Restoring and Managing Habitat for

Restoring and Managing Habitat for

Reptiles and AmphibiansIowa houses a diverse assembly ofreptiles and amphibians, collectivelycalled herpetofauna. Iowa is inhabit-ed by 22 species of amphibians and46 species of reptiles. Herpetofaunaplay an important role as insect androdent predators and as valuableprey for various birds, mammals,fish and insects. Four of Iowa'samphibians (18%) and fifteen ofIowa's reptiles (33%) are listed aseither threatened or endangeredspecies. The leading causes for her-petofaunal decline in Iowa andacross the world are attributed to

habitat destruction, degradation, andfragmentation.

The successful restoration and man-agement of wildlife areas for her-petofauna must take all stages oftheir life history into account.Restorations must provide access tofood, shelter and migration corridorsas well as hibernation, aestivation,breeding, and nesting sites. Thisdocument provides recommenda-tions for restoring and managingprairies, woodlands, streams, rivers,and wetlands for Iowa herpetofauna.

Helping People Help the Land1Natural Resources Conservation Service

The Blanding’s turtle is a threatenedspecies in the state of Iowa. This speciesis an indicator of diverse wetland com-plexes with intact aquatic migration corri-dors needed to meet this turtles life his-tory requirements. A female Blanding’sturtle can reach 80+ years of age andmay travel over a mile to reach nestinggrounds in the spring. (Photo by JenniferAnderson-Cruz)

Amphibian: Amphibians are vertebrate animals such as frogs, toads, and salamanders. Amphibians have a moist,permeable skin and are cold-blooded. Amphibians lay shell-less eggs in water which later hatch into gilled aquaticlarvae (ex. tadpoles). The aquatic larvae metamorphose into lunged adults that may or may not leave the waterdepending on the species.

Amphibians have an elevated exposure risk to pollutants due to their absorp-tive skin, bi-phasic aquatic and terrestrial life stages, and migratory behaviorpatterns. The northern leopard frog has been declining throughout its rangeand has been plagued by unexplained malformations over the last severaldecades. It is suspected that several environmental and land use factorsmay be to blame. (Photo by Jennifer Anderson-Cruz)

The Great Plains Skink is an endangered reptile species in Iowa.The dry skinand scaled body allow this lizard to live in dry prairies where its claws areused to burrow into loose soils to escape hot summer days or cool nighttimetemperatures. (Photo by Jeff LeClere)

Reptile: Reptiles are cold-blooded vertebrates such as snakes, turtles, lizards, and crocodiles that breathe withlungs and have dry skin covered with scales and horny plates. Reptiles lay shelled eggs on land with the exception ofseveral species of snake which retain the eggs and give live birth. Reptiles do not have a larval stage.

Restoring and Managing Habitat for Reptiles and Amphibians


Management practices commonlyused to manipulate the structure andcomposition of vegetation withinrestorations can exert immediate,short-term, and long-term effects onherpetofaunal assemblages. Prescribedfire, mowing, grazing, and forest thin-ning are examples of disturbance tech-niques habitat managers employ tomimic the natural process that shapedunique and contrasting ecosystemsprior to European settlement. Many ofIowa’s historic habitats, includingchestnut-oak-hickory forests, wetlandsand prairies were created and main-

tained by predictable, periodic distur-bances (fire, flood, wind, herbivory)of varying intensity, frequency, andduration. Within an ecosystem, adiversity of plant and animal speciesare housed, each with its own toler-ance for disturbance. Balancing theneeds of disturbance adapted and con-servative “climax” species within arestoration takes an understanding ofhow each management techniqueworks and the ability of a site's plant

and animal life to cope with theimpacts of management, both in theshort and long-term outlook. Withinthis section we will look at how habi-tat management practices may affectherpetofauna and how negative effectscan be minimized.

The best method for avoiding herpeto-faunal mortality due to site manage-ment is to conduct any of the belowmentioned management treatmentsoutside of herpetofaunal activity peri-ods. In general, Iowa’s herpetofaunahibernate from mid-October throughMarch and are least impacted by man-agement during this time period. Ifmanagement is to occur within theherpetofaunal active season, severaldifferent approaches may be taken tominimize impacts. Herpetofauna aremost active when air temperatures arebetween 50-80 degrees F and afterrain or flood events; therefore, a suit-able time to conduct management isduring the hottest part of the day, dur-ing a dry spell, or on unseasonablycool days. The highest potential formortality due to site managementoccurs during spring and fall migra-tions to and from breeding or winter-ing habitats. Becoming familiar withthe migratory behavior of herpetofau-nal species known to occur within therestoration area is critical in formulat-ing a management plan that willreduce the chances for managementduring mass movement of herpetofau-na. Due to the weak dispersal capabil-ities of many herpetofauna, emigrationof animals during and immigration ofanimals post-management is most suc-cessful for sites within 200 meters ofsuitable untreated habitat. It is there-fore advised that a site be managed ona rotational basis with no more than1/4 of the site impacted in any givenyear.

