Distribution, Abundance and Recruitment of Amphibian Species in Greatest Need of Conservation in the Vermilion River Conservation Opportunity Area

Home , Silvery salamander, Streamside salamander

Final Report for Illinois Department of Natural Resources State Wildlife Grant 108-R-1

Andrew R. Kuhns1, Kelsey M. Low1, John A. Crawford2, William E. Peterman3, and Christopher A. Phillips1

1 INHS, Prairie Research Institute, University of Illinois, 1816 S. Oak St. Champaign, IL 61820 2 National Great Rivers Research and Education Center, One Confluence Way, East Alton, IL 62024 3 Environmental & Natural Resources, Ohio State University, 2010 Coffey Rd. Columbus, OH 43210

INHS Technical Report 2019 (8)

Issue Date: 28 February 2019 108-R-1. EXECUTIVE SUMMARY OVERVIEW • This study assesses three amphibian species (Silvery Salamander, Ambystoma platineum; Four-toed Salamander, Hemidactylium scutatum; Wood Frog, Rana sylvatica) in greatest need of conservation (SGNC) in the Vermilion River Conservation Opportunity Area (VRCOA) of Illinois with the following objectives. • Objective 1. Determine distribution, relative abundance, and habitat characteristics of breeding ponds used by SGNC amphibians. • Objective 2. Evaluate the success of recently created wetlands in providing suitable breeding habitats for SGNC amphibians within the VRCOA.

METHODS (OBJECTIVE 1) • To determine the distribution of the three species (Objective 1) we identified 71 potentially suitable wetlands within the Vermilion River Conservation Opportunity Area (VRCOA) of Illinois and sampled 33 wetlands distributed across seven properties using collapsible minnow traps. • Each wetland was sampled four times with each sampling event occurring over two nights. • Habitat variables (wetland canopy cover, wetland slope, forest cover) and survey-specific variables (temperature and precipitation) were collected at each site.

RESULTS/DISCUSSION (OBJECTIVE 1) • Our Year 1 sampling methodology was ill-suited for detecting Four-toed Salamanders. • Silvery Salamanders are more prevalent on the landscape than previously thought but all records are currently restricted to the northern unit of study (Middlefork SFWA, Kickapoo SRA, Fairchild Cemetery) within the Vermilion River Conservation Opportunity Area. • This study documented the first population of Silvery Salamanders outside of protected lands in Illinois and the property adjacent to Fairchild Cemetery should be considered for conservation enrollment if the opportunity presents itself. • Future surveys for Silvery Salamanders should focus on private property between Kickapoo State Park and Forest Glen County Forest Preserve as well as vernal wetlands in wooded tracts north of Middlefork SFWA. • Wood Frogs appear to be common in large wooded tracts with vernal wetlands in the VRCOA. The species was documented from all properties except the Georgetown Land and Water Reserve Addition which primarily consists of land reclaimed from agriculture. • When the goal is to document species occupancy, repeated sampling, for both adult and larval life stages reduces the probability of errors of omission.

METHODS (OBJECTIVE 2) • We completely encircled six wetlands (two reference wetlands and four recently created wetlands) with drift fences to capture all amphibians attempting to enter or leave the wetlands.

• Pitfall traps were placed along the drift fence and were checked daily during the amphibian breeding and emergence periods. • We recorded wetland specific variables of canopy cover, slope, area, and depth for each wetland and survey-specific variables of temperature and precipitation. • Captured adult amphibians were identified to species, sexed, and up to ten adults of each captured species and all emerging metamorph captures were weighed and measured for snout-vent length to calculate body condition scores.

RESULTS /DISCUSSION (OBJECTIVE 2) • Seventeen of the twenty three amphibian species reported in Vermilion County, Illinois were captured from the six study ponds; including one state endangered, one state threatened and one Species in Greatest Need of Conservation. • Four-toed Salamanders were never encountered in recently created wetlands and were only encountered at one reference wetland. • Both Wood Frogs and Silvery Salamanders readily bred in the recently created wetlands. • When scaled to the number of adult females that entered the ponds there was no significant difference in recruitment numbers between reference and recently created wetlands. • Silvery Salamanders and male Wood Frogs that bred in created wetlands had lower Body Condition scores than those that bred in the reference wetlands. • Metamorphs that emerged from created wetlands had lower body condition scores than those that emerged from the reference wetlands. • Annual climatic factors played a greater role in determining recruitment success than wetland category (reference vs recently created). • SGNC species recruitment decreased with increasing average wetland water temperatures. Increased canopy cover values coincided with lower water temperature values. Wetlands created for the purpose of increasing breeding habitat for SGNC amphibians in the VRCOA should be constructed in closed canopy habitats. • Silvery Salamanders had greater recruitment success in ponds with greater slope values while the opposite was true for Wood Frogs. • The recently created wetlands examined in this study have been shown to benefit certain species but not necessarily the entire amphibian community. When creating wetlands for the benefit of wetland-breeding amphibians, efforts should be made to either ensure a heterogeneity of habitat types be present within each wetland or that multiple wetlands of different shape, depth, size and hydroperiod be created to benefit all species in the amphibian community. • Future studies should examine the effects of the observed lower body condition scores of recruiting metamorphs from the recently created wetlands. If the created wetlands are producing metamorphs with a lower likelihood of survival, they may be acting as population sinks.

EXECUTIVE SUMMARY ...... 1 TABLE OF CONTENTS ...... 3 LIST OF TABLES ...... 4 LIST OF FIGURES ...... 5 INTRODUCTION ...... 6 OBJECTIVE 1. DETERMINE DISTRIBUTION, RELATIVE ABUNDANCE, AND HABITAT CHARACTERISTICS OF BREEDING PONDS USED BY SGNC AMPHIBIANS ...... 8 METHODS ...... 8 JOB 1A & 1B. WETLAND SELECTION ...... 8 JOB 1B. WETLAND CHARACTERISTICS ...... 8 JOB 1D. SAMPLING METHOD ...... 8 JOB 1C & 1D. STATISTICAL ANALYSIS ...... 8 RESULTS ...... 9 JOB 1B. SPECIES PRESENCE ...... 9 JOB 1C. SPECIES ABUNDANCE ...... 9 JOB 1D. WETLAND CHARACTERISTICS ...... 9 DISCUSSION ...... 9 LITERATURE CITED ...... 11 OBJECTIVE 2. EVALUATE THE SUCCESS OF RECENTLY CREATED WETLANDS IN PROVIDING SUITABLE BREEDING HABITATS FOR SGNC AMPHIBIANS WITHIN THE VRCOA...... 15 METHODS ...... 15 JOB 2A. SAMPLING METHODOLOGY ...... 15 JOB 2B. QUANTIFYING KEY DEMOGRAPHIC PARAMETERS OF ADULTS AND METAMORPHS...... 15 RECRUITMENT RATES ...... 16 BODY CONDITION OF EMERGING METAMORPHS ...... 16 BODY CONDITION OF BREEDING ADULTS ...... 16 JOB 2C. EFFECTS OF CLIMATIC AND LANDSCAPE VARIABLES ON WETLAND USE, RECRUITMENT, AND PRODUCTIVITY ...... 16 RESULTS ...... 17 JOB 2A. SAMPLING RESULTS ...... 17 JOB 2B. QUANTIFYING KEY DEMOGRAPHIC PARAMETERS OF ADULTS AND METAMORPHS ...... 18 RECRUITMENT RATES ...... 18 BODY CONDITION OF EMERGING METAMORPHS ...... 18 BODY CONDITION OF BREEDING ADULTS ...... 18 JOB 2C. EFFECTS OF CLIMATIC AND LANDSCAPE VARIABLES ON AMPHIBIAN WETLAND USE, RECRUITMENT AND PRODUCTIVITY ...... 18 BODY CONDITION OF METAMORPHS AS A FUNCTION OF WETLAND CHARACTERISTICS ...... 18 METAMORPH RECRUITMENT AS A FUNCTION OF WETLAND CHARACTERISTICS ...... 19 DISCUSSION ...... 19 LITERATURE CITED ...... 21 APPENDIX A. AERIAL IMAGES DEPICTING THE LOCATIONS OF THE 33 WETLANDS SAMPLED FOR SGNC AMPHIBIANS IN THE VERMILION RIVER CONSERVATION OPPORTUNITY AREA FOR OBJECTIVE 1 ...... 34 APPENDIX B. LOCATIONS AND IMAGES OF THE SIX WETLANDS SURROUNDED WITH DRIFT FENCING IN THE VERMILION RIVER CONSERVATION OPPORTUNITY AREA FOR OBJECTIVE 2 ...... 38

