Photo of spotted frog.
Among the tasks of a biologist was to determine if the Columbia spotted frog still occurred in Idaho by surveying likely streams, springs, and ponds. 

Evolution of a Biologist

By Tim Carrigan

A photograph of a young boy staring eye-to-eye with a frog adorns the cover of Richard Louv’s 2005 bestseller “Last Child in the Woods.”  That boy could very well have been me 50 years ago in Minnesota where frogs were the most abundant and the easiest to catch wildlife.  My love of nature began there and continued as I moved to Contra Costa County in the San Francisco Bay area, an area unparalleled in America for richness and diversity of wildlife, especially herptiles, a group of animals made up of reptiles and amphibians.  It was these early encounters with animals and the outdoors that inspired me to study wildlife management in college and go on to become a wildlife biologist for the BLM. 

I was hired by the BLM after the Endangered Species Act was passed in 1973.  At that time, BLM biologists were given little direction, as regulations for the new law were still being written.  The wildlife program was not as well established as other BLM programs such as range or forestry.  Some biologists were given the task of managing small tracts of land close to urban or agricultural areas to provide hunting opportunities, while large expanses of public lands in their districts were often ignored.  BLM biologists eventually found a role managing the rangelands for big game.  Our approach was that if we managed the land well for megafauna, all wildlife species would thrive.  And that is how we carried on for a decade or more, sometimes getting involved in raptor management or monitoring of sage-grouse leks, but always concentrating on big game ranges.

A new vision for BLM wildlife management was cast with the release of the “Fish and Wildlife 2000” plan, and seemingly overnight, we were managing for species beyond mule deer, elk, pronghorn, and bighorn sheep.  We looked in far more detail at the needs of sage-grouse, riparian-dependent species, prey animals, and special status species.  I still remember my surprise when I was told I would be managing habitat for a hot springsnail, which is not much larger than the period at the end of this sentence.  Then came the day when the Great Basin population of the Columbia spotted frog became a candidate for listing under the Endangered Species Act.

Our first task was to determine if the Columbia spotted frog still occurred in our area by surveying likely streams, springs, and ponds.  On the first day of the search, we could hear frogs calling from an open area not far from a stream.  They were loud and numerous but would grow silent whenever we approached; we never saw a frog even jump.  Only by the low, angled light of late afternoon, with a high-powered spotting scope, did we discover that the frogs we heard were Pacific tree frogs using rodent burrow openings as a megaphone to project their calls. 

On day two, we learned to ignore the calls of abundant tree frogs and instead concentrate on surveying low-gradient, slow-moving streams.  For hours, none of us located a single spotted frog; my frustration grew and I began to think that the area no longer harbored the species.  I thought back to the frog-catching days of my youth.  I could visualize the exact locations of my quarry—the microhabitat where the frogs would hide.  Soon, I noticed a pool off the stream with overhanging vegetation and algae in the water, just like those I had seen in my childhood.  I simply stared at the spot for more than 5 minutes until I finally saw two bulging eyes blink at me.  We had located a Columbia spotted frog in an area with no recorded sightings in more than 50 years.

Over several years, the BLM and its partners, the Idaho Department of Fish and Game (IDF&G), U.S. Fish and Wildlife Service, and Boise State University, located several spotted frog populations and defined the frog’s habitat requirements in our area.  A limiting factor for the frogs was the lack of beaver ponds, which we decided to address at one site after frog numbers plummeted.  Boise State supplied the idea and workforce; the BLM provided the materials, biologists, and environmental paperwork; and the IDF&G supplied the live-trapped beavers.  We repaired a dam with lumber and irrigation cloth, reintroduced the beavers, and let nature do the rest.  Within 2 years, a large complex of beaver dams was established and there were too many frogs to monitor in the required 2-day period.  This simple project, which took just a few days to complete, was the most rewarding activity of my 30 years with the BLM.

As my career heads towards dusk, I am hopeful that initiatives such as Take It Outside will inspire the next generation to pursue careers in natural resources.  It would be a shame if one of my cohorts or I was the last child in the woods.


Tim Carrigan is a wildlife biologist on the Renewable Energy Team in the BLM Idaho State Office.  He was also the assistant field manager of the Bruneau Field Office and a wildlife biologist in the Boise District.  Prior to serving in the Army from 1985 to 1990, Tim was a range conservationist in Salmon, Idaho.