Restoring and Managing Habitat with Amphibians and Reptiles

Restoring and managing habitat for amphibians and reptiles requires knowledge beyond plants. In bringing the health back to our lands we are regenerating habitat and reestablishing ecosystems. This is not a linear process and involves more than plants. It involves using a variety of management techniques in differing seasons and tailored to various species. It’s certainly not a one-size-fits-all plan. When you read these guidelines by Rebecca Christoffel, it becomes clear the special needs of our herptiles. 

Author: Rebecca Christoffel, Christoffel Conservation

Restoring and managing land with amphibians and reptiles, i.e. herpetofauna, in mind is not the same as doing so for birds or mammals. Birds and mammals are warm-blooded and tend to be rather mobile. On the other hand, herpetofauna are generally not very mobile. In Wisconsin, amphibians and reptiles are either dormant or very sluggish during the colder months (~Nov – Feb). The same techniques to restore and manage habitat can be used for any of these animals, but timing and application of the techniques will differ.

Following are some general guidelines for using land management techniques when herpetofauna are present. It must be noted that any given technique can have effects that vary among species and can differ in how or when it is appropriate to use.

Herbicide Applications

Avoid broadcast spraying herbicides. Spot treat using a foliar application or cut and apply herbicide to the stem, stump or bark. These techniques provide much greater control of herbicide application, reduce the amount of herbicide used, and decrease the potential for herbicides to enter nearby surface waters or groundwater.

Pickerel frog, rana palustris
Pickerel frogs (Rana palustris) and other amphibians are very sensitive to broadcast spraying of herbicides

Prescribed Burns

The following discussion of herpetofauna and prescribed fire is taken largely from the Midwest Partners in Amphibian and Reptile Conservation (PARC) website.

There is a common misconception among some land managers that if they stomp around a burn site prior to ignition, turtles and snakes will flee the area.  This is untrue.  Most turtles and snakes “freeze” when heavy machinery or stomping happens in an area rather than fleeing.  Especially when herpetofauna have newly emerged from hibernation in the spring, and just prior to starting hibernation in the fall, they are likely to be very sluggish and unable to escape fire, mowers, predation, etc.

Repeated burns will have cumulative effects on population viability.  Populations of turtles and many snake species cannot persistently withstand even small increases in mortality.  While only a few individuals may be lost during a single burn, repeated losses of a few individuals can quickly deplete populations of long-lived, slowly maturing animals such as turtles and many snakes. Alternate burn periods and burn units among years to provide relief to vulnerable herpetofauna.

Plan for Refugia

Refugia is important for all wildlife. Avoid burns that completely expose soil over extensive areas. Active season burns should be conducted when weather or site conditions (high humidity, green vegetation, low temperatures) will result in spotty burns, thus providing refugia for herpetofauna.  Alternatively, fire breaks should be created around select snags, standing dead trees, and downed logs to provide places for animals to escape the heat and flames.

Winter Burns

Conduct prescribed burns during winter, when herpetofauna are inactive This period is from November 1 to March 15 generally, but varies based on fluctuations in annual precipitation and temperature conditions.  When soil surface temperatures exceed deeper soil temperatures, it indicates the onset of activity for many species.  But because some salamander species and Blanding’s turtles emerge from hibernation very early, February burns may impact them. Burns should only be used in habitat with ornate box turtle during their winter hibernation period.

Blanding’s turtle take 17 years to reach reproductive age. One wrongly timed burn can reduce populations substantially.

Spring Burns

When burning after March 15, you can minimize harm for many species if cool (overcast, and under 50°F) conditions have persisted for many days. Management plans should be flexible, allowing you to respond to each year’s conditions. Spring burns in close proximity to snake hibernacula should be conducted well before the active season or NOT AT ALL. Fire breaks and buffers constructed around known hibernacula may protect animals during a burn, but this isn’t a given.

Fall Burns

Fall burns should follow an approach that takes the above guidelines into consideration.  October is analogous to late March or early April, therefore many species may still periodically be on the ground surface and active.  Burning prior to November 1 is discouraged.

Ignition Patterns

Different kinds of fires and ignition patterns should be used when burning habitat with herpetofauna. It is important to know the species you are potentially impacting and their response to fire prior to using a particular burn method. In spring, sluggish herpetofauna are unlikely to be able to “outrun” a fire of any sort. Avoiding a ring or perimeter ignition pattern will allow snakes opportunities to escape a fire. Few herptiles can “outrun” fires in any season.  A rate such as 10 ft. per minute may allow time to flee for those species which evade fire. However, faster fires will leave unharmed areas under logs and other cover objects, providing safety to species that tend to hide.

Wetland Burns

Wetland shorelines should only be burned when a management objective specifically requires it.  Detritus provides cover for amphibians as they migrate to and from wetlands to breed.  Create burn breaks around these areas of at least 50 ft when possible, using a leaf blower or rakes.

