Prehistoric Life 15

by Carl Strang

This year’s winter series is a review of the prehistoric life and geologic history of northeast Illinois. Each chapter will summarize current understanding, gleaned from the literature, of what was going on with life on Earth in a particular span of time, what we know about the local landscape, and what we can say about local life. I include some references, particularly to papers published in the journal Science which commonly is available at public libraries. Contact me if you need sources for other items. The Earth is so old that every imaginable environment was here at some point, from ocean depths to mountaintops, from equatorial tropics to tundra, and from wetlands to desert.

Eocene Epoch (56.5-35.4 million years ago)

The Eocene Epoch, literally “dawn of the recent,” originally was defined by Lyell in 1833 according to the percentage of fossil marine mollusks in France’s Paris Basin still living today (3.5%).

Life on Earth. Reefs reappeared in the oceans 48 million years ago, as new species of reef-building corals evolved among the coelenterates (Science 312:857).

The greatest diversity of Cenozoic Era terrestrial plants in the New World tropics (greater even than today) occurred in the early to middle Eocene. Diversity across the era has correlated fairly well with climate, temperature in particular (Science 311:1893). In the Arctic, temperatures 55-50 million years ago were so mild that even in the darkness of winter they ranged from just above freezing to 70F. Large animals could live there without migrating or hibernating, subsisting on browse and evergreen material. Species in that region included brontotheres, early rhinoceroses, tapirs, alligators, turtles, snakes and flying lemurs.

Our area in most of the Eocene was a diverse tropical forest.

In the early Eocene, order Artiodactyla (even-toed ungulates) evolved, part of a large number of appearances of new mammalian groups and extinctions of older ones, associated with the global warming spike. This time produced the first North American true primates (2 families), didelphids (opossum relatives), perissodactyls and artiodactyls, and their numbers rapidly increased. The lagomorphs (the order containing today’s rabbits) began to diverge from the rodents early in the Eocene. A group called entelodonts, ancestors of pigs, lasted from mid-Eocene to late Oligocene. Camels originated in North America in the late Eocene. The perissodactyl rhinoceroses trace their ancestry to the early Eocene, as do the horses. The latter began with Protorohippus (= the less correct name Eohippus), with fossils in North America. (Europe’s Hyracotherium has been determined to be a different, non-horse, perissodactyl mammal). Perissodactyl brontotheres, which were rhinoceros-like ungulates, underwent much of their evolution through the Eocene. Uintatheres were primitive, Eocene ungulate-like animals, neither Perissodactyla nor Artiodactyla, in several genera, with tusks, horns and tiny brains. Mesonychids were still around, carnivorous species including the enormous Andrewsarchus of Asia and smaller Synoplotherium of North America. That group may have been the source of the whales, though recent evidence suggests that Asian artiodactyls were a more likely origin.

The opening environments of the late Eocene began the trend to increased herding and larger body sizes. The great diversification of artiodactyls and rodents began at the end of the Eocene. The squirrel family (Sciuridae) appeared in western North America at this time (Science 299:1568). The order Proboscidea (ultimately to include the elephants) appeared in the late Eocene in Africa. Whales, rabbits and hares appeared in the Eocene, and the late Eocene produced the first moles, and modern carnivore families. An impressive skeleton of a primate from the middle Eocene was reported in 2009. This individual was lemur-like, but may have been close to the line that led to us (Science 324:1124).

The first rabbits had evolved by the end of the Eocene.

Until the modern carnivore groups expanded, for most of the Eocene the creodonts remained the dominant predators. Hyaenodon was a diverse genus from late Eocene to the early Miocene, ranging from western North America through Europe to Asia and Africa, and with a size from small coyote to large grizzly bear. Sabertoothed carnivores of family Nimravidae appeared in the late Eocene, emigrating from Europe to North America. Felids appear at the Eocene-Oligocene boundary in North America and Eurasia. Other modern carnivore groups were represented by small, generalized forms.

Modern bird families did not exist through the Eocene, though many of the aquatic orders (e.g., Gruiformes, the order containing cranes) diversified. Diatryma was a 7-foot-tall North American flightless gruiform predator.