LIST OF TABLES

OBJECTIVE 1. DISTRIBUTION, RELATIVE ABUNDANCE, AND HABITAT CHARACTERISTICS OF BREEDING PONDS USED BY SGNC AMPHIBIANS Table 1. Location and physical characteristics of wetlands sampled for amphibians within the Vermilion River Conservation Opportunity Area ...... 13 Table 2. Estimated mean abundance and 95% confidence interval for Silvery Salamanders and Wood Frogs at 33 wetlands located at seven different properties in the Vermilion River Conservation Opportunity Area ...... 14

OBJECTIVE 2. SUCCESS OF RECENTLY CREATED WETLANDS IN PROVIDING SUITABLE BREEDING HABITATS FOR SGNC AMPHIBIANS WITHIN THE VRCOA Table 1. Summary of wetland characteristics ...... 23 Table 2. Species detected at drift fences by pond and year for reference and constructed wetlands in state managed properties in the Vermilion River Conservation Opportunity Area ...... 24 Table 3. Count data for adult female and metamorph wetland breeding amphibians encountered at the drift fences encircling recently created and reference wetlands in the Vermilion River Conservation Opportunity Area ...... 25 Table 4. Summary table from a negative binomial regression assessing differences in the number of emergent metamorphs between recently created wetlands and reference wetlands ...... 26 Table 5. Summary table from a Bayesian mixed effects model assessing covariate effects on A. platineum SMI. 95% credible intervals (CRI) of parameter estimates are reported27 Table 6. Summary table from a Bayesian mixed effects model assessing covariate effects on R. sylvatica SMI. 95% credible intervals (CRI) of parameter estimates are reported ...... 28 Table 7. Summary table from a Bayesian negative binomial generalized linear model assessing covariate effects on the number of A. platineum metamorphs produced. 95% credible intervals (CRI) of parameter estimates are reported...... 29 Table 8. Summary table from a Bayesian negative binomial generalized linear model assessing covariate effects on the number of R. sylvatica metamorphs produced. 95% credible intervals (CRI) of parameter estimates are reported ...... 30 Table 9. Summary of weather data collected from Danville, IL weather station. Data are summarized from 15 April – 15 July of each year...... 31

LIST OF FIGURES

Figure 1. Scaled Mass Index (SMI) of post-metamorphic emergent amphibians captured at drift fence arrays completely surrounding reference vs recently created wetlands in the Vermilion River Conservation Opportunity Area ...... 32 Figure 2. Scaled Mass Index (SMI) of adult A. platineum and R. sylvatica captured at drift fence arrays surrounding reference and created wetlands in the Vermillion River Conservation Opportunity Area ...... 33

INTRODUCTION

In Illinois, wetland conversion and drainage has matched or exceeded national trends, with an estimated 90% of original wetland area being lost (Suloway and Hubbell 1994). Amphibians make up critical ecological components of many wetland ecosystems where they play a prominent role in food webs as both predators of invertebrates and prey of larger vertebrates (Davic and Welsh 2004), and they often exceed the combined biomass of other terrestrial vertebrates within the system (Burton and Likens 1975, Peterman et al. 2008). Wetland loss currently threatens 32 of the 41 amphibians in Illinois that are dependent upon wetlands for reproduction (Phillips et al. 1999, U.S. EPA 2003). Statewide there is concern about apparent local amphibian extinction and widespread decreases in their abundance (IDNR 2005).

Due to the extensive loss of wetland habitats throughout Illinois, assessment and protection of wetlands is a high priority within the state (IDNR 2005). Action Item 2 of the Wetlands Campaign in the Illinois Wildlife Action Plan is to develop and manage additional wetland habitat by recreating ephemeral and other fishless, semi-permanent wetlands (IDNR 2005). Further, Action Item 3 is to fill information gaps and develop conservation actions to address remaining wetlands in Illinois. Specifically, the action item calls for: 1) research on the ecological aspects of high-quality wetland sites; and 2) assessment of the status and distribution of wetland-dependent amphibians.

Within the Vermilion River Conservation Opportunity Area (IDNR 2005) wetlands have the potential to provide breeding habitat for three amphibian species in greatest need of conservation (Silvery Salamander [Ambystoma platineum], Four-Toed Salamander [Hemidactylium scutatum], and Wood Frog [Rana sylvatica]). Both the Silvery Salamander and Four-Toed Salamander are afforded protection under the Illinois Endangered Species Act as state endangered and state threatened, respectively, while the Wood Frog is considered a species of special concern in Illinois (IDNR 2005, Mankowski 2014). All three species are considered rare, occurring in low population sizes and densities, in a restricted range and are believed to have significantly declined in abundance and distribution (IDNR 2005). Of additional concern for all three species is their dependence upon rare or vulnerable habitats. Both Silvery Salamanders and Wood Frogs utilize small ephemeral wetlands in hardwood forests (Phillips et al 1999) and Four-Toed Salamanders inhabit mature deciduous forests with seeps and springs, and swamps and ponds with ferns and mosses (Minton 2001). All three species and are considered a critical resource within the VRCOA and their current distributions and abundances are unknown. In fact, until recently the unisexual Silvery Salamander was known from only one wetland in Illinois. Of late, incidental observations and limited sampling documented the species from an additional nine wetlands in Vermilion County, IL but nothing is known about the demographics of these populations or if additional populations may exist.

In 2016, we began a study to assess amphibian SGNC populations in the Vermilion River Conservation Opportunity Area of Illinois with the following objectives:

Objective 1. Determine distribution, relative abundance, and habitat characteristics of breeding wetlands used by SGNC amphibians (to be completed by 12/31/2016).

Job 1a. Identify up to 40 potentially suitable wetlands within the VRCOA to sample for amphibian SGNC Job 1b. Sample up to 40 wetlands (both reference and recently created) in the Vermilion River COA for three amphibian SGNC (Wood Frogs, Silvery Salamanders, and Four-toed Salamanders). Job 1c. Estimate relative abundance of breeding adults and late stage larvae in up to 40 wetlands. Job 1d. Quantify the relationship between wetland characteristics (wetland slope, hydroperiod, canopy cover, substrate cover, wetland size) to presence, relative abundance and recruitment of SGNC amphibians.

