Mud Turtle Research: 2017

I’ve recently returned to South Dakota from my annual trip out to the Chihuahuan Desert of west Texas where I have been collaborating on multiple research projects involving the Yellow Mud Turtle (Kinosternon flavescens). I have been marking and studying turtles in both ephemeral and permanent cattle ponds at this study site for 11 years. In addition to taking morphometric measurements of individuals, we have tracked movement, used iButtons to measure temperatures (as a proxy for when turtles are moving to and from these ponds), and monitored an undescribed shell disease. This trip (6 days of mark-recapture) resulted in over 200 unique turtles collected, with numerous young (1–2 year-old), unmarked individuals.

      

JMIH 2017: Austin, TX

JMIH2017_logo_smallI recently returned from the Joint Meeting of Ichthyologists and Herpetologists (JMIH) in Austin, TX where I presented both an oral and a poster presentation. My oral presentation, “Physiological Stress and Pathogen Infection in Larval Salamanders from Agricultural Wetlands”, was on one of my dissertation chapters and my poster presentation, “Morphological Variation between two widely distributed populations of Plethodon albagula (Caudata: Plethodontidae)”, was a continuation of work that I began as an undergraduate at the University of Texas at Austin. To my surprise, the poster presentation won the Victor Hutchinson Award (Morphology and Physiology) from the Society for the Study of Amphibians and Reptiles! I had a great time visiting with current and future colleagues. Many thanks to the local hosts and organizing societies for a successful, fun, and engaging meeting.

JMIH2017_poster


 

 

 

New publications: two snake natural history notes

Two natural history notes were published in the June 2017 issue of Herpetological Review. One note reports a new prey item and a new maximum prey/predator mass ratio for the Chihuahuan Nightsnake (Hypsiglena jani) and is co-authored with Travis J. LaDuc. Previously, the maximum prey/predator mass ratio known for Hypsiglena was 0.54 reported by Lacey et al. (1996), but our observation increases the maximum to 0.58. The two prey items that were consumed by this individual were two Little Striped Whiptails (Aspidoscelis inornata). Additionally, this observation adds to the list of prey species known to be consumed by Hypsiglena as only two other species of Aspidoscelis have been reported in the diet of Hypsiglena

Davis DR, LaDuc TJ. 2017. Hypsiglena jani (Chihuahuan Nightsnake). Diet and Prey Size. Herpetological Review, 48:450–451. [PDF]

The second is a report of predation of a juvenile North American Racer (Coluber constrictor) by a theridiid spider from Vermillion, South Dakota. One of my co-authors, Mark Dahlhoff, photographed and observed this incident over several days. While the exact circumstances leading to the snake’s entrapment in the spider web are unclear, it may be that the juvenile snake was attempting to either capture and consume the spider or other insects in the web. While spiders are known as prey items of Coluber constrictor, this is the first report of spider predation on this species of snake and may suggest bidirectional predator-prey interactions between these two species.

Davis DR, Farkas JK, Kerby JL, Dahlhoff MW. 2017. Coluber constrictor (North American Racer). Predation. Herpetological Review, 48:446–447. [PDF]


 

New publication: historic distributional records for South Dakota

A new publication documenting the historic distributional records of amphibians and reptiles in South Dakota was published in the June 2017 issue of Herpetological ReviewThis publication is a series of 100 county records from South Dakota collected over the past several decades from 18 different natural history collections. Many of these specimens were part of the former South Dakota State University collection that is currently housed at the University of South Dakota (and will soon be transferred to the Biodiversity Collections at the University of Texas at Austin). Included in these records is the only specimen of a Mudpuppy from South Dakota, a species historically reported in lists of the amphibians of South Dakota (Over 1923; Over 1943), but until now, no specimens were known to exist. These records highlight the continued importance of natural history collections, and especially, collections housed at regional or small universities. These South Dakota records have been added to the Amphibians and Reptiles of South Dakota website and help fill gaps in the distributions of species across the state.

Davis DR, Farkas JK, Johannsen RE, Maltaverne GA. 2017. Historic amphibian and reptile county records from South Dakota, USA. Herpetological Review, 48:394–406. [PDF]


 

New publication: new species of Pseudogekko from the Bicol Peninsula, Philippines

The Philippines possess a remarkable species diversity of amphibians and reptiles, much of which is endemic to this Southeast Asia island nation. Lizard diversity in the family Gekkonidae is no exception, with more than 80% of the country’s gecko species endemic to the archipelago, including the entire genus of False Geckos (Pseudogekko). This small radiation of diminutive, slender, arboreal forest species has been the focus of several recent phylogenetic and systematic studies that have highlighted the prevalence of undocumented species concentrated in several geographical regions within the archipelago. Newly available genetic data have led to the revision of two species complexes in the genus Pseudogekko, one of which is the focus of this study. We describe a new member of the Pseudogekko brevipes complex, which represents the first population from this species group discovered in the Luzon Faunal Region. Because of the species’ secretive nature, rarity, or restricted geographic range, it has gone undetected despite recent biodiversity surveys targeting the central and northern portions of the Bicol Peninsula. We evaluate both morphological and genetic data to support the recognition of the new species. All three members of the P. brevipes complex have allopatric distributions situated within three of the archipelago’s distinct faunal regions. The recognition of the new species increases the total number of taxa in the genus Pseudogekko to nine species.

