Monday, June 04, 2018

Environmental Forensics

Anasazi Indian petroglyph. 
"Every contact leaves a trace." Those are the words of French criminologist, Dr. Edmund Locard, regarded as a pioneer in forensic science. Regarding a criminal, Locard stated, "Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him." Fingerprints, footprints, hair, fibers, scratches, broken glass, all of these are factual evidence, however trace they may be.  A prized piece of evidence is the fingerprint. Like DNA, each human has a unique print, a unique pattern of arches, loops, and whorls. Get a good fingerprint at a crime scene and you have identified a criminal.
There are traces of human contact in the desert southwest. There, the Anasazi Indians marked their dwellings. Some marks were fingerprints impressed in the mud chinking, others were red and white handprints slapped on high rock walls. One mark that appears regularly across the barren, silent landscape is a single whorl, carved in stone or painted onto rocks.
Today, there are green lawns in this desert landscape, apparently a sign of wealth and prosperity, but closer inspection reveals that the lawn is sprayed with a water-based green paint. Lawn dye. Grass paint. Who would have thought? From all appearances, it is a lush, prosperous lawn, but that is not the case.  
This leads to a realization: When we measure the condition of the landscape, it is valuable to compare the current wildlife condition, its population and range, to that which existed in pre-settlement days, what is sometimes called Pre-Columbian North America. This means that we need to look at what we see and what we don't see. 
What we see: Looking across the vast agricultural landscape today, the wealth of mammal and bird stock may lead one to conclude that the current condition is a thriving animal community, vigorous, teeming, healthy. But, upon closer inspection, we find that the fauna is dominated by domestic and introduced animals. In the United States, for example, there are about 95 million cattle, 68 million pigs, 5 million sheep, 9 billion chickens, 230 million turkeys, and, we might add, 120 million housecats and 90 million dogs. This list does not include the millions of Norway rats, city-dwelling mammals that appear to have assumed the role of a keystone species in the current commercial ecosystem and which are now quite able, through natural selection and the wonders of a sturdy western diet and untreated hormonal waste, to attain to the size of a healthy newborn human. We assume that the breast meat accounts for most of this weight. Nor do we mention concentrated animal feeding operations used to raise these animals. 
What we don't see: The majority of the original North American herds and flocks are, in comparative reality, extinct. In a previous blog we tallied some of the Pre-Columbian herds and flocks. The archetypal example is the American bison. Numbering some 40 million animals, it once had a range of 4,500,000 square miles, from Mexico into northern Canada, the Great Basin Desert to the Appalachian Mountains. Today, 500,000 bison occupy about 55,000 square miles, about 1.2% of the original range, all of which is in preserves, ranches, and other confined space, and "in no place express the full range of ecological and social values of previous times" (Sanderson, et. al, 2008). This map is from Willliam Hornaday's The Extermination of the American Bison, published in 1889. The whorls of colored lines show the gradual collapse of the herd. At its nadir, only 541 bison remained. This was not natural selection at work. 
Similar maps can be presented for hundreds of other mammals, birds, reptiles, amphibians, fish, and plants that have experienced an extreme reduction in population and range over the past 250 years.
There is a lesson in this: Just because a plant is green does not mean it is thriving. The same is true with natural ecosystems. Just because it is green or because it is teeming with animals does not mean it is thriving. The abundance of vegetation or animals alone does not indicate the actual condition of the landscape.
This becomes a pattern. As bison are a component of a herd, the herd is a component of an ecosystem. Thus, as falls the bison, so falls the prairie. Similar maps can be presented for many ecosystems that have experienced an extreme reduction in range over the past 250 years. Tallgrass prairie, prairie potholes, Great Lakes alvars, Oregon wet prairies, California vernal pools. It is difficult to project that the commercial ecosystems that have displaced the native ecosystems will escape the same retraction of range, given that they depend upon natural resources in one way or another. This concentric line pattern has become our collective fingerprint, the anthropogenic signature.
Meanwhile, research led by scientists at the University of Wyoming showed a 2% reduction in the size of trophy horns and antlers for 14 species of big game in North America. The study attributes this to hunting selection for trophy male animals (Monteith, et. al., 2013). While considering that fact, we are confronted with a complication: in certain parts of the United States, the illegal taking of wildlife now equals or exceeds the number of animals taken legally (Musgrave, et. al., 1993). This is not natural selection at work.
So this proves to be a volatile mixture. The ability to degrade our environment coupled with the willingness to break laws governing our environment, both man-made and natural, results in a precipitous decline of individuals, groups, and systems. That is to say, as a species, we have left our fingerprint: A series of concentric rings around an empty space. 

Musgrave, Ruth S., Sara Parker, Miriam Wolok. 1993. The Status of Poaching in the United States - Are We Protecting Our Wildlife? Natural Resources JournalMonteith, Kevin L.,  Ryan A. Long  Vernon C. Bleich  James R. Heffelfinger  Paul R. Krausman R. Terry Bowyer. 2013. Effects of harvest, culture, and climate on trends in size of horn‐like structures in trophy ungulates. Wildlife Monographs.