Life & Energy

Life, whether in the form of a single-celled organism or a human being, might be defined as the capacity to harness energy for the purposes of constructing and maintaining vital tissues and sustaining metabolic processes.  From the moment of conception (or budding in asexual life forms), energy must be acquired or generated to permit survival; depending on the organism, it is needed to fuel growth, cellular diversification, physiologic processes and mobility.

Bacteria and other unicellular organisms are able to "ingest" nutrients through their cell walls while photosynthetic algae and plants utilize solar energy to fuel their metabolism and growth.  Fungi recycle nutrients from decaying plants and animals and some deep sea invertebrates feast on bacterial mats that form on the flanks of sulfide-spewing hydrothermal vents.  Complex marine, freshwater and terrestrial food chains consist of producers (plants or algae), primary consumers (herbivores) and secondary consumers (carnivores); of course, a series of carnivorous activity leads to the top predator in each chain (e.g. mosquito, dragonfly, frog, snake, hawk).

Energy flows through these food chains, stored for periods of time in certain tissues (fat, glycogen, starch, bulbs) but eventually recaptured by scavengers and fungi when injuries, illness, predation or natural aging lead to the death of plants and animals.  Prior to death, living organisms transfer energy to the environment via heat production and in the organic waste that they produce; they may also lose vital nutrients to parasites.  While this cycle of energy and life is easily observed and readily accepted in nature, we humans often reject the fact that our own lives, from conception to death, reflect this universal process.  We are, in fact, transient conduits of energy.

A Stranded Duckling

Over the past two decades, I have made hundreds of visits to Eagle Bluffs Conservation Area, in Central Missouri, and have never failed to be inspired by its beautiful landscape and superb diversity of wildlife.  But nature offers both beauty and tragedy and, this morning, I was dismayed to observe a stranded duckling, swimming along the marshy edge of a floodplain pool.

The young wood duck may have prematurely left its nest box; however, he appeared well-developed and his siblings would surely have followed.  Perhaps he became separated from his mother and her brood but wood duck moms are very attentive.  This leaves the possibility that his mother was killed and that he is the sole survivor of her brood, the others picked off by water snakes, snapping turtles, great blue herons, mink, coyotes or bald eagles.

Few animals are as cute as a duckling and many humans would be inclined to rescue this youngster.  Naturalists, however, understand that it is best to minimize our impact on nature and that her cycle of life includes the death of young creatures.  A stranded duckling, sure to die without the guidance of his mother, is vital to this fabulous ecosystem, as important as the majestic eagles that survey its realm.

The Asian Carp Invasion

On my walks around Landen Lake this week (a small suburban lake north of Cincinnati), I have been repeatedly reminded that the Asian carp invasion is a significant problem throughout the Mississippi River watershed.  Introduced in the 1970s to control aquatic vegetation and to filter sewage water, they escaped containment areas during floods and have spread throughout most of the U.S.  Favoring shallow, sluggish waters, they often attract our attention as they thrash about, their dorsal and tail fins breaking the surface.

Represented by four species (grass, black, silver and bighead carp) these large fish are very prolific and soon dominate the aquatic ecosystems that they colonize; black carp, which feed on mollusks, threaten native snail, mussel and clam populations while the others reduce the availability of plankton and vegetation vital to native fish, amphibians and aquatic reptiles.  As video enthusiasts know, silver carp also pose a threat to boaters, jumping into the air (and into boats) in response to the sound of outboard motors.

Concerned that Asian carp will enter the Great Lakes and disrupt the ecology of their fisheries, efforts have been made to block carp migration along canals that connect those Lakes with streams of the Mississippi watershed; "electric fences" have been used with some success but carp also spread as eggs or fingerlings on boat hulls, via the use of live bait, during floods and perhaps even on the legs of wading birds.  Taking advantage of the carp bonanza, some companies are culling them to produce pet food or fertilizer; vultures also partake of the bounty, feasting on dead carp that were stranded by shrinking lakes or rivers.

Counting on the Coast

Today was designated Global Big Day by eBird, an effort to assess the health and diversity of avian populations across the planet.  Since we planned a morning visit to Mendocino Coast Botanical Gardens, just south of Fort Bragg, California, I decided to submit my observations from that location.

As we walked through the fabulous gardens, more birds were heard than seen but the wide diversity of foliage attracted an excellent variety of species; in addition, since the gardens extend to cliffs above the Pacific, a number of sea birds were observed.  Highlights of the morning count (which totaled 30 species) included pigeon guillemots, pelagic cormorants, Allen's hummingbird, olive-sided flycatchers, Steller's jays and a large number of white-crowned sparrows.  While my contribution to Global Big Day was modest, I was honored to participate and certainly enjoyed the experience.

South of the Gardens, we visited a magnificent sand dunes ecosystem at Manchester State Park and enjoyed a long, scenic hike to sea cliffs at Salt Point State Park.  Sea fog slowed our journey to Jenner where we turned inland, climbing along the beautiful Russian River; passing through the Coast Range, we escaped the fog and settled in a hotel room along Route 101.  Tomorrow we plan to visit the Point Reyes National Seashore before heading into San Francisco.