Category: Reptile

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Rising temperatures could benefit the Snapping Turtle.

snapping turtle Photo by Jason P. Ross

Rising temperatures could benefit the Common Snapping Turtle.

CHAMPAIGN, ILL. — A recently published study of snapping turtle nests at Gimlet Lake in Garden County Nebraska from 1990 – 2015 found that warmer fall temperatures positively correlate to larger eggs and larger numbers of eggs, while warmer spring temperatures are negatively correlated with egg size and number.

Nesting females were observed and after depositing eggs, captured, measured, marked, and released. The nests were excavated and eggs were counted and measured before being reburied.

Maximum egg size is limited in many turtle species by the size of the female, specifically the pelvic aperture, thus surplus resources are used to develop a greater number of eggs rather than larger eggs. Although this limitation is present in many species of turtles, it was clear a different pattern existed within Snapping Turtles (Chelydra serpentina). Large adult snapping turtles are not restricted in the size egg they can produce and in warmer years, produced larger eggs but the same number. Small adult snapping turtles, on the other hand, did not increase the size of their eggs, but produced larger clutches in warmer years.

Most temperate zone turtles begin developing their embryos in the fall, suspend development over the winter, and complete development in the spring. Snapping turtles complete the majority of their development in the fall, which may reduce the impact of winter and spring climate conditions.

Forming the eggs in the fall may enable snapping turtles to lay their eggs earlier and provide their young an advantage over other species. Herpetologist Michael Dreslik said,“Generalists like the Snapping Turtle tend to be more adaptable. The added benefit from warmer temperatures could allow Snapping Turtles to gather more resources for larger eggs or larger clutches.”

The mechanisms by which warmer temperatures influence egg and clutch size are unknown. Turtles are ectotherms, thus metabolism and physiology are impacted by environmental conditions.

“Warmer temperatures increase metabolism, but could result in greater food availability and more efficient processing of the food. Warmer temperatures could also affect the physiology of embryo development,” said lead author Ashley Hedrick. “Alternatively, in the spring, increased metabolism before food is readily available may require females to divert energy from egg development.”

While rising temperatures are generally considered problematic for most species, they could play in favor of the Snapping Turtle.

The paper “The Effects of Climate on Annual Variation in Reproductive Output in Snapping Turtles (Chelydra serpentina).” is available online from the Canadian Journal of Zoology.

Corresponding author: J.B. Iverson email:
To reach Ashley Hedrick, email arhedri11@gmail.com
To reach Michael Dreslik, email dreslik@illinois.edu
Photo by Jason P. Ross

 

 

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Midwest Fish and Wildlife Meeting

UBAP herpetologist Sarah Baker co-organized a symposium “Advances and Challenges in Amphibian and Reptile Conservation and Management” and presented “Impact of Snake Fungal Disease on Population Viability” at the 78th Midwest Fish and Wildlife Conference in Milwaukee, WI. Jan 28-31.

Student Kelsey Low presented a poster on “Ranavirus Effects on Body Condition and Growth of Developing Amphibians in Created Wetlands”

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UBAP staff present at Biology of the Snakes Conference

Members of the Urban Biotic Assessment Program, Michael J. Dreslik and Sarah J. Baker, recently attended and presented at the Biology of the Snakes 2017 Conference in Rodeo New Mexico.  They gave two oral and two poster presentations.

Oral Presentations
Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky. Spatial ecology of the Timber Rattlesnake (Crotalus horridus) from the mid-Atlantic coastal plain.

Dreslik, M. J., J. A. Crawford, S. J. Baker, W. E. Peterman, and C. A. Phillips. Detection probability and capture yield of an imperiled species.

 

Poster Presentations
Baker, S. J., M. J. Dreslik, C. A. Phillips, and M. C. Allender. Impact of snake fungal disease on population viability.

Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky. Factors affecting the movements of Timber Rattlesnakes (Crotalus horridus) from the mid-Atlantic coastal plain. View Poster

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Funding received to survey the Alligator Snapping Turtle

UBAP staff Ethan J. Kessler and Michael J. Dreslik received funding from The Nature Conservancy, Indiana to conduct surveying for the Alligator Snapping Turtle (Macrochelys teminckii).  The surveys will be a combined effort of trapping and eDNA sampling in the Patoka and White River watersheds.  The project also includes some proof-of-concept work for eDNA work at the southern Illinois release site.  Survey work will commence this summer through fall.

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UBAP staff present at Turtle Survival Alliance

UBAP staff Michael J. Dreslik and Jason P. Ross recently presented at the 2017 Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles.  The meeting was held in Charleston, South Carolina from August 6th – 9th and has international attendance.  At the meeting, they presented a poster on the effectiveness of passage gates along the Asian Carp Barrier and a co-authored oral presentation with a collaborator on the reproduction of Common Snapping Turtles which is in press in the Canadian Journal of Zoology.

 

Hedrick, A. R., H. M. Klondaris, L. C. Corichi, M. J. Dreslik. J. B. Iverson. The effects of climate on annual variation in reproductive output in Snapping Turtles (Chelydra serpentina).  Oral Presentation.

 

Ross, J. P., C. Y. Feng, and M. J. Dreslik. Evaluating turtle passage gates using remote camera traps and visual encounter surveys. Poster Presentation. View Poster

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UBAP staff present at theJoint Meeting of Ichtyhologists and Herpetologist

Members of the Illinois Natural History Survey’s Urban Biotic Assessment Program and Herpetology Lab recently attended the Joint Meeting of American Society of Ichthyologists and Herpetologists, Society for the Study of Amphibians and Reptiles, and Herpetologists’ League in Austin, Texas from 12 July to 16 July 2017.  They presented on a variety of topics from rattlesnakes to darters and from wildlife disease to community changes.  The combined topics for presentations and posters were:

 

Presentations:

Baker, S. J., M. J. Dreslik, C. A. Phillips, and M. C. Allender. Impact of snake fungal disease on population viability.

Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky.  Factors affecting the movements of Timber Rattlesnakes (Crotalus horridus) from the mid-Atlantic coastal plain.

Low, K. M., M. C. Allender, C. A. Phillips, and S. J. Kimble. A ranavirus-associated mass mortality event in an Illinois amphibian community.

Ross, J. P., C. Y. Feng, and M. J. Dreslik. Evaluating reptile and amphibian passage gates using remote camera traps.

Sites, A. J., J. L. Sherwood, J. S. Tiemann, and M. J. Dreslik. Assessing the distribution of Iowa Darters (Etheostoma exile) in streams of northern Illinois.

 

Posters:

Baker, S. J., and M. C. Allender. Comparison of testing methods for snake fungal disease.

Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky. Spatial ecology of the Timber Rattlesnake (Crotalus horridus) from the mid-Atlantic coastal plain. View Poster

Sherwood, J. L., and J. A. Stein. Habitat and fish community changes in Champaign County, IL over the past 100 years.

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Illinois team tackles mysterious disease afflicting wild and captive snakes

INHS scientists are collaborating to understand Snake Fungal Disease and its impacts on endangered snakes in Illinois. 

“We’re trying to protect an endangered species,” said INHS herpetologist and postdoctoral researcher Sarah Baker, a collaborator with Allender on several studies. “A lot of pit viper populations are declining – not only in Illinois, but nationwide. Snake fungal disease is just one more threat that they have to contend with, and anything we can do – to find effective treatments, for example, or disinfectants that stop people from spreading the disease from place to place – could make a difference for their long-term survival.”

Read complete article at the Illinois News Bureau

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