Local landscape. North America was isolated by the middle of the Eocene (and never again was connected to the east, though the western Bering Sea land bridge was to come and go several times). North America had no tundra, coniferous forest, grassland, desert, shrublands or savannas through the Eocene. There was a brief but intense global warming peak in the early Eocene, with much rain, then a cooling and drying to subtropical conditions in the late Eocene. The local environment made the transition from tropical forest to subtropical forest. The cause of the global warming peak is thought to be an episode of flood basalt eruptions (with attendant release of greenhouse gases) in the North Atlantic as North America and Europe split apart (Science 316: 587).

Local life. Bats probably have been here from the Eocene on, except during glacial times. Bats may have originated in North America, and they underwent a huge diversification in the early Eocene with all present-day families represented by the end of the period (Science 307:580). Primitive true primates likely were here in the Eocene, and possibly into the Oligocene (families Adapidae [lemur-like] and Omomyidae [tarsier-like]).

Bats diversified in the Eocene.

In the early Eocene, the first horse Protorohippus (“eohippus”) very likely was here. Coryphodon, the largest land mammal of its time, probably was here, as was the river-dwelling, hippo-like Metamynodon. The early browsing, running rhinoceroses, like Hyrachyus, were widespread in North America, Europe and Asia. Entelodonts, the predatory ungulates, had a likely representative in Archaeotherium. Condylarths still were around, with the rat-sized, squirrel-like Hyopsodus found all over the Northern hemisphere and lasting well into the Eocene, and the small, generalized Haplomylus also a likely local candidate. We probably had some artiodactyls and rodents by the end of the Eocene, as well as early carnivores (Miacis, Hesperocyon), and creodonts such as Prototomus or Hyaenodon. Crocodilians and turtles were on Ellesmere Island into the early Eocene, so presumably were here as well. The huge predatory bird Diatryma is another good possibility.

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Mayslake’s Winter Birds

by Carl Strang

An interesting mix of bird species wintered on Mayslake Forest Preserve this season, through the storms and the cold. Among them was a yellow-rumped warbler that mainly was active around the south and east shores of May’s Lake.

This warbler often chowed down on the berrylike cones of red cedars.

There always seemed to be jays around, and sometimes when a few became agitated their calls drew in as many as 10 of their kind.

I didn’t see the jays feeding, but there was a good acorn crop last fall and my guess is that the jays stored a sufficient supply.

Some winter residents were steady, and expected. These included cardinals

Cardinals sang for an unusually extended period this winter.

and juncos.

Mayslake’s juncos wandered widely, and I never got a sense of how many groups there were or how their home ranges were distributed.

American tree sparrow numbers fluctuated greatly, but there always were at least a few around. A common redpoll showed up one day and was gone the next. There also were rare appearances by white-throated sparrows.

I saw white-throated sparrows so seldom that I think they were wanderers rather than residents.

Though no red-winged blackbirds have shown up at Mayslake yet, I have seen them elsewhere in DuPage County and expect some at Mayslake any day. An equally sure sign of the transitional season was the arrival of this Canada goose pair at the stream corridor marsh yesterday.

Sure enough, the male had a band on his left leg. I take it that this is the same pair that nested successfully on the preserve last year. I saw no sign of the two surviving young that were with this pair the last time I saw them in the fall.

I am so ready for spring and the progression of migrants. Bring it on!

Fooled!

by Carl Strang

Yesterday I was gifted with a humbling lesson. On my lunchtime walk at Mayslake Forest Preserve I saw a string of fresh footprints in the shallow snow on the trail near the May’s Lake outlet.

My eye was drawn to the big, round-looking footprint lower left.

Mink, I thought: round looking, right size, 5 toes. The tracks led along the trail I was following. I was a little bothered by toenails that seemed a little too prominent, and the fact that this animal was following the trail rather than dropping down to the lake edge below. But I have followed mink over land before, and I kept seeing enough round looking footprints to shore up my mental image.

