ally black to mahogany-brown and may be marked 

with lighter whitish to yellowish rays of color. The 

lower shell, or plastron, is usually black with varying 

amounts of white or pale yellow patches. The body is 

very dark brown or black, sometimes with streaks of 

red or orange. The top of the head is usually speckled with black and the lower jaw may be spotted with 

red or orange. The upper jaw is notched creating two 

sharp points on the beak. 

There is a high degree of sexual dimorphism in bog 

turtles, making it fairly simple to distinguish between 

the male and female. Male shell lengths tend to average 31⁄2 to 4 inches, while females are 3 to 33⁄4 inches 

in length. The plastron is dished or concave in males, 

while the female's plastron is flat. Male bog turtles 

have long, thick tails with the cloacal opening extending past the edge of the under shell, and females have 

shorter tails with the cloacal opening inside the under 

shell.

Distribution

The northern populations of bog turtles are found 

in western Massachusetts and Connecticut, south to 

New York, New Jersey, Pennsylvania, Delaware, and 

Maryland. The southern population, separated from 

the northern population by 250 miles, begins in southwestern Virginia and ranges through North Carolina, 

Tennessee, and South Carolina to northern Georgia. 

October 2006 Fish and Wildlife Habitat Management Leaflet Number 44

Bog Turtle

(Clemmys muhlenbergii)

© 1988 WHC

WILDLIFE HABITAT COUNCILSM

Introduction

The bog turtle, North America's smallest turtle, is primarily found in fens, bogs, wet meadows, and emergent freshwater wetlands associated with streams 

and bordered by wooded areas in the Northeast and 

mid-Atlantic regions of the United States. Bog turtles 

have never been widely distributed, but continued 

loss and degradation of habitats have further reduced 

their occurrence to isolated pockets within northern 

and southern parts to their historic range. Because of 

dramatic population declines in the 1980s and 1990s, 

northern populations of bog turtles were listed as a 

federally threatened species on November 4, 1997. It 

is prohibited to collect individual turtles from these 

populations, and interstate and international commercial trade is banned. Because of the similarity in appearance between the southern and northern populations, pet dealers have difficulty distinguishing 

between the two. Due to this, the southern population 

has since been listed as threatened, as well. 

This leaflet provides an introduction to the habitat requirements of the bog turtle and is intended to assist landowners and managers plan, implement, manage, and monitor for bog turtles. The success of any 

species-specific management plan depends on targeting the needs of the desired species and analyzing existing habitat conditions to ensure that the required 

habitat elements are present. This leaflet provides 

a number of practical habitat management practices that can be used to improve bog turtle habitat. 

Landowners and managers are encouraged to enlist 

the expertise of wildlife and natural resource professionals to help identify additional habitat management 

needs and actions.

Description

Bog turtles are characterized by their small size 

(about 3 to 4 inches long), dark color, and large yellow 

to orange colorations on both sides of the head. Head 

coloration of juvenile and newly hatched bog turtles is 

lighter, whereas older adults have brighter and more 

intensely colored blotches. The upper shell is usuBog turtle (Clemmys muhlenbergii)
Bog Turtle (Clemmys muhlenbergii)

2

Currently, the range is diminishing, and fewer then 

200 sites in the northern range have been found to 

contain populations of bog turtles. Additionally, based 

on habitat quality, it has been found that only 35 of 

176 assessed sites in North Carolina were capable 

of supporting healthy bog turtle populations. Please 

reference the U.S. Fish and Wildlife publication Bog 

Turtle (Clemmys muhlenbergii) Recovery Plan at 

http://www.wcs.org/media/file/Cm_Recovery_Plan.

pdf for county specific locations of bog turtles within 

the above regions. 

Behavior

Bog turtles are a very secretive species, often burrowing in muck or vegetation undetected. Bog turtles 

are primarily diurnal and emerge from cover in early morning and bask until they move off in search of 

food or mates. In the hottest part of the day, bog turtles seek shade until the evening when activity resumes. Bog turtles are active at air temperatures between 60 and 87 degreesFahrenheit; however, as air 

temperature increases throughout the summer, bog 

turtles will congregate in wet areas and inhabit networks of tunnels partly or completely filled with water. 

The species begins hibernation in late September and 

will use abandoned animal burrows, cavities in mud, 

sedge clumps, the base of tree stumps, or shrubby 

hummocks for hibernacula (a hibernation location), 

occasionally hibernating with other species of turtles. 

Hibernacula tend to be in secretive, protected areas to 

hide the turtle from predators and the moderate temperature extremes during the harsh winter months. 

Turtles emerge in late March to April when the air and 

water temperature exceeds 50 degrees Fahrenheit. 

Reproduction

Mating occurs in spring (sometimes in the fall) near 

the hibernaculum. The females are known to be very 

secretive during mating season, and the males travel 

to locate them. Nesting usually occurs in the late afternoon or early evening from May to July. The female 

digs a cavity with alternating scoops of the hind feet 

The northern and southern populations are 

separated by 250 miles.

