Text Version

Home | Translate

Biological Monitoring: Amphibians and Reptiles

What's the difference?

Amphibians and reptiles are cold-blooded vertebrates (having a backbone) and are collectively called herpetofauna, or "herps" for short. Although they are often discussed together and some may even look similar, there are several differences between the two groups.

Amphibians such as frogs, toads, and salamanders:

Are tetrapods (have four limbs)
Have moist, glandular skin
Lack scales, feathers, hair, and claws

Amphibians spend at least part of their lives in water habitats such as flowing streams, seasonal pools, or other wetland types. The eggs of amphibians lack a hard outer covering and must be laid in water or in damp places. Most amphibians hatch as aquatic larvae with gills. As these animals grow into adults, most amphibians develop lungs which they use to breathe, and are capable of living both on land and in water (some salamanders never develop lungs and breathe entirely through their skin).

Reptiles such as snakes, turtles, and lizards:

Are covered with scales, shields, or plates
Have claws on their toes

Reptiles use lungs to breathe, and generally lay eggs in terrestrial habitats (on land). The eggs of reptiles have a thick, hard shell that protects the developing embryo from moisture loss, even on dry land.

Reptiles and amphibians can often be found together, but reptiles tend to prefer drier environments while moist-skinned amphibians need to remain near aquatic, wetland, or damp forest habitats.

Return to Top

Why are amphibians and reptiles important?

Amphibians are sensitive bio-indicators of degraded stream habitats and water quality.

Stream salamanders in particular are extremely sensitive to changes in their environment because they spend their entire lives (from egg to larva, to lungless adult) in or near streams and adults breathe exclusively through their skin.

Reptiles are an important part of the food web. In addition to maintaining the natural environmental balance, reptiles provide an ecological service to humans by controlling pests such as mice, rats, slugs, crickets, termites, and other insects.

Because amphibians live in water and on land, they are an important part of the community food web in aquatic and terrestrial habitats. Amphibians also assist in controlling insects viewed as pests—mosquitoes (larvae and adults), moths, fruit flies, house files, crickets, and slugs (among others).

Amphibians are important in medical research and compounds derived from them provide biomedicines.

Amphibians and reptiles also have played an important role in human culture.

Amphibians and Reptiles at Risk

Amphibians are impacted by a variety of stressors. They act as environmental "canaries in a coal mine." Declines in amphibians can be indicative of problems in the environment that affect humans.

Threats to amphibians include:

Habitat loss (wetlands, seasonal pools, and stream riparian areas)
Acid rain and environmental contaminants
Sedimentation from erosion and run-off from impervious surface
Deforestation
Ultraviolet radiation
Invasive species

Amphibians are also facing a global decline that is poorly understood.

Reptiles are at the greatest risk from habitat loss, fragmentation, and degradation.

While some snakes and lizards are able to adapt to an urban environment, many others cannot.
Turtles and certain snake species (queen snake, northern watersnake, red-bellied watersnake, and the state-endangered rainbow snake) depend on healthy wetlands and streams.
Additionally, some reptiles, such as the eastern box turtle have large home ranges and territories. When these areas are broken up by urban developments, these turtles have a difficult time obtaining the necessary food and nutrients they need and have extreme difficulty finding a mate and an appropriate nesting site.

All reptiles are at great risk of road mortalities. Cold-blooded reptiles may be inclined to warm themselves on paved surfaces or are killed while foraging for prey. Many turtles undergo migrations to find suitable breeding habitat or locate mates.

Return to Top

What can I do to help?

If you find an amphibian or reptile, show respect.

These animals are much happier in their natural homes, not your home. It is illegal to collect animals and/or sell them without special permits and some species that are considered rare, threatened, or endangered, have even more special restrictions. Handling a herp can stress and even injure the animal.

Do not kill a snake or any other herp that is unwanted.

There is only one venomous snake in Montgomery County—the Northern Copperhead. This species is rarely encountered and often confused with harmless species such as the Northern Watersnake and Eastern Rat Snake.
If you are concerned about a snake on your property, contact DEP at askdep@montgomerycountymd.gov or Maryland Department of Natural Resources' (DNR) Nuisance Animal Hotline at (1-877-463-6497). DEP can provide information and help you with identification. Maryland DNR can assist in removing an unwelcome animal.

Make your yard amphibian and reptile friendly

Avoid chemically treating your yard with fertilizer and pesticides. The majority of these compounds are harmful, and even lethal to amphibians!

Provide habitat by allowing dead trees and woody debris to decompose naturally or install a garden pond.

If you have a pond, do not stock fish. Amphibians need fish-free ponds to breed.

Plant and encourage the growth of native plants. Learn how to identify and control invasive plants, which can impede amphibian and reptile movement and eliminate wetland and other key habitats.

Keep your pets and the animals in your yard separate! Herps are appealing prey to cats and dogs. Not only can your pets fatally injure amphibians and reptiles, but your pets can become sick or hurt as well. Keep cats indoors and be watchful of your dog.

