standard “emetic units”

6 02 2008

Finished today:

Moth Catcher, by Michael M. Collins


The kind of book that you should read if and only if the subtitle “An Evolutionist’s Journey Through Canyon and Pass” sounds like your kind of book — this book doesn’t rise above the expectations set by that title, nor does it fail in the end to meet them, either.


For the most part, it’s just the story of the “ordinary” life of a modern scientist — following and illuminating his passion for caterpillars and moths, describing the work of a lifetime in the span of a 150 pages, the bits and pieces of the real contributions Collins has made to science. Not earth-shattering or sky-splitting, but a valuable gleaning of facts contributing to a better understanding of speciation and hybridization.


eupackardia calleta

Pasted from <>

This is a Eupackardia calleta larva. “The gaudy color and pattern suggest warning coloration , as does the blood chemistry.”


He describes one experiment in the book that bears repeating (in fact, I’ve already repeated it to my son.) Nestling blue jays were raised

…as naïve predators, feeding them palatable viceroy butterflies, a supposed mimic of the poisonous monarch. The birds eagerly accepted the viceroys and learned to recognize them by their color and pattern When they were then offered monarch, the jays at first could not discriminate them from viceroys. Each time they attacked a monarch they quickly spat it out and retched in response to the cardiac glycosides these butterflies sequester from milkweed during the larval stage. (Revealing his wry humor, Brower [one of the scientists] quantified glycoside levels in standard “emetic units.”) Still reeling from the experiement, the wretched brids subsequently refused to feed on viceroy adults, presumably solely on the basis of their visual resemblance to monarchs. More than a century after Henry Walter Bates proposed the idea of micry, the Browers and their students linked together plant biochemistry and predatoation to explain the evolution of warning coloration in the monarch model and of convergent patterns on the wings of the viceroy mimic.


Such is the progress of science — proving or disproving, logic isn’t enough; although one feels a bit of sympathy for those poor jays.


Near the end of the book, the tone suddenly shifts from memoir to science article with a closely reasoned and intellectually stimulating description of the debate over the meaning of species — essentially, where you draw the line. It’s clear from reading this, by the way, that humans at this point in time are all one species, although he doesn’t address this question.


One question I would pose to him, though. He says “The longer two species evolve along separate lineages, the more genetic differences they accumulate and the less successful their hybrids will be.” But my understanding is that after a “short” separation, crosses are more successful leading to hybrid vigor. ( )


Post-script — one interesting fact.

He usually collects his butterflies and moths in traps, baiting the traps with females raised from captured  caterpillars that he hopes will lure the males he is interested in. There goes my vision of chasing around fields with butterfly nets — although that does happen at one point, it’s not the norm. 🙂


This book was mentioned in an earlier post: Tracks of Tracks in the Snow

Tracks of Tracks in the Snow

1 02 2008


[this is an edited version of a personal letter I wrote shortly before I started this blog]

On Tuesday, I was snowed in and worked from home. Alas, without the kids here, I really did spend almost every moment of the day working, but I did get out for a couple of short walks on the property. I should have pulled the sled down and taken a few spins — 1 or 2 usually satisfies me. But I kept wanting to get one more hurdle overcome on the project I’m cooking up and so spent the day in bits and pieces.


It’s too bad that the kids didn’t get to see any real snow — next year we will get to the mountains no matter what! Perhaps we should take ski lessons, or just go cross-country skiing…or, in any case, we shall certainly go tubing or sledding.


In any case, it looks like I shall have the chance to go up to the mountains after all, since my group at work is going on a group outing into the snow in February, either to go tubing or snowshoeing.


