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Erika Nowak & Trevor B. Persons USGS Southwest Biological Science Center Colorado Plateau Field Station Inventory of Reptiles and Amphibians at Death Valley.

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Presentation on theme: "Erika Nowak & Trevor B. Persons USGS Southwest Biological Science Center Colorado Plateau Field Station Inventory of Reptiles and Amphibians at Death Valley."— Presentation transcript:

1 Erika Nowak & Trevor B. Persons USGS Southwest Biological Science Center Colorado Plateau Field Station Inventory of Reptiles and Amphibians at Death Valley NP Manzanar NHS Mojave NP

2 The Crew Laura Cunningham and Erika Trevor Persons Scott Hillard Shawn Knox AJ Monatesti Bob Parker Jason Pilarski Justin Schofer Eric Zepnewski Kevin Emmerich Bryan Hamilton Kris Heister/I&M Network David Morafka Dana York & all NPS staff CPFS administrative staff Thanks to:

3 2. Maximize the probability of detecting new species in certain areas (fill in holes in park species lists) Potential Inventory Objectives 1. Provide a basis for statistical inference about species richness (provide rigor and repeatability) -OR-

4 2. Maximize the probability of detecting new species in certain areas Targeted sampling (DEVA, MOJA) Potential Inventory Objectives 1. Provide a basis for statistical inference about species richness Stratified grid-constrained random sampling (MANZ) -AND-

5 OUR OBJECTIVES Inventory and document the occurrence of reptile and amphibian species –Within identified priority sampling locations (DEVA and MOJA) –Within all of MANZ –Provide one voucher specimen for each species if not previously collected Estimate inventory completeness at each park (Master List) Enter species data into NPSpecies and provide other deliverables http://sbsc.wr.usgs.gov/products/ofr

6 METHODS Time-recorded visual encounter surveys (VES, NVES) Road driving (ROAD) Random encounters (RE) One hour - one hectare time-area constrained VES (TACS; MANZ) 100 m-long lizard line transects (LL; MANZ) Pitfall traps (PF; DEVA, MANZ) Data mining (museum searches, literature review, contact area experts) –estimate inventory completeness

7 Owlshead PSA Owlshead PSA Greenwater PSA DEVA Priority Sampling Areas (6) 2002-2004

8 DEVA: NOTABLE SPECIES LIZARDS (16 species) *Southern Alligator Lizard (1) (Elgaria multicarinata) –Scotty’s Castle Mojave Fringe-toed Lizard (Uma scoparia) –state species of concern –Ibex Dunes SNAKES (16 species) *Ring-necked Snake (1) (Diadophis punctatus) –near Scotty’s Castle Rosy Boa (Charina trivirgata) –rare, collected by poachers –Darwin Falls * = new park record L. Cunningham

9 DEVA: NOTABLE SPECIES DESERT TORTOISE (Gopherus agassizii) Federally threated –Greenwater range AMPHIBIANS (4 species) Bullfrog (Rana catesbeiana) –Saline Valley and Furnace Creek golf course Odd-looking Western toads (Bufo boreas) hybrids?? –Darwin Falls No salamanders documented (Batrachoseps seen outside park in Waucoba Canyon) B. Parker

10 MANZ: COMPARISON OF METHODS 2002-2003 # Species TACSLLVES/ NVES PFROADRE Total (per pers-hr) 7 (0.36) 6 (0.11) 6 (0.09) 4 (245 t-days) 7 (0.09) 5 Lizards546455 Snakes220020 ** NO ONE METHOD CAUGHT ALL SPECIES

11 MANZ: NOTABLE SPECIES LIZARDS (7 species) Southern Alligator Lizard (Elgaria multicarinata) –apparently rare SNAKES (3 species) Nothing unusual: Gophersnake (Pituophis catenifer) Glossy Snake (Arizona elegans) Coachwhip (Masticophis flagellum) AMPHIBIANS NONE!!!!! T. Persons

12 MOJA PRIORITY SAMPLING AREAS (4) 2004-2005 Clark Range Piute Range Piute Creek Cornfield Spring (Providence Mtns)

13 MOJA: NOTABLE SPECIES LIZARDS (15 species) Mojave Fringe-toed Lizard (Uma scoparia) –Kelso Dunes Did not find Gila Monster (Heloderma suspectum) –seen in 2005 by tourist bet. Clark and Kingston ranges SNAKES (14 species) Nothing unusual except high road mortality DESERT TORTOISE federally threatened –Not uncommon AMPHIBIANS (1 species found) Red-spotted Toad (Bufo punctatus) –deformities in Piute Creek (post-fire) Did not find Pacific Treefrog (Hyla regilla) –introduced at ZZYZX T. Persons

14 OVERALL RESULTS

15 OVERALL RESULTS: % INVENTORY COMPLETENESS DEVAMANZMOJA Overall925095-100 Amphibians73067-100 Reptiles955497-100

16 DISCUSSION: TIMING ISSUES 2002-2004: Impact of drought on survey results –Likely decrease in numbers of individuals detected and esp. on detected amphibian species richness –Possible longer-term effects on age class structure 2005: WET! –Limited surveys done at MOJA Importance of longer-term studies –Done by park-based researchers

