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How the Red-Legged frog got its name


It was drizzling outside - the first moisture San Juan Island had seen for some time. The gray countenance that embraced the dawn was a welcome change from an unusually long stretch of clear, dry days. I was eager to go exploring and a mid-July rain promised the possibility of finding red-legged frogs. Little did I know my quest would lead me all the way to the Smithsonian Institute.

Why go looking for frogs on an overcast day? For a naturalist, the question might be why not? It is a captivating vision not always easy to find. Like many animals, they are creatures of habit and habitat and I knew just the secluded spot to search. I did not expect to find one of the cryptic little creatures but there would be fun in the quest among towering old growth, huge mysterious (to me) mushrooms, irascible woodpeckers, and the last of the summer breeding birds.

Rana aurora aurora is the largest native western frog. It is fairly common on the coast from southern British Columbia to northern California. It is not believed to be common in the San Juans, but each island has its own unique fauna. Few surveys have been done here and biologists consider its status unknown. Ranidae are true frogs defined, in part, as having smooth skin, a narrow waist, and long legs perfect for jumping (think perhaps of Twain’s frog of Calaveras County).

Picture a moist old or second growth forest of western red cedar, hemlock, Douglas fir all festooned with mosses and lichens, and lots of sword ferns, wood ferns, and salal. Add a secluded meandering creek or slow moving stream and you have the ideal habitat for red-legged frogs. The frogs are small – only about 3-5 inches long - characterized by a dark mask, light jawline strip, a prominent fold from their eye strip along the side, and a pinkish to reddish wash over their lower abdomen and underside of their hind legs. Their Latin name “aurora” means sunrise. It also refers to the Roman Goddess of dawn. The frog exemplifies Nature’s perfect camouflage in a world of leaf litter and tangles of woody debris along muddy wetland realms.

As it turned out, once on my path the search did not take long. I inadvertently startling a “red-leg” sitting beneath a sword fern right next to the deer trail I was following. It made one short leap to get out of my way then settled in the duff beneath the ferns looking up at me looking down at its charming masked presence.

I smiled at the discovery, then bent down and took two photographs of the wide-eyed amphibian; then a third image from a different perspective. The frog did not move and we had a momentary faceoff – assessing one another, I suspect, before I withdrew a safe distance so as not to disturb it further.

What a great find! I settled in the duff to watch it and to listen to the sounds of the forest. It was mid-day; many of the birds were quiet but, as elsewhere this time of year, the Swainson’s thrush was fluting, the Olive-sided flycatcher was calling an exuberant “quick-three-beers”, nuthatches were beeping, and a Pacific slope Flycatcher called Pee-U-Weet from far away. Wrens ranted, a handsome towhee trilled, and a flock of juvenile chickadees noisy worked on their foraging skills. The small creek fifty feet below my post had nearly dried up and struggled to emit even a soft gurgle in the mud amidst the amphitheater of sword ferns surrounding the scene. The only bright color in the forest was the pink inflorescence of Cooley’s Hedge nettle growing along the creek. Both woodland starflower and Linnaeus’s beloved twinflower had gone to seed, and there were woodchips everywhere from the excavations of a pileated woodpecker that occasionally took up its drumbeat while I sat under the canopy.

Can you find the frog?

It was a fine frog. When I looked away to check on the Brown Creeper’s nest in a nearby Douglas fir I struggled to find it again when I looked back so perfect was its concealment in the understory. Each aspect of the frog’s coloration was assimilated to the setting - the blotched tan back mimicking bark and dried leaves, and dark stripes and mask a disruptive pattern in the maze of vegetation.

A slight breeze riffed the sword ferns in the shade fanning the earth-toned amphibian. After a few minutes it grew more relaxed and changed its position. At one point, it rose a bit on its partially webbed toes as if straining to hear something and then settled back down. I did not linger long with “Aurora”, though. Even from a distance, using binoculars, I feared stressing it and that would be no kindness for the gift of its appearance I had been given.

