Driloleirus macelfreshi lives!

This week marked the third anniversary of a significant scientific discovery made by my dogs.  We were out on a walk on a messy afternoon marked by mud, driving rain, and wind, courtesy of a Pacific winter storm.  Young dogs still need their walks, and so do their owners.  I can't really say quite how it happened, other than as I bent down to discharge my responsibility as a dog walker after my old dog had finished her business, I glanced back and saw the young one standing with a long pinkish stringy thing hanging from his jaws.  He looked quite pleased with himself, and was an instant away from flinging up his head and consuming his prize.  I witnessed this in the split second between discovery and annihilation. And somehow I knew that he absolutely must not be allowed to eat this thing, not for any risk to himself, but because of what it was. 

I leaped at him, howling at him to drop it, which is absolutely not how you are supposed to train a six-month old pup to surrender highly desired objects.  Fortunately for science, he was so shocked at my behavior he did drop it, and in his moment of indecision I swooped on his find and scooped it into a spare plastic bag.  The dog was utterly unimpressed at my inexusable theft of what he regarded as rightfully his.  There are times when I wonder whether he still remembers this.

At that time, however, we went home, and I laid the dog's find out on the counter.  It was an earthworm, and it measured four feet four inches long.  It was flabby, pale pinkish-gray, impossibly thin, and quite dead.  It was also the first specimen of the Oregon giant earthworm, Driloleirus macelfreshi, to be documented in twenty-seven years.  We know very little about this species, other than it seems to be endemic to the wooded bottomlands of the Willamette Valley.  It had been pretty much assumed to be extinct.

There are many little pieces to this discovery, each of which made that sudden, instinctive recognition on my part possible.  Over a decade ago, I had the great fortune to meet two of the last earthworm taxonomists in the world, Dorothy McKey-Fender and her son, Bill Fender.  This in itself was a culmination of improbable circumstances, but the crux was a workshop, conducted by Dorothy who was then in her eighties, on how to identify native earthworms.  The workshop was followed by a search for native worms in 2000.

Bill Fender and Dorothy McKey-Fender with a specimen of Driloeirus macelfreshi in their laboratory in 2000.  Photo: D. K. Rosenberg

I know a little about earthworms, as much probably as any average gardener or curious naturalist knows.  Native worms have been largely replaced by exotic species, and most of the worms we see as we go about our daily lives are descendants of recent immigrants to this continent as most of us are.  Ecologically speaking, we do not even know what we've lost, because the native worm fauna has been very poorly studied and described.  We do know that different families of worms behave differently, and affect nutrient turnover and soil humus in different ways.  We do not understand all the implications, although they include reducing the humus layer, which is itself a vital habitat for many organisms, and allowing exotic weeds to establish on the surface of soil no longer protected by that deep blanket.  For the most part, though, we just don't know what we've broken or what pieces remain somewhat intact.

There are earthworms out there, native worms, very different from the nightcrawlers we all immediately identify as the ultimate worm.  Even more amazing, there happens to be a gigantic native worm called the Oregon giant earthworm, Driloleirus macelfreshi.  Dorothy McKey-Fender herself had studied most of the specimens that have ever been collected- a scant few dozen in all.  They were far too rare to allow the workshop participants to examine, but Dorothy moved around the lab room set up with dissecting scopes and trays filled with other worms pinned to the black wax, delighted to share some of the knowledge accumulated over a lifetime.  Her love and respect for these animals was palpable, and her excitement contagious.  I've been more aware of worms since then, for their own sake, not just for what they do.

So there we were, in a wet riparian forest at the tail end of a storm dumping heavy rains, swelling the Willamette River until it licked and curled at the bases of the cottonwood trees along its banks.  A party of several people and several dogs ahead of us had walked right by the corpse of the giant worm lying on a bed of fallen leaves, not far from the floodwater's edge.  I would not have noticed it either, if my young dog hadn't loved to eat dead things.  But at least in that instant of seeing it, I was open to the existence of giant native worms.  Without that, the discovery would not have been possible, even if I had still looked straight at my dog in that instant before he snatched and swallowed.

Looking for another giant worm- the last one was right around here somewhere...

The worm is now among those in the McKey-Fender collection, although a small segment of the tail sits in a vial on my desk for possible genetic analysis.  More importantly, we know we can still look along the rivers and woods and hope for more than we recently dared hope for, that one of the unique forms of life on this planet may still be with us.  If we can be open to those possibilities, I hope we can also be open to more creative visions of how to live more gently and equitably among all of our fellow species.

Hope in a White Plastic Box

Among all the bad news about the environment, you don't hear so much about the success stories.  There really are some, and they are very useful not only in what we can learn from them, but also for the hope they can inspire.  Hope is a great motivator for human behavior, probably far greater than we typically realize.  It also generally makes us feel better, and although that observation could naturally lead to a discussion of how we may be hard wired to respond to hope, to a kind of innate optimism, I'd rather discuss a specific event for now.