Male bog turtle (right) with the concave plastron and 

the female (left) with the flat plastron

Nests are often located inside an open, grassy tussock.
Bog Turtle (Clemmys muhlenbergii)

3

and lays one to five eggs in the nest, generally located inside the upper part of an open, grass tussock, or 

sphagnum moss (Sphagnum spp.). Incubation lasts 42 

to 56 days.

Eggs are white and elliptical in shape and hatch in 

August to September; however, some of the young 

remain in the nest, emerging the following spring. 

Sexual maturity is reached at 8 to 11 years. The eggs 

of the bog turtle are preyed upon by birds, snakes, rodents, and other mammals. 

Habitat

The bog turtle home range is relatively small (ranging from 1 to 74 acres). Bog turtles are found in seepage or spring-fed emergent freshwater wetlands associated with streams and bordered by wooded areas. 

Clear, slow moving rivulets or brooks with soft, highly 

organic substrates are required. These wetlands have 

a variety of micro-habitats that include dry pockets, 

saturated areas, and areas that are periodically flooded. The turtles depend upon this diversity of microhabitats for foraging, nesting, basking, hibernation, 

shelter, and other needs. Primary habitats in these areas include fens, bogs, wet meadows, and drainage 

ditches. They prefer shallow water (4 inches deep or 

less) and saturated soils that contain surface water 

year round. 

Unless disrupted by fire, beaver activity, grazing, or 

periodic wet years, open-canopy wetlands are slowly 

invaded by woody vegetation and undergo a transition 

into closed-canopy, wooded swamplands that are unsuitable for habitation by bog turtles. Bog turtles are 

dependent on open-canopy sedge meadows and fens 

bordered by wooded areas for foraging, reproduction, 

nesting, hibernation, and maintaining body temperature. Open canopies allow for dense growth of low 

vegetation providing a habitat for the range of animals that contribute to the diet of bog turtles, as well 

as providing ample opportunities for basking which 

helps maintain body temperature. 

Plant species commonly associated with bog turtle 

habitats include alders (Alnus spp.), willows (Salix

spp.), sedges (Carex spp.), spike rushes (Eleocharis

spp.), jewelweed (Impatiens capensis), rice cut-grass 

(Leersia oryzoides), tearthumb (Polygonum sagittatum), arrow arum (Peltandra virginica), red maple 

(Acer rubrum), skunk cabbage (Symplocarpus foetidus), cattails (Typha spp.), juneberry (Amelanchier 

spicala), sphagnum moss (Sphagnum spp.), and bulrushes (Juncus spp. and Scirpus spp.). Tussock sedge 

(C. stricta) and sphagnum moss is commonly used 

for nesting and basking.

Typical sedge meadow habitat for bog turtles in 

Maryland. Note spring-fed flow of shallow water meandering between clumps of sedges. Woody vegetation 

is encroaching from the upper right.

Sphagnum moss is important in bog turtle habitats. 

Bog turtles frequently use sphagnum for nesting and 

basking areas.

North Carolina bog turtle habitat (Photo courtesy of 

Romy Myszka)
Bog Turtle (Clemmys muhlenbergii)

4

As an omnivore and opportunistic feeder, the bog turtle readily consumes any available food source in land 

or water. However, bog turtles prefer invertebrates 

such as slugs, worms, spiders, and insects. Additional 

food sources include frogs, snails, root hairs, seeds, 

fruits, leaves, carrion, and moss. The turtles feed during the daylight hours; however, they are seldom active during the hottest part of the day and are inactive 

on chilly mornings.

Habitat communities and components that are absent 

or present in limited amounts are likely limiting bog 

turtle habitat quality. Management actions should be 

taken to address these limiting factors. Land uses on 

adjacent properties may need to be considered to accurately rate the quality of a habitat management area 

for bog turtle. Limitations can become quite common, 

especially if there is little habitat to work with.

Population densities and home range

Densities of bog turtles have been estimated at 5 to 

125 individuals per 2 acres. Many populations, however, contain fewer than 50 animals. Home ranges and 

movement reports are variable with an average home 

range found in eastern Pennsylvania of 3 acres for 19 

bog turtles. In Maryland, sites were surveyed finding 

an expansion in home range when compared to historic studies in the same area. It was suggested that 

the expansion in home range size may indicate a decrease in habitat quality from succession or invasive 

species. 

Home range sizes and distances traveled are not significantly different between sexes, although, one 

study did find that males expand their home ranges 

during the mating season. Occasionally, individual turtles will cross roads a considerable distance from any 

apparent suitable habitat. These long distance movements may be the result of emigration, or the moving 

out of habitats that are declining in quality through 

succession or invasive encroachment. 

