
There have been only two recorded discoveries of bog turtle fossils. The late J. Alan Holman, a paleontologist and herpetologist, first identified bog turtle plastral remains in Cumberland Cave, Maryland (near Corriganville), which are of Irvingtonian age (from 1.8 million to 300,000 years ago). The second discovery was of Rancholabrean (between 300,000 and 11,000 years ago) shell pieces in the Giant Cement Quarry in South Carolina (near Harleyville), by Bentely and Knight in 1998.[23]
The bog turtle's
Ecology and behavior
Behavior
The bog turtle is primarily
Late September to March or April[40] is usually spent in hibernation, either alone or in small groups in spring seeps.[29] These groups can contain up to 12 individuals, and sometimes can include other species of turtles.[35] Bog turtles try to find an area of dense soil, such as a strong root system, for protection during the dormant period.[20] However, they may hibernate in other places such as the bottom of a tree, animal burrows, or empty spaces in mud.[35] The bog turtle emerges from hibernation when the air temperature is between 16 and 31 °C (61 and 88 °F).[39]
The male bog turtle is territorial and will attack other males if they venture within 15 centimeters (5.9 in) of his position. An aggressive male will crawl toward an intruder with his neck extended. As he approaches his foe, he tilts his carapace by withdrawing his head and raising his hind limbs. If the other male does not retreat, a fight of pushing and biting can follow. The bouts typically last just a few minutes,[39] with the larger and older male usually winning.[22] The female is also aggressive when threatened. She will defend the area around her nest, usually up to a radius of 1.2 meters (3.9 ft), from encroaching females, but when a juvenile approaches, she ignores it, and when a male appears she surrenders her area (except during mating season).[39]
Diet
Bog turtles are
Predators, parasites, and diseases
A host of different animals, including
Bog turtles may suffer from bacterial infections. Aeromonas and Pseudomonas are two genera of bacteria that cause pneumonia in individuals.[43] Bacterial aggregates (sometimes known as biofilms) have also been found in the lungs of two deceased specimens discovered in 1982 and 1995 from colonies in the southern population.[44]
Movement
Day-to-day, the bog turtle moves very little, typically basking in the sun and waiting for prey. Though it is not especially lively on sunny days, the bog turtle is usually active after rainfall.[36] Various studies have found different rates of daily movement in bog turtles, varying from 2.1 to 23 meters (6.9 to 75.5 ft) in males and 1.1 to 18 meters (3.6 to 59.1 ft) in females.[45] Both sexes are capable of homing when released at distances up to 0.8 kilometers (0.50 mi) from their site of capture.[39] The bog turtle will travel long distances to find a new habitat if its home becomes unsuitable. The species is most active during the spring, and males generally exhibit greater migration distance and seasonal activity than females as they defend their territory. Home-range migration distances have been recorded at 87 meters (285 ft) for males and 260 meters (850 ft) for females.[46] Home-range sizes in Maryland vary from 0.0030 hectares (0.0074 acres) to 3.1 hectares (7.7 acres) with considerable amounts of variation between sites and years.[47]
The bog turtle is semiaquatic and can move both on land and in the water. The distance and frequency of movements on land help herpetologists understand the behavior, ecology, gene flow, and the level of success of different bog turtle colonies. The vast majority of bog turtle movements are less than 21 meters (69 ft), and only 2 percent are of distances over 100 meters (330 ft); large, expansive trips (i.e., between neighboring wetlands), are rare.[48]
The movement of bog turtles between colonies facilitates genetic diversity. If this movement were to be prevented, or limited in any significant way, the species would have a higher likelihood of becoming extinct because genetic diversity would fall. Some aspects of a bog turtle's movement that remain unresolved include: phenomena that motivate bog turtles to move outside their natural habitat; the distances an individual can be expected to travel each day, week, and year; and how separation of small groups affects the genetics of the species.[49]
Life cycle
Bog turtles are sexually mature when they reach between 8 and 11 years of age (both sexes).[30] They mate in the spring after emerging from hibernation, in a copulation session that usually lasts for 5–20 minutes, typically during the afternoon, and may occur on land or in the water. It begins with the male recognizing the female's sex. During the courtship ritual, the male gently bites and nudges the female's head. Younger males tend to be more aggressive during copulation, and females sometimes try to avoid an over-aggressive male. However, as the female ages, she is more likely to accept the aggressiveness of a male, and may even take the role of initiator. If the female yields, she may withdraw her front limbs and head. After the entire process is over, which usually takes about 35 minutes,[50] male and female go separate ways.[12] In a single season, females may mate once, twice, or not at all, and males try to mate as many times as possible.[50] It has been suggested that it is possible for the bog turtle to hybridize with Clemmys guttata during the mating season.[50] However, it has not been genetically verified in wild populations.