The subject: Oregon spotted frogs, Rana pretiosa.  These animals might not seem a likely source of hope.  They're a candidate species for listing under the Endangered Species Act.  Candidate species are those that the U. S. Fish and Wildlife Service has determined to be worthy of listing, but the agency just hasn't quite got around to getting the paperwork all done.  There's no regulatory muscle behind the designation.  It just formally states that Oregon spotted frogs might be in some pretty serious trouble.  Unfortunately, it is a common story especially for a species of amphibian.

Oregon spotted frog, Rana pretiosa.  Photograph by Dan Rosenberg.

All is not gloom and doom, however.  A group of people, including biologists with the Washington (state) Department of Fish and Wildlife, NorthwesTrek Wildlife Park, the Woodland Park Zoo, the Oregon Zoo, and other organizations has been working to reintroduce populations of frogs into areas where they've been driven out.  It is a complex process, involving a several-year-long evaluation of site hydrology, presence of exotic species like bullfrogs, and potential for disease.  It isn't easy to find sites that pass muster for biological reasons, and the candidate sites are also subject to more human considerations, such as land ownership and other land uses.

Then there's the issue of where you get your frogs.  The animals released on October 6 were collected as egg masses from two sites whose populations were robust enough to handle some baby-snatching.  Egg masses from both sites were then distributed to the zoos and other organizations who reared the frogs. 

This is an even more formidable task than finding a place to release any frogs you might raise.  A suitable wetland doesn't look all that spectacular, but it provides the right water temperatures, nutrition, and shelter to turn an egg into a frog.  Mimicking that is actually very, very difficult.  Every species is different.  Will  Oregon spotted frogs thrive on one of the pre-formulated tadpole chows (yes, there are such things), or some new recipe?  Are conditions optimal for proper development?  How do you clean the rearing pens without accidentally throwing out the babies with the tank water?  When you're dealing with a rare species, failure to raise healthy young individuals really isn't an option.

Thankfully, much of the needed husbandry has been worked out, and the project collaborators brought over a thousand young frogs for release into the site.  Frogs were first introduced several years ago, but each year the population is augmented to ensure it gets established and begins to grow on its own.  Although it wasn't the first time, the people involved clearly viewed the release as sweet reward for the arduous care they'd given the thousands of eggs, tadpoles, and little frogs over the last seven months.

Rana pretiosa just before release.  Photo by J. A. Gervais

Plastic containers were lugged down to the muddy shoreline, lids removed, and the young frogs burst out like popcorn.  Some animals dove right down, seeking shelter.  Others hit the water and bounced right back onto the land, and a few even leaped for the containers.  I had to wonder what passes through the mind of a frog at a moment like this.  "This water is COLD!"  "Where's the frog chow?"  "Whoa!  This isn't what I signed up for, where's that plastic box?" 

More serious questions include how exactly an animal raised in a tank is going to know how to find wild food and life-saving shelter, recognize danger in time to escape, and learn to deal with an environment staggeringly more complex and changeable than the conditions it has experienced since hatching.  Incredibly, a large proportion of young frogs seem to figure it out.  I was told that the six-week survival rate is actually quite high.  Not the sort of release strategy that would work for an animal that depends on parental guidance to learn how to survive, but frogs don't look after their young, and they seem to start life with all they fundamentally need to know already programmed into their neurons.  Frogs are much easier to deal with than, say, condors or elephants.  Humans may have invented formal schools, but plenty of other species believe in education.  Not frogs, fortunately, which simplifies things like reintroductions.

Releasing 300 young frogs into the wild.  Photo by J. A. Gervais

It was all over at each release site in a matter of minutes, at least from our perspective.  We plodded back through the muck, put the now-empty containers back into vehicles, and went our separate ways. 

Back in the pond, the new arrivals were dealing with amphibian-centered immigration issues, determining who will get what space with access to which resources.  They were learning how to navigate a new world much bigger than a rearing tank, and populated with river otters, herons, kingfishers, and raccoons.  The long-term payoff that justifies all the work will be the number of egg masses that these animals will eventually lay, and the persistence of this population of the species.  The short-term payoff may be equally significant to the humans involved, a rush of hope, of empowerment, a sense that the situation hasn't completely gotten away from us after all.  There is a chance we can still fix some of the things we've broken. 

There's a trick to this hiding thing.  Newly released R. pretiosa not quite "getting it".  Photo by J. A. Gervais

It's a brave new world we must face, one full of unimaginable threats.  Recognizing our vulnerability is a crucial first step to survival.  Hope will be equally necessary to motivate us to move forward into the future with strong hearts and open hands, oriented to find solutions to save what we love.  It is good to know that redemption can be found in something as simple as a white plastic box.