Prescribed fire is commonly used toreduce the presence of unwanted,weedy vegetation, to encourage oakdominance in woodlands, and nativevegetation in wetlands, prairies, andsavannas. To a certain degree, her-

petofauna have physiological and/orbehavioral strategies for survivingevents of fire. Examples of fire avoid-ance include the fossorial behavior ofsalamanders and toads, the use ofmammal burrows by the bull snake,and the use of crayfish burrows bywetland dependant snakes and frogs.Several studies on the effects of pre-scribed fire have shown negativeimmediate impacts on herpetofaunalcommunities, but upon further study itwas found that herpetofaunal commu-nities responded positively over thelong-term with increased species rich-ness on sites where burns hadoccurred within the past decade.

The herpetofaunal species most sensi-tive to the effects of fire are thosewhose habitat requirements includesignificant amounts of leaf litter, duff,or other cool, moist substrate normallyconsumed during a burn. Many ofIowa’s salamander species fall intothis category and may not return to aburned site until litter has accumulat-ed for several years after a burn. Insuch situations, it may be wise to cre-ate fire breaks around cover objects,brush piles, etc., to protect these vitalhabitat components. As with all distur-

Habitat ManagementPractices

In Iowa, cricket frogs prefer water bodieswith exposed, muddy banks commonlyassociated with early successional envi-ronments. A study found that 100 ofthese nickel-sized frogs can eat morethan 480,000 insects in one season. TheBlanchard’s cricket frog is undergoingrange restriction in the Midwest forunknown reasons. (Photo by JenniferAnderson-Cruz)

The effects of fire vary depending uponthe frequency, intensity, and seasonwithin which the prescribed burn is con-ducted. (Photo by Angela Biggs)



bances, frequency will determinewhether a given species will persist orexpire on a site; therefore, fire inter-vals of 3-7 years or greater have beenrecommended in order to maintain ahealthy plant and herpetofaunal com-munity.

Mowing is a common managementtechnique used to manipulate vegeta-tion, especially on sites where firemay not be feasible. Herpetofaunamay be run over by a mower or killedby the mowers blades; instances foundto cause mortality of herpetofauna ifconducted during peak foraging timesor during migrations. Increasing the

deck height of a mower to 10-12 inch-es will reduce the potential for her-petofaunal run-ins with blades andmeets the requirement for mowingwarm season vegetation. When possi-ble, begin mowing at the center of atreatment area, progressively mowingout from the center to allow wildlifeto flee in all directions and notbecome trapped to one side. To reducethe area impacted by the mowers tires,effort should be made to follow theoutermost tire track of a previous passwhich will reduce animal mortalityand soil compaction. Cover objects,logs, or other potential refugia shouldbe avoided and left undisturbed whilemowing.

Disking is a practice used to controlunwanted vegetation and to provideareas of bare ground and sparse vege-tation to encourage inhabitance ofearly successional species such as thecricket frog and massassauga. Diskingshould be no more than 6 inches deepand occur on a rotational basis outsideof herpetofaunal activity periods.Areas containing turtle nestinggrounds, hibernation areas, woodydebris, or other cover objects shouldbe avoided.

If managed properly, grazing canimprove grassland habitats for her-petofauna by maintaining evenness inthe vegetative community and by pro-viding basking areas. Prescribed graz-ing and flash grazing are examples ofsuitable grazing practices whoseintensity and frequency can be set toachieve the maximum benefit for cat-tle and wildlife. If located within pas-ture, it is advised to minimize accessto water bodies (streams, rivers, wet-lands, and ponds) through controlledaccess, constructed crossings, or toexclude cattle from the riparian corri-dor with fencing. It is important toinclude riparian buffers in a pasturemanagement plan to protect shorelinehabitat and water quality (see sectionon buffers).

Nutrients and pesticides may beused for various reasons on and/oradjacent to restoration areas, posingserious risks to herpetofauna if usedincorrectly. Prior to the purchase andapplication of fertilizers or pesticides,there are several things to consider.

Mowing an area from the center outallows wildlife a greater chance of escapethan traditional mowing patterns.

There are several disking techniques usedto restore or maintain early successionalplant communities and associated wildlife.In this particular area, the US Army CorpsOf Engineers is utilizing strip diskingwhich will create a mosaic of early suc-cessional and established plant stands.(Photo Courtesy of USACOE)

Fencing cattle from stream corridors willpromote both instream and riparian habi-tat for wildlife, including herpetofauna.

Habitat ManagementPractices cont...

Toads are hardy amphibians with burrow-ing capabilities that allow them to escapefire. Toads also have a drier skin thanmost amphibians which reduces evapora-tive loss in drier, recently burned habi-tats. The American toad is the onlyamphibian that has been found toincrease in population in response tourbanization in Iowa and Wisconsin.(Photo by Jennifer Anderson-Cruz)



The first consideration; what’s to beaccomplished? If attempting toimprove soil fertility, conduct a soiltest to determine which nutrients aredeficient, where they are deficient,and the amount of each nutrient need-ed to reach set goals. If trying to rid asite of unwanted pests and plants,scout the area to determine whether

the entire site needs to be treated orwhether there are certain “problemareas” that can be spot treated.Secondly, be sure to apply nutrientsand pesticides at the correct time andin the approved places. All pesticideshave use restrictions. For example,some pesticides should not be appliednear water bodies or above certain airtemperatures. Whether used on arestoration site, crop field, or an urbanlawn, all chemical applicators shouldbe regularly maintained and calibratedto ensure nutrients and pesticides arebeing applied at the correct rate. Over-applying fertilizers and pesticides orapplying them at the incorrect timeand/or place poses risks for transportto surface and ground waters or to theair through volatilization. Severalstudies have found that high nutrientor pesticide content in breeding ponds

can cause malformation and death inlarval amphibians or have indirecteffects on growth and food resources.Becoming familiar with the restric-tions and instructions for the fertilizeror pesticide planned for use willensure your treatment is effective,safe, and legal.