I headed out with a tip of my cap to the red-legged frog that made me smile. I spent a few minutes taking notes of my encounter but wondered if readers were ready for 2000 words about frogs.

Once home, I hit the books looking for details of Rana aurora aurora’s life. The female lays large egg masses in still water in early spring; the tadpoles grow legs and leave the water near the end of their second year. They may not wander far from this watery natal ground preferring to remain a few leaps away from the relative safety of water in case a predator (raccoon, snake, or bird) comes their way. Interesting information, but lacking in the “gee wiz” quality I was looking for.

I noted in the species descriptions: (Baird and Girard 1852). The names acknowledged who had first described the northern red-legged frog. A literature search revealed an impressive list of reptiles and amphibians credited to the two biologists. Baird was an important figure in the world of natural history in the mid to late 1800s. My curiosity about the frog lead to a fascinating story of the early years of the Smithsonian Institute.

Spencer Fullerton Baird was born in Pennsylvania in 1823. He was considered one of the great naturalists of the 19th century. As a young man John James Audubon tutored him on the scientific illustration of birds. While initially interested in medicine, by 1846 (the year the Smithsonian was established) Baird was teaching natural history at Dickinson College. He was a skilled ornithologist, ichthyologist, and herpetologist. The 1800s were a time of important scientific discovery in America. Baird did extensive field work mostly within the eastern United States collecting and trading specimens and developing methods for cataloguing. His work and vast contacts with other naturalists and biologists were so impressive that in 1850 he was named the first curator / Assistant Secretary of the Smithsonian Institute.

Baird had dreamed, since boyhood, of establishing a National Museum. Now he was in his element. He collaborated with the great ornithologist Robert Ridgway, arctic explorer and anthropologist William Dall, American zoologist Clinton Hart Merriman who helped found the National Geographic Society, John Wesley Powell, anthropologist and explorer of the American West who made the first known passage through the Grand Canyon, and many others. He befriended C.B.R. Kennerly, one of the naturalists for the U.S. Boundary Survey of the San Juan Islands from 1857 to 1860. During this period, Baird mentored Charles Girard who would work closely with him on species descriptions at the Smithsonian.

Baird enthusiastically supported scientific investigation and countless expeditions including the Pacific Railroad Surveys and North Pacific Exploration Expedition. In 1878 he was named the second Secretary of the Smithsonian Institution and remained so until his death in 1887.

Baird’s achievements were legendary. Audubon gave him the greatest part of his collection of birds including most of his types of new species. Baird was the primary writer (along with Ridgway and Brewer) of the History of Birds of North America in 1847, Catalogue of North American Reptiles (1853) and Mammals of North America (1859). He urged Congress to establish the U.S. Commission of Fish and Fisheries (precursor of the National Marine Fisheries Service and U.S. Fish & Wildlife Service) in 1871, became its first Commissioner, and worked diligently to lesson human impact on fisheries along the coast. Baird advocated for the Alaska Purchase in 1867 realizing what a natural resource treasure it was. He was ahead of his time in foretelling the possibilities of human actions destroying treasured natural areas.

Spencer Fullerton Baird published over a thousand works in his lifetime. In 1881, this long dreamed of National Museum building was completed and became a part of the Smithsonian. He was honored often for his contributions to science. Several species including Baird’s Sparrow, Baird’s Sandpiper, Baird’s beaked whale, and Baird’s Flycatcher were named for him.

Now, getting back to the red-legged frog. Baird described over 50 new species of reptiles and amphibians in the 1850s either alone or with Girard. Searching for the original species description I found several references to the specimen having been collected on the U.S. Exploring Expedition under the command of Captain Charles Wilkes (the so-called Wilkes Expedition of 1838-43) that passed through Puget Sound Country in 1842. Several place names in the San Juans were attributed to that expedition most notably the Wasp Islands tucked between Orcas and Shaw named by Wilkes for his sloop of war Wasp.