I decided to climb up and see if the local skunk had been out. Last week I found that the skunk-sized den entrance I first noticed last October near the friary (shown in this photo from a posting then)…

Freshly dug in October, the den entrance was around 5 inches in diameter: skunk sized.

…in fact was occupied by a skunk, which had begun to emerge in answer to February’s mating call. Yesterday the area around the den was well trampled, and there had been much coming out and going in.

Here is the same den, yesterday.

Some of the tracks looked suspiciously like the “mink” tracks I had been following. I went back down, and soon found these.

There was no denying that the footprints on the extreme left and right in this frame were those of a skunk.

As I returned to the place where I first had seen the tracks, I worried over how I had been fooled. Eventually I concluded that there were in fact several lessons. First impressions had been one factor. My eye had been drawn to the largest footprints, the round-looking ones. I failed to look closely at all the tracks. If I had done so, I would have noticed the unmistakable creviced, narrow heel markings characteristic of skunks.

I also learned about an unusual substrate. The footprints were in very shallow snow, much of it deposited over slick ice. Where the skunk had stepped on that ice, the toes had spread abnormally to produce those uncharacteristic, round-looking tracks.

Finally, I should have given more credence to those little doubts about the toenail marks and the animal’s following the trail rather than the lakeshore.

That’s the thing about tracking. There always is something new to learn. And it doesn’t hurt to be taken down a peg now and then, too.

Winter Plant Puzzle

by Carl Strang

Today we return to winter botany, focusing on four species that are connected to one another in ways that are instructive, if not obvious. All grow in the same spot, Mayslake Forest Preserve’s south stream corridor prairie. It’s a fairly low area, and is enjoying considerable improvement thanks to Mayslake’s volunteer restoration crew. Let’s start with the common water horehound.

This plant stands a foot tall or so, and likes its feet wet. The clusters of spiky fruits radiate out from spaced points along the stem.

Here is what it looks like when flowering.

The common water horehound is not an imposing plant in flower.

Next we’ll move on to yarrow. Here is its winter form.

The various species of genus Achillea figure prominently in the folklore of Europe and Asia.

And, in bloom:

Yarrow is an attractive plant. The leaves have a fernlike featheriness.

Finally, let’s take a look at mountain mint (two species occur in this prairie; they are so similar that the photos work for both).

One easy way of distinguishing the common and slender mountain mint species is by presence or absence of a strong minty odor and flavor. I found that the dried and shriveled winter leaves of the common mountain mint hold that flavor.

Their flowers are identical or nearly so.

The mountain mint flowering period goes on for a long time in summer.

OK, so I’ve shown you the three genera (for present purposes placing the two mountain mint species together). Now the question is, which two are most closely related phylogenetically?

Superficially the nod would go toward placing the yarrow and mountain mint together, because at first glance their overall shapes are very similar. As it happens, though, the common water horehound is in the mint family, and so yarrow (a composite) is the odd plant out. One feature that separates yarrow from mints in winter is that yarrow has alternate leaves, while mint leaves are opposite (visible in the above photos). Let’s finish by enjoying close-up looks at the dried heads of those two superficially similar plants. Yarrow first:

Winter yarrow heads look like beautiful little pale cones.

Now, mountain mint.

The perforated look of the little mountain mint heads reminds me of the larger ones of wild bergamot, which is yet another member of the mint family.

That may be it for this year’s installment of winter botany, unless we get some well timed fresh snow to provide a backdrop.

Stitching the Roesel’s Katydid Gap

by Carl Strang

I am pleased to report progress in our understanding of Roesel’s katydid, an immigrant from Europe that has become common in northeast Illinois. My previous update was last summer.

Roesel’s katydid is an early season, predaceous species. The yellow crescent on the side of the pronotum is characteristic, along with its distinctive song.

Scott Namestnik and I passed our observations of this species in much of northern Indiana on to Tom Walker, who operates the Singing Insects of North America website (SINA). Tom pursued some of his contacts in Ohio and hit the jackpot. One of them, Philip Chaon, has found Roesel’s in 4 scattered counties in eastern Ohio. Their placement renders the gaps in the species’ distribution small enough to make it seem likely now that Roesel’s is more or less continuous between northern Illinois and the Montreal area where the species first was found on our continent, and on to New Jersey and New Brunswick where published accounts have reported it. Tom already has added our observations to SINA’s map for Roesel’s.