Low to no input nutrient and pestmanagement techniques are effectivein protecting environmental qualityand reducing the long-term costs ofsite management. Planting a widearray of plant species will reduce therisk of catastrophic disease or pestinfestation within a restoration andwill increase resource competitionreducing the threat of invasion byunwanted plants. Legumes, plants thathouse nitrogen fixing microrhiza, canbe planted within a restoration toimprove soil fertility in a slow release,plant available fashion. Organic fertil-izers, like legume manufactured nutri-ents, are systemically released intosoils during optimal microbial condi-tions which coincide with optimalplant growth. Organically derivednutrient sources are stable and rela-tively unavailable for transport bywater, posing little risk for surface orground water contamination comparedto those that are applied chemically.Another way to reduce potential con-tamination and reduce the risks tonon-target species would be to usebiological controls (i.e. ladybugs,preying mantis, BTI, etc.) for pestmanagement.

Woodlands are vertically stratifiedinto vegetative zones including theforest floor, understory, shrub, sub-canopy and canopy, providing struc-tural complexity for herpetofauna toexploit. Promoting structural andspecies diversity within the forestplant community can be accomplishedthrough manipulation of the forestcanopy, by using prescribed fire, andby undertaking invasive species con-trol. Each of these management tech-niques should be used according tosite conditions and with the assistanceof a forester.

Forest management strategies for rep-tiles differ from those for amphibians.Amphibians prefer forests with densecanopy cover that promotes a shaded,cool, moist environment with sparseunderstory vegetation and a highamount of litter on the forest floor.Salamanders have been found to pre-fer woodland habitats with low edgeto volume ratios, whereas the presence

Scouting for pests to catch infesta-tions early may reduce the amountand extent of pesticide needed, reduc-ing the use of potentially harmfulchemicals that could pollute herpeto-faunal habitats and food items.

314 Brush Management

338 Prescribed Burning

472 Use Exclusion

528A Prescribed Grazing

590 Nutrient Management

595 Pest Management

645 Upland Wildlife HabitatManagement

647 Early Successional HabitatDevelopment

Applicable Iowa NRCSStandards -

Habitat Mgmt. Practices

Woodlands

Habitat ManagementPractices cont...



of frog and toad species do not seemto be as affected by this habitat attrib-ute.

Forest openings as well as walkingpaths and roadways promote warmer,drier forest conditions by allowing airflow, a consideration that should beaddressed if such openings are expect-ed to be part of a management plan.Drier, more open woodland habitatsare generally preferred by reptiles.Managing habitat for reptiles may

include tree harvesting (thinning,regeneration cuts, shelter wood cuts,clear cuts, selective cuts) every 10-20years to open the forest canopy or byintroducing prescribed fire. Woodlandareas visited by ornate box turtles andwood turtles may be enhanced by theestablishment of fruiting species suchas wild raspberry, blackberry, plum,strawberry, and grape which constitutea large part of the turtles diet duringpart of the year.

Due to the stark differences in wood-land habitat preference between rep-tiles and amphibians, rotational man-agement techniques are stressed toprovide cover and refuge for both fau-nal groups within a restoration.

Prairies and savannas can be main-tained for herpetofauna by providing astructurally and species diverse plantcommunity that will support diversefood resources as well as animals thatconstruct burrows used by prairiedependent herpetofauna for shelter,nesting, and as hibernacula. Coverobjects, constructed hibernacula,brush and rock piles are commonly

missing in traditional restoration plansand should be included to provide anarray of habitat for prairie dwellingherpetofauna (see microhabitat sec-tion).

Dense tallgrass stands are unsuit-able for most herpetofauna due toimpedance of movement and a lack ofsuitable basking habitat. Increasingthe forb and short-grass componentsof a seeding mix will result in greatervegetative coverage by plants thatprovide interstitial space conducive toherpetofaunal movement and basking.This is especially true when using var-ious hemiparasitic plants such aslousewort, toadflax, or paintbrush.Within existing grass stands, managedgrazing practices, mowing, diskingand interseeding can be implementedto open the grass canopy, improvingits appeal to herpetofauna and otherwildlife alike. Conversely, frequentlyand/or recently disturbed sites withsparse vegetation offer too little shel-ter from temperature extremes, thesun, and predators. Examples of thiscondition may be apparent in over-

Wood turtles frequent riparian woodlandsin search of food and shelter. When infruit, plants such as blackberries, wildgrape, plum, and strawberry becomeimportant wood turtle food plants. (Photo Courtesy of Cornell College)



612 Tree/Shrub Establishment

643 Restoration and Managementof Declining Habitats


666 Forest Stand Improvement

Applicable Iowa NRCSStandards - Woodlands

Woodlands cont...