But I was going to tell you about the snow at our house. I like the snow for making a record of the goings on around our property. Like a photo or, in a way, like this letter, the snow preserves a memory of the animals so that others can share them. Of course, we know that many creatures live on our property, but even the deer seem like a treat to see. But I’m sure that they visit our property every day, as do the possum, coyote, field mice, owls, and raccoons that we see only occasionally. And the snow lays out the tracks like a story. I have a book here with me, rather melodramatically entitled Mystery Tracks in the Snow, one of those marvelous near gifts from the library discards. Someday I hope to find a mysterious track that I can eventually decipher — to puzzle out a porcupine path, perhaps, or decipher those of a bobcat or some other of the wildcats that are known to come to our area on occasion, but for now I fancy I know what the tracks are just from the fact that there are so few animals that they could be from. I see my book has a description of a porcupine’s tracks (so I’ll be ready):


…life is easy for the porcupine, and it is neither intelligent nor highly motivated…

If you do find the tracks of a porcupine, you will see that it walks with a waddling gait, with the back feet stepping almost in the tracks of the front feet.

In dust or light snow its swinging tail will make swishing marks between the tracks.

The flat-footed tracks look much like miniature bear tracks. They are about three inches long and the long claws show plainly. There are five toes on the back feet and four on the front.

With its short legs and heavy body, it plows a deep furrow through soft snow.


Of course, porcupines don’t have it too easy — everything has its checks and balances. Given that the world isn’t overrun with porcupines, we can know that there are some forces out there keeping their numbers down. In some parts of the world, people eat them. Mostly Africa, but also, according to the all-knowing Wikipedia, in parts of Italy — presumably the parts where porcupines live — and in Vietnam. We can also excuse porcupines their lack of a quick wit — their fearsome quills mean that they don’t have to use their brain to evade most predators, and a diet of bark, needles (conifer needles, not to be confused with the needles that the porcupines grow on their personal skin), leaves and other plant parts don’t put up much of a challenge either. I suppose there is a rather conventional lesson here about the challenges in life making us who we are, and a life of ease being a dissipative and weakening one.


I’m particularly interested in spotting porcupine evidence because they are cryptic creatures that I’ve never encountered. I’m sure that I’ll see one someday.


It’s funny that we all take such an interest in the large creatures of the world. Not just the so-called “mega-fauna,” or lions and tigers and elephants, but the mammals of all sizes, even though there are so few of them. Do any of them really live a more interesting life than a wasp or a spider or a butterfly? Of course, at this exact moment a surprisingly large moth flutters through the room where I am writing, as if to remind me that beside my bed upstairs is a book titled Moth Catcher, the memoir of a biologist, a resident of Arizona, by the way, who has devoted his life to studying them. (I bought it on the trip to Elliot Bay Books when the kids were here — managed to buy a few presents without notice, also.) There are many people who love bugs and birds, but I think they are many who wouldn’t be interested to hear about a butterfly or a Stellar’s jay, but who would be excited by reports of a porcupine or a ‘coon. (perhaps even by the story I intend, eventually, to relate.) It is interesting, though, that I have a book that lists and describes nearly every species North American mammal (lumping only some of the rodents into entries together). This task would be futile for the insects. There are only about 5,400 different species of mammals in the world — a good portion, nearly half (around 40%), are rodents. One could imagine a nice set of bound volumes with all of the mammals of the world laid out, one or two per page… Try to imagine, now, that there are also around 5,000 described species of lady bugs. I say “described” because there are almost certainly at least a few species overlooked to date…


Anyway, it was pleasant and refreshing to walk through the property in the snow, seeing the beauty of the trees and land covered in snow and the tracks of the deer and the coyote, just where I’d expect them from seeing them travel our property — the deer tracks crisscrossing the back yard and the front, and the coyote still skirting the border and trotting down the part of the driveway running between our property and our neighbors to the south. The animals are neither indifferent to our paths or bound by them — they follow along them for a while, then it what seems a sudden departure, continue on, probably following some path well known to them. I saw the same thing from work out of Carl’s window — a sidewalk near the parking garage was a common path for all of the folks walking in that direction, but there was a fan of tracks across the lawn where the sidewalk took a jog to the right when everyone else wanted to head off somewhat to the left. The fan of tracks didn’t project the sidewalk’s path forward, but reflected the varied destinations of the walkers, each with his own idea of the best route. I’m sure that on most days they each walk that same course, at least when the lawn is not too soggy. But only with a great deal of attention, observation, and perhaps even careful record keeping, would the fan-like pattern of their tracks have been apparent to an observer, and never with the clarity of that fan of tracks in the snow, evident to anyone who cared to look. I think that was what I was trying to get at earlier in this letter — the snow records a path, or many paths, and plays them back all at once in a single glance, revealing all this interesting behavior that would have been so difficult to perceive, indeed would never have been perceived, without its record keeping. I suppose this is the job a writer or a poet or a reporter strives to achieve — to sum up an event or call up a scene in the mind’s eye with the brevity and clarity of tracks in the snow.