I still intend to make a trip to Cleveland (and the Rock and Roll Museum) in the spring, spot checking for Roesel’s along the way, but now my search can be more targeted, and I will be surprised if I do not find them in the remaining gap counties. Also, as Scott has pointed out, we still need to see how far south the critter has spread.

Prehistoric Life 14

by Carl Strang

This year’s winter series is a review of the prehistoric life and geologic history of northeast Illinois. Each chapter will summarize current understanding, gleaned from the literature, of what was going on with life on Earth in a particular span of time, what we know about the local landscape, and what we can say about local life. I include some references, particularly to papers published in the journal Science which commonly is available at public libraries. Contact me if you need sources for other items. The Earth is so old that every imaginable environment was here at some point, from ocean depths to mountaintops, from equatorial tropics to tundra, and from wetlands to desert.

Cenozoic Era, Paleogene Period (65-23.3 million years ago), Paleocene Epoch (65-56.5 mybp)

The Cenozoic Era was named (1841) for the fossil life that characterized it, literally translated “recent life.” Formerly it was divided into two periods, the Tertiary and Quaternary, which no longer are recognized. In recent years it officially has been divided into two different periods, the Paleogene and the Neogene. A proposal under consideration would subdivide the Neogene, reinstating a Quaternary Period that would contain the most recent Pleistocene and Holocene Epochs. The Paleogene Period, established in 1866, defines a time when only a small portion of its fossil species or their very close relatives still are in existence today. It is subdivided into epochs, the first of which is today’s focus. The Paleocene Epoch, first defined in 1874, literally means “ancient recent.” Following Lyell’s original scheme of dividing the Cenozoic Era’s time according to percentage of marine fossil mollusk species still living, the Paleocene has none still living today.

Life on Earth. In New Zealand, researchers have found a heavy layer of fungal spores representing the first few years after the “Chixculub impact” that ended the Mesozoic Era and began the Paleocene (see below). Such abundant fungi performed the decomposition that followed a “wholesale dieback of photosynthetic vegetation” (and this was halfway around the world from the impact site). The fungi were followed by a burst of ferns, a delay then until conifers got going, then a greater delay to the recovered dominance of flowering plants (Science 303:1489). The largest vertebrate to survive the Cretaceous was the freshwater fish-eating reptile Champsosaurus, which survived to the Eocene in North America and Europe.

Imagine a world covered in fungi. That is the image we have of the Earth during the months to years immediately following the impact of the asteroid that marked the beginning of the Paleocene Period. Surviving animals had to be small sized and capable of living on fungi, seeds, or other small animals.

Plant diversity and insect diversity generally were much lower in the Paleocene than in the late Cretaceous, with interesting exceptions that indicate millions of years were needed to re-establish equilibrium in communities of plants and the insects eating them. For instance, in southeastern Montana a high diversity of plant-eating insects occurred on a low-diversity plant community, while another community in Colorado had high plant diversity but low insect diversity (Science 313:1112).

The warmth of the late Paleocene allowed narrow-snouted crocodilians to live in North America and Europe as far north as New Jersey.

The Cenozoic was the time when mammals came to dominate terrestrial animal life on Earth, with the greatest rate of evolution of new families and genera occurring in the early Paleocene. Australia became isolated in the Paleocene, cutting off the flow of marsupials from Antarctica and South America and setting the stage for the most significant marsupial fauna on Earth to evolve from then until recent times. However, North America remained connected to both Asia and Europe through the Paleocene.

Today’s marsupial-dominated Australian fauna, including this wombat, continue a legacy established in the Paleocene.

Paleocene mammals included the multituberculates, a primitive group now extinct, that had been the dominant Cretaceous mammal group. They reached their diversity peak in the Paleocene.

