Monday, June 22, 2009

Solstice Bounty

On solstice Sunday I set off to do some errands and meander country roads. Before I went a half mile, I saw these bumble bees (probably Bombus impatiens according to my bee consultant) and a lone male Monarch Butterfly (Danaus plexippus) feasting on nectar in a patch of Common Milkweed (Asclepias syriaca). Later, at the entry to the hardware store, I feasted my eyes on flats of annuals, blazing in every color. On my way home, sweet local cherries at a roadside stand made for another kind of feast! It occurs to me that we have insects to thank for so much beauty and bounty in our world.
Our native pollinators like bumblebees, solitary bees, flies, wasps, beetles, butterflies and moths are important to the production of many crops, including sweet cherries. All grasses, many trees and other plants depend on the wind to distribute pollen. But up to a third of the foods that make up our diet depend on insects for pollination including apples, almonds, blueberries, broccoli, cucumbers, peaches, soybeans, strawberries, kiwis, melons, onions, pears, plums and squash. More than half of the fats and oils in our diet owe a debt to insect pollinators.
Certain bats and birds also go after the nectar in flowers, and by doing so, spread pollen. But insects far outdo them. The annual value of the services of native pollinators to U.S. agriculture is estimated between $4.1 and $6.7 billion. Flowering plants provide food not only for humans, but also for animals that in turn provide us with milk or meat. Without our wild pollinators, it is questionable whether humans could survive. Entire ecosystems rest on the relationship between plants and pollinators.
How flowers and insects co-evolved is a fascinating subject. Those plants that depend on wind for pollen dissemination must produce vastly more pollen than those plants that have helpers in the process. Plants have developed colorful blossoms, enticing scents, alluring shapes, and graphic markings to attract these helpers. For example, orchids are famous for their mimicry of female insects of a variety of species. They are able to lure male insects by their odor and appearance. Some plants are pollinated only by one particular species of insect. For example, Darwin predicted that the Comet Orchid of Madagascar, with a deep, seemingly inaccessible nectar source, would have an insect pollinator adapted to reach it. And eventually that insect was identified: a moth with a proboscis that unfurled to awesome proportions.
Biologists tell us that worldwide pollinator populations are waning at an alarming rate. Here in the U.S. more than 50 pollinator species are listed as threatened or endangered. They suffer from the loss and fragmentation of pollinator habitat and the overuse of pesticides.
It would be impossible to replace all the services of native pollinators with those of managed bees. Colonies of bumblebees and honeybees are used commercially in agriculture but are increasingly threatened by disease. Escapees may be spreading disease to native bees.
Anyone who owns property, has a tiny backyard garden, or even a balcony can assist in maintaining habitat -- food, water, shelter and nesting materials--for native pollinators.
When I learned about the importance of native pollinators it underscored how every part of nature is connected to everything else. Now I know that each scrubby pasture, overgrown roadside, or weedy vacant lot is not unproductive. It is home and pantry to multitudes of tiny lives that are crucial to our own existence.

Friday, June 19, 2009

Deceive and Perceive

One type of animal camouflage is known as cryptic coloration. The colors of the animal mimic its habitat to fool the eye of predators or prey. Matching patterns of dark and light in order to blend in with the natural play of shadows, lines and textures in the environment is a highly effective strategy. Predator and prey have co-evolved in their abilities to perceive and deceive one another.

This young black rat snake Elaphe obsoleta obsoleta was coiled on the back of a wrought iron chair in the gazebo of our rented house in Great Cacapon WV this past weekend. My daughter entered to set the table for our evening meal and had quite a surprise. The snake makes a nice addition to the floral design, don't you think? However, my son-in-law removed the snake before we sat down to eat. I would imagine humans' ability to see snakes despite their attempt to camouflage themselves would be an important evolutionary advantage!

