Dr. John B. Iverson
Department of Biology
Earlham College
Richmond, Indiana 47374
Office: (765)
983-1405
Fax: (765) 983-1497
johni@earlham.edu
Teaching
responsibilities at Earlham
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 offer Physical Education courses in Trail Building and Invasive Species Control. 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 my personal funds,
this study has involved 33 Earlham students and five graduate students
(through Miami University and the University of Nebraska at Lincoln)
and has produced 24291 captures of yellow mud turtles alone.
2009 report ; 2010 report; 2011 report; 2012 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 127 different Earlham students (and six faculty). Reports on long-term growth, nesting ecology, and population demographics have been published (links below). A short summary of our research is available in our brochure. Support for this research has been provided by Mrs. Sandra Buckner of Nassau, 7-C’s Charters, Powerboat Adventures of Nassau, the Bahamas National Trust, Dr. Ned and Sally Test of Indianapolis, and the Cope Museum Fund of Earlham College, 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 2011 ; report of activities 2012; 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 have been
ongoing since 1979, and have involved at least 105 Earlham students.
Through 2012, we have made at least 8483 turtle captures representing
eight species. We have individually marked 1952 painted turtles, and
412 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). Funding for this work has been provided by Earlham
College. Images from our recent field work are available here.
Systematics and evolution of kinosternid and geoemydid turtles
Studies 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
Understanding the behavioral,
morphological, and physiological adaptations of hatchling turtles to
their first winter of life in temperate climates is 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. This research has been funded by Earlham College, the Howard Hughes
Medical Institute and the National Science Foundation.
Reforestation of an Indiana hardwood forest
For 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. 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. 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.