17 Detectability near zero for some: – Secretive snakes – Rain-breeding amphibians Patchy spatial / temporal distribution – Does not support detection at randomly-generated plots Over half of rare species added by random encounters outside standard methods DISCUSSION: RARE SPECIES J. Pilarski

18 DISCUSSION: SAMPLING ISSUES VES surveys most efficient for limited $$ inventories TACS and lizard line transects have limited utility for species inventory –TACS could be useful for monitoring if properly stratified Pitfalls useful if long monitoring periods (or inventory if $$$$) –Will occasionally detect rare or secretive species –** MUST BE CHECKED FREQUENTLY **

19 DISCUSSION: HERP ISSUES Monitor/control non-native or introduced species –Bullfrogs (eat everything) –Fish/crayfish (eat amphibian eggs/larvae) Monitor amphibians at springs –Toad deformities at MOJA Piute Creek –Salamanders in DEVA Panamints?? Throw money at surveys in wet years More general surveys at MANZ Road mortality of snakes at MOJA B. Parker

20 There are several “populations” of herp species that differ primarily by detectability relative to method used Use a variety of methods for documentation Random points are inefficient for inventories: largely document common, already listed species Time, luck, cameras needed to detect rare species Herp inventories uncompleted in Mojave and other Network Parks Relative abundance estimable only for common species Droughts necessitate longer inventory periods Park-funded best CONCLUSIONS I: Implications for Future Herpetofauna Inventories T. Persons

21 Statistical inference or specific sample designs should not become ends in themselves Don’t confuse inventory and monitoring methods/objectives Documentation (of new species or locations) is simple! Easily done by park-based NPS staff or tourists Need camera, GPS, date http://sbsc.wr.usgs.gov/products/ofr CONCLUSIONS II: Implications for Future Herpetofauna Inventories

22 J. Pilarski

23 DEVA: EFFORT BY METHOD PFs at Hummingbird Springs, Mahogany Flats (also Cunningham and Emmerich traps at Scotty’s Castle and Last Chance Range)

24 MOJA: EFFORT BY METHOD

25 MANZ Random Plots* (*TACS & LL) 2002-3003

26 DEVA Potential Reptile Species List Review long-tailed brush lizard tree lizard northern alligator lizard southern alligator lizard gila monster ringneck snake Mojave rattlesnake western rattlesnake western diamondback rattlesnake rubber boa western terrestrial garter snake previously seen in Greenwater Valley not likely present – out of range low probability of presence in N. mtns we documented at Scotty’s Castle not likely present- out of range we documented at Scotty’s Castle high probability of presence in S. high probability of presence in N. mtns not likely present- out of range low probability of presence

27 DEVA Other Potential Species western skink Mediterranean or house gecko CA mountain kingsnake slender salamanders (Batrachoseps) ensatina (Ensatina escholtzii) or web-toed salamander (Hydromantes) northern leopard frog Great Basin spadefoot black toad specimen misidentified- not likely unconfirmed reports at Scotty’s Castle- unlikely possibly present in moist habitats slight probability of presence in canyons of Panamint Mountains previously recorded on Telescope Peak, low probability of finding it likely present historically, low probability of presence in wetlands low-fair probability of presence introduced in the Saline Valley Marsh

28 MANZ Potential Species List- Amphibians Slender Salamander (Batrachoseps sp.) Owens Valley web-toed salamander (Hydromantes sp.) Great Basin Spadefoot (Spea intermontana) Boreal (Western) Toad (Bufo boreas) Pacific Treefrog (Hyla regilla) low probability of presence along Bairs Creek not likely present – out of elevational range good probability of presence fair probability of presence low probability of presence along creek

29 MANZ Potential Species List- Lizards Western Banded Gecko (Coleonyx variegatus) Desert Night Lizard (Xantusia vigilis) Great Basin Collared Lizard (Crotaphytus bicinctores) Western Fence Lizard (Sceloporus occidentalis) Sagebrush Lizard (Sceloporus graciosus) Western Skink (Eumeces skiltonianus) high probability of presence good probability of presence low probability of presence fair probability of presence

30 MANZ Potential Species List - Snakes Ringneck Snake (Diadophis punctatus) Common Kingsnake (Lampropeltis getulus) Longnose Snake (Rhinocheilus lecontei) Western Patchnose Snake (Salvadora hexalepis) Ground Snake (Sonora semiannulata) low probability of presence along Bairs Creek high probability of presence

31 Manz Potential Species List – More Snakes Western Terrestrial Garter Snake (Thamnophis elegans) Western Aquatic Garter Snake (Thamnophis couchii) Night Snake (Hypsiglena torquata) Southwestern Black-headed Snake (Tantilla hobartsmithi) Sidewinder (Crotalus cerastes) Speckled Rattlesnake (Crotalus mitchelli) low probability of presence along Bairs Creek not likely present- unsuitable habitat high probability of presence good probability of presence high probability of presence


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