Siler CD, Davis DR, Watters JL, Freitas ES, Griffith OW, Binaday JWB*, Lobos AHT*, Amarga AKS, Brown RM. 2017. The first record of the Pseudogekko brevipes Complex from the northern Philippines, with description of a new species from Luzon Island. Herpetologica, 73:162–175. [PDF]


 

Funding awarded by SD Game, Fish and Parks to support website

I was recently awarded a Wildlife Diversity Small Grant from South Dakota Game, Fish and Parks to promote and develop additional resources for the newly launched website www.sdherps.org. These funds were awarded to me and partners at HerpMapper, Inc. to promote the use of this website, increase public awareness of this resource, and encourage user-submitted observations of amphibians and reptiles from across the state. An additional goal will be to travel to the University of Nebraska State Museum (UNSM) in Lincoln, NE to examine and verify species identifications of voucher specimens that were formerly part of the University of South Dakota Herpetological Collection. The collection at UNSM represents the largest collection of amphibians and reptiles from South Dakota and represents a large portion of the data used to map species distributions (see www.sdherps.org/about). I am particularly interested in examining similar species pairs (i.e., Plains Leopard Frog vs. Northern Leopard Frog, Plains Gartersnake vs. Common Gartersnake) and rare species (i.e., Common Watersnake, Dekay’s Brownsnake).

Grant Title: Creating online resources to engage South Dakota citizens in amphibians and reptile identification and conservation


 

New publication: Chelydra serpentina diet note

A natural history note describing a new prey item of Snapping Turtles (Chelydra serpentina) was published in the March 2017 issue of Herpetological Review. My co-author, Doug Backlund, photographed an adult male Northern Shoveler (Anas clypeata) being attacked by an adult Snapping Turtle on Farm Island, Hughes County, South Dakota. This observation adds to the list of waterfowl that have been reported as prey of Snapping Turtles and provides an account of predation events that are infrequently observed. Descriptions of the natural history of species such as this are critical and add to our understand of species.

Davis DR, Backlund DC. 2017. Chelydra serpentina (Snapping Turtle). Diet. Herpetological Review, 48:174–175[PDF]


New publications: species distribution records in South Dakota and Michigan

Four new publications documenting the distributions of amphibians and reptiles in South Dakota and Michigan were just published in the March 2017 issue of Herpetological Review. Three of these notes are individual distribution records (2 in South Dakota, 1 in Michigan) and one is a series of 26 county records from South Dakota collected during field work in 2015 and 2016. These South Dakota records have been added to the Amphibians and Reptiles of South Dakota website and help fill gaps in the distributions of species across the state. Even though there has been considerably more herpetological research conducted in Michigan than in South Dakota over the past century, many distributional gaps exist for Michigan species, with species underrepresented in natural history collections. This Michigan record (Ambystoma laterale from Mecosta Co.) was collected as part of a recreational road-trip across the state with Jillian Farkas and highlights the need to continue to document species occurrence.

Davis DR, Farkas JK, Johannsen RE, Leonard KM, Kerby JL. 2017. Distributional records of amphibians and reptiles from South Dakota, USA. Herpetological Review, 48:133–137. [PDF]

Davis DR, Zimmer MB. 2017. Geographic distribution: USA, South Dakota, Edmunds Co.: Opheodrys vernalis (Smooth Greensnake). Herpetological Review, 48:129–130. [PDF]

Farkas JK, Davis DR. 2017. Geographic distribution: USA, South Dakota, Yankton Co.: Apalone spinifera (Spiny Softshell). Herpetological Review, 48:122. [PDF]

Farkas JK, Davis DR. 2017. Geographic distribution: USA, Michigan, Mecosta Co.: Ambystoma laterale (Blue-spotted Salamander). Herpetological Review, 48:117. [PDF]


New publication: high prevalence of chytrid fungus in southern Oklahoma

Marhanka.etal.2017_Fig1As part of a collaborative effort with the Siler Lab at the University of Oklahoma, I have been involved in efforts to help screen amphibian skin swabs for the pathogenic fungus, Batrachochytrium dendrobatidis (Bd). This manuscript presents the results of pathogen surveys conducted during 2015 in eight counties in southeastern Oklahoma. Overall Bd prevalence was 64.8% and all families swabbed and 15 (of the 18) species of amphibians had individuals that were Bd+. Given the high Bd prevalence and widespread occurrence of Bd across species and sites, this pathogen has the potential to have profound negative impacts on native Oklahoma amphibians.

Marhanka EC*, Watters JL, Huron NA, McMillin SL*, Winfrey CC*, Curtis DJ, Davis DR, Farkas JK, Kerby JL, Siler CD. 2017. Detection of high prevalence of Batrachochytrium dendrobatidis in amphibians from southern Oklahoma, USA. Herpetological Review, 48:70–74. [PDF]


Funding awarded to survey for state-monitored​ species

I was recently awarded funding by Prairie Biotic Research, Inc. to survey four remnant prairies sites in southeastern South Dakota for state-monitored species of amphibians and reptiles. The highest species diversity of amphibians and reptiles is in this corner of South Dakota and many state-monitored species are expected to occur in this region, though recent occurrence records are lacking for many species. These state-monitored species include Eastern Hog-nosed Snake, Lined Snake, Ring-necked Snake, Western Foxsnake, Plains Leopard Frog, Cope’s Gray Treefrog, and Blanchard’s Cricket Frog. With this funding, I hope to add additional occurrence records for these species and others, generate critically important voucher specimens, and highlight the importance of prairie habitats on a landscape that is dominated by row crop agriculture. Data from this project will be added to the website: Amphibians and Reptiles of South Dakota.

Grant Title: Amphibian and reptile surveys in remnant prairies in southeastern South Dakota, with special emphasis on state-monitored species