Objective 2. Evaluate the success of recently created wetlands in providing suitable breeding habitats for SGNC amphibians within the VRCOA (to be completed by 12/31/2018).

Job 2a. Construct drift fences at two recently created wetlands and two reference wetlands to determine use and recruitment out of the wetlands. Job 2b. Quantify key demographic parameters (sex ratio, body size, body condition of adults and juveniles) at the fenced wetlands. Identify all individuals entering and leaving the wetlands to species and sex. Record length and weight of all amphibian SGNC captured to assess body condition. Significant differences in any of these metrics may indicate critical differences between created and reference sites in terms of wetland function for amphibian SGNC. Job 2c. Determine how climatic and landscape variables affect wetland use, recruitment, and productivity. In addition to the habitat metrics collected in Job 1c above, place iButton data loggers (±1°C accuracy) in each of the fenced ponds to continuously monitor water temperatures. Data will be used in regression analyses to determine factors most affecting differences between created and reference wetlands in terms of SGNC reproductive potential and recruitment. Job 2d. Determine if recently constructed wetlands are functioning to the benefit of amphibian SGNC. Because our study will intensively monitor the same wetlands over two seasons, we will be able to make initial assessments of the role of temperature, precipitation periodicity, precipitation amount, and hydrology on amphibian reproductive effort, success, growth and survival.

Objective 3. Finalize project

Job 3a. Prepare a report with recommendations on the management of VRCOA lands for amphibian SGNC.

OBJECTIVE 1 Determine distribution, relative abundance, and habitat characteristics of breeding ponds used by SGNC amphibians

METHODS

Jobs 1a & 1b. Wetland selection. In order to determine distribution, relative abundance, and habitat characteristics of breeding wetlands used by SGNC amphibians we identified 71 potentially suitable wetlands within the VRCOA. Sixty-three of the wetlands were ground- truthed to determine if the wetland remained structurally intact and was likely fish-free. Forty- nine wetlands were extant and included for potential sampling. When sampling began on 01 March 2016, some wetlands we intended to sample were not holding water and we were unable to make contact with private landowners of other wetlands; thus, 33 wetlands were sampled (Table 1). These 33 wetlands were distributed across six properties (Appendix A) in the VRCOA. For logistical purposes these wetlands were subdivided into two sampling units. The north unit included wetlands in Middlefork State Fish and Wildlife Area (n=13), Kickapoo State Park (n=4), and property adjoining Fairchild Cemetery (n=1), while the south unit included wetlands in Harry “Babe” Woodyard State Habitat Area (n=11), Georgetown Addition of the Little Vermilion Land and Water Reserve (n=2), and Forest Glen County Forest Preserve (n=2).

Job 1b. Sampling method. We conducted four rounds of sampling with each round consisting of two sampling nights. Two sampling rounds occurred in the late winter-early spring during two of the target species breeding seasons (Silvery Salamanders and Wood Frogs), and two rounds occurred in early summer directly preceding the emergence of metamorphic amphibians and the breeding season of the third target species (Four-toed Salamander; N=8 total sampling events per wetland). We used dip nets and minnow traps for sampling. The number of traps and dip net sweeps deployed was scaled to the size of the surface area of the wetland to ensure equal sampling effort between wetlands.

Job 1d. Wetland characteristics. At each wetland we obtained the geographic location using a hand-held Global Positioning System recorded in decimal degrees using North American Map Datum NAD 83 (CONUS). We determined the surface area of the wetland using either a ruled tape or digital rangefinder. We estimated canopy cover along each of the four sides of the wetland using a spherical concave densiometer. These four values were then averaged to provide a wetland estimate of canopy cover (CC). Finally, we estimated wetland slope (SLOPE) using a folding metric ruler, recording wetland depth, in centimeters, at four locations around the wetland. Depth measurements were recorded at a distance of 1 meter from the shore. These four values were averaged and the resulting value for each wetland is reported in cm/m.

Jobs 1c. & 1d. Statistical analysis. We modeled abundance of SGNC amphibians at 33 ponds using N-mixture models to account for imperfect detection. Models were constructed using the R package ‘unmarked’ (Fiske and Chandler 2011). Detection was modeled as a function of the average temperature and total precipitation in the preceding day, and abundance was modeled 8

as a function of canopy cover over the wetland, slope of the wetland basin, and presence/absence of fish.

RESULTS

Job 1b. Species presence. Four-toed Salamanders (Hemidactylium scutatum) were not detected from any of the sampled wetlands. Silvery Salamanders (A. platineum) were detected in 17 of the 18 wetlands sampled in the north unit but were not detected from any of the wetlands in the south unit (Table 2). We failed to detect larvae in four of the wetlands where adults were detected, and in five wetlands we detected larvae but did not detect any adults during the winter sampling. Wood Frogs (R. sylvatica) were found throughout both the north and south units, occurring in 25 of the 33 sampled wetlands. Similar to Silvery Salamanders, four of the wetlands where we caught adults we did not detect larvae, and we detected larvae in five wetlands where adults had not been detected (Table 2).

Job 1c. Species abundance. Silvery Salamanders were found breeding only in north unit wetlands at Kickapoo State Park, Middlefork State Fish and Wildlife Area, and Fairchild Cemetery Nature Preserve. Observed counts of breeding Silvery Salamanders in the field ranged from 0 to 330. Estimated adult abundances ranging from 3–349 at occupied sites, and estimated larval abundances ranging from 180–3678 (Table 2). In contrast, Wood Frogs were widely distributed across all of the sampled properties. Observed counts of breeding adult Wood Frogs in the field ranged from 0–796 individuals. Abundance estimates for breeding adults ranged from 30–815. Abundance estimates for larvae ranged from 8 to >3000 (Table 1). Larval Wood Frog abundance estimates are likely quite imprecise due to wetland drying, which concentrated individuals into a small area. Further, because of the large variation in counts among wetlands and between surveys, it was not possible to reliably fit a statistical model. Nonetheless, the abundance summaries in Table 1 provide a meaningful relative index of abundance among wetlands and between properties.

Job 1d. Wetland characteristics. Due to the extreme variability in counts among sample periods, partly attributable to wetlands drying at some sites and apparent disease outbreaks at others (see discussion), statistical model fits were marginal for Silvery Salamanders and poor for Wood Frogs. No wetland-level covariates were meaningful predictors of abundance for Silvery Salamanders; however, Wood Frogs were much less likely to breed in wetlands containing fish.

DISCUSSION

Despite extensive sampling effort no Four-toed Salamanders were documented in any of the wetlands sampled. Four-toed Salamander phenology and life history differs from the other two SGNC species in that they breed in the fall and then females travel to boggy pools and seeps in April where they brood their eggs in vegetation overhanging water. Thus our sampling sessions may have occurred before and after the brooding season of Four-toed Salamanders and there may not yet have been free swimming larvae available for capture at the later sampling dates.

Further, the vast majority of wetlands within the VRCOA lack emergent aquatic vegetation and do not meet the typical habitat requirements of the species.