Baby bog turtles are about 2.5 centimeters (0.98 in) long when they emerge from their eggs,[19] usually in late August or September.[53] Females are slightly smaller at birth, and tend to grow more slowly than males.[53] Both genders grow rapidly until they reach maturity.[54] Juveniles almost double in size in their first four years, but do not become fully grown until five or six years old.[12]
The bog turtle spends its life almost exclusively in the wetland where it hatched. In its natural environment, it has a maximum lifespan of perhaps 50 years or more,[52] and the average lifespan is 20–30 years.[21] The Bronx Zoo houses several turtles 35 years old or more, the oldest known bog turtles. The zoo's collection has successfully sustained itself for more than 35 years.[55] The age of a bog turtle is determined by counting the number of rings in a scute, minus the first one (which develops before birth).[25]
Conservation
Protected under the United States Federal Endangered Species Act,
The
The development of new neighborhoods and roadways obstructs the bog turtle's movement between wetlands, thus inhibiting the establishment of new bog turtle colonies. Pesticides, runoff, and industrial discharge are all harmful to the bog turtles' habitat and food supply.[18] The bog turtle has been designated as a threatened species to "conserve the northern population of the bog turtle, which has seriously declined in the northeast United States."[59]
Today, the rebounding of bog turtle colonies depends on private intervention.[60] Population monitoring involves meticulous land surveys over vast countrysides.[61] In addition to surveying land visually, remote sensing has been used to biologically classify a wetland as either suitable or unsuitable for a bog turtle colony. This allows for comparisons to be made between known areas of bog turtle success and potential areas of future habitation.[62]
To help the existing colonies rebound, several private projects have been initiated in an attempt to limit the encroachment of overshadowing trees and bushes, the construction of new highways and neighborhoods, and other natural and man-made threats.[12]
Methods used to recreate the bog turtle's habitat include:
Captive breeding is another method of stabilizing the bog turtles' numbers. The technique involves mating bog turtles indoors in controlled environments, where nutrition and mates are provided. Fred Wustholz and Richard J. Holub were the first to do this independently, during the 1960s and 1970s. They were interested in educating others about the bog turtle and in increasing its population, and over several years they released many healthy bog turtles into the wild.[12] Various organizations, such as the Association of Zoos and Aquariums, have been permitted to breed bog turtles in captivity.[64]
The study of bog turtles in the wild is a significant aid to the development of a conservation strategy.
Notes
References
- Footnotes
- ^ . Retrieved 9 May 2023.
- ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
- ^ "Bog Turtle (Glyptemys muhlenbergii) - Species Profile". USGS Nonindigenous Aquatic Species Database. Retrieved 2022-12-11.
- ^ "Bog Turtle | State of Tennessee, Wildlife Resources Agency". www.tn.gov. Retrieved 2022-12-11.
- ^ Our map differs slightly from these sources.
- S2CID 87809001.
- ^ Schoepff, J. D. (1801). Historia testudinum iconibus illustrata. Erlangen: Sumtibus Ioannis Iacobi Palm.
- ^ a b c d e f g Ernst & Lovich 2009, p. 263
- ISBN 978-1-4214-0135-5. (Glyptemys muhlenbergii, p. 184).
