Saturday, December 22, 2012

Monarchs of Winter

I have been reading Winter World, by Bernd Heinrich.  It is a broad discussion, both scientific and poetic, of the ways creatures survive winter.  He covers not just hibernation and migration, but explores torpor, supercooling and animals' use of endogenous antifreeze.  It is a complex subject made clear and entertaining.

Monarch Watch
Typical of the new ideas he introduced me to was the nature of the migration of monarch butterflies.  Their wondrous sojourn for thousands of miles to a patch of mountain forest in Mexico is familiar to most of us.  How their great-grandparents, who left the area the previous spring transmit the location to them three generations later remains a mystery.  (Hint: it isn't Apple Maps or even Google.)

I had always assumed that they headed south to seek warmth, but this is only partially true.   Heinrich explains that migration, like hibernation, is more a matter of preserving energy while food resources aren't available.  They mass on the Mexican trees, hanging out for three months without eating, burning their fat much like a hibernating mammal.  Their stored energy as fat must last until food is again available.

Here is where temperature comes in.  They actually require cool temperatures rather than warmth. The area where most of our monarch population overwinters is above 10,000 feet where the temperature is close to but above freezing.  As described by Monarch Watch, they cluster together in a very specific ecosystem, on specific tree species on steep southwest-facing slopes.  In warm spells they may fly off to get a drink but otherwise they rest, conserving their precious energy.

Clustered Monarchs- Wikimedia
Temperature is critical, for reasons similar to the cooling we use in some heart surgery. Cool tissue uses less energy.  At 15 degrees centigrade (59 Fahrenheit) their energy stores will last 3 months, at 30 degrees centigrade, less than 10 days!  Activity such as flight further depletes their stores.

Knowledge of the details of migration is relatively recent.  Their lifecycle was proven by chemical analysis of their cardenolides, the toxic substance the larvae acquire from feeding on milkweed.  There are differences in the "chemical fingerprint" of the cardenolides.  Studies showed that the chemical found in wintering butterflies and those first heading north from Mexico was distinctive, produced only in milkweed plants from the Northern US and Canada.  Their wintering grounds weren't even discovered until 1975. 

Their spring migration northward is timed to the growth of milkweed food plants which their larvae require to develop.  Within a short time the eggs hatch, the caterpillars go through their instars and enclose (form a chrysalis).  When the adult emerges, it heads north to the next range of emerging milkweed, a procession not unlike the giant combines that follow the wheat harvest in the summer.

Come to think of it, we aren't so different as we adjust our thermostats and throw another log on the fire, seeking not warmth, but the perfect temperature to conserve our energy for the start of spring.

Thursday, December 20, 2012

Beetle Wood

Insects and fungi not only damage trees and break up downed wood, they also can provide decorative touches.  One of my favorites is the cyprus bark beetle which lays its eggs in some of our misnamed eastern red cedar which are actually junipers (Juniperus virginiana).  The larval grubs which hatch then burrow under the stringy bark, creating interesting tunnels filled with powdery frass (insect poop).  After brushing out the frass, you are left with a decorated branch, a ready made walking stick.

At other times, pealing away the cedar bark reveals a colorful staining, possibly left by a fungus.  In this case, it didn't tunnel or break the surface of the wood, leaving only its colorful pattern.

A similar phenomenon is produced by the blue stain fungus, Grosmannia clavigera, which is introduced into pine trees in the west by the mountain pine beetles.  This has turned into a major ecological disaster, wiping out massive forests of pine and leaving dead trees and the fire risk they create.
This fungus has created a new product which has become the hot new "must-have" for wealthy home owners.  The Wall Street Journal reports that the marbled blue-gray wood is now highly sought after for cabinets and paneling.  Now that huge areas are being deforested, removing the wood is not only beneficial to prevent fire, it is a growth industry in wood products.

The whole story of the interaction of the mountain pine beetle, Dendroctonus ponderosae, and the blue stain fungus, Grosmannia clavigera, is both complicated and much more interesting than just the blue wood it produces.  The fungus is integral to the beetle's success, so much so that the beetle carries it along between trees.

The fungus has developed a symbiotic relationship with the beetle.  It is transported in a specialized structure in the beetle's head.  Once the beetle bores into the wood, the fungus spores germinate and produce mycelium which fill the phloem and sap wood, the tree's vascular system, plugging it similar to blood clots in our vessels.  This not only starves the tree by blocking the flow of nutrients but it also blocks the production of resin which would otherwise inhibit the beetle larvae.