Silvery Salamanders appear to have expanded their range since their documentation from two adjacent wetlands in Kickapoo State Recreation Area in 1988 (Morris 1981). As recently as 1999, no additional breeding wetlands had been documented (Phillips et al. 1999). Extensive sampling of amphibians on managed properties throughout east-central Illinois from 2011– 2013 documented species presence in two recently created wetlands in Kickapoo State Recreation Area, and eight of nine wetlands sampled in Middlefork SFWA as well as from wetlands in the Crawford County Conservation Area near Hutsonville, IL (Crawford et al. 2014; Kessler et al. 2013). While this study detected their presence at all properties sampled in the north unit, no Silvery Salamanders were detected in the southern units. Thus, there is no indication that they have been missed by prior sampling efforts at Babe Woodyard, Georgetown LWR, or Forest Glen.

Wood Frogs appear to be more common in the Vermilion River Conservation Opportunity Area than previously thought. With the exception of the Georgetown Land and Water Reserve Addition, they were detected in most fishless wetlands sampled. However, we did observe high larval mortality at a number of wetlands we sampled during this study including complete larval die-off from at least two wetlands. As Wood Frogs are known to be highly susceptible to Ranavirus (FV3), and prior FV3 outbreaks had occurred near these wetlands, dead tadpoles were submitted to the Wildlife Epidemiology Lab at the University of Illinois College of Veterinary Medicine where they tested positive for Ranavirus (FV3). Further information on these outbreaks will be discussed in detail in the report for T-104-R1. There is a possibility that continued Ranavirus outbreaks may adversely affect Wood Frog commonality in parts of the VRCOA.

Finally, it is important to note that our survey regime of sampling for both adult and larval forms was more effective than either method alone. Had we sampled for only one stage class we would have reduced our naïve occupancy estimates by up to 27% for Silvery Salamanders, and 15% for Wood Frogs.

LITERATURE CITED

Burton, TM, GE Likens. 1975. Salamander populations and biomass in the Hubbard Brook Experimental Forest, New Hampshire. Copeia 1975:541–546.

Crawford JA, AR Kuhns, and P Mettler-Cherry. 2014. Ecological Assessment of Created Wetlands in Illinois. INHS Technical Report 2014 (20): 1–200.

Davic RD, HH Welsh. 2004. On the ecological roles of salamanders. Annual Review of Ecology, Evolution and Systematics 35:405–434.

Fiske IJ, RB Chandler. 2011. unmarked: An R package for fitting hierarchical models of wildlife occurrence and abundance Journal of Statistical Software 43:1–23.

IDNR 2005. Illinois Wildlife Action Plan. Accessed at http://dnr.state.il.us/orc/wildliferesources/theplan/.

Kessler EJ, AR Kuhns, JA Crawford, CA Phillips, EM Wright, WJB Anthonysamy, TL Esker, J Gillespie, LJ Jacques, RS Saffer. 2013. New county records of reptiles and amphibians from managed properties in east-central Illinois. Herpetological Review 44: 286–288.

Mankowski, A. 2012. The Illinois Endangered Species Protection Act at Forty: a review of the Act’s provisions and the Illinois List of Endangered and Threatened Species. Illinois Endangered Species Protection Board, Springfield, IL. 152 pp. Published online at: http://www.dnr.illinois.gov/ESPB/Pages/default.aspx.

Minton SA. 2001. Amphibians and reptiles of Indiana. Indiana Academy of Science. Indianapolis, IN. p. 404.

Morris, MA. Taxonomic status, reproductive biology, and larval life history of two unisexual forms of Ambystoma from Vermilion County, Illinois. Unpubl M.A. Thesis. Southern Illinois University, Carbondale.

Phillips CA, EO Moll, and RA Brandon. 1999. Field guide to the amphibians and reptiles of Illinois. Illinois Natural History Survey Manual 8: 1–298.

Peterman WE, JA Crawford, RD Semlitsch. 2008. Productivity and significance of headwater streams: population structure and biomass of the black-bellied salamander (Desmognathus quadramaculatus). Freshwater Biology 53:347–357.

Suloway L., M Hubbell. 1994. Wetland resources of Illinois: an analysis and atlas. Illinois Natural History Survey Special Publication 15:1–88.

U.S. EPA. 2003. Protecting wetlands for amphibian and reptile conservation. Office of Water, EPA Fact Sheet 843–F–03–015.

Table 1. Location and physical characteristics of wetlands sampled for amphibians within the Vermilion River Conservation Opportunity Area in 2016. Wetland Property Unit Latitude Longitude Area Slope Canopy (m2) (cm/m) Cover 66 Kickapoo North 40.14115 -87.74766 109 15.0 88 67 Kickapoo North 40.14105 -87.74585 257 16.5 48 68 Middlefork North 40.24204 -87.78233 100 26.5 89 69 Middlefork North 40.24295 -87.77992 380 25.5 94 70 Middlefork North 40.24284 -87.77950 755 37.5 94 71 Middlefork North 40.23972 -87.78572 908 34.3 95 75 Middlefork North 40.20912 -87.75722 140 15.0 70 76 Middlefork North 40.20920 -87.75572 145 13.0 93 282 Kickapoo North 40.14137 -87.74766 113 20.5 7 283 Kickapoo North 40.14251 -87.74768 1810 4.8 95 284 Middlefork North 40.20992 -87.75798 6082 14.8 72 285 Middlefork North 40.20868 -87.75626 81 6.3 78 286 Middlefork North 40.20780 -87.75871 252 15.3 0 287 Middlefork North 40.22720 -87.76707 70686 10.0 98 288 Middlefork North 40.22399 -87.76435 3848 4.3 NR 289 Middlefork North 40.24244 -87.77956 346 35.8 97 290 Middlefork North 40.23994 -87.78409 43 NA 97 291 Fairchild Cemetery North 40.21599 -87.70907 573 6.5 94 292 Georgetown South 39.96854 -87.63164 896 15.5 83 293 Georgetown South 39.95448 -87.62903 660 9.8 86 294 Babe Woodyard South 39.96561 -87.56376 264 14.3 99 295 Babe Woodyard South 39.96524 -87.56535 50 17.0 100 296 Babe Woodyard South 39.96526 -87.56628 444 33.8 100 297 Babe Woodyard South 39.96532 -87.56670 560 19.3 63 298 Babe Woodyard South 39.96511 -87.56717 200 5.3 100 299 Babe Woodyard South 39.96384 -87.57516 540 27.3 60 300 Babe Woodyard South 39.96651 -87.57848 346 16.8 98 301 Babe Woodyard South 39.96045 -87.57261 201 12.3 98 302 Babe Woodyard South 39.96003 -87.57205 975 22.8 99 303 Babe Woodyard South 39.95247 -87.56316 253 19.3 100 304 Babe Woodyard South 39.95252 -87.56348 360 24.8 98 305 Forest Glen South 40.00805 -87.56027 414 10.5 0 306 Forest Glen South 40.01655 -87.57471 312 47.3 98

