John Iverson

Earlham College
Biology Department

John weighing a turtle


Dr. John B. Iverson
Department of Biology
Earlham College
Richmond, Indiana 47374
Office: (765) 983-1405
Fax: (765) 983-1497

Curriculum vitae
Published photographs

Teaching responsibilities at Earlham
John and Seth Munson (EC '01)

Although I semi-retired from teaching in the Biology Department and directing the Joseph Moore Museum in July 2012, I continue to teach informally as a guest lecturer in Biology courses, and during May Term field biology courses.†I also continue to involve Earlham students in my research during the school year and during the summer.

Checklist with distribution maps of the turtles of the world

Since 1972, I have been amassing colleague, museum, and literature records of localities for each of the world's turtle species. These records formed the basis for my self-published "Checklist with Distribution Maps of the Turtles of the World" (1986), and "A Revised Checklist with Distribution Maps of the Turtles of the World" (1992). Another revision is in preparation. Since 1989, with funding from the EPA and NSF (through Oregon State University), we have been developing an electronic version of this Checklist, including my global turtle data base linked to individual points on individual species maps: Turtles of the World . A preliminary Tree of Life for turtles is also available. For the most updated Checklist of the Turtles of the World produced annually by the Turtle Taxonomy Working Group (TTWG) download here.

Natural history and population biology of turtles of the Nebraska Sand hills

Since 1980, I have regularly employed mark-recapture and radio telemetry studies to describe the ecology of the turtles and snakes of the Crescent Lake National Wildlife Refuge in the Sand hills of western Nebraska. Funded by Earlham College, the Joseph Moore Museum, and the National Science Foundation, this study has involved 39 Earlham students and seven graduate students (through Miami University, Iowa State Universit, and the University of Nebraska at Lincoln) and has produced 28241 captures of yellow mud turtles alone.

2017 report; 2018 report


Conservation biology of the Allen Cays Rock Iguana

Since 1980, nearly annual mark and recapture studies of the only two known natural populations of the Allen Cays Rock Iguana in the Exumas islands of the Bahamas have been undertaken with the help of 146 different Earlham students (and eight faculty).†Reports on long-term growth, nesting ecology, and population demographics have been published (links below).†.†Support for this research has been provided by Mrs. Sandra Buckner of Nassau, 7-Cís Charters, Powerboat Adventures of Nassau, the Bahamas National Trust, Dr. Ned and Sally Test of Indianapolis, the Cope Museum Fund of Earlham College, and the National Science Foundation, but primarily by the students who have participated.†Tax-deductible contributions to support this project can be made to Iguana Project, c/o Development Office, Earlham College, Richmond, Indiana 47374.

report of activities 2017; Nesting Ecology     Popular account  Longterm demography
Recent images    Nesting imovie
   Checklist of living iguanas ; Iverson 1979 Bull. FSM

Population biology of the turtles at Dewart Lake in northern Indiana

Mark and recapture studies of the turtles of Dewart Lake (formerly the Earlham College Biological Station) in Koskiusko County in northern Indiana were ongoing from 1979, and nvolved at least 109 Earlham students. Through 2016, we have made at least 9694 turtle captures representing eight species. We have individually marked 2017 painted turtles, and 473 northern map turtles, as well as hundreds of redeared sliders, snapping turtles, spiny softshells, Blandings turtles, and one spotted turtle. Recently published papers have reviewed changes in sex ratios in musk turtles, daily activity patterns in each of the species; and long-term changes in the turtle species composition at our site (including surveys done in the mid-1960's). Earlham studnets continue to be involved in analyzing data and preparing papers for publication. Images from past field work are available here.

Systematics and evolution of kinosternid and geoemydid turtles

MauremysStudies of the taxonomy and phylogenetic relationships among the New World mud and musk turtles (family Kinosternidae), based primarily on morphological variation, have been ongoing since the early 1970's; however, the recent inclusion of DNA sequence data has helped resolve many of the evolutionary relationships within this group. Work in progress is directed at the relationships within the Kinosternon scorpioides species complex, and a phylogenetic analysis of life history evolution in the Kinosternidae. Similar studies of the Old World Pond Turtles (Family Geoemydidae) have been ongoing for the last decade and a collaborative phylogenetic study of DNA sequence variation in the family has been published: Geoemydidae

Cold adaptations of overwintering turtles in the northern USA

Hatchling turtleUnderstanding the behavioral, morphological, and physiological adaptations of hatchling turtles to their first winter of life in temperate climates was the primary subject of my collaboration with Drs. Jon Costanzo and Richard Lee in the Laboratory for Ecophysiological Cryobiology at Miami University in Oxford, Ohio both now retired. This research was funded by Earlham College, the Howard Hughes Medical Institute and the National Science Foundation.

Reforestation of an Indiana hardwood forest

hardwood forestFor recreation I have been reforesting a 76 acre tract of land southwest of Richmond, Indiana. Half of the tract (36 acres) is middle-growth forest from which the valuable trees were heavily logged in the 1980s; this tract is being managed with the usual methods of TSI (timber stand improvement), as well as for the removal of invasive exotic species. This tract was donated to Earlham College in early 2018 to provide permanent access to djacent Wildman Woods, already owned by the college. The remaining 40 acres was agricultural field in 1996, but in 1996-97 35 acres was placed in the federal CRP (Conservation Reserve Program) when we planted 40,000 trees and created 9 wetlands, and it is being managed for maximum hardwood diversity and growth. The number of wetlands constructed for amphibians has now grown to 33, most of which John dug by hand. We live on the remaining 5 acres, most of which is also now forested. In December 2003, we established a conservation easement on the two large tracts (71 acres total) through the Red-tail Conservancy Land Trust out of Muncie that insures that the land will never be deforested or developed in any way in perpetuity. Other images. A photo essay of succession on the tree plantation is available here.

Biology Home Page               Earlham Home Page

Copyright ©1997-2012 Earlham College. Revised January 13, 2010. Send corrections or comments to John Iverson