I saw a raccoon follow for just a stretch the path of compressed snow that I’d trampled with my truck tire at the bottom of the driveway, where the ground on either side is marshy. Or rather, of course, I saw the snow’s record of those nighttime perambulations. She — I call her she for no good reason as there were what appeared to be two set of tracks, or the same raccoon on two trips, and I find it convenient to think of one set as male and the other female– She came from the woods on one side, where we always crash our sleds when we toboggan down the straightaway, and walked along the track left by my truck before veering at an oblique angle across the driveway toward the dark pond where the stream descends to pass under the driveway.



A bloody small raccoon-edible something (formerly someone, I suppose), was dropped or rested on the snow, leaving a smallish blood-stained hole near the tracks, which then veer to the water’s edge in a V, headed to the water and then away. (I suppose the raccoon will have no qualms eating corn, or simply eating the mice directly) I fancy this visit was to indulge the raccoon’s habit of washing its food. The tracks head back along the water in a straight path, meeting and overlapping with the other set that come from the direction of the street, before, in what seems a surprising turn of events to me, beelining across the water to emerge on the other side. It’s natural, I suppose, that the ‘coons would live back there in the marsh, but I can’t really imagine that they enjoy crossing the icy water — they seems to choose a fairly narrow point to do so..


This leads me to reflect what a great invention shoes and boots are, even now in the warmth of my (perhaps overwarm) home. I’ll bet that a raccoon would appreciate a good set of waterproof footwear as much as any creature, so long as they were easy to put on and off…


I’m trying to read more poetry — I don’t always enjoy it, but when I do, it’s a different kind of pleasure than other kinds of reading — like carefully examining a photograph instead of watching a movie. Part of it is learning how to read some of the poetry — the Writer’s Almanac, and Garrison Keillor’s  evocative reading style, has helped.




Here’s my poem of the week:


What’s In My Journal


Odd things, like a button drawer. Mean

Thing, fishhooks, barbs in your hand.

But marbles too. A genius for being agreeable.

Junkyard crucifixes, voluptuous

discards. Space for knickknacks, and for

Alaska. Evidence to hang me, or to beatify.

Clues that lead nowhere, that never connected

anyway. Deliberate obfuscation, the kind

that takes genius. Chasms in character.

Loud omissions. Mornings that yawn above

a new grave. Pages you know exist

but you can’t find them. Someone’s terribly

inevitable life story, maybe mine.


by William Stafford, from Crossing Unmarked Snow


I don’t have much of a journal, but that’s an apt description of what a journal should resemble, if not, perhaps, particularly for me (I have no especial genius for being agreeable, I fear.) Despite the joys of reflecting on one’s journal and the advantage illustrated by the snow of being able to scan over a record of events, I have not found it easy to write at length to my future self, although I am probably my most appreciative audience. The brain is better at recognizing and recalling things with a trigger rather than summoning them from thin air, and rereading an accounting brings black a flood of all-but-forgotten memories. But perhaps I can write a letter to someone, as in this case, then share it with others and preserve it for myself here on my blog. Perhaps few will be interested in getting barbs in their hands, and others will scorn marbles. But I will send it all your way and trust it does not find most of itself unwelcome. And if parts do, well, then I shall call them journal entries and be content with reading them myself someday, tracks of tracks in the snow.


p.s. Dusk from the deck