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Anthropogenic impacts have degraded the function of many large river-floodplain ecosystems. Habitat rehabilitation/management, in the form of water level management, often emphasize the promotion of wetland vegetation. Wetland management is believed to enhance macroinvertebrate populations. To test this assumption, I evaluated macroinvertebrate response to habitat rehabilitation, habitat type, and vegetation density in Swan Lake, an Illinois River floodplain lake located in Calhoun County, Illinois. Results indicated wetland rehabilitation generally enhanced macroinvertebrate availability for spring migrating waterfowl. Results comparing habitats available at Swan Lake indicated moist soil habitats provided greater abundance and biomass of water column macroinvertebrates in the fall season, while spring was more variable. In addition, benthic macroinvertebrate communities indicated inconsistent differences between habitat types. Fall estimates indicated inundation can be an effective mechanism for controlling the timing of water column macroinvertebrate colonization. Vegetation manipulations did not consistently impact macroinvertebrate taxonomic and functional groups, but results indicated some specific taxonomic groups were influenced by vegetation presence/absence and were correlated (positively or negatively) with coarse organic matter. This research supported the principle that management of habitat and hydrologic regime can be effective tools for improving macroinvertebrate populations in order to optimize nutritional resources for waterfowl.

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The past two decades have witnessed an unprecedented decline in Lepidopteran species, with more than a third of the UK’s butterflies now either considered threatened, or already lost from the country. The vulnerable marsh fritillary, Euphydryas aurinia, after a long term loss in the UK of 73% in abundance, has become an almost iconic species as the target of many well-funded conservation projects across the UK. Despite extensive ecological studies, populations of E. aurinia are shown in Chapter 2 to still be declining in south-west UK even after recommended management strategies have been implemented. This necessitates the need for prompt research beyond that of management requirements and butterfly habitat preferences. In Chapter 3, microsatellite markers (EST-SSRs) were developed for E. aurinia and using these markers in Chapter 4, it is shown that E. aurinia populations in southern UK and Catalonia, Spain, are severely genetically differentiated at all geographical scales, and genetically depauperate, causing huge concerns for the conservation of this enigmatic and ecologically important species. Dispersal is fundamental to metapopulation existence and survival. Phosphoglucose isomerase (PGI – an enzyme in the glycolysis pathway) is a well-endorsed candidate gene for dispersal, extensively studied in the Glanville fritillary (Melitaea cinxia) and Orange Sulphur (Colias eurytheme). In Chapter 5, an analysis across 27 sites in the UK discovered six non-synonymous SNPs (single nucleotide polymorphisms) within PGI. A single charge-changing SNP of interest showed no evidence of balancing selection, contrary to findings in M. cinxia, instead appearing to be neutral when analysed alongside microsatellite markers developed in Chapter 3. No link was found between genotype and flight, morphology or population trend. These findings challenge the emerging perspective that PGI could be used as an adaptive molecular marker for arthropods. Wolbachia are endosymbiotic bacteria capable of dramatically altering the reproductive system of their host. In Chapter 6, a PCR-based diagnostic in conjunction with MLST (multi-locus sequence typing) identified 100% prevalence of a single strain of Wolbachia across all sampled E. aurinia populations in the UK. Total prevalence suggests that Wolbachia probably has little phenotypic impact on its host, but the potential impacts of this endosymbiont on uninfected populations should be considered during any management plans for the conservation of E. aurinia. Current management plans will need to incorporate all areas of research, from basic ecological requirements to molecular adaptation and unseen manipulators of host biology, to be able to fully and effectively conserve declining fragmented species.

The spotted turtle (<i>Clemmys guttata</i>) and Blanding’s turtle (<i>Emydoidea blandingii</i>) are two state-endangered species in Indiana whose populations are in decline. Historically, both species were found across the northern portion of Indiana in various wetland habitats. There are multiple causes of population decline for both species, including habitat fragmentation, habitat loss and degradation, urban development and encroachment, poaching, and road mortality. Despite efforts to record these species across the state, there has been no intensive population assessments. Based on this need, I conducted both visual encounter surveys across the state and used Maximum Entropy (MaxEnt) modeling to facilitate understanding the current distribution of both species in Indiana. Twenty-three locations were visited and surveyed in Indiana, with trapping being conducted at an additional four locations where populations were known to be larger. Surveys aided in delineation of six populations of Blanding’s turtles and five populations of spotted turtles. A total of 69 Blanding’s turtles and 70 spotted turtles were observed between surveying and trapping. Delineated populations were mainly found in the northern third of Indiana. This data and other occurrences were used to predict suitable habitat across Indiana. The Blanding’s turtle models were sufficiently resolved to predict potential localities or potential sites for focused management or repatriation. Spotted turtle model performance reflected the need for more samples, but also the likelihood of fewer numbers due to declining habitat availability. Both Blanding’s turtle and spotted turtle models argue for the need of more intense survey efforts based on historical occurrences, as well as restoration efforts across the state. Most models for both species were observed to have a trend towards suitable habitat in the northern third of the state, correlating with the results of the survey efforts. The results of this project indicate that Blanding’s turtle and spotted turtle populations are still in decline likely due to limited habitat availability.

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