Burning Brush Piles

Avoid constructing brush piles unless you plan to burn them immediately. Brush piles attract many amphibians and reptiles.  Snakes and other wildlife will take advantage of new habitat like brush piles, creating traps during burns. If piles are left for more than a few weeks, disassemble them prior to the burn. Older brush piles with burn breaks around them provide refugia during a fire.

Burning a brush pile
We burn piles as we create them unless we plan to leave them as habitat.

Mowing

Mow to restore or manage habitat when herpetofauna are least active. To reduce herpetofauna injuries and mortality, mow at high blade settings (8” or higher) and use mowing systems that do not create suction.  If you must mow during the active season, do so once wildlife breeding season is over and turtle hatchling emergence has not begun (generally after July 10 but before August 15), mow during the warmest part of the day on sunny, hot days (>88°F), and mow only a portion of contiguous habitat at a time.  Disking is discouraged as it causes direct mortalities and disrupts soil structure.

Brush Clearing

If cutting down trees or clearing out shrubs, do not use heavy machinery. Use hand-operated tools, such as chain saws and brush cutters. Large machinery should be restricted to the overwintering period (Nov 1 to Mar 15), ideally when there is frost in the ground to minimize vegetation damage.

It’s important to leave cover for amphibians and reptiles, even those that are typically thought of as “prairie” specialists.  For example, juvenile ornate box turtles that were radio-tracked for a season were found to heavily use patches of sumac and black locust rather than be exposed to the greater temperatures and lesser humidity in more open and sunny areas of the prairie.

Other Considerations

Consider structural needs of the species present.  Although some habitats are not botanically rich, many such places support populations of herpetofauna. These species often associate with structure or prey base rather than specific plant assemblages and can flourish in areas that are of low botanic quality. For example, population levels of some larger snakes, such as bullsnakes, are more dependent on availability of small mammals, their prey, than on the quality of the habitat.  With a good prey base, they will frequent open areas with very little native vegetation. Consult local experts prior to initiating intensive restoration efforts in such areas as these actions may have greater negative effect on animal communities than no action at all.

For more information:

 Midwest PARC Habitat Management Guidelines

Midwest PARC Prescribed Burning Guidelines –

Wetland Restoration Handbook for Wisconsin Landowners

Protecting turtle nests in Wisconsin 




Bio Blitz-ing

I attended my first insect bio blitz last Saturday (26 Jul 2014) at the Erickson Wetlands in Argyle, WI. The Driftless Area Land Conservancy (DALC) is responsible for this fabulous new land legacy which encompasses 220-acres of diverse habitat which contains multiple sloughs and oxbow lakes and over a mile of Pecatonica River frontage.

Earlier in the year, we joined the folks from Applied Ecological Services (AES) on several bio blitzes that identified plants, aquatic life, birds, and “herptiles.” DALC has hired AES to create a mangement plan for the property. In order to do that effectively and responsibly, it’ important to understand the biota in the area. Here’s some photos from an earlier bio blitz.

We did some seining in the river first. Here's a tadpole.
We did some seining in the river first. Here’s a tadpole.

Mike McGraw with a Common Snapping Turtle (Chelydra serpentina).
Mike McGraw with a Common Snapping Turtle (Chelydra serpentina).

Mike checking for eggs from Blanding's Turtle (Emydoidea blandingii).
Mike checking for eggs from Blanding’s Turtle (Emydoidea blandingii).

Susan Lehnhardt photo'g the biggest ant mound we've ever seen!
Susan Lehnhardt photo’g the biggest ant mound we’ve ever seen!

The purpose of this particular blitz is to learn about what insects use this property. These events are never a “one and done” occasion; they are merely one of countless that will occur over many years into the future. They do provide an initial assessment of the life that is present, which in turn, provides data that will be used for ascertaining land management plans.

We had a great turnout with a number of members from the Wisconsin Entomological Society (WES). We had beetles experts, tree cricket experts, moth experts, and generalists. We met at 4pm and did some collecting and surveying of the area to figure out the best place to set up for the night event. Then off to Good Fellas, a local pub, for some tasty dinner and great conversation.

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A few of the WES folks getting oriented before we begin. L-R: PJ Liesch, Steve Bransky, Kyle Johnson, Susan Lehnhardt

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We started by checking out some insects on a beating sheet.

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Trekking down one of the paths.

There was a black light set up and two mercury vapor set ups, each with white sheets hanging vertically near them. A black light is an ultraviolet (UV) light which broadcasts light spectrums that are highly visible to insects. The mercury vapor light emits a higher spectrum of UV light and a much more intense light than black lights; they attract more insects and possibly a larger diversity of insects. Since night-flying insects navigate by the stars and the moon, the lights create an artificial moon, attracting them to the white sheets; this makes it easy for humans to observe, collect, and photograph these insects.

