In 1945 Stebbins was hired an assistant professor of zoology at the
University of California, Berkeley, and became the first curator of herpetology at the
Museum of Vertebrate Zoology, where he would remain throughout his career. The first faculty member to teach herpetology at Berkeley, he wrote new lab manuals, created the herpetology teaching collection, and co-taught a popular course on vertebrate natural history.
Ring species in salamanders Stebbins soon became interested in
Ensatina salamanders, which occur from British Columbia to Baja California and are present in both the
Sierra Nevada and
Coast Ranges of California but absent in the Central Valley. Finding the salamanders in Berkeley very different from the ones he was used to seeing in the mountains of Southern California, he embarked upon a research program examining color differences throughout California. In his resulting monograph, published in 1949, he proposed that the color varieties—many previously regarded as distinct species—were actually various races or
subspecies of a single species that in most locations interbreed where two forms co-occur, creating hybrids that partially resemble both forms. However, at the southern edge of the Central Valley, where the Sierra foothill populations come into contact with those of the Coast Range, the populations do not interbreed, instead acting as distinct species. This phenomenon is known as a
ring speciation, with different populations representing different stages of
speciation, the process by which one species becomes two. Zoologist
Arnold Grobman called Stebbins' research "without doubt, the most outstanding study of a genus of American salamanders that has yet appeared." The
Ensatina complex has been the focus of research ever since, and is a widely used textbook example of evolutionary processes.
Reptilian parietal eye Stebbins' early work with lizards in the southern California desert led to a series of papers from the 1950s through the 1970s exploring the
parietal eye of reptiles (also called the "third eye", a tiny light-sensitive organ on the forehead) and the associated
pineal gland, both of which are now known to influence
circadian rhythms. Aided by a Senior Postdoctoral Fellowship from the National Science Foundation, Stebbins and colleagues found that lizards with the parietal eye surgically removed changed their behavior: they became active much earlier in the day, spent more time in the sun, and remained active much later than
control lizards. Further studies over the next few decades focused on the parietal eye of the
tuatara, the pineal gland's effects on lizard reproductive behavior, and parietal skull openings in fossil "mammal-like reptiles" such as
Lystrosaurus. His work had implications beyond reptile biology: Nobel laureate
Julius Axelrod, after reading the work of Stebbins and others, began investigating the pineal gland in mammals, with emphasis on the effect of
melatonin on activity cycles. Melatonin has since been found to influence human health. Stebbins was proud of his parietal and pineal work, calling it "possibly the single piece of research which gives me the most satisfaction."
Other research, conservation, and field guides In 1949 Stebbins received a
Guggenheim Fellowship that allowed him to extend his studies throughout the western United States and to collect enough material to begin preparing his first amphibian field manuals. The first of these to appear was
Amphibians of Western North America (1951, University of California Press), covering the U.S. and Canada roughly west of the
102nd meridian. Praised for its thoroughness as well as its illustrations, Stebbins' second herpetological field guide,
Amphibians and Reptiles of Western North America (1954,
McGraw-Hill), was similarly praised. s In 1964 Stebbins visited the Galápagos Islands on a research expedition and studied the ecology and behavior of
marine iguanas and
lava lizards. Also on the expedition was
Roger Tory Peterson, who recalled "While the rest of were enjoying high adventure on the more remote islands and sea-girt rocks, he patiently snared 200 frisky lizards with a noose of thread suspended from a rod. He took their cloacal temperatures, marked them with dye, and then dosed them with radioactive iodine, which enabled him to locate the elusive reptiles later with a Geiger counter." In 1966, Stebbins produced what became his best-known book,
A Field Guide to Western Reptiles and Amphibians (
Peterson Field Guides), which Peterson called "a classic ... one of the most beautiful as well as scholarly works in the series". Stebbins was also committed to education and conservation. He made appearances on the TV series
Science in Action, traveled to Asia to promote science education, and chaired a U.C. elementary school science project which recommended that science be taught to children as early as six. In conjunction with the
Sierra Club he produced two educational films:
Nature Next Door (1962) and
No Room for Wilderness? (1967). Stebbins co-authored revisions of the widely used textbooks
General Zoology (5th ed.,1972; 6th ed., 1979) and
Elements of Zoology (4th ed., 1974), books originally written by
Tracy Storer and
Robert Usinger. In the late 1960s Stebbins became concerned about the impacts that increasingly popular
off-road vehicle (ORV) driving was having on desert ecosystems of southern California—witnessing environmental degradation in some of the same places he had studied during graduate school—and became actively involved in over a decade of conservation efforts. Stebbins and colleagues studied the diversity of organisms in and around ORV areas, communicated research to
Bureau of Land Management officials, and petitioned President
Jimmy Carter to limit all-terrain vehicle use in deserts. Stebbins faced opposition from ORV riders and their lobbyists:
American Motorcyclist magazine called him a "staunch abolitionist in the war against motorized vehicles in the desert." Stebbins' efforts eventually helped secure the passing of the
California Desert Protection Act of 1994 which established the
Mojave National Preserve and elevated
Joshua Tree and
Death Valley from national monuments to more protected national parks. Other research included field work in Colombia, South Africa, and Australia, and the description of several species: the
Jemez Mountains salamander,
southern torrent salamander,
yellow-eyed ensatina, and the
panamint alligator lizard. Two salamanders were named in his honor during his time at Berkeley: the
Tehachapi slender salamander (
Batrachoseps stebbinsi) and the
Sonora tiger salamander (
Ambystoma tigrinum stebbinsi). Over his 32 years at Berkeley, Stebbins was the advisor to 29 graduate students, including
Wade Fox,
Richard G. Zweifel, and
R. Bruce Bury. Upon his retirement from UC Berkeley in 1978, Stebbins was awarded the highest faculty honor, the Berkeley Citation. == Retirement years (1978–2013) ==