Inventory and Evaluate Burrowing Crayfish Monitoring Methods in the MS Sandhill Crane NWR
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Final Report on Inventory and evaluate burrowing crayfish monitoring methods in the MS Sandhill Crane NWR Interagency Agreement Number F16PG00142 Creaserinus oryktes--MSCNWR. Photo by G.A. Schuster. ©US Forest Service September 11, 2018 Submitted by Susan B. Adams, Ph.D. USDA Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research 1000 Front St., Oxford, MS 38655 E-mail: [email protected]; Phone: 662-234-2744 ext. 267 Submitted to: Mr. Scott Hereford Senior Wildlife Biologist, Mississippi Sandhill Crane NWR 7200 Crane Lane, Gautier, MS 39553 1 EXECUTIVE SUMMARY The study was undertaken in part to assess how habitat management for Mississippi sandhill cranes influenced priority at-risk crayfish species on the Mississippi Sandhill Crane National Wildlife Refuge (hereafter, Refuge). Additional goals were to assess methods for sampling and monitoring crayfishes on the refuge and to provide educational materials about the Refuge’s crayfishes. We compared: (1) crayfish burrow densities to vegetation characteristics across Refuge units with differing management histories, (2) various methods for sampling burrowing crayfishes on the Refuge, and (3) various methods for sampling crayfishes and fishes in aquatic habitats. Crayfish burrow densities were negatively associated with woody plant coverage and height and with tree densities, indicating that habitat management to create and maintain prairie and savanna habitat for cranes is also beneficial to burrowing crayfish populations. Burrowing species collected were the speckled burrowing crayfish (Creaserinus oryktes) and the spinytail crayfish (Procambarus fitzpatricki). The latter is a FWS priority, at-risk species. For sampling burrowing crayfishes, burrow excavation and suctioning were more successful than trapping, but neither approach could be readily standardized. The former varied dramatically among collectors, and the latter varied in relation to rainfall. In aquatic habitats, we caught red swamp crayfish (Procambarus clarkii) and least crayfish (Cambarellus diminutus) during systematic sampling and added ditch fencing crayfish (Faxonella clypeata), Gulf crayfish (P. shermani), and spinytail crayfish during non-systematic sampling. In systematic sampling, active methods (dipnetting and seining) produced a higher crayfish catch-per-unit-effort and more fish species than passive methods (baited minnow and habitat traps), but passive methods caught more adult crayfish and all of the amphibians. We caught 10 fish and 2 amphibian species during systematic aquatic sampling. Crayfish photographs and information for educational materials were provided to Refuge staff. 2 TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................ 2 INTRODUCTION .......................................................................................................................... 4 TERRESTRIAL .............................................................................................................................. 5 Methods--Terrestrial ................................................................................................................... 5 Habitat and burrow counts—systematic sampling ................................................................. 5 Crayfish sampling ................................................................................................................... 6 Statistical analyses .................................................................................................................. 7 Results--Terrestrial ..................................................................................................................... 8 Habitat and burrow counts—systematic sampling ................................................................. 8 Crayfish capture and sampling efficiency ............................................................................... 8 AQUATIC..................................................................................................................................... 10 Methods--Aquatic ..................................................................................................................... 10 Statistical analyses ................................................................................................................ 11 Results—Aquatic ...................................................................................................................... 11 Standardized sampling .......................................................................................................... 11 Non-standardized sampling .................................................................................................. 12 DISCUSSION ............................................................................................................................... 12 Sampling recommendations .................................................................................................. 15 ACKNOWLEDGEMENTS .......................................................................................................... 15 LITERATURE CITED ................................................................................................................. 16 TABLES ....................................................................................................................................... 17 FIGURES ...................................................................................................................................... 22 Appendix A. Collectors ................................................................................................................ 32 Appendix B. Terrestrial sampling and results ............................................................................... 33 Appendix C. Aquatic sampling and results................................................................................... 36 3 INTRODUCTION Habitat management on the Mississippi Sandhill Crane National Wildlife Refuge (hereafter, Refuge) has focused primarily on creating open-canopy prairie and savanna habitat for Mississippi sandhill cranes (Grus canadensis pulla). Burning is the preferred habitat management method, but in units where frequent burning is not feasible, mechanical treatment (cutting and mulching vegetation) has been used. Such management potentially benefits an entire community adapted to wet prairie and pine savanna habitats. However, responses of some US Fish and Wildlife Service (FWS) priority at-risk species to the habitat management approaches are unknown. The FWS sought more information about the distribution of priority crayfishes on the Refuge and how the land management influenced primary burrowing crayfish species. This study was designed to fill information gaps regarding four crayfish species designated as priority at-risk species by the FWS region and listed as target species for the Refuge: angular dwarf crayfish (Cambarellus lesliei), burrowing bog crayfish (Creaserinus burrisi), speckled burrowing crayfish (Creaserinus danielae), and spinytail crayfish (Procambarus fitzpatricki). Note that a recent taxonomic revision moved all Fallicambarus species in Mississippi to the genus Creaserinus (Crandall and De Grave 2017). Crayfish species are often placed into one or more overlapping categories as primary, secondary, or tertiary burrowers (Hobbs 1942, 1981). Tertiary burrowers live in surface waters, occasionally occupying simple burrows to escape a drying habitat or very cold temperatures, brood eggs, and perhaps avoid predation. Secondary burrowers spend part of most years in surface waters and part in burrows. Primary burrowers rarely or never use surface waters, instead occupying complex burrows that intersect the water table throughout their lives and emerging to forage, find mates, and probably to disperse. Primary burrowers may be further categorized as habitat generalists or specialists (Rhoden et al. 2016). Generalists occupy woodland or open- canopy habitats, whereas many specialists are primarily restricted to open-canopy habitats, often with specific soil types. Primary burrowing crayfishes that are habitat specialists may use mowed road right of ways (Rhoden et al. 2016) or prairie or savanna habitats maintained in an early successional stage by fire or other means (Welch 2004). In the Ouachita Mountains, Arkansas, and Camp Shelby, Mississippi, burrow densities for several burrowing crayfishes were positively related to open canopy and availability of water relatively near the soil surface (Welch 2004, Rhoden et al. 2016). Because the water table is relatively shallow throughout most of the Refuge, canopy cover was a logical candidate as a driver of habitat-specialist burrowing crayfish population densities. The study goals were to assess crayfish population responses to the ongoing habitat management, to begin documenting crayfish distributions on the Refuge, and to test sampling methods on the Refuge. Our objectives were to: 1) document presence of and habitat types used by the four priority at-risk crayfish species thought to occur on the Refuge, 2) test the efficiency of various sampling methods for a potential crayfish monitoring program, 3) compare burrowing crayfish densities among sites with differing vegetation management histories, 4) survey other crayfish species present on the Refuge, and 5) photograph crayfishes for educational materials. 4 Ancillary to the