If you have a stream in your yard, do not mow down to the stream's edge. Streams need vegetation, especially trees, to protect them and keep them healthy—and the herps need the stream! Setting the blade at the highest setting when mowing can also help!

If you have wetlands in your yard, no matter how small or mucky, leave them be and don't worry about mosquitoes—frogs, toads, and other wildlife like birds and bats attracted to the wetlands will take care of the mosquitoes for you!

Create a compost pile. Reptiles and amphibians will come to forage for food, hide, and nest.

Follow proper procedures for disposal of motor oil, chemicals, trash and other waste.

Chemicals cause death and deformities in amphibian larvae, adults, and aquatic reptiles.

Old cars, tires, and appliances can leak contaminants into the groundwater, wetlands, and streams. These items can also collect stagnant water where mosquitoes breed and harbor disease.

Improperly handled trash can attract raccoons, crows, and other wildlife that will eventually prey on amphibians and reptiles (most notably turtle nests).

Report illegal dumping

Do not release unwanted amphibian and reptile pets.

These animals do not belong outside of captivity and will either die or cause harm to the environment by killing other animals directly or by carrying harmful diseases.

Do not use amphibians as fishing bait.

There are plenty of other alternatives.

Be careful when using All-terrain vehicles; do not drive through streams and wetlands and minimize soil disturbance.

ATVs can kill animals, damage wetlands, and cause erosion and stream degradation. Limit ATV use during the spring—this is prime amphibian breeding time when the chance for mortalities and the destruction of eggs and larvae are highest.

Control sediment runoff and erosion in agricultural and urban areas.

Report sediment violations

Visit a park, your local stream, or look in your own backyard and connect to nature.

Partners in Amphibian and Reptile Conservation (Mitchell et al. 2006) promote that "an appreciation and love of nature most often begins in childhood and may generate and interest in amphibians and reptiles." Find wild places in Montgomery County

Return to Top

Where can I find amphibians and reptiles?

Herp Group	Active Period	Habitat	How to find
Salamanders	Early Spring & Fall	Spring seeps, stream margins, and wooded ravines.	Look under rocks, logs, and in leaf litter. Looking carefully in the stream channel or in a seasonal pool can help you spot larval salamanders. Salamanders are also very active in rainy periods and at night.
Frogs and Toads	Early Spring & Summer	Often encountered by stream margins.	Flip cover objects, walk slowly along stream and pond edges. Listen carefully—a lot of frogs, especially treefrogs, will announce their presence with a call! Frogs are particularly active during rainy periods and at night.
Lizards	Emerge from winter dormancy in late April, breed in the spring, and active throughout. Begin hibernating in late September.	Skinks are found in the vicinity of streams. Active during the day.	Flip cover objects and look carefully at stone walls and debris piles. Look for them basking in the sun or running away from you!
Turtles	Active March/April to October.	Most species are aquatic; typically in larger streams and rivers. Terrestrial turtles can still typically be found by streams.	Walk carefully and look closely. Turtles are most often encountered when they are basking on a log or on vegetation.
Snakes	Most active from mid-April to mid-June and again in late August and early September.	Along the margins of streams and lakes and around human habitation. Small to medium-sized terrestrial snakes are most likely to be found under cover objects.	Flip cover objects, especially rotting logs, rocks, stick piles, and tin and metal sheets. Look carefully at shrubs, bushes, and trees for some species.

Return to Top

Monitoring Goals

DEP recognizes the importance of amphibians and reptiles as indicators of water quality and includes them in the County's biological monitoring program.

DEP is using its amphibian and reptile monitoring program to:

Assess stream conditions

Stream salamanders are good candidates as a second indicator of water quality (where benthic macroinvertebrates are the first) in small headwater streams where fish are not reliable indicators.
Trend analysis can be used to help assess effectiveness of land use practices and policies directed at water quality protection.

Evaluate watershed health

Amphibians and reptiles are important contributors to aquatic biodiversity and vital components of aquatic and terrestrial food webs. They are included in the evaluation of stream and riparian habitat quality and overall watershed health.
Distribution data is needed to best understand how to protect amphibians and reptiles and their key habitats. Amphibian and reptile habitat is directly linked to streams, wetlands, and overall water quality. By comparing present distributions to historic records we can infer what changes have occurred that caused a loss of individuals in an area, what conditions are needed to keep the individuals we have, and possibly restore species that were displaced.

Provide a service to County Residents

Amphibians and reptiles are easily recognized by the public, which associates them with the natural ecology of this region. They can be used as symbols of public support for their conservation and protection.

Return to Top

Monitoring Design

Montgomery County began a pilot program in 2001 to gather distributional data. The methods and data were evaluated in 2007, after which a full amphibian and reptile monitoring program was established in 2008.