Prairies and Savannas

Remnant sand prairie, Polk County,Iowa. (Photo by Jennifer Anderson-Cruz)

Berry's Woods Preserve, Warren County,Iowa. (Photo by Jennifer Anderson-Cruz)



grazed pastures, recently disturbedfields, or in urban environments.When dealing with sites under suchcondition, reduce the frequency andintensity of the disturbance affectingthe site and develop a managementplan to improve the vegetative com-munity. The creation and placement ofsuitable shelter throughout the sitewill provide refuge for herpetofauna

while natural refugium is developing.Prescribed burning is often used as amanagement tool to deter encroachingwoody and invasive vegetation inprairie habitats and to manipulate thestructure and composition of nativevegetation. Prairie burns are generallyhotter and more intense than those inwoodlands. A hot, high intensity burnmay reduce organic matter, result inelevated soil temperatures that areintolerable for burrowing organisms,and cause deleterious effects on thevegetative community. Cautiouslyplanning and conducting a prescribedburn with a trained professional will

prevent unintended, adverse effects ona site's flora and fauna and will offer asafer burning environment. As always,rotational management will ensurethat there are areas within the prairiewith sufficient duff to provide cool,moist, shaded habitats preferred bysome herpetofauna.

Many of Iowa’s streams have beenphysically degraded through bank andchannel modifications such as hardbank stabilization, channelization,dredging, and the construction of cul-

vert and impoundment structures.Resultantly, these streams have losttheir sinuous riffle-run-pool sequencesalong with associated point bar, beach,and bank habitats important to river-ine herpetofauna. Modifications ofstream flows have also taken a toll onherpetofauna by hindering the mainte-nance and creation of habitat withinboth the channel and adjacent flood-plains.

Fortunately, streams and rivers aredynamic systems capable of repairingthemselves when extraneous forcesare ceased. Lessening or removing thedisturbances contributing to an imbal-ance in stream function will allow thestream to progress to equilibrium nat-urally, a process that may takedecades. In situations where streamimprovements are urgent, activeapproaches may have to be taken tohelp the stream evolve into a self-sus-taining body. Active managementtechniques can include tow stabiliza-tion, stream bank bioengineering, damremoval, and stream length, pool-rifflesequence, and grade restoration. Thedevelopment of a stream restorationand management plan is complex,must be well thought-out, include

Prairies and Savannascont...

Herpetofauna such as the smooth greensnake may use ant mounds for basking,shelter, and as hibernacula. (Photo byJennifer Anderson-Cruz)



327 Conservation Cover

528A Prescribed Grazing



647 Early Successional Habitat Development


Prairies and Savannas

Rivers and Streams

Skunk River, Polk County, Iowa

Iowa's water snakes are often mistakenfor the venomous cottonmouth which isnot found in Iowa. When water snakesprey upon fish, the fish are often sick orold. By partaking in this hunting strategy,water snakes are a natural means of pro-moting healthy fish populations. (Photoby Jeff LeClere)



guidance from many resource profes-sionals, and must individually suitethe watercourse at hand. Streamrestoration extends far beyond thescope of this document; therefore, it isrecommended that stream restorationspecialists be contacted to initiatesuch projects.

Adjacent land use practices may haveprofound impacts on the water qualityand quantity of a river or stream. Theuse of best management practices (notill, nutrient and pest management,grassed waterways, buffers strips, etc.)will reduce offsite movement of soilsand pollutants, increase infiltrationrecharging aquifers, and provide corri-dors and habitat for many species ofwildlife including herpetofauna.Monitoring the quality and quantity of

water in a stream may help identifyresource concerns and best manage-ment practices required to addressthese concerns. The most successfulway to improve the water quality andquantity of a stream or river is to use awatershed-based approach with com-munity-led conservation and participa-tion by local stakeholders. There arenumerous state and federal programsaimed at providing funds and assis-tance for watershed based projects.Contact your local NRCS ServiceStation to learn more about the vari-ous watershed-based programs avail-able in your area.

Restoring diversity in the physicalstructure of a stream will offer anassortment of habitats for wildlife toexploit, assuming water quality andquantity issues have been addressed.Lack of suitable instream habitat suchas woody debris, snags, leaf litter,boulders, clean sand, gravel, or cobblesubstrate will limit diversity and den-sity of herpetofauna, the foodresources they require, and organismssuch as the salamander mussel whichrequires the presence of an amphibian,the mudpuppy, to complete its lifecycle. Instream habitat restoration(bank hides, gravel beds, log andboulder structures, etc.) has become apopular practice in recent years, pro-viding carefully placed and anchoredcover where naturally forming covermay be aesthetically displeasing orposes risk to infrastructure (bridges,culverts, etc.). Other than highly aquatic turtles andthe mudpuppy, riverine herpetofaunaspend the majority of their time alongstream shores, shallows, and adjacentfloodplains. Managing stream banksto support a multitude of habitatsincluding sand and gravel bars, over-

hanging vegetation and natural cut-banks will offer refugia and foraginghabitat for numerous species. Indeveloping restoration and manage-ment plans for a riverine site, provi-sions for a friendly, traversable con-nection to the upland landscape areessential. For instance, where barrierslie between riparian and upland habi-tats, refer to the corridor and safe pas-sage sections of this document todevelop potential solutions.