Early carnivore-like mammals, the creodonts (now extinct), appeared in the Paleocene of North America and Europe (with the departure of the dinosaurs, there was an open niche for predators of terrestrial vertebrates as the Paleocene began). True carnivores also emerged in the Paleocene, but the Carnivora of the Paleocene and early Eocene were relatively small and generalized predators, comparable to martens. Thus the creodonts were the significant predatory mammals of these times, rising to prominence in the late Paleocene. 

Another important Paleocene mammal group were the condylarths, a somewhat artificial order that gave rise to the ungulates and whales. The earliest condylarths were rat-sized, but they diversified and ultimately included enormous species. Most were generalized in diet, though some tended more toward herbivory and others were more carnivorous.

Treeshrews arose in the early Paleocene (Science 318:792). In the late Paleocene, new groups that appeared were order Perissodactyla (including horses in North America), bats (early bats were flying before they developed the echolocation ability: Science 318:1237), Edentata (in S. America), and rodents (in N. America). Unusually well preserved skulls of a species in the extinct family Apatemyidae reported in 2010 tie the primates to the rodents, treeshrews and flying lemurs.

Fossil bird, Field Museum collection. Modern birds came into their own in the Paleocene.

Out of the great diversity of early bird groups, only one (Neornithes, the modern birds) survived past the end of the Cretaceous. The modern orders of birds diverged during the Paleocene.

Local landscape. Our area may have been directly affected by the meteorite that struck the Yucatan area to end the Mesozoic era. There is evidence that the meteorite came in at a shallow angle from the south, and so scattered debris into North America. Our continent’s forests were flattened except in the far north and in refugia where mountains provided protection from the blast. A tsunami would have been funneled straight into the mid-American sea, and conceivably could have reached Illinois. After the time when photosynthetic vegetation was largely or entirely killed off, as mentioned above, much of the continent may have been “little more than a field of ferns” for up to thousands of years (Science 294: 1668-9) as surviving spores and seeds in the soil re-established terrestrial vegetation. Incidentally, astronomers are 90% certain that the source of the Cretaceous-ending meteorite was a collision between asteroids beyond Mars nearly 100 million years earlier (Science 317:1310).

Our area remained dry land throughout the Cenozoic, though the sea touched the southern tip of Illinois in the Paleocene and Eocene (leaving the nearest deposits for those epochs to here). The climate was warm, moist and tropical with little seasonality in the Paleocene. Tropical forests developed here after the recovery from the meteorite damage.

Local life. At our latitude in the Paleocene there were diverse ferns, ginkgoes, araucarias, palms, members of the walnut and birch families, dogwoods, chestnuts, oaks, sycamores, hackberries, elms, spicebush, sassafras, magnolias, and members of the grape family. Our forest would have been tropical, and evergreen or seasonally deciduous at different points in the Paleocene.

Later in the Paleocene, creodonts were likely here. The first large local mammalian predator was likely a cat-like creodont in the genus Oxyaena. Other creodonts showed adaptations for scavenging. Hyaenodontids were creodonts adapted for running, like dogs or hyenas.

There was an early North American group of primitive mammals, the Taeniodonta, resembling ground sloths but not related to them, that lasted from the early Paleocene to the late Eocene (widely distributed, but always rare; the genus Ectoganus probably was represented locally by a species in the 100-200-pound range).

Most known species of the diverse “order” of condylarths were North American. They were mainly omnivorous, though the most primitive one, Protoungulatum from the early Paleocene of North America and Europe, was more of a specialized predator. The majority, however, were ecologically more like raccoons or bears. Others were more on the vegetarian end of the scale, like pigs and peccaries. The widespread, sheep-sized Phenacodus, late Paleocene to middle Eocene, and its relatives are a good candidate as the ancestors of the Perissodactyla (odd-toed ungulates such as horses). Ungulates in the order Mesonychia tended to predatory habits, and among them were the largest mammals of the early Paleocene (10x the usual rat size). Later, still larger members of this group shared predatory dominance with the creodonts. Coyote-sized Dissacus occurred all over the northern hemisphere.

