ENHS Nature Trails November 2005 Article 1

This month's speaker: Jay Bowerman

Two years ago Jay Bowerman spoke to us about an ongoing study and conservation effort that began with the relocation of an entire population of spotted frogs removed from a site scheduled for burial. The frogs were released into a newly created series of ponds, where they stayed and survived to breed. "The research opportunities presented by this project were immense," according to Jay, "especially since the opportunity exists to follow an expanding population for which we have DNA finger prints for every member of the founding population." Jay reported that early research suggested that "Oregon spotted frogs have evolved an impressive, perhaps unique ability to tolerate cold low oxygen conditions in shallow ice-covered ponds where oxygen levels routinely fall to one part per million or lower."

Friday evening Jay will take us into three other areas of his research: "Submerged calling by Oregon spotted frogs, amphibian deformities, and frog parasites." We will learn about that leech on the cover. Before I share with you the details of his talk, here are some excerpts from the May, 2003 Nature Trails' interview with Jay Bowerman.

MOM WELCOMES THE SPOTTED SKUNK

 We moved to the Coburg Hills outside Eugene when I was in the second grade and I quickly discovered the world was well populated with lizards, snakes, frogs and salamanders. I grew up roaming the forested hills and banks of the McKenzie River, mostly alone.

Mother encouraged curiosity and delight in the myriad things we discovered on regular forays through woods around home. Despite her own upbringing in a mostly urban environment, Mother accepted the endless parade of small creatures that arrived on their own or were brought home by three growing boys, determined to make pets of mice, lizards, snakes, mink, and even a fox. She was grateful for and fond of the little spotted skunk who came to rid us of white rats that proliferated under our house after my brother brought them home from seventh-grade science class.

Father too, was pretty cool about unexpected encounters with local creatures. When we found a rattlesnake living beneath lumber while building our house, he gathered it up in a 5-gallon bucket and took it to Dr. Lockley in the U of O Biology Department. Oh my amazement when Dr. Lockley reached barehanded into the bucket and picked up the snake, holding it carefully behind the head.

THE SPELL OF JIM KEZER

 At the U of O I managed to avoid biology until my senior year. Fortunately, the wisdom of a great liberal arts college required that I complete at least one year of lower division biology. So, as a senior, I enrolled in freshman biology and came under the spell of the late Jim Kezer. (A much loved herpetologist and pioneer of the Eugene Natural History Society). I was so excited by the subject that I enrolled for a summer session of upper division invertebrate biology at the marine station at Charleston, and never looked back. Three years after graduating, I returned for a master's degree. Dr. Kezer was without graduate students at the time, and I had little difficulty convincing him to let me join his team. What a heady time that was, making slides of salamander chromosomes, learning about opera, and having the opportunity to study with the likes of Jim Kezer and Herbert MacGregor. Oskewowow!

More than 20 years ago, as the resident naturalist for Sunriver Resort and the community, I brought Hooter, the great horned owl, to Eugene for a presentation to the Natural History Society. And for more than 25 years I was mostly an administrator and fundraiser for the Sunriver Nature Center. The work was rewarding but the Kezerian influence was deep and I longed for the chance to do science. I eventually convinced our board of directors to put administration into another's hands. I now devote as much time as possible to serious investigations involving amphibians. And, it is still memorable to visit Northwest coastal rain forests and look for salamanders, like we used to with Kezer.

Jay's enthusiasm for his work is always reflected in his presentations. He graciously wrote out the following details of Friday evening's talk. Entice some friends to come and get a real insight into the world of spotted frogs, deformed amphibians, and Frog parasites from a fine speaker.

"According to James Platz, the guru of submerged calling among frogs, about half of the species of Ranid frogs call underwater, while the other half call from the surface. Tree frogs and bullfrogs call from the surface and are easily heard. They also use the large inflatable sacs we see when these frogs call. Submerged calling, however, is frequently inaudible to those of us not in the water with the frogs. As a consequence most people are unaware of frogs calling from below the surface. Not much is known about submerged calling in a number of species, including red-legged frogs, yellow-legged frogs, and spotted frogs. There are a number of intriguing ecological and evolutionary questions regarding calling from beneath the surface. I will describe calling patterns in Oregon spotted frogs, play recordings of calls from beneath and at the surface, discuss our ongoing studies of submerged calling.

"Although media attention to amphibian deformities has waned in recent years as studies showed that many of the most spectacular types of deformities, such as multiple extra limbs, result from tiny parasites that form cysts in the developing limb buds of tadpoles, there continue to be studies linking specific types of deformities to other causes. I will summarize results of two studies demonstrating high rates of deformities caused by specific predatory attack, one by an insect predator in Cascades' frogs, and the other by a fish no larger than the toad tadpoles it attacks.

"Investigations by a colleague at Sunriver Nature Center have identified three kinds of blood parasites in Oregon spotted frogs, including two intracellular forms that reside within red blood cells, and one, a trypanosome, that is extracellular. I will show photomicrographs of these three parasites and a rather pretty leech that is a prime suspect as the vector for one or more of the parasites. However, we have indirect evidence that there are other vectors involved in transmission of these parasites. I will describe our experimental efforts to transmit parasites from infected to uninfected frogs, including attempts to infect nonnative bullfrogs which, to date, have consistently tested negative for these parasites. I will also discuss some exciting discoveries involving the frog leech."

The Sunriver Nature Center & Observatory is a private, not-for-profit scientific and educational organization in Sunriver, Oregon. Experience hands-on exhibits about mammals, reptiles, amphibians, and birds that live in Central Oregon. Learn more about the animals of the area during a nature talk. Observe the closest star to our home planet--the Sun. View sunspots and solar prominences through special filters at the Observatory. Stroll through forest and marsh habitats on the Sam Osgood Nature Trail. Observe the resident bald eagles, listen for birds in the marsh, look for animal tracks, and see a dormant volcano. Learn about native wildflowers, shrubs, and trees in the Botanical Garden. Say hello to Jay Bowerman, Principal Researcher. Please call 541-593-4394 for information.

[ Back ]

Page last modified: 30 January 2006
Location: http://biology.uoregon.edu/enhs/archive/nov05/nov051.html
E-mail the WebSpinner: cpapke@gmail.com