Table 2. Estimated mean abundance and 95% confidence interval for Silvery Salamanders (Aplat) and Wood Frogs (Rsyl) at 33 wetlands located at seven different properties. Estimates are derived from N-mixture models fit with the R package ‘unmarked’. Wetland Property Aplat adult Aplat larvae Rsyl adult Rsyl larvae 66 Kickapoo 330 (232 – 472) 0 (0 – 0) 527 (513 – 543) 0 (0 – 3) 67 Kickapoo 109 (60 – 203) 1372 (971 – 1945) 31 (21 – 43) 417 (388 – 502) 68 Middlefork 0 (0 – 0) 970 (640 – 1477) 113 (95 – 134) 38 (32 – 45) 69 Middlefork 204 (52 – 861) 809 (510 – 1291) 587 (518 – 601) 99 (89 – 110) 70 Middlefork 0 (0 – 0) 483 (267 – 883) 286 (254 – 321) 347 (324 – 372) 71 Middlefork 248 (62 – 914) 3678 (2947 – 4572) 0 (0 – 0) 72 (60 – 86) 75 Middlefork 215 (139 – 334) 0 (0 – 0) 0 (0 – 0) 0 (0 – 3) 76 Middlefork 200 (128 – 317) 180 (74 – 453) 0 (0 – 0) 4 (2 – 9) 282 Kickapoo 3 (1 – 47) 0 (0 – 0) 162 (152 – 174) 0 (0 – 1) 283 Kickapoo 349 (246 – 496) 3063 (2420 – 3879) 344 (326 – 364) 1757 (1395 – 2143)* 284 Middlefork 86 (43 – 173) 1268 (882 – 1830) 0 (0 – 0) 0 (0 – 0) 285 Middlefork 3 (1 – 47) 0 (0 – 0) 81 (72 – 92) 0 (0 – 3) 286 Middlefork 14 (4 – 68) 6 (2 – 175) 30 (22 – 40) 0 (0 – 1) 287 Middlefork 0 (0 – 0) 118 (38 – 409) 0 (0 – 0) 0 (0 – 0) 288 Middlefork 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 289 Middlefork 0 (0 – 0) 148 (55 – 422) 0 (0 – 0) 72 (57 – 88) 290 Middlefork 172 (44 – 791) 52 (13 – 266) 124 (106 – 143) 18 (13 – 24) 291 Fairchild 0 (0 – 0) 1905 (1404 – 2591) 0 (0 – 0) 7 (3 – 13) 292 Georgetown 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 293 Georgetown 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 294 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 328 (312 – 345) 0 (0 – 0) 295 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 88 (75 – 104) 0 (0 – 5) 296 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 44 (34 – 57) 71 (60 – 83) 297 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 258 (244 – 273) 10 (7 – 14) 298 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 44 (34 – 56) 0 (0 – 5) 299 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 0 (0 – 2) 300 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 64 (59 – 70) 301 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 89 (72 – 109) 53 (47 – 60) 302 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 340 (307 – 375) 66 (52 – 82) 303 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 229 (215 – 244) 73 (65 – 83) 304 Babe Woodyard 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 0 (0 – 0) 305 Forest Glen 0 (0 – 0) 0 (0 – 0) 815 (800 – 909) 3214 (3109 – 4325)* 306 Forest Glen 0 (0 – 0) 0 (0 – 0) 398 (380 – 419) 599 (568 – 631) * Abundance estimates are imprecise and biased high due to issues with statistical model convergence. The relative abundance estimates among ponds is, however, reflective of different population sizes.

OBJECTIVE 2. Evaluate the success of recently created wetlands in providing suitable breeding habitats for SGNC amphibians within the VRCOA

METHODS

Job 2a. Sampling methodology. To evaluate the success of recently created wetlands in providing suitable habitat for SGNC amphibians within the Vermilion River Conservation Area, we proposed to construct drift fences at two recently created wetlands and two reference wetlands. However, because of the outbreaks of Ranavirus that occurred in 2016, we fenced two additional recently created wetlands so that additional outbreaks would not prevent us from a full assessment of their efficacy. Thus, we installed drift fences at six wetlands (two reference, four recently created) rather than the four we proposed. All six wetlands were in the Northern Unit because Silvery Salamanders did not occur in the southern unit. Three ponds (Reference 283, Created 67, Created 282) were in Kickapoo SRA and three (Reference 71, Created 76, Created 285) were in Middlefork SFWA. Locations of the wetlands can be found in Appendix B.

Fences were constructed of aluminum flashing that completely encircled each wetland (Appendix B). We proposed to place pitfall traps (19L buckets) every 5 meters along the interior and exterior of the fence. However, topography and hydrology prevented the bucket placement at specific 5 m intervals. Because we had no need to assess directionality of movements in or out of the wetlands to meet our objectives, bucket placement was not an important factor.

We placed moist sponges in the buckets during active trapping periods to prevent desiccation of captured animals. We also placed a stick in each bucket (that extended above the bucket lip) during active trapping sessions to allow captured mammals the possibility of escape. Finally, during active trapping sessions we secured a half bucket lid to the side of the bucket farthest from the fence. This reduced the possibility of raccoons reaching into the buckets to depredate amphibians, but still left a large opening for amphibians to drop into the bucket. Traps were typically checked daily but were always checked at least once every 48 hrs when open.

In the deepest part of each wetland, staff gauges were placed to monitor daily water levels. In addition, data loggers were placed at the benthos layer and surface of each of the six wetlands to monitor water temperatures.

Job 2b. Quantifying key demographic parameters of adults and metamorphs. All individuals entering and leaving the wetlands were identified to species and sex (for adults). We recorded length and weight of all amphibian SGNC captured to assess body condition. Significant differences in any of these metrics (body condition & recruitment of metamorphs) may indicate critical differences between created and reference sites in terms of wetland function for amphibian SGNC.

Recruitment Rates: The effects of site, wetland classification, and the interaction between these terms on the number of metamorphic amphibians that emerged from the wetlands were tested using negative-binomial regression, with the number of breeding females detected at each wetland as an offset. Species that were excluded from analyses include Rana catesbeiana and Pseudacris maculata due to the small number of detected individuals; and Ambystoma opacum because sampling did not concur with the breeding migration for this species and the complete lack of detection of A. opacum metamorphs in created wetlands. All analyses were performed in R v. 3.5.1 using the package “MASS”.

Body Condition of Emerging Metamorphs: To evaluate whether amphibians that emerge from created wetlands have the same probability of surviving to adulthood compared to reference wetlands, we tested for differences in the Scaled Mass Index (SMI) used by Peig and Green (2009). Briefly, to calculate the SMI, the slope (b) and Pearson’s correlation coefficient (r) of an ordinary least squares linear regression of the natural logarithms of mass and length was used to calculate a scaling index for each species. Then, for each individual the scaled mass index is calculated as follows:

where is the mass, and is the snout to vent length of individual i, and is the mean snout to vent length for species j. We looked for differences in SMI for each species using Student’s two-sample t-tests, or a Wilcoxon-Mann-Whitney test if the SMI data were not normally distributed. All tests were evaluated at alpha of 0.05, and were performed in R v. 3.5.1.

Five species were excluded from analyses either because they were only detected in the reference wetlands (A. opacum, H. scutatum) or because of the small number of detected individuals (R. catesbeiana, P. maculata, A. fowleri).

Body Condition of Breeding Adults: We calculated SMI values for SGNC species (A. platineum and R. sylvatica), as described above. SMI values were calculated and analyzed separately for male and female R. sylvatica because gravid females have a different SMI value. We excluded H. scutatum from this analysis as it only occurred at a single site. To determine if SMI differed between created and reference wetlands, we conducted two-sample Bayesian t-tests using the R package BayesianFirstAid (Bååth 2013).

Job 2c. Effects of climatic and landscape variables on amphibian wetland use, recruitment, and productivity. In addition to the habitat metrics collected in Job 1c. above, we placed data loggers (±1°C accuracy) in each of the fenced wetlands to continuously monitor water temperatures. This data was used in regression analyses to determine factors most affecting

differences between created and reference wetlands in terms of SGNC reproductive potential and recruitment.