In the late Paleocene and early Eocene our area may have had a species of Coryphodon, a genus ranging through Europe, Asia and North America, possibly a swamp dweller with a generalist diet. These were members of the Paleocene-Eocene order Pantodonta, among the earliest post-Cretaceous mammals to attain large size. Species ranged from tapir- to ox-sized.

Multituberculates were important in nearly all Paleocene faunas in North America. They ranged from small mouse to beaver in size. An example is Ptilodus, a squirrel-like tree-dweller that probably was an omnivore (I think here of the scrat, the acorn-obsessed critter in the Ice Age animated films). Another North American multituberculate, Taeniolabis, was beaver sized and (unusual for the time) a specialized herbivore.

Early arboreal mammals in North America were primates or primate relatives similar to today’s treeshrews. A late-Paleocene genus, Plesiadapis, occurred in both North America and Europe. Another family culminated in the genus Carpolestes, possessing the only fingernails (as opposed to claws) known outside the true primates. Two families were lemur-like.

The fish-eating Champsosaurus, mentioned above, may have inhabited local rivers. There would have been a variety of birds, locally, too.

Savannah Sparrow Dossier

by Carl Strang

The species dossiers I have shared to date have contained plenty of information, but such certainly is not the case for all of my files. Today I share one of the more limited examples. Though I was surrounded by savanna sparrows in Alaska where I did my graduate research, my focus was on other species. These sparrows seem to be increasingly common in DuPage County as restored prairies continue to grow and improve, but I have not had the opportunity to do much more than see them here and there, and reminisce about the Alaska days when I hear their song.

Sparrow, Savannah

Known best from summers in western Alaska, where it was the only lowland tundra sparrow and was very common. Often their noisy early morning territorial squabbles on the tent frame roof served as our alarm clock.

7OC00. Two observed near Sea of Evanescence, Fermilab. After I flushed them, they flew to exposed perches.

22OC01. One among the cattails at Heron Trail marsh, South Blackwell. Streaks on the flanks are narrow and sharp, against a yellow background that contrasts with the paler color of the undersides generally; streaks on the upper chest not as distinctive. Yellow spot at base of bill clearly visible.

4MY02. For the second spring bird count in a row, I observed savannah sparrows at the Mallard Lake Forest Preserve parking lot, singing in the small planted trees in an otherwise open, short-grass area.

15SE02. A single savannah sparrow was in a sod farm field close to 3 buff-breasted sandpipers, the only birds on the ground anywhere near that spot.

12OC02. Savannah sparrows at edge of cattails beside extensive mudflat at the south end of Lake Law, Fermilab. A couple of them were out on the open mud, well away from cover. An American pipit approached them. One of them displaced the pipit, which immediately turned and chased the sparrow in a lengthy, twisting and turning flight that took them into the cattails.

Recent springs, Timber Ridge Forest Preserve. We usually find a few savannah sparrows around the farm paddocks and fields on the spring bird count.

Asters! Aargh!

by Carl Strang

Recently I tackled the identification of winter asters at Mayslake Forest Preserve. As I mentioned in the last of those two posts, I had some reservations about my conclusions. Fortunately my good friend, Indiana botanist Scott Namestnik, sent me a back-channel e-mail with some helpful comments about my admittedly shakiest ID’s. Thanks to the combination of a healing calf muscle and melting snow, I was able to get back to all the plants in question yesterday. I grabbed some chunks of plants and took them back to the office for close, bleeding-eyeballs study. (That image comes from Tom Brown, such language being one of his ways of passionately encouraging his students to push the envelope in tracking and other natural history studies). I conclude that the aster I called “hairy aster” in fact is another New England aster.

Not a hairy aster after all, this photo in fact showed a New England aster as Scott suspected. When I looked at the lower leaves I saw what I missed before, the characteristic wrap-around ears at the bases of the stalkless leaves.

The other species in question is the one I called panicled aster, the most abundant species on the preserve. I studied pieces of 8 or so different plants, and found that despite their superficial similarity there is enough variation to suggest they fall into at least two different species. Here is the photo I showed in the recent post.

This one remains puzzling.

