Distribution, Abundance and Recruitment of Amphibian Species in Greatest Need of Conservation in the Vermilion River Conservation Opportunity Area 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. 1 • 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. 2 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