Wetlands are important habitat com-ponents of prairie, forest, and riverineecosystems. Naturally occurring wet-lands are incredibly important attrib-utes to local wildlife. Restoring wet-land function is extremely challeng-ing; therefore, the protection of exist-ing wetlands is strongly recommend-ed. Breaking and removing tile, fillingditches, or creating berms are effec-

Rivers and Streamscont...

Woody cover provides essential habitatfor stream related herpetofauna andtheir prey. Herpetofauna use emergedlogs for basking and submerged logs asunderwater cover.

326 Clearing and Snagging

390 Riparian Herbaceous Cover

391 Riparian Forest Buffer

393 Filter Strip

395 Stream Habitat Improvementand Management

410 Grade Stabilization Structure

580 Streambank and ShorelineProtection

582 Open Channel

584 Channel Stabilization


Rivers and Streams

Wetlands



tive ways to create wetlands or torestore the natural hydrology of a sitethat has been manipulated in the past.Restorations requiring little to noexcavation with very gradual sideslopes (>20:1 optimal) will maximizethe shallow wetland habitats (<4-6”)that are the most attractive to a broadrange of herpetofauna.

Iowa experiences 10-11 year droughtcycles rendering wetlands suitable forinhabitance by herpetofauna in wetyears unsuitable in dry years and viceversa. Consequently, wetlands con-structed for herpetofauna should berestored in a mosaic pattern with wet-lands of varying shape, depth, andproximity to each other to provideneeded habitat throughout time andspace. Diverse water regimes shouldbe included with a minimum hydrope-riod of 2.5 months and shallowephemeral pools no further than 300meters from a permanent water source

to provide herpetofauna with waterduring drought periods. Water levelsshould not be manipulated during thebreeding or hibernation seasons, apractice that may result in the desicca-tion and death of hibernating herpeto-fauna or amphibian eggs and larvae(see table 1 for egg laying and larvalperiods for amphibians).

Fish and bullfrogs should not be intro-duced into natural or restored habitatsthat do not or did not naturally housethese species. Predatory fish and bull-frogs will eat amphibian eggs, larvae,and adults; therefore, most amphibiansrequire wetlands devoid of these pred-ators. In addition, several studies havefound that the presence of non-preda-tory fish in breeding pools can reducelarval survival of many amphibians bydisrupting predator avoidance behav-iors. Fish and bullfrogs can be exclud-ed from and controlled within arestoration by minimizing permanentwater and by creating stands of waterthat are shallow enough to causehypoxia and desiccation duringdrought years.

To improve the vegetative quality ofan existing wetland, mowing, pre-scribed burns, or light disking may beused following the methods men-tioned in the management practicessection. For newly restored wetlands,leaving the site rough rather thansmoothing it out adds complexity tothe wetlands bottom structure result-ing in variable water depths, chem-istry, and aspect which improves thesite's ability to house numerous plantspecies. The use of aquatic herbicidesand pesticides within wetlands is dis-couraged, due to the potential for neg-ative impacts on a wide range of non-target species, including amphibians.Emergent wetland, sedge, and wetmeadow habitats with 50-80% vegeta-tive cover offer optimal shelter, food,foraging habitat, and egg attachmentsites for most herpetofauna; whereas,wetlands with sparse plant, algal, andperiphyton communities house mini-mal food resources for tadpoles andturtles with herbaceous diets. Urban,industrial, and agricultural pollutants(nutrients, pesticides, heavy metals,

Wetlands cont...

Sedge meadows are dominated by satu-rated soils with pockets of water held indepressions during the spring months.Research in the Midwest has found thatwetland areas containing less than 6 inch-es of standing water provide extraordi-nary herpetofauna habitat. Duke Prairie,Clinton County, Iowa. (Photo by JenniferAnderson-Cruz)

Many herpetofauna utilize crayfish bur-rows to reach the groundwater table dur-ing dry spells or for hibernation.Recognizing the dependency of selectedherpetofaunal species on other wildlife isessential in conserving these species inIowa. (Photo by Jennifer Anderson-Cruz)

The natural range of the American bullfrogoccurred over the southern 1/3 of Iowaand up the Missouri and Mississippi RiverCorridors. Today, the bullfrog can befound in permanent waters state-wide dueto anthropogenic introduction which iswrecking havoc on amphibian species notadapted to life with this foreign predator.(Photo by Jennifer Anderson-Cruz)



organo-chemicals, sediment, etc.) poseserious risks to herpetofaunal commu-nities; therefore, potential sources ofpollutants should be identified andaddressed in a wetland managementplan prior to restoration.

In a recent study on riparian depen-dant herpetofauna, it was suggestedthat habitat should, at a minimum, beprotected within a 300-meter radiusfrom the edge of a wetland or stream;an area termed “core habitat”. Theestablishment of core habitat is essen-tial to the survival of riparian herpeto-fauna that require upland habitat forforaging, nesting, aestivation, andhibernation. It is also suggested that a50-meter buffer zone be created adja-cent to core habitat (see buffer sectionbelow) and land use zones be delin-eated to set use restrictions for hiking,birding, etc.

