4/10/2018 Conserving Tennessee’s Largest Salamander Jeronimo Silva Graduate Student Tennessee State University Outline • Amphibian decline and diversity • What are Hellbenders??? • How are Hellbenders doing??? • Where are Hellbenders??? • Impact of land use on occupancy • Conservation implications and future research Source: International Union for Conservation of Nature (IUCN) 1 4/10/2018 Amphibian declines • Highest proportion of species threatened with extinction (Cushman 2006) • Major threats (Beebee and Griffiths 2005) • Habitat destruction • Diseases • Invasive species • Exploitation • Climate change • Amphibians are particularly vulnerable • Good indicators of environmental conditions Amphibian Classification and Diversity • Includes three major Orders - Anura (Frogs and Toads) - Gymnophiona (Caecilians) - Caudata (Salamanders) • Anura = greatest diversity 6,824 species • Caudata = 707 species • Gymnophiona = 206 species Caudate Phylogeny Plethodontidae Derived Amphiumidae Rhyacotritonidae Ambystomatidae Dicamptodontidae Salamandridae Proteidae Sirenidae Hynobiidae Cryptobranchidae Primitive Courtesy: Rebecca Hardman 2 4/10/2018 Family Cryptobranchidae • Crypto- “hidden”, -branch “gill”, - idae “family” • Two genera (Cryptobranchus and Andrias) Bishopi ssp. – Federally Endangered Alleganiensis ssp. – under review NY IL PA IN OH MO WV KY VA TN NC AR MS AL G A **Research by Paul Hime revealed unknown diversity** 3 4/10/2018 PC: David Herasimtschuk PC:TVA 4 4/10/2018 onegeology.org 5 4/10/2018 Hellbender Total Length: 1990s Calfkiller River: 4 hellbenders; 40.2 – 54.5 cm Duck River: 3 hellbenders; 45.4 – 55.5 Collins River: 42 hellbenders; 40.8 – 54.5 Buffalo River: 28 hellbenders; 11.1 – 60.8 • Calfkiller, Collins, and Duck rivers were sexually mature (Eastern Highland Rim streams) • By contrast, 25% (n = 7) from the Buffalo River were juveniles (111 mm – 253 mm). Western Highland Rim stream Blue Ridge Population Surveys 6 % % 10 15 20 25 30 % % 0 5 Cherokee NF PopulationNF Cherokee Size Structure 10 15 20 25 30 0 5 10 15 20 25 30 20 25 30 35 10 15 0 5 0 5 <9 Courtesyof Dr.Cathy Jachowski <9 9-12 <9 <9 9-12 13-15 ↓ 80 ↓ 80 % 9-12 9-12 13-15 16-18 13-15 16-18 13-15 19-21 GSMNP Population Structure GSMNP 19-21 16-18 CreekTumbling Total length Total (cm) 16-18 22-24 Hiwassee River 22-24 19-21 River Oconaluftee 25-27 19-21 Length Total (cm) 25-27 22-24 28-30 Little River Little Total length (cm) length Total 22-24 28-30 31-33 25-27 length(cm) Total 31-33 25-27 34-36 28-30 34-36 28-30 37-39 31-33 37-39 X 31-33 40-42 34-36 40-42 43-45 34-36 37-39 43-45 X 46-48 37-39 46-48 40-42 49-51 49-51 43-45 40-42 52-54 X 52-54 46-48 43-45 ↓ ? 49-51 46-48 52-54 49-51 ? 52-54 Undergoing status Undergoing federal Stable % ↓ % 10 15 20 25 30 10 15 20 25 30 0 5 0 5 % % 10 15 20 25 30 assessment 0 5 <9 10 15 20 25 30 35 <9 ? 0 5 9-12 <9 9-12 <9 13-15 13-15 ↓ 9-12 16-18 9-12 16-18 Stable 13-15 19-21 13-15 19-21 Tellico River Tellico 16-18 Rough Creek Total length Total (cm) 22-24 Total length/cm Total Stable 16-18 22-24 Noland Creek 19-21 25-27 25-27 19-21 28-30 22-24 DeepCreek Total length (cm) length Total 28-30 22-24 length (cm) Total 25-27 31-33 31-33 25-27 34-36 28-30 34-36 28-30 37-39 31-33 37-39 40-42 31-33 34-36 40-42 ↓ 43-45 34-36 37-39 46-48 43-45 37-39 40-42 49-51 46-48 40-42 43-45 52-54 49-51 52-54 43-45 46-48 46-48 49-51 49-51 52-54 52-54 4/10/2018 7 4/10/2018 The use of species distribution models (SDM) and environmental DNA to evaluate the distribution of the Eastern Hellbender (Cryptobranchus a. alleganiensis) In Tennessee Jeronimo Silva – Tennessee State University William Sutton – Tennessee State University Stephen Spear – The Wilds Michael Freake - Lee University PC: David Herasimtschuk Final Goal • Guide sampling efforts and depict areas of highest conservation concern • Ground truth our habitat model and evaluate model accuracy • Use occupancy modeling to further evaluate the status of C. alleganiensis within its range in Tennessee 8 4/10/2018 Species Distribution Model - MaxEnt Presence data Distribution data 153 occurrence points 1950 – 2015 Stream flow Hillshade Elevation Precipitation Environmental information Land cover Geology Stream order Temperature Across Tennessee Potential distribution **Now I know where to focus my sampling effort** 9 4/10/2018 Environmental DNA PC: Becky Hardman Green = Unknown Red = Seasonals = Detectability purposes • 69219 sites sites • 30 sites sampled during June, July, and August • 1 sample – 1 time 10 4/10/2018 Occupancy model • Naïve vs. Corrected occupancy • Modeling techniques described by MacKenzie et al. (2002, 2003) • Single species • Single season • 29 models • Detection (observation covariate) ->Julian date • Occupancy (site covariates) -> elevation, geology, Strahler order, land cover, and ecoregion • AICc -> evaluate model performance Results – Habitat Model Results – Habitat Model *12% of total available stream *75% of suitable streams fall within area is predicted as suitable low and medium category 11 4/10/2018 For size reference Corpus Christi = land area 416 km^2 New Orleans = land area 439 km^2 Results – Field Sampling Results – Occupancy modeling 12 4/10/2018 Results – Occupancy (post hoc analysis) 69.2 ± 0.07% etection per ecoregion 42.6 ± 0.11% 42.2 ± 0.15% 54.2 ± 0.24% D 72.4 ± 0.10% 25.1 ± 0.10% ted occupancy 55.5 ± 0.24% Correc 40.9 ± 0.24% Results – Occupancy modeling Discussion • Limited available habitat for the species within its range in Tennessee • Ecoregion is a strong determinant of occupancy and detection • Geomorphology • Hydrology • Where are the stronghold populations? • Ecoregion and occupancy Proxy for effect of land use practices • Legacy effect • Current effect • eDNA was an effective tool 13 4/10/2018 Conclusions and Conservation Implications • Habitat degradation seems to be the MVP of hellbender decline • Future conservation of the species may rely on prioritizing populations and areas of highest conservation need • Where would you focus your conservation efforts? • Future research • Compare microhabitat between areas with declining populations functional populations. • Quantify sediment input over time • Further evaluate effect of land use • CONSERVATION TOOLBOX • Ruth • Jessica • Thais Lopes • Private Landowners 14 4/10/2018 If you were a policy maker, what would do to improve hellbender conservation in Tennessee? 15.