Because our focal SGNC amphibians are forest-dependent species, we calculated the amount of forested habitat within 500 m and 1 km of each study wetland (Table 1); we also measured canopy coverage over each wetland. HOBO data loggers were deployed in each wetland to record hourly water temperatures and these data were summarized to report an average temperature for each wetland. These data, in addition to the wetland-level covariates mean depth, slope and canopy were incorporated into Bayesian mixed effects models to determine factors contributing to variation in the SMI of metamorphs of SGNC species. Because density can affect growth rates, we calculated a density measure for each wetland by dividing the number of females captured at drift fences by the wetland area. This composite measure was highly correlated with wetland area (r = 0.85), so it was used in place of area in all models. Prior to model fitting, we assessed the correlation among predictor variables to minimize collinearity. If variables were correlated (r > 0.7), one of the two variables was used in analyses. Final models were parameterized with the following variables: classification (reference/created), year (2017/2018), density (breeding females / m2), basin slope, and temperature (mean water temperature from 15 March – 15 July each year). Mean water temperature and canopy coverage over the wetland were highly correlated (r = -0.97); we retained mean temperature in our models as it more specifically reflects conditions experienced by larval amphibians.

We also assessed how wetland-level covariates affected the number of metamorphs emerging from wetlands. The same covariates were modeled as described above, except area (meter2) was used in place of density. We fit Bayesian negative binomial generalized linear models to the data and used number of females captured at the drift fence as an offset in the models. All Bayesian models were fit with the R package brms (Bürkner 2016).

RESULTS

Job 2a. Sampling results.

We captured 17 species of amphibians from the six fenced ponds (Table 2). Two species, Southern Two-lined Salamander, Eurycea cirrigera, and Eastern Red-backed Salamander, Plethodon cinereus, do not utilize vernal wetlands for reproduction. Eurycea cirrigera is a streamside salamander that deposits eggs on the underside of rocks in flowing water, and the larval stage of P. cinereus occurs in the egg, which are laid terrestrially. Both species were considered by-catch in this study and removed from the dataset prior to analyses.

Only four species (Silvery Salamander, A. platineum; Smallmouth Salamander, A. texanum; Spring Peeper, P. crucifer; and Wood Frog, R. sylvatica were encountered in every wetland in both years (Table 2). The Four-toed Salamander, Hemidactylium scutatum, and Southern Leopard Frog, Rana sphenocephala, were encountered only in reference pond 71 in Middlefork State Fish and Wildlife Area (Table 2). Neither the Spotted Salamander, Ambystoma

maculatum, nor the Marbled Salamander, Ambystoma opacum, were encountered in the parcel of Middle Fork SFWA that had recently created wetlands (Table 2).

Job 2b. Quantifying key demographic parameters of adults and metamorphs

Recruitment Rates: When comparing reference to created wetlands, there was no significant difference in recruitment rates of metamorphs emerging from reference versus created wetlands when the number of females entering the wetland to breed was taken into account (Table 3–4). Differences between sites were detected for R. sylvatica, with the average ratios being 14.3 times greater in Kickapoo State Recreation Area (Table 3; p = 0.0169, ANOVA). However, the interaction between site and wetland status did not affect any species.

Body Condition of Emerging Metamorphs: Ambystoma platineum, P. crucifer and R. sylvatica emerging from created wetlands had a lower Standard Mass Index (SMI: aka body condition) than those that emerged from reference wetlands (p < 0.05; Figure 1). The American Toad, Anaxyrus americanus showed the opposite trend; emerging from created wetlands with higher SMI (p < 0.01). Species that were apparently unaffected by wetland type were A. maculatum, A. texanum, P. maculata, and R. clamitans (p > 0.05). However, very few individuals of these species were detected at the created wetlands (Table 3), which greatly diminished our ability to detect true differences in the SMI for these four species.

Body Condition of Breeding Adults: The SMI of A. platineum and male R. sylvatica was significantly lower at created wetlands than reference wetlands when both years were analyzed using a Bayesian t-test (probability of being lower = 0.998 and 0.965, respectively). There was no significant difference in SMI between created and reference wetlands for R. sylvatica females (probability of difference = 0.229; Figure 2).

Job 2c. Effects of climatic and landscape variables on amphibian wetland use, recruitment, and productivity.

Body condition of metamorphs as a function of wetland characteristics When accounting for wetland-level covariates, there was no difference in A. platineum SMI values between created and reference wetlands (Table 5). SMI values were also not affected by the density of breeding females or basin slope. There was, however, a notable decrease in metamorph SMI between years (lower in 2018, 82% probability). Also, SMI decreased significantly as the mean wetland temperature increased (Table 5, 99% probability).

Wetland-level covariates were also important for explaining variation in metamorph R. sylvatica SMI (Table 6). Like A. platineum, there was no significant effect of wetland status or basin slope on R. sylvatica SMI. SMI measures were lower in 2018 (91% probability) and there was a negative effect of mean water temperature (100% probability). Interestingly, R. sylvatica showed a moderate increase in SMI as the density of breeding females in wetlands increased (99% probability).

Metamorph recruitment as a function of wetland characteristics The number of metamorph A. platineum produced at wetlands was not affected by wetland classification or year (Table 7, probabilities < 0.7). However, increasing basin slope increased the number of metamorphs produced (95% probability). Higher average wetland temperatures significantly decreased the number of metamorphs produced (88% probability).

None of our wetland-level predictor variables were effective at explaining variation in the number of R. sylvatica metamorphs produced (Table 8). Increasing pond basin slope had a moderate (82% probability) negative effect on the number of metamorphs. Wetland classification, year, and average water temperature were not significant predictors (support probability < 73%).

DISCUSSION

Regarding the species in greatest need of conservation in this study (R. sylvatica, A. platineum), the reference wetlands produced metamorphs in better body condition at emergence than the nearby created wetlands, which is indicated by the increase in SMI (Figure 1). The SMI used here has been shown to strongly correlate with body fat percentage and muscle mass in amphibians in various life stages, so it is a reasonable proxy for body condition (MacCracken & Stebbings, 2012). For many species of amphibians, including R. sylvatica, metamorphic amphibians with a low body condition have a lower probability of survival (Altwegg & Reyer, 2003; Beck & Condgon, 1999; Berven, 1990; Scott, Casey, Donovan, & Lynch, 2007). A lower body size confers greater risk for desiccation and predation, and decreases in body condition leave animals with a greater risk of infection to pathogens and parasites (Gervasi & Foufopoulos, 2008).

Our results indicate that the created wetlands in this study may be acting as population sinks for certain species in these areas by drawing breeding adults away from the ideal habitat for larval development and post-emergence survival. Although compensatory growth post- emergence has been observed to negate initial differences in size at metamorphosis in some anurans (Beck & Condgon, 1999; Boone, 2005; Gramapurohit, 2009), trends in body condition were still evident in breeding adults in our study (Figure 2). Both A. platineum and male R. sylvatica breeding at reference wetlands had higher SMI values than individuals breeding at created wetlands. This pattern was not observed in female R. sylvatica. As such, there may be no or limited deleterious effects to R. sylvatica recruitment as a consequence of SMI.

