Listing
Dec 30, 1982
Dec 30, 1982 Listing
Review of Vertebrate Wildlife for Listing as End. or Thr. Species
- Publication type: CNOR
Item 1
FWS Focus
Overview
Characteristics
Overview
Bog turtles are one of the smallest turtle species in the world, and the smallest in North America. Adults are no more than 4.5 inch long. They are also known for having remarkably long lifespans: researchers have found that some bog turtles live longer than 60 years in the wild.
The bog turtle was listed as threatened under the Endangered Species Act in 1997 due to a variety of factors. Land-use changes, like residential and commercial development, have caused degradation and fragmentation of their wetland habitat. Natural succession of vegetation has also reduced the availability of their habitat. When low-growing wetland plants are overgrown by shrubby plants, they eventually become forested wetlands. Mature trees shade out the wetland plants the bog turtle depends upon. Like many other native turtle species, bog turtles are also at risk from collection and the illegal trade.
There is a 250-mile gap in the bog turtle range, effectively causing a separation between a northern and southern population. The northern population is federally listed as “threatened,” while the southern population is listed as “threatened by similarity of appearance.” At the time of the listing, the northern population was in greater decline than the southern population and needed more protection. But the authors of the listing determination explained that listing the southern population as threatened “eliminates the ability of commercial collectors to commingle northern bog turtles with individuals from the southern population or to misrepresent them as southern bog turtles for commercial purposes.”
Scientific Name
Glyptemys muhlenbergii
Common Name
Bog Turtle
Identification Numbers
Characteristics
Characteristic category
Food
Characteristics
Food
Characteristic category
Physical Characteristics
Characteristics
Size & Shape
Adults can grow up to 4.5 inches in length.
Color & Pattern
Bog turtles are mostly dark brown and have a prominent orangey-yellow blotch behind and above each tympanum. A tympanum is the ear of the turtle, which looks like a circle on their head and is located behind their eye. This is generally seen as their identifying feature, but they also have flecks of orange or yellow on the head, neck and limbs. Both the carapace and plastron (the shell on their underside) are dark brown or black, but the plastron can have orangey-yellow blotches toward the tail end of it. When they are very young, they have visible growth rings, called scute annuli, on the carapace. These growth rings become harder to see as a turtle ages or they get worn over time due to turtles burrowing in gritty mud in a wetland.
Characteristic category
Life Cycle
Characteristics
Reproduction
Eggs are often laid in elevated areas, such as on top of hummock-forming tussock sedge about May-June (depending on latitude), and each nest has about 3-5 eggs. Hatching begins in late August or September.
Characteristic category
Habitat
Characteristics
Habitat
Bog turtles occupy shallow wetland habitats. They are semi-aquatic, meaning sometimes they like to spend time in the water and sometimes they like to be on land or on top of hummocky vegetation above the water. The wetlands they occupy tend to be open-canopy herbaceous sedge bogs, fens or wet meadows, meaning there aren’t a lot of trees present that shade out plants that bog turtles like, such as the tussock sedges that form hummocks used for basking and nesting, shrubby cinquefoil, poison sumac, grass-of-parnassus, and cattail, among many other plant species.
Their preferred wetlands comprise microhabitats that bog turtles rely on for many parts of their life-cycle activities, such as foraging, nesting, basking, hibernating, and sheltering. These microhabitats are characterized by soft muddy bottoms, interspersed wet and dry pockets, vegetation dominated by low-growing grasses and sedges, and a low volume of standing or slow-moving water, which often forms a network of shallow pools and rivulets. Bog turtles prefer areas with ample sunlight, high humidity in the near-ground microclimate, and perennial saturation of portions of the ground in which to bury themselves to get cool during hot summer months.
Bog turtles generally retreat into more densely vegetated areas (different areas than what they typically use during spring and summer months), under the roots of trees or shrubs, rock walls, or even muskrat burrows to hibernate from mid-September through mid-April (depending on latitude).
Geography
Characteristics
Range
There are two distinct populations of bog turtles. The northern population is found in Connecticut, Delaware, Maryland, Massachusetts, New Jersey, New York, Pennsylvania. The southern population is found in Georgia, North Carolina, South Carolina, Tennessee, Virginia
Timeline
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