Recent studies have "identified genes in Grosmannia clavigera that are responsible for the fungus's ability to bypass the lodgepole pine's natural fungicide -- and use it as a carbon source for fungal growth."  This co-evolution is an interesting mechanism which has led to disastrous consequences in our western pine forests.

Monday, December 17, 2012

Hairy Vines

This is the time of year when the beautiful red leaves of the poison ivy and Virginia creeper have fallen off, leaving the hairy vines alone as they climb the trees.  Ordinarily I depend on the clusters of three leaves to identify poison ivy.  Virginia creeper generally has five leaves which serve as hosts to several sphinx moths and small blue fruits for songbirds to enjoy so we don't want to disturb them.

Poison ivy berries are also a healthy source of bird nutrition.  At least one source recommends that when controlling or eliminating it that you leave a few for the birds.  While a very wildlife friendly suggestion, remember that birds that eat the seeds also serve to deliver them all around.  On our land poison ivy isn't threatened with extinction unless Barb finds it.

Virginia Creeper- Jim Mason*
Poison Ivy- Jim Mason*

Now that firewood cutting is in season, differentiating the vines becomes crucial.  Many of the dead or fallen trees are festooned with grape vines or Virginia creeper with poison ivy intertwined, trying to look innocent.  Large poison ivy vines may not even have visible leaves at ground level, while sprouting large clusters of tree like leaves high up.  Separating the ivy from the creeper is critical to maintaining a healthy, itch-free complexion.

The "hairs" of the two vines may look similar but they are quite different.  Poison ivy (Toxicodendron radicans) has thin aerial roots which attach to the tree by penetrating the dead outer layer of bark.  These are adventitious roots which in some other species are capable of extracting water and nutrition without being in the soil.  Poison ivy aerial roots simply cling harmlessly to the tree and do not function as extractors.  Although they seem to invite touching, don't, as they contain urushiol, the same toxic oil as the leaves and sap, all of which cause the same itching and blistering reaction.

The "hairs" on Virginia Creeper are actually tendrils.  The story of tendrils is the subject of another future blog.  They are modified leaves, petioles or stems adapted to climbing by wrapping around upright host plants. provides these details.
"Like the wild grapes to which it is related, Virginia Creeper produces stem tendrils, but their branched tips form into flat disks that produce a sticky substance. Once the mucilage dries and anchors the disk, the tendril coils contract and pulls the vine closer to its support (below right). This grasping mechanism is so powerful that Virginia Creeper can adhere to tree trunks, cliff faces, brick chimneys, and even plate glass windows. It's no wonder that Virginia Creeper often grows just as tall as the tree that supports it, and that it thrives in hardwood forests where trees are allowed to mature."
Now look again at the pictures above.  The fine hairy aerial roots of poison ivy are somewhat distinctive.  That said, it is best to avoid handling any hairy vine if you can't see the leaves, unless you are "itching" for trouble.

*Jim Mason, Naturalist at the Great Plains Nature Center in Wichita, Kansas.  More of his pictures and information are at

Another site with pictures of look-alikes is at

Monday, December 10, 2012

Liberalized Deer Hunting

Wikimedia Commons
Alan Keller sent me a link to an interesting story on Slate, Hipsters Who Hunt.  In it, Emma Morris describes the gradual conversion of "lefties," a term used respectfully, to hunting deer, duck and other wildlife and then eating same.  Happily there is a growing interest in "nature" and preserving our environment.  We have watched as more urban gardens and chicken houses crop up around our cities.  In some cases we even feed deer some of the produce we intended for ourselves.

When Master Naturalists start orientation, there are always some who are wary of hunting and trapping wild animals.  Understanding that our ecosystem requires management isn't the first thing you think about in conservation.  It can take some time to understand that the food web is part of our natural world.

What could be more "natural" in this world than deer hunting?  Our forefathers depended on wild game, dating back to when we were running around on the savana.  The evolution from clubs to spears, atlatl, bow and arrow, and eventually guns came from the need to put food on the table, even as they morphed into protecting our food sources from other fellow bipeds.

We know by now that for many of the species crowding into our urban spaces, we are the main predator and we frequently aren't doing a very good job of it.  Several years ago in Joplin, half the deer died of hemorrhagic disease in a season, the effect of crowding, lack of habitat and overpopulation.  Judicious hunting within the regulations spawned by population management would provide food on the table as well as healthier deer populations.