Reasons for decline

Bog turtles are very sensitive to habitat changes and 

have suffered greatly from habitat loss and degradation such as wetland filling, fragmentation, and drainage. Other reasons for their decline include nonnative 

and native plant species invasions, increased nutrient 

load from runoff, and woody encroachment. Due to 

East Coast urban sprawl, these alterations have seriously changed many turtle habitats and have had a serious effect on the bog turtle because of their specific 

habitat needs. Illegal collection has also contributed 

to the bog turtle's decline as they are highly prized in 

the pet trade. 

Certain amounts of light must reach the ground in 

bog turtle habitat through openings in the canopy for 

them to effectively regulate their body temperature. 

Unless disrupted by beaver activity, grazing, periodic wet years, or some human interference, open-canopy wetlands are slowly invaded by woody vegetation 

and undergo a transition into closed-canopy, wooded swamplands that are unsuitable for habitation 

by bog turtles. Historically, turtles moved from one 

open-canopy wetland patch to another as succession 

progressed and the canopies closed in one area and 

natural disturbances (fire, beaver, buffalo) opened 

canopies in another. Today, however, development 

(such as roads, ditches, culverts, and urbanization) inhibits the turtle's ability to move to new habitat, preventing new populations from being established as 

old sites deteriorate.

Habitat management recommendations

Restoration and enhancement projects are often complicated as the hydrology, climate, and current and 

historic plant and animal communities must be considered. Extensive planning must be done before a 

restoration or enhancement project can be implemented. 

A bog turtle survey and determination of current conditions should be conducted before beginning a habitat management project.
Bog Turtle (Clemmys muhlenbergii)

5

The landowner must understand the problems (bog 

turtle habitat that has been compromised) and opportunities (how lost habitat can be restored) that exist. 

For wetland restoration or enhancement projects, the 

local landscape and historical factors that led to the 

creation and function of the wetland in the first place 

must be understood. These factors include land use, 

topography, climate, precipitation patterns, soil types, 

ground and surface water flows, and vegetation communities. The factors contributing to the wetland loss 

or degradation must also be researched, as well as the 

possible opportunities to restore or enhance the wetland. For bog turtle habitat, locations should be surveyed to determine whether or not the site can support (or does support) populations of bog turtles. 

Once the problems and opportunities are understood, objectives for restoration must be outlined. 

Objectives might include implementing rotational 

grazing systems, increasing habitat for bog turtles, or 

reducing habitat fragmentation. The resources available to undertake the restoration or enhancement 

project must be inventoried and analyzed to formulate 

a plan of action and any alternative plans of action 

that might be considered. Available resources might 

include wetland restoration expertise or financial resources. Armed with all this information, landowners 

will be well equipped to make decisions and decide 

on the proper plan of action for their bog turtle habitat restoration or enhancement project. 

Before implementing their plan, landowners and managers are strongly urged to discuss their restoration 

or enhancement plans with experts from Federal, 

State, or local government agencies or qualified personnel from conservation organizations. Evaluation of 

the plan, throughout the planning process, as well as 

during and after its implementation, is vital to the success of the project, as well as future wetland restoration and enhancement projects. 

Habitat assessment

Before beginning a habitat management project, planners should determine the current conditions of the 

planned site including the soil conditions, current 

plant diversity, and future successional management. 

A bog turtle site-quality analysis protocol was developed to assess capacity of sites to maintain viable 

population of bog turtles. Sites are ranked on the basis of their size and degree of fragmentation, presence of invasive plants and later successional species, 

immediate threats (ditching, draining, filling, excavation), and type and extent of land use in the area. 

While this protocol was developed to be used by persons qualified to conduct bog turtle surveys and delineate wetlands, the same assessment can be used by a 

landowner to achieve a general understanding of the 

status of their habitat in relation to bog turtles. For a 

more detailed description including the assessment 

matrix, please reference the U.S. Fish and Wildlife 

publication Bog Turtle (Clemmys muhlenbergii) 

Recovery Plan at http://www.wcs.org/media/file/Cm_

Recovery_Plan.pdf.

Before surveys are conducted, the areas should first 

be assessed to establish if the key elements are present to qualify for bog turtle habitat. Bog turtle habitat 

is recognized by the characteristics of its soils, hydrology, and vegetation. Suitable hydrology, soils, and vegetation are necessary to provide the critical wintering sites and nesting habitats for bog turtles; however, 

one or more of these criteria may be absent from portions of a wetland or wetland complex supporting bog 

turtles. Absence of one or more criteria does not preclude bog turtle use of these areas to meet important 

life functions including foraging, shelter, and dispersal. If these criteria (suitable soils, vegetation, and hydrology) are present in the wetland, then the wetland 

is considered to be potential bog turtle habitat, regardless of whether that portion of the wetland occurring within the project boundaries contains all three 

criteria. 

Soils

Soils should be soft muck and rock. Some areas may 

have scattered pockets of peat (6 inches or deeper) 

instead of muck. Soils should have low permeability, a restrictive underlying layer, or high water tables. 

These soils will ensure that the site can support a wetland ecosystem.