Finally I found the frog’s documentation in the Proceedings of the Academy of Natural Science, Philadelphia, Volume 6 (1852-53) p. 174. I had to use a magnifying glass to read the print so faded was the text from the original book. The entire description was less than 100 words noting one specimen was collected in Puget Sound. “…the body is orange red with here and there black irregular patches…” it reported. And so, the northern red-legged frog got its name and place in the scientific literature 162 years ago.

And I ask, as I often do: What does it matter? Not much to Rana aurora aurora who is living in the sword fern forest on San Juan Island. Its priorities are surviving and breeding in a natural world where avoiding predators is the order of every day. It has its place in the food web of the bountiful forest.

But might there be more? My search for information put the frog’s life in greater perspective than I imagined when I started my inquiry. I appreciated Baird’s accomplishments in the 19th century and all he helped to identify, procure, understand, and protect.

Spencer Fullerton Baird walked in the shadow of giants in the scientific world and became one himself. The northern red-legged frog walks each day in the shade of our rainshadow world and survives because we continue to care enough about the islands to identify and protect its home. Scientific investigation continues. New discoveries are made every day.

While writing this piece I contacted colleagues to ask if they had information about this species. Doug McCutchen of the San Juan County Land Bank had seen it several times over the years and knew of others who had similar experiences. Maybe the red-legged frog was more numerous here than we knew.

I emailed Ruth Milner, District biologist for the Washington Department of Wildlife, and suggested we collaborate on an informal survey of Rana aurora aurora in the San Juans to better determine its status. She thought that was a fine idea.

And, so, here we go. If you have seen the red-legged frog and, especially, if you have photographs of it on your property or in your travels about the archipelago, send them to me. The details are below. We will start a database on this species – for every island – and forward all the information to the WDOW. It’s a project by islanders for islanders (frogs included) to better define the status of this beautiful little creature that lives among us.

So, I tip my cap again to the red-legged frog for its appearance on that gray day. And to Spencer Fullerton Baird for the inspiration to keep collecting data and moving forward with public education about our nation’s treasured wildlife.

I shall keep you posted as sightings come in. It’s a fine little frog -- a member of our islands wildlife community – and well worth our time to appreciate and protect.

Note: Please send photographs and sightings with: (1) data of sighting; (2) name of reporting party; (3) address of the sighting; and (4) if possible, GPS locator. The information will be included in the Washington Department of Wildlife’s database for this species and a similar database here in the islands. susanvernon@sanjuanislander.com


Susan Vernon is the author of Rainshadow World – A Naturalist’s Year in the San Juan Islands.

List of Nature Notebook columns


1. AmphibiaWeb –Rana aurora /http://www.amphibiaweb.org/cgi-bin/amphib_query?where-genus=Rana&where-species=aurora / (general information).

2. Auk: Quarterly of Ornithology; January 1888. Vol V, No. 1 Accessed at: http://vertebrates.si.edu/birds/Hall_of_fame/InMemoriamPDFs/Barid.pdf( Ridgway notation of Audubon’s gift to Baird).

3. Integrated Taxonomic Information System (ITIS) (http://www.itis..gov) Retrieved July 20, 2014. (partial list of papers by Baird & Girard).

4. Kozloff, Eugene N. Plants and Animals of the Pacific Northwest, 1976. University of Washington Press, Seattle, p. 212.

5. Proceedings of the Academy of Natural Science, Philadelphia, Vol 6, p. 174-177. Baird & Girard 1852. Species description of Rana aurora aurora. Accessed at: http://www.biodiversitylibrary.org/item/17888#page/196/mode/1up.

6. Smithsonian website: Baird as Assistant Secretary and the Growth of a Dream: Accessed at: http://siarchives.si.edu/oldsite/history/exhibits/baird/bairdc.htm.

Last modified onSaturday, 27 September 2014 22:05