Some of these asters are hairier than others. They also show a range of variation in the hyaline (translucent) edges of their phyllaries (flower head bracts). Though I would say that in none of them are the phyllary tips truly hyaline, as those of hairy asters should be, that may be a judgment call I am missing due to lack of experience. On the other hand, it is true that the hairier ones have more extensive hyaline edges to their phyllaries, and those edges come closer to the tips. Therefore I suspect that some may in fact be hairy asters. Others may be panicled asters. Still other species may be involved. This problem will have to wait until the next flowering season.

So, I am coming out of this experience feeling I got two-thirds of the species right, not bad for such a difficult group. More importantly, I know more than I did coming in.

Experiment on Self: Setback

by Carl Strang

Running is part of my identity. It saved me from couch potato chubbiness in Junior High, and it hurt emotionally when joint problems forced me to switch to bicycling as my main exercise several years ago. In two previous posts I described my recent return to running, made possible by trying a different, low-impact running technique that combines shorter strides with landing on the forefoot rather than the heel. As part of that process I have been experimenting with shoes designed for this “barefoot” technique. I slowly transitioned to the most extreme of these shoes, the Vibram FiveFingers.

I also bought a pair of Newton running shoes, designed for the barefoot technique but with slightly more heel elevation that does not demand quite so much from the plantar fascia-Achilles tendon-calf muscle axis, and I used these for longer and faster runs.

All was going well until two weeks ago. I decided to tack on an extra half-mile to the 4-mile distance that had become my standard in the FiveFingers. About a quarter-mile into the addition I felt a sharp pain in the center of my right calf muscle. I’d pulled something, and as I read my sports medicine references I became concerned that it might be serious. However, as I applied ice treatments, rested, compressed the muscle with an elastic bandage and elevated it whenever possible, I found recovery happening quickly. After a couple of days I could do bike trainer workouts without pain, and after a couple more I tried a 4-mile jog in my clunky old shoes and got through it fine, though at 500 miles I knew those shoes were at the end of their service. I tried the Newtons, but there was still a little pain. I decided to go back to the store and get yet another pair of shoes, the newly modified Asics gel-DS trainer 16’s.

Though a little heavier than the Newtons, and not specifically designed for the forefoot plant, these shoes didn’t stretch the calf painfully even when I used the barefoot technique. So I am back on track, literally as well as figuratively. I hope to get back into the Newtons in another week or so. Eventually when I have strengthened my calves enough I expect to try the FiveFingers again. I enjoyed their feel once I got used to it, and they are extremely light. If I were younger (I’ll be 60 in a couple months), or if I had realized I needed to build my calf strength even more, I probably would have had no problem. After all, I had run 100 miles in them altogether before getting that little muscle pull. It feels good, though, to have a range of shoes to draw on as my training resumes. In fact, recent runs have been so strong that I am thinking I may be able to do something I would not have thought possible a year ago: run a half-marathon before the end of this year.

Literature Review: Cricket Voyeurs

by Carl Strang

I have a final study to review from last year’s scientific literature. This was reported in Science, and was interesting enough that in addition to the technical paper itself there was an interpretive article (Zuk, Marlene. 2010. Dance like no one is watching, sing like no one is listening. Science 328: 1237-1238). Frankly I thought she explained the study more clearly than did the researchers themselves (Rodríguez-Muñoz, R., A. Bretman, J. Slate et al., p.1269-1272).

Our fall field cricket is a relative of the European species that was the focus of this study.

They monitored a population of European field crickets, Gryllus campestris, in the field with 64 motion-sensitive and infrared-reading cameras aimed at the crickets’ burrows. All individuals were marked and their genetics known. “Both sexes mated with multiple partners, and both left more surviving offspring when they had more mates.” Males were more variable in their reproductive output than females, but not because of differences in mating rates. The variability in success thus is tied more to something else, like variable sperm quality or higher quality offspring. One surprising result was “that the vast majority of individuals, whether male or female, did not successfully reproduce at all.” Despite the females’ ability to lay dozens of eggs, none had more than 10 surviving young, and only a couple males did so. Among males, the best fighters did not have greater fitness. This is good stuff, challenging a lot of assumptions and raising interesting questions for future study.

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