Hydrology

The area should be spring-fed or with a high water table close to the surface providing shallow surface water or saturated soils year round. Dry and wet pockets are often intermittent throughout. There is often 

subsurface flow and shallow rivulets (less then 10 cm 

deep). In Delaware, pH ranged from 5.5 to 7.4, and the 

salinity was always zero. 

Vegetation

The area should consist of low grasses, sedges, and 

shrubs characteristic of scrub-shrub wetlands. Some 

wetlands may already have desired openness with a 

high diversity of native herbaceous and woody plants. 

At such sites the need to manage vegetation may 

be minimal. However, at sites with closed canopies 

caused by dense, mature woody plants (red maple, 

Acer rubrum; willow, Salix spp.), invasive, nonnative 

plants, or some combination of the two factors, vege-
Bog Turtle (Clemmys muhlenbergii)

6

tation management will be required to open the canopy and favor native grasses and sedges.

Water management

In drained and degraded basins, structural modifications may need to be undertaken to restore wetland hydrology. Wetland restoration and management 

plans are site specific and legal restrictions often apply, so landowners are strongly encouraged to contact 

a wetlands specialist before beginning work. 

Removing hydrologic alterations

Ditch filling can be used where wetlands have previously been drained. Drainage ditches can be filled and 

plugged which restores the wetland to pre-drainage 

levels and maintains the ideal level of surface water. 

A spillway or outlet control gate can be constructed, 

located at the downstream end of a drainage ditch as 

it exits the wetland, to allow for manipulation of the 

surface water level. The original soil that is commonly 

left beside the ditch upon its creation is a source of fill 

for the channel. Soil with the same approximate composition, grain size, and permeability of the soil that 

was originally removed from the ditch should be used 

to refill it if the original soil is not available. The ditch 

plug should be at least 150 feet long at minimum, and 

the plug should rise 33 percent above the grade to allow for settling. Additionally, appropriate native vegetation should be established to secure soils.

Drain tile, or “field tile” as it is often called, is a section of underground agricultural tile set to drain a 

wetland basin. Drain tile is usually made of clay or 

perforated plastic and buried at a depth of 2 to 6 feet. 

If the site contains drain tiles, tile removal is a simple 

form of restoration. A contractor with a backhoe generally removes or crushes a section of tile about 25 or 

50 feet long downstream from the wetland. Following 

this, the downstream or outlet pipe is plugged with 

concrete or clean clay fill, and the trench is filled. 

To slow water flow and increase the diversity of flow 

conditions, it may be necessary to reestablish bends 

and meanders in straightened waterways. This restoration option should be conducted in unison with a revegetation plan that places the appropriate native vegetation in wet and dry areas when modifications are 

complete. 

Managing water level

Sometimes it is necessary to create a very low earthen berm to impond sufficient water to reach a desired water level. A berm is created using subsoil, often mixed with clay. Topsoil is spread on top of the 

Many farmers use drainage ditches when converting 

wetlands into croplands.

This outlet pipe is a sign of drain tile located in this 

field. Removal of drain tile is fairly simple, and outlets such as these are subsequently plugged.

berm to provide a medium for plant growth. To prevent over flooding, a riser may be installed to remover 

overflow through a tub once it reaches a certain level. This berm can prevent the drainage of water downstream; however, it requires a spill way or other water-control structure to regulate the water level and 

prevent the dike from being washed away during periods of heavy runoff. Since water management is critical, a professional biologist should be consulted for 

design specifications suitable for specific wetlands. 
Bog Turtle (Clemmys muhlenbergii)

7

Vegetation management

Succession of wetlands is a natural process that may 

result in significant changes to a wetland over time 

(see Fish and Wildlife Habitat Management Leaflet, 

Number 41: Early Successional Habitat for more information on successional management). Primary 

changes include the invasion of wetlands by trees 

and shrubs and canopy closure over wetlands. 

Considering that bog turtles require open canopy habitats, plans to periodically (every 10 to 15 years) reverse the effects of succession on some or all of the 

project area are important to consider. Management 

can reverse succession by mimicking natural disturbance such as flooding, grazing, fire, or using timber harvesting, mowing, or herbicide treatment. Any 

management effort should consider possible negative direct and indirect effects and plan accordingly (see Fish and Wildlife Habitat Management Leaflet, 

Number 37: The Importance of Disturbance in Habitat 

Management for more information on disturbance).

If a wetland is already established, the vegetation in 

the area must be managed to keep the wetland in an 

early successional state. Chemical use, invasive species control, prescribed grazing, and mechanical management, as well the reduction or elimination of beaver control can be used to change vegetative structure 

to suit bog turtles. 

Chemical use

Herbicides are commonly applied to wetlands as 

sprays, liquid paints, or injections. Care must be taken whenever chemical manipulations of wetland vegetation might have impacts broader than the target 

goals. There should always be concern for the sensitivity of nontarget species to herbicide chemicals or 

their by-products in the wetland. For additional information on application and use of herbicides, see 

Fish and Wildlife Habitat Management Leaflet Number 

24: Wildlife and Integrated Pest Management (IPM). 