Once the lights were set up, it didn’t take long for the insects to arrive! The lights coupled with the fog arising from the water and moist ground created an eerie green glow across the land.

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Nancy Collins took a great photo of the essence of this nighttime blitz!

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Once the lights were up, it was great fun checking out all the interesting insects! In the foreground is Jordan Marche checking out the beetles.

Within minutes, two uncommon/rare moths were found. One was an Underwing (Catocala sp) and the other was called a Silphium moth. Many county records were established on this night but it will be sometime in the winter before the insects are vouchered and the photo IDs made. When that list is created and shared, it will be the same level of excitement all over again!

Here’s a few more random shots from the evening.

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Frogcicles

As the thermometer suddenly dipped low this week to single digits and below-zero temps, my thoughts go to the critters outside and how they are surviving and dealing with this cold.  Most recently, I’ve been thinking of and reading about amphibians.

Most amphibians survive winter by burrowing below the frost level either in the ground or at the bottom of a pond or lake. If that lake or pond freezes completely though, those nestled in will not survive. There are 3 frogs in Wisconsin that actually freeze and overwinter in our woods under leaf litter, rocks, or logs.  These three freeze-tolerant species are wood frogs (Rana sylvatica), spring peepers (Pseudacris crucifer), and gray treefrogs (Hyla versicolor).  Wood frogs and spring peepers use glucose as their antifreeze and the gray treefrogs use a type of alcohol.

John Himmelman’s book entitled Discovering Amphibians has offered the easiest explanation of how frogs “freeze” that I’ve found. I’ll paraphrase the process. When the frogs freeze, it’s all done outside of the individual cells with 50-65% of the body freezing and becoming hard. Any freezing inside of the cells would kill them. While the liver is increasing its productions of glucose or alcohol, the cells and organs are removing water, sending it to other areas of the frog’s body. This prevents ice crystals from forming in these areas and the resulting physical damage of those crystals. There is a particular sequence which the freezing follows and not surprising, the spring thawing processing uses the same sequence in reverse.

Thawing has its 2 major hazards: a large dose of oxygen entering and the unavoidable ice crystal damage. Cells that are inundated with oxygen after they have been without this gas can be fatal. To deal with this, frogs have an abundant source of antioxidant enzymes that balance the chemical reaction caused by this onslaught of oxygen. For those who read about health and aging issues, it’s those free radicals that we want to tame to prevent aging that the frogs need to tame in order to safely thaw. To combat the ice crystal damage to blood vessels, which would cause bleeding and clotting issues, the liver produces a protein that counters this and assists with repairing any damage.

For the wood frogs and spring peepers, they have an additional third hazard – excess glucose. This is similar to diabetes in humans and likewise, it is harmful to the frog’s metabolism. Understanding the frog’s ability to safely clear this excess from their bodies is just one of many ways that our fellow critters on earth can help us to improve our lives.

While I watch the snow fly and I snuggle in for another Wisconsin winter, I’m always mindful of the many ways we all deal with overwintering!




A Chorus of Song

The Western Chorus frogs (Pseudacris triseriata), now known as the Midland Chorus frogs, are singing loud and clear. Their voices are huge and can be heard from a ½ mile away! Their name was changed when it was discovered that their range was much smaller than originally thought. 

western chorus frog, Pseudacris triseriata
Western chorus frog (Pseudacris triseriata), also known as striped chorus frog.

Their song is one of the first frog songs I learned. It’s easy to remember and easy to pick out when in the field. It sounds like someone raking their thumb across a comb. They love the woods and the dense, wet vegetation near the streams behind us and across the highway from us.

These frogs are ¾ – 1 ½” in size, greenish body with thick brown stripes running from head to rear. When they call, they are advertising themselves to the females. Interestingly, they call from an upright stance, positioning their bodies parallel to grass blades. Makes it difficult for us to find them but apparently not for the females!

To hear their song, go to:
If you want to learn the songs of frogs and toads, The Frogs and Toads of North America by Lang Elliott, Carl Gerhardt, and Carlos Davidson is a worthy read. It includes photos for each and a CD of their songs.



Spring Peepers

Spring has sprung, according to our amphibian friends. The Spring Peepers are one of the first frogs to start calling and they were out in fury last night. They live in moist woods but breed in adjacent wetlands. They stay pretty much to the ground and hibernate under logs and loose bark. We don’t keep a “tidy” woods so this is perfect for them and with the neighboring spring-fed stream, they are pretty happy. I’ve had the pleasure of seeing them before, but it’s rare.
National Geographic has a color picture and a place you can click to hear their purrrreeeek call.