The creation of a buffer zone willreduce off-site impacts on core habitatand herpetofaunal contact withunfriendly land use. Buffer zones areused to protect restored areas frompollutants such as nutrients, pesticidesand sediments, and from physicalimpacts such as encroachment. Thedesired width of a buffer zone isdependant upon topography, adjacentland use, and the home ranges of the

herpetofauna present. It is generallyrecommended that buffer zones be aminimum of 50-meters wide.

Edge habitats, also called ecotones,create unique ecosystems that bufferthe effects of one habitat as it merges

into the next by gradually shiftingplant composition, moisture regime,and climate across the landscape (i.e.prairie - forest transition). Several her-petofauna, such as fox snakes andbrown snakes, are edge species requir-

ing ecotone habitats.Recent studies in Iowahave shown that as lengthof edge habitat increasesamphibian use increases,making edge habitat animportant factor to consid-er when developing amanagement plan foramphibians.

Herpetofauna require cor-ridors to facilitate every-day home range move-ments, seasonal andbreeding migrations, dis-persal, and range shifts in

Wetlands cont...

327 Conservation Cover



393 Filter Strip

472 Use Exclusion


644 Wetland Wildlife HabitatManagement

647 Early Successional HabitatDevelopment

657 Wetland Restoration

658 Wetland Creation

659 Wetland Enhancement

Applicable Iowa NRCSStandards - Wetlands

Core Habitat, Corridors,Buffers, and Ecotones

Providing 300-meters of core habitat from the edge ofany water body will protect the home range of mostMidwestern herpetofauna. The addition of a 50-meterbuffer protects core habitat from offsite pollutants andland use.

Connecting critical habitat by strategicallyplacing wildlife corridors will allow her-petofauna to exploit a multitude ofresources without traversing unfriendlysurfaces such as barren fields, roads, ormowed lawns.

Diverse plant communities offer shelter,food, and water purification while regulatingclimatic conditions such as temperature andhumidity in wetland habitats. These newlymetamorphosed chorus frogs are using wet-land plants as emergence strata.



response to environmental and climat-ic changes. Corridors connecting frag-ments of isolated habitat provide asafe and friendly passageway allowingfor immigration and emigration ofanimals aiding gene flow and decreas-ing the chance of local herpetofaunalextinction events. It has been found

that wetland areas adjoined by forestor prairie have greater herpetofaunaldiversity and have higher colonizationrates after restoration than isolatedwetlands without corridors. Suitablecorridors can be constructed by plant-ing grasses, trees, and shrubs in widestrips connecting two habitats isolatedby barriers such as crop fields androads. The most effective wildlife cor-ridors are those constructed alongriparian areas, which also improvewater quality, bank stability, andinstream habitat.

In areas with high road density, safepassages should be provided for her-petofauna, especially in areas whereroads bisect important corridors (i.e.roads that parallel water bodies).Barriers that run parallel to roads maybe constructed to prevent herpetofau-

na and other wildlife from crossingroads, thus reducing animal mortalityand road hazards. There are a varietyof road barriers in use, ranging fromfencing and sheet piling to concretewalls. Road barriers may be used inconjunction with pre-existing (cul-verts, bridges, etc.) or constructed“safe crossings” to route wildlife tosafe passageways under or over road-ways.

Microhabitats are very small, special-ized habitats located within largerhabitats. Constructing various micro-habitats within any restoration will

improve habitat quality for a numberof herpetofauna and other wildlife.

Brush Piles: brush piles provideshelter from wind, rain, and otherenvironmental stressors. Brush pilesshould be 15'W x 15'L x 8'H in sizeand number 3-4 per acre. The founda-tion of the pile should be designedwith 6-10 inch diameter logs placedparallel to each other one foot apart(old pallets make excellent founda-tions for a brush pile). Secondly, placebranches and logs perpendicularly ontop of the foundation. Lastly, smallerdebris is added on top to form amound. Brush piles may be placedrandomly on land or partially sub-merged at the waters edge.

Rock Piles: Pile rocks (riprap, con-crete, etc.) up to 12 inches high.Finish by angling several 4-6 inchdiameter logs over the rock pile.

Hibernaculum: hibernacula are per-manent below-ground structures thatprovide shelter for hibernating rep-tiles. Constructed hibernacula shouldface south, preferably along a shel-tered wooded edge. To build a hiber-nacula (made available by the IowaDNR), dig a hole 10'Wx15'Lx6-10'D;fill the hole with logs, rocks and

Core Habitat, Corridors,Buffers, and Ecotones

cont...

Safe crossings and road barriers helpkeep wildlife off roads, preventing animalmortality, road hazards, and accidents.(Photo Courtesy of FHWA/US DOT)

380 Windbreak/ShelterbeltEstablishment

386 Field Border


393 Filter Strip

472 Use Exclusion

612 Tree/Shrub Establishment

650 Windbreak/ShelterbeltRenovation

Applicable Iowa NRCSStandards - Core Habitat,

Corridors, Buffers, andEcotones

Microhabitats

Brush piles shelter a whole host of wildlifespecies and are just as effective underwa-ter as they are on land.