Always consult with State and local authorities and 

wildlife professionals for proper timing and application techniques, and to obtain applicable permits. 

For more information involving chemical treatments, 

please visit the USDA NRCS Web site at http://www.

wsi.nrcs.usda.gov/products/piedmont/c-5.pdf.

Invasive species control

Invasive plants may produce undesirable functional and structural changes in bog turtle habitats. For 

example, some invertebrate foods preferred by bog 

turtles cannot survive in wetlands dominated by invasive plants. Consequently, when invasives spread 

so significantly that they out-compete native plants, 

the suitability of bog turtle habitat may be reduced. 

Eliminating these nonnative invasives from wetlands, 

even relatively small wetlands, takes substantial effort. For more information on invasive species and 

their control, visit The Nature Conservancy invasive 

species initiative Web site at http://tncweeds.ucdavis.

edu/.

The most common invasive species in wetlands include purple loosestrife (Lythrum salicaria), reed 

canarygrass (Phalaris arundinacea), phragmites 

(Phragmites spp.), and multiflora rose (Rosa multiflora).

Purple loosestrife—This plant is easiest to detect 

when it flowers in late July to August. Biological control is available for significant infestations. The USDA 

Animal and Plant Health Inspection Service approved 

the use of a root-mining weevil (Hylobius transversovittatus), two leaf-eating beetles (Galerucella calmariensis and Galerucella pusilla), and a flower-feeding weevil (Nanophyes marmoratus). These insects 

can significantly reduce coverage of loosestrife, opening up the ground layer and allowing other plants to 

thrive. Chemical and manual control is inexpensive 

for small infestations (less than 100 plants). Manual 

control would involve pulling up the roots and then 

applying an herbicide. This treatment should not 

be used after flowering because rough handling can 

spread the seeds. Mowing, burning, and flooding are 

not effective techniques to control purple loosestrife. 

Purple loosestrife is a common wetland invasive species that requires careful management.
Bog Turtle (Clemmys muhlenbergii)

8

Reed canarygrass—This plant is one of the most 

persistent invasive species and one of the most difficult to remove. In areas that have high densities of 

canarygrass, repeated burning in late autumn or late 

spring may useful; however, annual burning for 5 to 6 

years may be necessary to be effective. Canarygrass 

can also be treated with herbicides; however, mowing, tilling, and biological control are not effective 

control methods. 

Phragmites—Species of phragmites can be largely 

controlled with herbicides. Success depends primarily 

on the growth stage of the plant and population size. 

Herbicides are most effective when applied in the autumn on new shoots with at least four true leaves. 

In areas with high population numbers of phragmites, plastic sheeting can be used to kill the root system. Sheeting is less labor intensive then cutting, but 

stands must be mowed or burned prior to sheeting 

to reduce plant mass. Six-millimeter black plastic is 

used, secured with stakes or sandbags to create the 

barrier. The temperature will increase under the plastic and kill surface growth. 

Multiflora rose—Control of this plant involves removing all roots, as new plants can grow from severed roots. Prescribed grazing can be effective, as 

well as prescribed burning. In areas with extensive infestation, repeated mowing (three to six times during 

the growing season) for 2 to 4 years is effective. An 

application of herbicide on freshly cut stems destroys 

the root system and prevents resprouting, removing 

the necessity for many years of mowing. Herbicide 

should be applied after the stem is cut, or to flowering 

or budding plants. 

Many species of invasives thrive in areas with high 

nutrient and sediments enrichment from runoff and 

erosion. Simple steps can be taken to reduce the 

amount of excess nutrients and sediment in the area. 

For more information, please visit the Environmental 

Protection Agency's Web site on polluted runoff at 

http://www.epa.gov/owow/nps/facts/.

Prescribed grazing

Prescribed grazing is one of the most effective methods to remove many woody or invasive plants. 

Grazing is also cost effective as livestock owners 

are usually willing to maintain animals on the selected site. Grazing animals can provide favored microhabitats for turtles by creating deeper pockets of water in animal footprints and creating low mounds of 

earth for foraging and nesting. Grazing also promotes 

a warmer, more open environment for basking and 

nesting. When properly controlled, grazing has few 

potential side effects on wildlife. 

Grazing has been shown to be effective in controlling 

invasive species such as purple loosestrife (Lythrum 

salicaria), reed canarygrass (Phalaris arundinacea), cattail (Typha spp.), phragmites (Phragmites

spp.), and multiflora rose (Rosa multiflora). The type 

of plant that is to be managed and the size of the habitat are considerations when selecting what herbivore 

to use in grazing. Goats and sheep are used in smaller 

sites (less than an acre) where the primary vegetation 

consists of reedgrass, shrubs, and briars. These animals search for forage in the core of dense vegetation 

whereas cattle dislike thicket like habitats and prefer to forage more in the open. Goats are additionally 

very effective in removing woody species. Larger herbivores, such as cattle and horses, are used primarily in locations greater than 1 acre. Horses are least 

effective as they tend to stay away from wetter land, 

grazing primarily on dry sites. 