Eating corn fed beef (disclaimer- I do too) isn't any better for the environment- remember all that methane coming out of the other end of your friendly filet producer.  Also there is a lot of petroleum that goes into producing the corn they consume.  There isn't enough deer or grass fed beef to feed all of us but at least venison deserves a place at the table.
You will know when the trend matures in the Ozarks when you see a hunter like this one pedaling down Glenstone.  Meanwhile, read up on the growing interest in "Green Hunting" at Hipsters Who Hunt.

Friday, December 7, 2012

Versatile Pitcher Plants

Pitcher Plants- Wikimedia
Pitcher plants are pretty incredible.  They are carniverous just like venus flytraps and Audry in Little Shop of Horrors.  Their long tubular leaves shaped like a test tube and produce an enticing liquid nectar at the bottom of the cup.  There is a curved lid-like structure  covering the tube to prevent rain from diluting the nectar.  Insects are drawn to the slippery rim and fall in, only to drown and then be digested by bacteria in the plant's juices or by mutualistic insect larvae living there.

That was the story when I was in school, enough to excite a young boy to having fantasies of dropping ants in and hearing their tiny screams.  Now several new findings- stranger than fiction- show just how versatile these plants can be.

A report in Natural History Magazine describes a species named Nepenthes gracilis which has an important modification.  The underside of the lid is coated with particles that allow an insect to crawl on it.  When rain hits the lid, it loses its grip and takes the fatal plunge.

Even more incredible is a report from of a species of giant mountain pitcher plants (Nepenthes rajah) of Borneo.  In a territory notably devoid of restroom facilities, it has filled a niche by becoming a toilet for shrews and rats.  

The underside of its curved lid produces an enticing nectar which the tree shrews (Tupaia montana) and summit rats (Rattus baluensis) lick up while standing over the open tubular leaf.  As mammals are wont to do, they occasionally defecate as they eat, their feces dropping to the bottom of the pitcher plant.  

Researchers set up cameras on selected pitcher plants and recorded the mammals' toilet activities.  They also collected droppings for 61 days.  (What the researchers told their children that they did for a living isn't recorded.)

The plants received their fecal snack on an average of every 3.4 days.  The nitrogen-rich feces provides the plant the nutrition it requires because of the otherwise nutrient-poor, acidic soils .  
"To learn how the pitchers attract rats and shrews, the researchers analyzed the milky substance secreted by pitcher lids. The team found more than 40 aromatic chemicals, including some commonly found in fruit—the mammals’ usual fare."
Apparently the mammals are conned into licking the chemicals without getting nutritional value.  But hey, where else can you find a clean restroom in the jungle?

Wednesday, December 5, 2012

Wilderness Comes to Town

A new book by Jim Sterba called Nature Wars: The Incredible Story of How Wildlife Comebacks Turned Backyards into Battlegrounds has received a lot of attention recently.  It focuses on the wildlife invasion into urban areas like we are facing in Springfield with deer.  There are even an estimated 2,000 coyote in Chicago alone.  While we are justifiably concerned with the accidental shooting deaths of 100 deer hunters a year, he points out that 250 people each year are killed in deer-vehicle accidents with another 30,000 injured.

Sterba's article opened my eyes to an unappreciated expansion of forests.  We usually think of woodlands being threatened by urban sprawl and housing developments.  Indeed, these trends are causing a lot of habitat fragmentation around our local counties.  On the other hand, it turns out that there has been dramatic reforestation occurring since the original agricultural clearing of land by early European settlers.  As Sterba writes in his Wall Street Journal article America Gone Wild,
"Today, the eastern third of the country has the largest forest in the contiguous U.S., as well as two-thirds of its people. Since the 19th century, forests have grown back to cover 60% of the land within this area. In New England, an astonishing 86.7% of the land that was forested in 1630 had been reforested by 2007, according to the U.S. Forest Service. Not since the collapse of Mayan civilization 1,200 years ago has reforestation on this scale happened in the Americas, says David Foster, director of the Harvard Forest, an ecology research unit of Harvard University. In 2007, forests covered 63.2% of Massachusetts and 58% of Connecticut, the third and fourth most densely populated states in the country, not counting forested suburban and exurban sprawl (though a lot of sprawl has enough trees to be called a real forest if people and their infrastructure weren't there)."
We certainly have experienced this in the Ozarks.  Following the timber harvests in the late 1800s and the suppression of natural and set fires, the previous balds and sparsely treed savannas described by Henry Rowe Schoolcraft have become covered with the dense woodlands and cedar forests we see today.