Newly constructed snake hibernacula on aWetland Reserve Program easement inClinton County, Iowa.



debris in a pile 4 ft. higher thanground level; place rock on the southfacing side of the hibernacula; coverall but the south facing side of rockwith 3 ft. of soil and seed with nativeshort grasses and forbs. If space andmaterials are lacking, a second designis available utilizing 36” cement cul-vert pipe, riprap, flagstone, and engi-neering fabric. The culvert pipe, withthe bottom covered with engineeringfabric, should be set into a hole atleast 7 ft. deep and be several feetbelow the high water table if placedwithin wetland or riparian areas. Oncein place, fill the culvert pipe withriprap or rerod-free broken concrete.As a final step, loosely place flagstoneor flat rocks 2’ high over the top ofthe culvert.

Cover Objects: Cover objects canbe logs, rocks, boards, etc. placed outin the open, along forested edges, orpartially in or underwater. It is veryimportant that cover objects be scat-tered along the length of corridors toprotect migrating amphibians fromdesiccation. Large objects such as

slabs of concrete, limestone, and logsare suitable cover objects that areinexpensive and easy to provide.Cover objects have a dual purpose in

providing above ground basking plat-forms and below ground shelter fromthe midday sun. Cover objects alsoconcentrate invertebrates and becomean important feeding area for insectiv-orous herpetofauna. The developmentof suitable conditions (temperature,humidity, etc.) under cover objectsmay take a considerable amount oftime; therefore, disturbance of suchhabitat should not occur.

Nesting sites: Traditional nestingsites may be scarce or have uniquecharacteristics that can not be recreat-

ed; hence, the disturbance of knownnesting sites should be avoided at allcosts. Suitable reptilian nesting habitatmay be created by providing coverobjects, den trees, or constructed sandpiles on south and west facing slopesin full sun. Amphibian breeding pondsshould be monitored for water qualityto determine whether the site providesa safe environment for developingeggs, larvae and aquatic adults. Manyamphibian species attach eggs to sub-merged vegetation and debris, habitatattributes that should be provided ifnot naturally present.

Den sites: Dead den trees, logs, andsnags should be included in the man-agement plan to provide shelter andnesting sites for herpetofauna.Optimally, a minimum of five dentrees/logs/snags per acre should beprovided to benefit herpetofauna andother wildlife alike. If ample den sitesare not naturally present, trees can begirdled or stumps and logs from offsite can be brought in and placed ran-domly throughout the restoration area.

Inventory and evaluation of a restora-tion's success in attracting herpetofau-na can be easy, enjoyable, and allowsa restorationist to deduce whether suc-cessional progression of flora andfauna is taking place or whether fur-ther management is needed to achievethe restoration goals for the site. As asite matures, herpetofaunal use willshift from a community of early suc-cessional exploiters to a stable, evenclimax community. Above and beyondmonitoring adult animals, one must

Microhabitats cont...

The climatic conditions developed underwoody debris are very stable while pro-viding excellent substrate for the colo-nization of macroinvertebrate decom-posers which serve as a food source forherpetofauna. (Photo by JenniferAnderson-Cruz)

Rocks and boulders absorb the suns heatenergy during sunlight hours and releaseit slowly, providing a source of warmth forreptiles during cool evening and morninghours. (Photo by Jennifer Anderson-Cruz)

Many turtle species return to maternalnesting sites to lay eggs generation aftergeneration. The loss of a maternal nestingsite may result in the local extinction ofcertain turtle species. (Photo Courtesy ofMissouri Dept. of Conservation)

Inventory andEvaluation of a

Restoration



remember to monitor nest sites, juve-nile and larval stages of herpetofaunato ensure that reproductive success istaking place and that a site is not act-ing as a population sink. Listed beloware numerous programs and materialsavailable to those interested in moni-toring herpetofauna and their habitatin the Midwest. In addition, there areseveral documents listed within thereference section below that are ofgreat value in the identification andhabitat requirements of Midwesternherpetofauna.

Amphibian Index of Biotic Integrity(AmphIBI) for Wetlands

Ohio EPA 2002. Wetland Ecology Group

Division of Surface Water122 South Front Street, P.O. Box 1049

Columbus, Ohio 43216-1049

Frog Watch USANational Wildlife Federation11100 Wildlife Center Drive

Reston, VA 20190-5362Phone: 1-800-822-9919

Iowa Frog and Toad SurveyIowa Dept. of Natural Resources

Wildlife Diversity Program 1436 255th Street

Boone, IA 50036-7557 Phone: (515) 432-2823

Iowa Nature Mapping Iowa State Extension Service

Ecology and Management124 Science II

Iowa State University Ames, Iowa 50011-3221

Phone: 515-294-6440

IowaterIowa Department of Natural

ResourcesWallace State Office Building

502 East 9th StreetDes Moines, Iowa 50319

515-281-6640

Methods for Evaluating WetlandCondition: Using Amphibians in

Bioassessments of WetlandsU.S. EPA. 2002. Office of Water U.S. Environmental Protection

AgencyWashington, DC. EPA-822-R-02-022.

Partners for Amphibian and ReptileConservation

Midwest RegionBruce Kingsbury, Director

Center for Reptile and AmphibianConservation and Management

Science BuildingIndiana-Purdue University2101 East Coliseum Blvd.