Grazing will require the instillation of a fencing system around the area to be managed. It is recommended that a three to four strand electrified high tensile 

should be used when considering using cattle and 

sheep in bog turtle habitats . For goats, either woven 

wire or five to six strand electrified high tensile has 

been used on sites. Planners can refer to NRCS fencing standards and specifications for further information. Multiple paddocks should be considered to allow 

rotation of animals through the habitat. Rotational 

grazing prevents overgrazing and manipulates succession simultaneously. Excluder fencing should be used 

in areas known or suspected to have nesting turtles, 

and fencing constructed around the entire site will allow a buffer of native vegetation to filter polluted runFencing opens up opportunities for rotation grazing. 

Note the different vegetative growth stages on either 

side of the fence.
Bog Turtle (Clemmys muhlenbergii)

9

off. If fencing is not practical, it is possible to tether 

some animals depending on the overall size of the location and number of animals needed to effectively 

graze. 

Grazing should not take place during the nesting or 

incubating seasons (approximately May to August), 

and the density of animals should be about one to two 

large animals (cows or horses) per acre, or 5 to 10 

small grazers (goats, sheep) per acre. Higher numbers 

of animals per acre can be used briefly to achieve a 

higher level of control for a short period of time; however, on small sites greater numbers of animals can 

cause damage through trampling. 

Prescribed burns

Prescribed burns maintain bog turtle habitat by bringing vegetation back to an early successional, or disturbed, state. Historically, fire caused by lightning 

strikes, sparks from falling rocks, or even spontaneous combustion of organic plant material had successfully maintained portions of the landscape in a 

natural state of early succession. Unfortunately, human suppression of fire during the last century has reduced its effects on most ecosystems even though the 

results can significantly improve existing habitats. 

Prescribed burn frequency varies among forestlands, 

wetlands, grasslands, and scrublands. In general, 

however, burns should be conducted on a 4- to 5-year 

(2- to 3-year in the Southeast) rotational basis in late 

winter or early spring (February–April, depending 

on the region). Dividing the burn area into strips or 

plots can leave undisturbed escape and nesting cover for wildlife adjacent to burned plots. Disked firebreaks should be created around burn areas to mainPrescribed burns are a useful tool to bring bog turtle 

habitat bach to an early successional state.

tain control of prescribed burns. Refer to the Fish and 

Wildlife Habitat Management leaflet number 37: The 

Importance of Disturbance in Habitat Management 

for additional information.

Although beneficial, prescribed burning is a highly regulated activity and should only be conducted in 

cooperation with State fish and wildlife agencies and 

with assistance from licensed burners. These agencies 

and individuals can help in the development of a burn 

plan, provide necessary tools, equipment, and supervision, and assist in obtaining all required permits.

Mechanical management

Mechanical management includes physical techniques that can be used directly on plants such as 

cutting, clipping, bark girdling, mowing, and haying. 

Depending on the size of the land and the amount of 

vegetation to be manipulated, a variety of equipment 

can be used. Smaller wetlands, like most seeps and 

bogs, are easily managed by using hand tools, without 

the need for heavy machinery. However, large areas 

like flood plain forests may require larger equipment 

to achieve management goals. In general, care should 

be taken when using manual labor or machinery in 

these sensitive habitats. 

Cutting of woody wetland vegetation can have a positive impact by opening up the canopy allowing light to 

penetrate. Plants can be completely removed, limbed 

or topped to create these openings. Selective cutting with hand tools or hand-held power equipment is 

the most effective method of removing or modifying 

woody plants. Allowing light to reach the ground surface generally has a positive impact on reptiles, amphibians, and insects. Cutting suggestions include: 

• Use the least impact method available.

• Plan to use or manage the cuttings.

• Avoid stepping on hummocks and other areas 

where hatchlings or eggs could be disturbed.

Bark girdling is another method to remove woody 

vegetation and has a positive impact in addition to increasing light. Bark girdling removes the bark, cutting 

off nutrient supplies to the roots resulting in the death 

of the plant. Once dead, the remains are referred to 

as a snag. Standing snags can provide additional habitat for a variety of species for many years. Girdling is 

an effective, inexpensive, and relatively easy selective 

technique to remove woody vegetation using simple 

tools.

Mowing and haying can be used to manage vegetation 

around and in a wetland site. Timing of such management should be such that no harm is done to native 
Bog Turtle (Clemmys muhlenbergii)

10

species of plants and animals. Care should be taken to not cut vegetation so low that it damages nests 

or kills small animals. Delaying mowing just a few 

weeks to late June or early July, or leaving unmowed 

areas as a buffer and refuge may be critical to flowering or nesting species reproductive success for that 

year. Additionally, turtles often move out of wetlands 

in late spring to utilize nearby pastures and meadows 

for feeding. Early mowing could be potentially fatal to 

some individuals.