- ^ Morse, Silas (1906). Annual report of the New Jersey State Museum. Trenton, New Jersey: New Jersey State Museum. pp. 242–243.
- ^ U.S. Fish and Wildlife Service (2001). Bog Turtle (Clemmys muhlenbergii), Northern Population, Recovery Plan (PDF). Hadley, Massachusetts. p. 2. Archived from the original (PDF) on 2017-07-15. Retrieved 2010-05-01.
{{cite book}}
: CS1 maint: location missing publisher (link) - ^ a b c d e f g h i Bloomer 2004, pp. 1–2
- ^ Holman, J. A.; Fritz, U. (2001). "A new emydine species from the Middle Miocene (Barstovian) of Nebraska, USA with a new generic arrangement for the species of Clemmys sensu McDowell (1964) (Reptilia: Testudines: Emydidae)" (PDF). Zoologische Abhandlungen. 51: 331–354.
- JSTOR 3892960.
- ^ a b c d "Bog Turtle – Fact Sheet" (PDF). North Carolina Wildlife Resource Commission. 2006. Retrieved 2009-09-19.
- ^ a b c d e Smith 2006, p. 1
- ^ a b c d e "Bog Turtle". Department of Environmental Protection. State of Connecticut. 2002. Retrieved 2009-09-19.
- ^ a b "Bog Turtle Fact Sheet". New York State Department of Environmental Conservation. 2009. Retrieved 2009-09-19.
- ^ a b c Bloomer 2004, p. 2
- ^ a b "Bog Turtle" (PDF). Massachusetts Division of Fisheries & Wildlife Natural Heritage & Endangered Species Program. Archived from the original (PDF) on 2009-09-12. Retrieved 2009-09-20.
- ^ a b c Shiels 2007, p. 23
- ^ S2CID 86136335.
- ^ a b c Ernst & Lovich 2009, p. 264
- ^ a b "Bog Turtle, Clemmys muhlenbergii" (PDF). New Jersey Endangered and Nongame Species Program. Archived from the original (PDF) on December 15, 2004. Retrieved 2009-09-20.
- ^ a b Walton 2006, p. 32
- ^ a b c d e f Shiels 2007, p. 24
- ^ a b c Bloomer 2004, p. 3
- ^ a b Walton 2006, p. 23
- ^ JSTOR 3802798.
- ^ a b Smith 2006, p. 3
- hdl:10919/23804.
- ^ Walton 2006, p. 28
- ^ a b Smith 2006, p. 4
- ^ a b "Bog Turtles". Keystone Wile Notes. U.S. Fish and Wildlife Service, Pennsylvania Department of Conservation and Natural Resources. Archived from the original on September 12, 2009. Retrieved 2009-09-20.
- ^ a b c Smith 2006, p. 2
- ^ a b c d e f Ernst & Lovich 2009, p. 265
- ^ Walton 2006, p. 24
- ^ Rosenbaum, Robertson & Zamudio 2007, p. 331
- ^ a b c d e Ernst & Lovich 2009, p. 267
- ^ a b c Ernst & Lovich 2009, p. 266
- ^ Bloomer 2004, p. 5
- ^ a b c d Ernst & Lovich 2009, p. 270
- ^ a b Ernst & Lovich 2009, p. 271
- ^ a b Carter, Shawn; Horne, Brian; Herman, Dennis (2005-09-03). "Bacterial pneumonia in free-ranging bog turtle, Glyptemys muhlenbergii, from North Carolina and Virginia" (PDF). Journal of the North Carolina Academy of Science. 121 (4): 170–173. Archived from the original (PDF) on 2010-12-06. Retrieved 2010-04-28.
- ^ Ernst & Lovich 2009, pp. 266–267
- JSTOR 1446649.
- JSTOR 1566025.
- JSTOR 1565241. Archived from the original(PDF) on 2010-06-02. Retrieved 2010-04-05.
- ISSN 1071-8443. Retrieved 2010-04-14.