Fort Wayne, IN [email protected](260) 481-5755

Resources for Monitoring Pond-breeding Amphibians in the

Northcentral USAby Knutson, Lyon, and Parmelee

USGS Upper Midwest EnvironmentalSciences Center

2630 Fanta Reed RoadLa Crosse, Wisconsin 54603

Inventory andEvaluation of a

Restoration cont...

Due to the creation of manmade ponds,tiger salamanders are one of the fewMidwestern amphibians that haveincreased in number since European set-tlement. Voracious aquatic predators,one larval tiger salamander can eat asmany as 300 mosquito larvae in onehour. (Photo by Jeff LeClere)

The following documents requireMicrosoft Excel.

Amphibians of Iowa*

Reptiles of Iowa*

*Adapted from PARC document


13

References

Christiansen, J.L.; Baily, R.M. 1991. The Lizards and Turtles of Iowa. Iowa Department of Natural Resources. DesMoines, Iowa. 24pp.

Christiansen, J.L.; Baily, R.M. 1991. The Salamanders and Frogs of Iowa. Iowa Department of Natural Resources.Des Moines, Iowa. 24pp.

Christiansen, J.L.; Baily, R.M. 1991. The Snakes of Iowa. Iowa Department of Natural Resources. Des Moines,Iowa. 24pp

FISRWG (10/1998). Stream Corridor Restoration: Principles, Processes, and Practices. By the Federal InteragencyStream Restoration Working Group (FISRWG) (15 Federal agencies of the US govt). GPO Item No. 0120-A; SuDocsNo. A 57.6/2:EN 3/PT.653. ISBN-0-934213-59-3.

Forman et. al. 2003. Road Ecology: science and solutions. Washington, DC: Island Press. Pp 481.

Habitat Management Guidelines for Amphibians and Reptiles of the Midwest. 2002. Partners in ReptileConservation.http://herpcenter.ipfw.edu/index.htm http://herpcenter.ipfw.edu/outreach/MWHabitatGuide/index.htm&2

Iowa Herpetology www.herpnet.net

Knutson, MG; Sauer, JR; Olsen, DA; Mossman, MJ; Hemesath, LM; Lannoo, MJ. 1999. Effects of LandscapeComposition and Wetland Fragmentation on frog and toad abundance and Species Richness in Iowa and Wisconsin,U.S.A. Conservation Biology. Vol. 13, no. 6, pp 1437-1446.

Lannoo, M. ed. 1998. Status and Conservation of Midwest Amphibians. University of Iowa Press, Iowa City, IA. Pp448.

Lannoo, Michael. 1996. Okoboji Wetlands; a lesson in Natural History. University of Iowa Press. 156pp.

Natural Resources Conservation Service Agronomy Technical Note 27 Guidance for Seeding Pothole, Floodplain, andOther Wetlands.

Natural Resources Conservation Service Biology Technical Note 24 Shallow Water Excavation for Wildlife.

Natural Resources Conservation Service National Biology Handbook Part 190, Part 614.4 Conservation CorridorPlanning at the Landscape Level: managing for wildlife habitat.

Parmelee, J. R., M.G. Knutson, and J.E. Lyon. 2002. A field guide to amphibian larvae and eggs of Minnesota,Wisconsin, and Iowa. U.S. Geological Survey, Biological Resources Division, Information and Technology ReportUSGS/BRD/ITR-2002-0004, Washington, D.C. iv + 38 pp.http://www.umesc.usgs.gov/terrestrial/amphibians/mknutson_5003869_field_guide.html

Schurbon, J.M. and Fauth, J.E. 2003. Effects of Prescribed Burning on Amphibian Diversity in a Southeastern U.S.National Forest. Conservation Biology. Vol. 17, No. 5. pp 1338-1349.

Semlitsch, R.D. and Bodie, J.R. 2003. Biological Buffer Zones around Wetlands and Riparian Habitats forAmphibians and Reptiles. Conservation Biology. Vol. 17, No. 5. pp 1219-1228.

Smith, Jane, ed. 2000. Wildland Fire in Ecosystems: effects on fauna. Gen.Tech. Rep. RMRS-GTR-42-vol. 1.Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 83p.

U.S. Fish and Wildlife Service. 2000. Homeowner’s Guide to Protecting Frogs – lawn and garden care. http://con-taminants.fws.gov/documents/Homeowners_Guide_Frogs.pdf

Weyrauch, S.L. and Grubb, T.C. Jr. Patch and Landscape Characteristics Associated with the Distribution ofWoodland Amphibians in an Agricultural Fragmented Landscape: an information-theoretic approach. BiologicalConservation. Vol. 115. pp 443-450.

Fred G. Bank, C. Leroy Irwin, Gary L. Evink, Mary E. Gray, Susan Hagood, John R. Kinar, Alex Levy, Dale Paulson,Bill Ruediger, Raymond M. Sauvajot, David J. Scott, Patricia White. 2002. Wildlife Habitat Connectivity AcrossEuropean Highways. Office of International Programs, Office of Policy Federal Highway Administration, U.S.Department of Transportation. Report No. FHWA-PL-02-011.

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