Case studies

Conserving Maryland's threatened bog turtle

One innovative partnership in Maryland brought together private landowners and farmers with key partners such as the Natural Resources Conservation 

Service, U.S. Fish and Wildlife Service, Environmental 

Defense, and Maryland Department of Natural 

Resources to help recover the threatened bog turtle in 

Maryland. Farmers are working with agencies to find 

turtles and are carrying out monitoring of turtles by 

radio-tracking tagged animals. To date, three important wetlands have been restored, and another three 

restorations began in autumn 2005. For more information, please visit http://www.cooperativeconservationamerica.org/viewproject.asp?pid=572.

Restoring bog turtle habitat in New York

In New York, farmers have teamed up with New 

York Natural Resources Conservation Service, 

Environmental Defense, U.S. Fish and Wildlife 

Service, New York Department of Environmental 

Conservation, New York Natural Heritage Program, 

Friends of the Great Swamp, and The Nature 

Conservancy to use prescribed grazing, mechanical, 

and manual clearing of woody vegetation and limited use of herbicides and biocontrol agents to restore 

bog turtle habitat. Farmers are enthusiastic about the 

project because they are gaining new pasture, improved fencing and, in some cases, reimbursement 

for providing livestock grazing services to the project. 

Four projects got underway on private lands during 

the 2004 field season, and another six projects began 

development in 2005. For more information, please 

visit http://www.cooperativeconservationamerica.

org/viewproject.asp?pid=806. 

Assistance programs

Financial and technical assistance for wetland habitat projects are available from an array of government 

agencies and public and private organizations. Table 1 

lists the contact information of organizations that can 

provide information about wetland management, as 

well as other natural resource projects, and describes 

their associated conservation incentive programs. 

Bark girdling is an easy and effective way to remove 

selected woody vegetation while leaving additional 

habitat for wildlife.
Bog Turtle (Clemmys muhlenbergii)

11

Program Land eligibility Type of assistance Wetland restoration or enhancement 

opportunities

Contact

Conservation 

Reserve 

Program 

(CRP)

Highly erodible land, wetland and certain 

other lands with 

cropping history. Streamside 

areas in pasture 

land

50% cost-share for 

establishing permanent cover and conservation practices, and annual rental 

payments for land 

enrolled in 10- to 

15-year contracts. 

Additional financial 

incentives available 

for some practices

Plant long-term, resource-conserving covers in wetland and upland areas to improve water quality, control erosion, and enhance 

wildlife habitat 

NRCS or FSA 

State or local 

office

Partners 

for Fish 

and Wildlife 

Program 

(PFW)

Most degraded 

fish and/or wildlife habitat

Up to 100% financial and technical assistance to restore 

wildlife habitat under minimum 10-year 

cooperative agreements

Restore wetland hydrology; plant 

native trees, shrubs, grasses, and 

other vegetation; install fencing 

and off-stream livestock watering 

facilities to allow for restoration 

of stream and riparian areas; remove exotic plants and animals

U. S. Fish 

and Wildlife 

Service local 

office

Waterways for 

Wildlife

Private land Technical and program development 

assistance to coalesce habitat efforts 

of corporations and 

private landowners 

to meet common watershed level goals

Enhance wetland and adjacent 

upland habitats by planting buffers, creating habitat structures, 

and other activities

Wildlife 

Habitat 

Council

Wetlands 

Reserve 

Program

Previously degraded wetland 

and adjacent upland buffer

75% cost-share for 

wetland restoration 

under 10-year contracts and 30-year 

easements, and 100% 

cost-share on restoration under permanent easements. 

Payments for purchase of 30-year or 

permanent conservation easements

Restore and protect wetlands and 

limited adjacent upland area; improve wetland wildlife habitat

NRCS State or 

local office

Wildlife at 

Work

Corporate lands Technical assistance 

on developing habitat projects into programs that allow 

companies to involve 

employees and the 

community

Enhance wetland and adjacent 

upland habitats by planting buffers, creating habitat structures, 

and other activities

Wildlife 

Habitat 

Council

Wildlife 

Habitat 

Incentives 

Program 

(WHIP)

High-priority 

fish and wildlife 

habitats

Up to 75% cost-share 

for conservation 

practices under 5- to 

10-year agreements

Establish and improve fish and 

wildlife habitat, including wetland 

and adjacent upland habitats, particularly those for wildlife species 

experiencing declining or significantly reduced populations

NRCS State or 

local office

Table 1 Technical and financial assistance to restore or enhance wetlands
Bog Turtle (Clemmys muhlenbergii)

12

References

Online sources

Campbell, M. and M. Jones. 2000. Habitat fragmentation and birds. http://faculty.ncwc.

edu/mbrooks/pif/Fact%20Sheets/fragmentatio

n%20fact%20sheet.htm [Accessed 20 October 

2005].