- ^ a b c d e Ernst & Lovich 2009, p. 268
- ^ Smith 2006, pp. 2–3
- ^ a b Walton 2006, p. 31
- ^ a b c d e Ernst & Lovich 2009, p. 269
- ^ a b Ernst & Lovich 2009, pp. 270–271
- ^ Herman, Dennis. Captive husbandry of the eastern Clemmys group at Zoo Atlanta. Proceedings First International Symposium on Turtles & Tortoises: Conservation & Captive Husbandry. California Turtle & Tortoise Club. pp. 54–62. Retrieved 2009-09-20.
- ^ Copeyon, Carole. "Bog turtles in North Carolina". Pennsylvania Field Office. U.S. Fish and Wildlife Service. Archived from the original on 2010-07-23. Retrieved 2009-09-19.
- ^ "Bog Turtle (Clemmys muhlenbergii) Northern Population Recovery Plan" (PDF). U.S. Fish and Wildlife Service. Archived from the original (PDF) on 2017-07-15. Retrieved 2010-08-20.
- ^ a b c d Shiels 2007, p. 25
- ^ Copeyon, Carole (1997-11-05). "Bog turtles protected by Endangered Species Act". U.S. Fish and Wildlife Service. Archived from the original on 2016-03-03. Retrieved 2010-01-14.
- ^ Pittman & Dorcas 2009, p. 781
- ^ Walton 2006, p. 20
- ^ Walton 2006, p. 21
- ^ Walton 2006, p. 30
- ^ a b Tryon, Bern W. (May 2009). "Defining success with bog turtle conservation in Tennessee". CONNECT. Association of Zoos and Aquariums. Archived from the original on 2010-06-15. Retrieved 2010-01-14.
- S2CID 30931168. Archived from the original(PDF) on 2010-06-15. Retrieved 2010-01-14.
- Bibliography
- Bloomer, Tom J. (2004) [1970]. The Bog Turtle, Glyptemys muhlenbergii... A Natural History (PDF). (PDF) from the original on 2011-07-16. Retrieved 2008-12-17.
- Ernst, C. H.; Lovich, J. E. (2009). Turtles of the United States and Canada (2nd ed.). JHU Press. pp. 263–271. ISBN 978-0-8018-9121-2.
- Palmer, William; Braswell, Alvin L. (1995). Reptiles of North Carolina. Chapel Hill, North Carolina: The University of North Carolina Press. pp. 49–52. ISBN 978-0-8078-2158-9.
- Pittman, Shannon E.; Dorcas, Michael E. (2009). "Movements, Habitat Use, and Thermal Ecology of an Isolated Population of Bog Turtles (Glyptemys muhlenbergii)". Copeia. 2009 (4): 781–790. S2CID 85924864. Archived from the originalon 2012-08-28. Retrieved 2010-03-28.
- Rosenbaum, Peter A.; Robertson, Jeanne M.; Zamudio, Kelly R. (2007). "Unexpectedly low genetic divergences among populations of the threatened bog turtle (Glyptemys muhlenbergii)". Conservation Genetics. 8 (2): 331–342. S2CID 20619110.
- Shiels, Andrew L. (2007). "Bog Turtles Slipping Away" (PDF). Nongame and Endangered Species Unit. Commonwealth of Pennsylvania, Fish and Boat Commission. Archived from the original (PDF) on 2011-09-28. Retrieved 2009-09-18.
- Smith, Erika (October 2006). "Bog Turtle". National Resources Conservation Service. Retrieved 2017-07-30.
- Walton, Elizabeth M. (2006). "II. Literature Review" (PDF). Using Remote Sensing and Geographical Information Science to Predict and Delineate Critical Habitat for the Bog Turtle, Glyptemys muhlenbergii (M.A. thesis). University of North Carolina at Greensboro. Retrieved 2010-04-09.
External links
- Media related to Glyptemys muhlenbergii at Wikimedia Commons
- NatureServe Explorer: An Online Encyclopedia of Life