Size at metamorphosis is influenced by a variety of biotic and abiotic conditions. High larval density, and predator presence has been shown to decrease metamorphic size (Berven, 1990; Lawler, Dritz, Strange, & Holyoak, 1999; Relyea & Hoverman, 2003). Short hydroperiods also decrease size at metamorphosis (Leips, McManus, & Travis, 2000; Richter-Boix, Llorente, & Montori, 1980). The created wetlands in this study were smaller, and shallower than the reference wetlands, which increases desiccation rates and water temperatures (Table 1). In fact, one created wetland (285) failed to hold water in 2018. To maximize amphibian

recruitment by creating wetlands, the wetlands should be deep enough to hold water through July, and receive as much canopy cover as is possible to sustain cooler water temperatures.

Our analyses of SGNC species’ responses to wetland-level covariates suggested less specific influence of wetland classification (created vs. reference). Rather, our analyses highlight the year-to-year variation typical of wetland-breeding amphibians (Richter et al, 2003). There were differences in weather between 2017 and 2018 (Table 9); notably that more rain fell from 15 April –15 July in 2018, but did so in 10 fewer rain events. This marked shift in rain frequency contributed to many wetlands having mean depths up to 10 cm lower in 2018 (Table 1). Shallower ponds tend to have higher temperatures, and mean temperature was the most influential parameter among wetland-level characteristics assessed. Mean water temperature was a prominent and significant predictor of A. platineum and R. sylvatica SMI and metamorph recruitment. In all cases, higher water temperatures had negative impacts. Water temperature was found to be negatively correlated with canopy coverage over wetlands (r = -0.97). As such, one of the most important wetland features to consider in future management of SGNC species and their breeding habitat is maintenance of high canopy cover over wetlands.

There were mixed results for the effects of basin slope on SMI and metamorph recruitment. Slope had no effect on SMI, a positive effect on A. platineum metamorph recruitment, and a negative effect on R. sylvatica metamorph recruitment. The estimate of slope may be serving as a surrogate of wetland hydroperiod in this study. A steeper slope translates to a more impounded basin with a longer hydroperiod necessary to allow A. platineum larvae time to survive and grow to successfully reach metamorphosis. Conversely, R. sylvatica have shorter larval periods and need shallow water refugia for tadpoles to forage and avoid predation. Basin slope has previously been shown to provide the structural heterogeneity in wetlands that is important for colonization, reproductive success, and maintenance of biodiversity (Peterman et al., 2013; Shulse et al., 2012). A general guideline is to maintain a variety of slope gradients to ensure shallow and deep-water areas to maximize the function for a diversity of amphibian species. Further, the differential wetland requirements (wetland size, slope, hydroperiod, and placement) for various species of amphibians should be achieved by ensuring a variety of wetlands exist within a metapopulation.

LITERATURE CITED

Altwegg, R & H-U Reyer. 2003. Patterns of natural selection on size at metamorphosis in water frogs. Evolution 57: 872–882.

Bååth, R. 2013. Bayesian First Aid. https://github.com/rasmusab/bayesian_first_aid

Beck, CW & JD Condgon. 1999. Effects of individual variation in age and size at metamorphosis on growth and survivorship of southern toad (Bufo terrestris) metamorphs. Canadian Journal of Zoology 77: 944–951.

Berven, KA. 1990. Factors affecting population fluctuations in larval and adult stages of the Wood Frog (Rana sylvatica). Ecology 71: 1599–1608.

Bürkner, P-C. 2016. brms: An R package for Bayesian multilevel models using Stan. Journal of Statistical Software 80:1-28.

Boone, MD. 2005. Juvenile frogs compensate for small metamorph size with terrestrial growth: overcoming the effects of larval density and insecticide exposure. Journal of Herpetology 39: 416–423.

Gervasi, SS, & J Foufopoulos. 2008. Costs of plasticity: Responses to desiccation decrease post- metamorphic immune function in a pond-breeding amphibian. Functional Ecology 22: 100–108.

Gramapurohit, NP. 2009. Catch-up growth during juvenile life can compensate for the small metamorphic size in Euphlyctis cyanophlyctis. Current Science 97: 1243–1246.

Lawler, SP., D Dritz, T Strange & M Holyoak. 1999. Efects the of introduced mosquitofish and bullfrogs on tereatened California Red-Legged Frog. Conservation Biology 13: 613–622.

Leips, J, MG McManus & J Travis. 2000. Response of treefrog larvae to drying ponds : comparing temporary and permanent pond breeders.Ecology 81: 2997–3008.

MacCracken, JG & JL Stebbings. 2012. Test of a body condition index with amphibians. Journal of Herpetology 46: 346–350.

Peig, J & AJ Green. 2009. New perspectives for estimating body condition from mass/length data: the scaled mass index as an alternative method. Oikos 118: 1883–1891.

Peterman, WE, TL Anderson, DL. Drake, BH Ousterhout & RD Semlitsch. 2014. Maximizing pond biodiversity across the landscape: a case study of larval ambystomatid salamanders. Animal Conservation 17:275–285.

Richter, SC, JE Young, GN Johnson & RA Seigel. 2003. Stochastic variation in reproductive success of a rare frog, Rana sevosa: implications for conservation and for monitoring amphibian populations. Biological Conservation 111:171–177.

Relyea, RA & JT Hoverman. 2003. The impact of larval predators and competitors on the morphology and fitness of juvenile treefrogs. Oecologia 134: 596–604.

Richter-Boix, A, GA Llorente & A Montori. 1980. Effects of phenotypic plasticity on post- metamorphic traits during pre-metamorphic stages in the anuran. Evolutionary Ecology Research 8: 309–320.

Scott, DE, ED Casey, MF Donovan & TK Lynch. 2007. Amphibian lipid levels at metamorphosis correlate to post-metamorphic terrestrial survival. Oecologia 153: 521– 532. doi:10.1007/s00442-007-0755-6

Shulse, CD, RD Semlitsch, KM Trauth & JE Gardner. 2012. Testing wetland features to increase amphibian reproductive success and species richness for mitigation and restoration. Ecological Applications 22:1675–1688.

Table 1. Summary of wetland characteristics. Are a Canopy Mean depth Mean depth Mean temp Mean temp Forest w/in Forest w/in Pond Age (m2) Cover (%) Fish Latitude Longitude Slope 2017 (cm) 2018 (cm) 2017 (°C) 2018 (°C) 500m (ha) 1km (ha) Site Status 282 19 113 6.76 Absent 40.14137 -87.74766 20.5 35.9 28.0 20.0 20.2 7.38 11.52 Kickapoo Constructed 283 NA 1810 94.64 Absent 40.14251 -87.74768 4.75 30.2 20.6 17.0 16.6 70.56 196.47 Kickapoo Reference 285 9 81 77.74 Absent 40.20868 -87.75626 6.25 19.4 8.2 17.7 17.0 2.25 11.25 Middlefork Constructed 67 9 257 48.1 Absent 40.14105 -87.74585 16.5 28.1 20.6 18.1 17.9 3.78 12.87 Kickapoo Constructed 71 NA 908 94.64 Present 40.23972 -87.78572 34.25 40.8 40.1 17.5 17.2 50.76 181.17 Middlefork Reference 76 9 145 93.34 Absent 40.2092 -87.75572 13 37.5 37.6 15.6 16.3 59.22 203.22 Middlefork Constructed

Table 2. Species detected at drift fences by wetland and year for reference and constructed wetlands in state managed properties in the Vermilion River Conservation Opportunity Area in Vermilion County, Illinois.

