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Iowa Herpetology


  • The Natural History and Management Recommendations for Iowa's Reptiles
  • The Natural History and Management Recommendations for Iowa's Amphibians
  • These works are analyses of the past, present, and potential future distributions of the Amphibians and Reptiles of Iowa, compilation of over 140 person-years of Iowa ecological data, analysis of reproduction of each species with threats to the species' reproductive success, and development of management recommendations tailored to Iowa and adjacent states.
    These works will be co-authored by Terry VanDeWalle and edited by Neil Bernstein. See JLC Publications page for published works on various Iowa species.

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    snake frog

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    turtle sand dunes fence

    Texas Studies

    Ongoing, ecological studies of the Yellow Mud Turtle in Presidio and Jeff Davis Counties in West Texas with specific objectives of analysis of reproductive and behavioral adaptations to aridity.   In this very arid part of the species' range, Dr. Travis LaDuc and I have learned that the annual activity cycle and the reproductive cycle differ greatly from the yellow mud turtles of Iowa and Nebraska and much of New Mexico.   Combined with the excellent work of Dr. John Iverson, we have a database almost unequaled for such a wide-ranging species.

    The Texas studies have resulted in discovery of a new shell disease of turtles, characterized by invasion and destruction of the shell by common filamentous algae. In aridity-adapted turtles exposed to specific environmental conditions, this disease may completely destroy the epidermal components of the shell. We have added the expertise of Dr. Elliott Jacobson in developing our analysis, staging, and description of this disease.

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    turtle tx West TX

    Adaptation of Reptiles and Amphibians to the Dell Webb Community Design

    . This 20-year study will determine the impact of an urban design that brings wildlife corridors into the back yards of almost every resident.   It will map the changes in distribution of each amphibian and reptile species over the 20 years of the study and compare the results with the survival of these animals in other urban environments.   Our early results suggest that the Dell Webb Community Design preserves much more Texas Wildlife than do standard community designs
    Other Texas studies include work with Dr. Ben Pierce on small, mostly subterranean plethodontid salamanders, additions to the known ranges of Texas reptiles and amphibians, and ecological studies of reptiles in the Dell Webb Communities

    A Phylogenetic Analysis of Melanomacrophages


          Fifteen years of work with Dr. James Johnson has shown that these melanin-producing macrophages (MM) are found in fishes, amphibians, and most reptiles. They are absent in advanced mammals.   We have learned that they are functional at very low temperatures, unlike mammalian macrophages and are probably a significant part of reptilian immune system's defense against slow-growing infections at very low temperatures.  When in the evolutionary scheme did these cells disappear?   We are examining livers of old individuals of as many taxa as possible to answer this question.

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    MM culture fluorescent bacteria MM agregations Electron Micrograph MMs

    2016 James L. Christiansen