A childhood experience that made a big impression on me was the late summer evening when my father asked who wanted to accompany him on the short drive down to our small pumphouse. My younger sister and brother eagerly jumped up to go with him, but uncharacteristically for me, I hung back, preferring to stay on the porch with my mother. When my father returned he had a story for us. While my siblings had fumbled at opening the heavy car door, my father started toward the pumphouse. Directly in front of him were two stumpy mottled sticks lying across the path. Just before stepping on them, he realized what they were--a pair of copperhead snakes out for their evening hunt, or perhaps mating, but now attempting to camouflage themselves in the waning light. My father pointed out in a serious tone that if I had joined them on the errand, I may have jumped out more quickly than my siblings and encountered the snakes before he did. I believe this was the first time I grasped the meaning of the word "fate."

I don't remember if my father killed those particular snakes, but we frequently encountered copperheads, black snakes, and tiny ringneck snakes when I was growing up in Maryland. Sometimes the poisonous copperheads and even the larger of the nonvenomous black snakes (often 5 or 6 feet long) were slain if they encroached near our mountainside home. Mostly they seemed to stay in the nether region of overgrown briars and poison ivy between the driveway and the public road.

Our German Shepherd "Rinnie" would kill a snake by repeatedly grasping it in his mouth,violently shaking it from side to side, then flinging it away through the air.. He seemed able to avoid its jaws by this method. One time however, he was bitten on his paw by a copperhead. I remember pleading with my father to take him to the veterinarian as Rinnie began to show the effects of the venom. I rode along to the doctor's office in the back seat of our car with the dog's head cradled in my lap. Rinnie survived to hunt copperheads another day.

Despite the presence of these creatures, my siblings and I ran freely around the meadows and woods of our country property. For a while my older sister kept a milk snake in what I remember as a tall finely crafted wooden case with glass windows and a hinged door that latched with a metal clasp.

The local folk lore said that black snakes were a good thing to have around your house-they kept copperheads away. I don't know if this true. I do know they make pleasant pets, except for the problem of feeding them live prey. It would have been nostalgic to have caught the little rat snake for the enjoyment and study of my 4 year old grandson (and my own), if only I still had that beautiful wooden case. I do prefer to leave wild things wild and study them in their natural habitat.

The other photo is a Fowler's Toad Bufo fowleri seen at Eidolon Nature Preserve. It blended in perfectly with the leaf litter. My eye and camera snagged it only because it moved and disrupted the camouflage pattern. B. fowleri uses its earth toned skin to elude predators such as birds and small mammals. Like other toads, it can also release a foul liquid from the 'warts' on its back to irritate a predator's mouth. Another survival tactic it might use is to play opossum-it will lie belly up as if dead.

The genius of crytic coloration is the cuttlefish, a relative of the squid and octopus. It has special cells in its body that can change in color, pattern and texture almost instantly to mimic the variety of surfaces it encounters on the sea floor, allowing it to merge seamlessly with its surroundings. It has a very complex brain in order to control the up to 20 million cells that produce these optical illusions.

Wednesday, June 10, 2009

Friendly Ferns

Herbert Durand's Field Book of Common Ferns, 1928 opens with:

To All Who Follow the Long Brown Path

Here are fifty fascinating ferns of the wild, whose ancestry antedates Adam by unnumbered eons, and whose myriads of fair and friendly children await your coming in every field and every forest, by every stream and on every mountain. Their ways are truly ways of pleasantness and the path to their dwelling place is a path of perfect peace. May this unpretentious Field Book of Ferns spur you to follow this path with eyes opened to the exquisite beauty that greets you on every hand

These friendly children greet visitors to Eidolon Nature Preserve in Morgan County, WV.
Clockwise from top left: Common Polypody, Ebony Spleenwort, Sensitive Fern, Bracken Fern, Rock with Southern Lady Fern. Durand writes that Spleenworts were so named due to the belief in their ability to treat diseases of the spleen, and that Common Polypody was a favorite remedy for the 'blues' and for 'fearsome and troublesome' dreams and nightmares. I call these ferns 'heavenly.'