Pilot Program

The goal of the pilot program was to get a general idea of presence or absence of herpetofauna species in the County and to investigate a future index of biological integrity (IBI). From 2001-2007, DEP collected herpetofauna data as part of a pilot program. The pilot program consisted of spring and summer ten-minute visual encounter survey searches on both sides of the stream and in the stream channel. Findings of herpetofauna habitat were also recorded. Amphibians and reptiles were anecdotally noted in electrofishing or benthic collections.

In addition to general herpetofauna searches, targeted searches for vernal pools were done with the intent of better understanding their distribution throughout the County. Vernal pools, also known as seasonal pools, are small temporary wetlands that are isolated from other permanent surface water connections, have fluctuating water levels and dry periodically. Vernal pools have a distinctive biological community of animals that are specially adapted to these conditions (Brown and Jung 2005).

Two methods were utilized for surveying vernal pools:

Search of the riparian area during spring monitoring at the biological monitoring sites and recording only location and size of pools.
Watershed walks to locate pools with a GPS, searching specifically for pools, and recording attributes and amphibian community information for each pool.

Established Monitoring Program

In the summer of 2007, Montgomery County conducted stream salamander sampling using Maryland Biological Stream Survey methods (MD DNR, CBWP/MANTA 2007) at twelve stations. Stations were selected based on an inferred likelihood of encountering stream salamanders, crayfish, and freshwater mussels.

Three-part Sampling Techniques

Following evaluation of the pilot program, DEP determined that herpetofauna data is important to collect, and moved to monitoring via:

Time-constrained searches
Incidental encounters
Stream salamander targeted sampling

Time-constrained searches are conducted during spring and summer in conjunction with other biological monitoring (benthic macroinvertebrates and fish). The stream channel and left and right riparian areas (vegetated areas paralleling the stream) associated with the 75 meter stream sampling segment are searched for 10 minutes each. Searches are based on visual encounter surveys of best available habitat. Preferred herpetofauna habitat consists primarily of cover objects (logs, rocks, vegetation, and even trash) and wetlands (such as seeps, springs, and seasonal pools). Species, life stage (adult, larva, egg), number of individuals, and type of habitat searched are recorded. Amphibians and reptiles found in vernal/seasonal pools are recorded, but no special search effort or data collection is applied to seasonal pools.

Incidental encounters of herpetofauna consist of any amphibian or reptile observed outside of a search effort. This could occur while collecting organisms for benthic macroinvertebrate or fish sampling, evaluating habitat, collecting water quality, accessing a site, setting up a block net, or just walking around. The species, life stage, and number of individuals found are recorded along with the method of observation (incidental stream channel, riparian, D-net/electrofishing).

Stream salamander targeted sampling is being incorporated as a focus of the amphibian and reptile monitoring. In 2008, stream salamander data was collected at sites too small to fish (where only benthic macroinvertebrates had been collected) and in areas selected for long term monitoring (Special Protection Areas and Clarksburg Integrated Ecological Study Areas).

Stream Salamander Index of Biotic Integrity

Data from the first year (2008) of stream salamander sampling will be evaluated using the Stream Salamander Index of Biotic Integrity (SS-IBI) (Southerland et al. 2004; Southerland and Franks 2008). The current metrics for the SS-IBI in the Piedmont Region are:

Species richness and composition (Number of species)
Abundance (Number of salamanders)
Species tolerance (Number of intolerant salamanders)
Reproductive function (Number of adult salamanders)

This evaluation will determine if a modification to the IBI scoring methodology is needed. The IBI is being evaluated by the Maryland Biological Stream Survey.

Return to Top

Data and Species List

View a list of species found in Montgomery County (PDF, 1 pg, 52K)

Available Data: Montgomery County has amphibian and reptile data from its pilot program (2001-2007). Data from 2008 is expected to be available in the future.

Data Description: Herpetofauna Pilot Program (2001-2007) Data Table
Field	Description
Station	The station field is a nine character code that identifies the monitoring station name. The stations are a combination of the two letter code for the watershed + the two letter code for the subwatershed + the single digit stream order code (1-4) + the sequential reach number (01-99).
SampleDate	The date that the station was sampled.
Cname	The common name of the species found followed by the life stage found (A=adult, L=larval, E=Egg). Example: American Bullfrog_A.
Scientific_Name	The scientific name of the species found.
RBCount	The number of individuals found during the right bank effort search.
LBCount	The number of individuals found during the left bank effort search.
StrChCount	The number of individuals found during the stream channel effort search.
A_StrCh	The number of individuals found in the stream channel anecdotally from collection in the D-net in the spring, or during summer electrofishing.
A_InStr	The number of individuals found in the stream anecdotally.
A_RipZone	The number of individuals found in the riparian zone anecdotally.

Submitting a Data Request

If you are interested in obtaining data or protocols, please contact DEP at askdep@montgomerycountymd.gov. In your request, please provide the following information:

Name, organization (if applicable), phone number, and/or email address
Type of data requested
Time frame requested
Explanation for use of data (helps to personalize the data request)
Preferred method of data retrieval (email, CD by mail, FTP, pick up CD or materials from DEP offices)

Return to Top