Click to enlarge
In Missouri we tend to think of the forests as the Mark Twain National Forest, but in fact of the 14,000 million acres of our forested land, 85% is privately owned.  This is true across the country as seen on this forest ownership map from the Private Land Owner Network.

Much of the early short leaf pine forest is now replaced with deciduous forest and our challenge now is maintaining quality growth.  A truly mature forest takes 150 years to develop on its own so it takes time and money to speed the process up by timber stand improvement and other management techniques.

We will be coming back to visit some of Sterba's ideas later, but meanwhile, I would recommend reading his America Gone Wild article which is available here.

Monday, December 3, 2012

Resident Canada Geese

Geese at Close Park
Ever wonder how we got so many Canada geese that don't seem to know where Canada is located?  You know, the ones you see on local ponds like Lake Drummond at Close Memorial Park.  The ones that poop all over the sidewalk and chase you if they think you might have bread for them.

I was told years ago in Rochester, Minnesota that wounded or deliberately injured geese were used as living decoys in the early 1900s and lost the ability to migrate.  It appears that this story is only partially true.

The giant Canada goose subspecies, Branta canadensis maxima, was a common species in the Upper Midwest before settlers arrived.  Wetlands were drained extensively to develop rich crop land.  Illinois has lost 90% of its wetlands including the 60 mile area around Chicago which is now rolling farmland.  There was also unlimited hunting of these large birds.

One could say they were "sitting geese" In addition to being big and juicy targets, they do not migrate and tend to adopt a body of water as home.  Because of this they could be depended upon to return to the scene of a hunting crime against their relatives, a hunter's dream.  As wetlands disappeared, they ran out of habitat.  By the 1950s they were thought to be extinct.

Dr. Harold Hanson of the Illinois Natural History Survey identified the geese that wintered on Silver Lake in Rochester, Minnesota in 1962 as giant Canada geese.  With controlled hunting regulations, additional man-made habitat and migratory bird regulations protecting their nests and territory, they have flourished.  This is a heart warming conservation success story unless they are filling your favorite pond.  
"Since its rediscovery, the giant Canada goose has recovered more quickly than any other subspecies and now makes up the bulk of our resident goose populations. There are estimated to be as many as 1 million giant Canada geese in the Mississippi flyway, as many as all other Canada geese subspecies in the flyway combined."  Illinois EPA
How did this happen?  In addition to the protection of hunting regulations, we made them our tame pets.  They are herbivores and can survive on a wide range of corn, grain and grasses, but who hasn't seen a family with a loaf of bread feeding the geese down by the lake as the flock gathers around to enjoy an urban treat.  Our ponds are safe havens with few of the usual predators such as coyotes.  Their eggs are even safe from all but the most aggressive predators and migratory waterfowl laws protect their nests from human disturbance.  They can be aggressive when they feel threatened, intimidating even the neighborhood dogs.  In short, they have it real good.
"Canada goose "paradise" would include acres of short tender grass, a freshwater pond for drinking water and security, and no predators. It would look much like a public park, corporate office campus, golf course, cemetery, or waterfront yard. However, while other Canada goose subspecies are wary of humans, giant Canada geese are predisposed to ignore people. The biologist who rediscovered the giant Canadians noted that the "placid disposition of the giant Canada goose sets it apart from all others."   Illinois EPA
Back to the living decoy story, there is some truth to that.  Eastern states such as New York and Massachusetts imported giant Canadian geese for hunting.
"The second is the resident population: descendants of captive geese used by waterfowl hunters. When live decoys were outlawed in the 1930s, many captive birds were liberated. With no pattern of migration, these geese began nesting. Lawns at houses, golf courses and mowed parks, well-watered, fertilized and bordering water, provided an excellent source of food. In suburban areas, there were few predators. The habitat for grazers was perfect."
This is summarized by the words of Jim Sterba in writing in the Wall Street Journal:
"Commercial and sport hunters long kept live birds (in addition to wooden facsimiles) as decoys to lure migrating waterfowl.  The use of these live flocks wasn't outlawed until 1935.  They hadn't migrated in generations.  The outlaw birds were used to stock newly created refuges in the hope that they would join migrating flocks and help them to grow.  But they stayed put.  Their descendants include the four million or so resident Canada geese that now occupy golf courses, parks, athletic fields, corporate lawns and airline flight paths."   America Gone Wild