Middle Fork SFWA Kickapoo SRA Reference Constructed Reference Constructed 71 76 285 283 67 282 A. maculatum A. opacum A. platineum A. texanum 2017 E. cirrigera † 2018 H. scutatum† 2017 & 2018 P. cinereus † Never A. blanchardi H. chrysoscelis P. crucifer P. maculata A. americanus A. fowleri R. catesbeiana R. clamitans R. sphenocephala R. sylvatica † Denotes species that do not typically breed in vernal wetlands

Table 3. Count data of adult females (Fem) and metamorph (Met) wetland breeding amphibians encountered at drift fences encircling recently created and reference wetlands in Kickapoo State Recreation Area and Middle Fork Fish and Wildlife Area, Vermilion County, Illinois. The recently created and reference wetlands at MFSFWA are in parcel of the property separated by 4 km and there was no indication that A. maculatum or A. opacum occur in the parcel with the recently created wetlands (shaded grey).

Kickapoo State Recreation Area Middle Fork State Fish and Wildlife Area Recently Created Wetlands Reference Wetland Recently Created Wetland Reference Wetland 67 282 283 285 76 71 2017 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 2018 Fem Met Fem Met Fem Met Fem Met Fem Met Fem Met Fem Met Fem Met Fem Met Fem Met Fem Met Fem Met A. maculatum 10 5 2 100 9 265 43 63 88 52 17

A. opacum 1 2 397 5 201 3 47

A. platineum 75 7 195 36 6 55 19 742 22 395 25 36 8 40 2 129 8 49 132 310 199 252 143

A. texanum 42 4 13 11 1 22 2 111 1 63 10 4 4 7 2 18 53 7 193 14

Anaxyrus sp. 9 1 7 10 14 2 9 12 1 1 11 4 31 3 9 11

Hyla sp. 1 1 6

P. crucifer 3 1 4 8 6 1 52 25 25 18 19 123 1 25 56 17 9 5 25 23

P. maculata 1 1 1 2 22 4 1 6 8 5 13 2

R. catesbeiana 2 1 2 17 6

R. clamitans 1 3 16 1 5 8 1 2 20 13 149 6 3

R. sylvatica 21 882 39 33 11 123 16 258 89 2678 25 187 6 1 11 79 36 52 150

Table 4. Summary table from a negative binomial regression assessing differences in the number of emergent metamorphs between recently created wetlands and reference wetlands. To account for different sizes in breeding population size, the number of unique adult female detections was used as an offset. Estimates are reported as exponentiated model coefficients, with associated 95% confidence intervals (CIs).

Estimate Lower 95% CI Upper 95% CI p Intercept 1.852 1.107 5.772 0.033 Treatment - Reference 1.315 0.518 3.703 0.579

Table 5. Summary table from a Bayesian mixed effects model assessing covariate effects on A. platineum SMI. 95% credible intervals (CRI) of parameter estimates are reported. Support indicates the probability that a parameter has the estimated effect. Low probabilities of support indicate 95% CRI that extensively overlap 0. Rhat is a measure of Bayesian model convergence, with values < 1.05 indicating suitable convergence.

Estimate Est.Error lower-95% CRI upper-95% CRI Support Rhat Intercept 1.765 1.046 -0.181 3.709 0.970 1.002 Treatment–Reference -0.353 1.304 -2.627 1.777 0.674 1.003 Year–2018 -0.052 0.058 -0.162 0.067 0.820 1.005 Density -0.023 0.050 -0.117 0.080 0.698 1.003 Slope 0.124 0.601 -1.098 1.252 0.666 1.001 Mean Temp -0.244 0.099 -0.432 -0.027 0.992 1.004

Table 6. Summary table from a Bayesian mixed effects model assessing covariate effects on R. sylvatica SMI. 95% credible intervals (CRI) of parameter estimates are reported. Support indicates the probability that a parameter has the estimated effect. Low probabilities of support indicate 95% CRI that extensively overlap 0. Rhat is a measure of Bayesian model convergence, with values < 1.05 indicating suitable convergence.

Estimate Est.Error lower-95% CRI upper-95% CRI Support Rhat Intercept 0.611 3.201 -6.090 7.384 0.750 1.007 Treatment–Reference -0.206 4.592 -9.719 9.850 0.579 1.009 Year–2018 -0.020 0.014 -0.047 0.008 0.913 1.000 Density 0.043 0.018 0.007 0.079 0.990 1.000 Slope 0.269 2.323 -3.738 6.322 0.571 1.018 Mean Temp -0.225 0.061 -0.341 -0.102 1.000 1.000

Table 7. Summary table from a Bayesian negative binomial generalized linear model assessing covariate effects on the number of A. platineum metamorphs produced. 95% credible intervals (CRI) of parameter estimates are reported. Support indicates the probability that a parameter has the estimated effect. Low probabilities of support indicate 95% CRI that extensively overlap 0. Rhat is a measure of Bayesian model convergence, with values < 1.05 indicating suitable convergence.

Estimate Est.Error lower-95% CRI upper-95% CRI Support Rhat Intercept -0.405 0.819 -1.773 1.522 0.732 1.002 Treatment–Reference -0.035 1.090 -2.029 2.338 0.546 1.002 Year–2018 0.325 0.898 -1.523 2.105 0.660 1.001 Slope 0.895 0.510 -0.161 1.901 0.955 1.002 Mean Temp -0.525 0.481 -1.450 0.483 0.876 1.002

Table 8. Summary table from a Bayesian negative binomial generalized linear model assessing covariate effects on the number of R. sylvatica metamorphs produced. 95% credible intervals (CRI) of parameter estimates are reported. Support indicates the probability that a parameter has the estimated effect. Low probabilities of support indicate 95% CRI that extensively overlap 0. Rhat is a measure of Bayesian model convergence, with values < 1.05 indicating suitable convergence.

Estimate Est.Error lower-95% CRI upper-95% CRI Support Rhat Intercept 2.418 1.222 0.921 5.357 0.998 1.002 Treatment–Reference 0.072 1.781 -3.631 3.162 0.553 1.002 Year–2018 -0.387 0.935 -2.221 1.629 0.701 1.001 Slope -0.375 0.589 -1.429 0.743 0.820 1.007 Mean Temp 0.395 0.914 -1.493 2.075 0.728 1.005

Table 9. Summary of weather data collected from Danville, IL weather station. Data are summarized from 15 April – 15 July of each year.

Total Mean Number of Average Year precipitation (mm) precipitation (mm) rain events temperature (°C) 2017 460 3.8 51 23.7 2018 491 4.06 41 22.9

Figure 2. Scaled Mass Index (SMI) of adult A. platineum and R. sylvatica captured at drift fence arrays surrounding reference and created wetlands in the Vermilion River Conservation Opportunity Area. Male and female R. sylvatica were assessed separately because females were gravid when captured entering ponds. Bayesian t-test determined that SMI of A. platineum and R. sylvatica males were significantly greater at reference wetlands than at created wetlands. There was no significant difference in SMI between wetland types for R. sylvatica females.

APPENDIX A. Aerial images depicting the locations of the 33 wetlands sampled for SGNC amphibians in the Vermilion River Conservation Opportunity Area in 2016.

Wetlands

APPENDIX B.

Locations and images of the 6 wetlands surrounded with drift fencing in the Vermilion River Conservation Opportunity Area.