Mchugh, M.J. 2000. The plight of the bog turtle. http://

www.fws.gov/northeast/njfieldoffice/FieldNote

s%20WEB%20PDF/2004_Spring_PDF/31&32_

McHugh_fullpage.pdf [Accessed 5 October 

2005].

New Jersey Division of Fish and Wildlife. 2005. Bog 

turtle: Clemmys muhlenbergii. http://www.

nj.gov/dep/fgw/ensp/pdf/end-thrtened/bogtrtl.

pdf [Accessed 9 October 2005].

New York Department of Environmental Concern. 

2005. Bog turtle fact sheet. http://www.dec.state.

ny.us/website/dfwmr/wildlife/endspec/botufs.

html [Accessed 21 October 2005].

U.S. Department of Agriculture, Natural Resources 

Conservation Service. NRCS electronic field office technical guides. http://www.nrcs.usda.

gov/technical/efotg/ [Accessed 9 February 2006].

U.S. Department of Agriculture, Natural Resources 

Conservation Service. 2005. Stream and wetland 

restoration. http://www.wsi.nrcs.usda.gov/products/stream.html [Accessed 9 February 2006]. 

The Nature Conservancy. 2005. The global invasive 

species initiative. http://tncweeds.ucdavis.edu/

[Accessed 1 March 2006]

Tortoise Reserve. 1995. Project bog turtle. http://

www.tortoisereserve.org/Research/Project_Bog_

Body2.html [Accessed 11 October 2005].

Printed sources

Bloomer, T.J., and R.J. Holub. 1977. The bog turtle, Clemmys muhlenbergii: a natural history. 

Bulletin of the New York Herpetological Society 

13:9–23.

Bury, R.B. 1979. Review of the ecology and conservation of the bog turtle, Clemmys muhlenbergii. 

U.S. Fish and Wildlife Service, Special Scientific 

Report, Wildlife No. 219. 

Chase, J.D., K.R. Dixson, J.E. Gates, D. Jacob, and 

G.J. Taylor. 1989. Habitat characteristics, population size, and home range of the bog turtle, 

Clemmys muhlenbergii, in Maryland. Journal of 

Herpetology 23:356–362.

Copeyon, C. 1997. U.S. Fish and Wildlife Service: Final 

rule to list the northern population of the bog 

turtle as threatened and the southern population 

as threatened due to similarity of appearance. 

Federal Register 62(213).

Ernst, C.H. 1977. Biological notes on the bog turtle, 

Clemmys muhlenbergii. Herpetologica

33:241–246. 

Ernst, C.H., R.T. Zappalorti, and J.E. Lovich. 1989. 

Overwintering sites and thermal relations of hibernating bog turtles, Clemmys muhlenbergii. 

Copeia:761–764. 

Garber, S.D. 1995. A 20-yr study documenting the relationship between turtle decline and human 

recreation. Ecological Applications 5:1151–1162. 

Klemens, M.W. 1993. Standardized bog turtle sitequality analysis. Unpubl. report to U.S. Fish and 

Wildlife Service, American Museum of Natural 

History, NY. 

Lee, D., and A. Norden. 1996. The distribution, ecology and conservation needs of bog turtles, with 

special emphasis on Maryland. The Maryland 

Naturalist 40: 7–46. 

Morrow, J. L., J.H. Howard, S.A.Smith, and D.K 

Poppel. 2001. Home range and movements 

of the bog turtle (Clemmys muhlenbergii) in 

Maryland. Journal of Herpetology 35:68–73. 

U.S. Fish and Wildlife Service. 1997. Endangered and 

threatened wildlife and plants; proposed rule 

to list the northern population of the bog turtle as threatened and the southern population 

as threatened due to similarity of appearance. 

Federal Register 62:4229–4239.
Bog Turtle (Clemmys muhlenbergii)

13

Primary author: Erika T. Smith. Drafts reviewed by Raissa Marks, Wildlife Habitat Council; Bill Hohman, 

U.S. Department of Agriculture Natural Resources Conservation Service; Molly Connerton, Environmental 

Defense; Jennifer Anderson, U.S. Department of Agriculture; Matt Flint, U.S. Department of Agriculture; 

Ann Somers, University of North Carolina.

www.nrcs.usda.gov

Wildlife Habitat Council

8737 Colesville Road, Suite 800

Silver Spring, Maryland 20910

(301) 588–8994

The mission of the Wildlife Habitat Council 

is to increase the amount of quality wildlife 

habitat on corporate, private, and public land. 

WHC engages corporations, public agencies, 

and private, nonprofit organizations on a 

voluntary basis as one team for the recovery, 

development, and preservation of wildlife 

habitat worldwide.

www.wildlifehc.org

© 1988 WHC

WILDLIFE HABITAT COUNCILSM

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