Archive for the 'Durango Herald' Category

Benefit from the Natural World

Saturday, February 21st, 2009

Benefit from the Natural World

© Richard Grossman MD, 2009

There is a fountain of youth, and it may be very close to you. A remarkable new study shows a way to prolong life.

People who live near green space live longer than those who live surrounded by treeless city. Research from England describes the value of green space. This careful study controlled for potential confounding factors. The researchers looked at the death rates of over 40 million people during a five-year period and found that people were less likely to die if they lived near green space.

The authors hypothesize that green space, defined as “open, undeveloped land with natural vegetation,” promotes health by encouraging exercise. Indeed, it is estimated that every hour of physical exercise prolongs a person’s life by two hours. This study’s authors also theorize that green space is psychologically and physiologically restorative. Being in nature can promote relaxation and lower a person’s blood pressure. Presumably, it is the tranquil vistas, pleasant odors and the sounds of nature that are pleasing and beneficial.

Of these two factors, the researchers felt that exercise is valuable, but relaxation is even more important. There is a possible third factor that they did not mention, however.

A couple of years ago a news release puzzled me. It stated that people in some of Colorado’s highest counties were the longest lived in the whole nation. At first, this report didn’t make sense, since life is arduous in the high, cold mountains. Then I learned the importance of air quality; put simply, bad air kills. Very fine particles in the air, such as from diesel exhaust, are serious contributors to heart and lung disease. Presumably people who live at altitude breathe purer air and are poisoned by fewer of these tiny particulates. This may be why they approach Methuselah in longevity.

It turns out that plant life helps filter out air impurities. Particles settle on plant surfaces, and then are washed to the ground by rain. In addition, vegetation absorbs some impurities and makes them harmless. This may be a third way that green space helps people live longer. Promoting exercise, promoting relaxation and purifying air are all important rôles for the natural world, even though they are poorly recognized by our capitalistic system.

Business and politics attach little value to undeveloped natural resources. The above study illustrates how valuable land with natural vegetation really is. There are many other examples of how the natural world benefits mankind.

New York City learned the value of environmental resources when its water quality deteriorated. Its water comes from the Catskill Mountains, where natural processes had always purified the water. With the growing human population, the streams and lakes became contaminated by agricultural runoff and sewage. The City considered building a huge water purification system, but found that it was much less expensive to rehabilitate the watershed. By purchasing more land and cleaning up the pollution they regained pure water, saved money, and avoided the continuing cost of running a decontamination system.

Honey bees (Apis mellifera) are appreciated for their sweet product. The value of the honey produced in the USA is about $150 million each year. We benefit from bees in another way that is even more important. These little insects are invaluable for pollinating crops. The worth of this service has been estimated at $15 billion annually—one hundred times as much as honey production! We are starting to realize how truly helpful bees are now that they are disappearing for mysterious reasons. The impact on agriculture—and on natural vegetation—will be tremendous if this loss continues.

Closer to home, beavers (Castor canadensis) are seldom seen, but their dams and lodges are common. They almost became extinct in the American west during the 19th century when they were trapped for their fur. Without beaver ponds to hold water, stream beds washed out, resulting in floods and droughts. The dams and ponds create fertile bottom land and help purify water by filtering out impurities. Fortunately, beavers were reintroduced starting in the 1950s, helping to provide pure water for communities downstream.

It is difficult to assign a value to natural resources. In the past green space was considered pleasant, but optional. Our perception of its value may increase now that we know that it promotes health and longevity.

Preserving and restoring as much as possible of the natural world, especially green space, has benefits that may not be immediately evident. We should resist the urge to destroy natural resources before understanding their true value.

This article first appeared in the Durango Herald 1-2009

The article above may be copied or published but must remain intact, with attribution to the author. I also request that the words “First published in the Durango Herald” accompany any publication. For more information, please write the author at:

Favorite Species Contest Results

Saturday, February 21st, 2009

Favorite Species Contest Results

© Richard Grossman MD, 2008

In September I announced a contest to promote knowledge of biodiversity. Readers were invited to describe their favorite species of animal and to tell why they favor that species. For the Birds, a Durango store featuring products to explore backyard nature, kindly offered to supply prizes in both adult and kids’ categories.

One of the requirements for all entries was to include the animals’ scientific name, which is more exact than the common name. Another requirement was to mention the animal’s conservation status. In judging I looked for originality, persuasiveness and a good description of the animal.

You know that some animals are already extinct, some are endangered and some are plentiful. What animals are at risk? The best authority is the International Union for the Conservation of Nature and Natural Resources (IUCN). It publishes an annual Red List of species in several categories, from “extinct” to “endangered” to “vulnerable” to “least concern.”

November’s article touched on the importance of biodiversity to humans. It described my favorite animal, Hyles lineata (the white lined sphinx moth), and told why it intrigues me. Fortunately it is common—in the “least concern” category.

I was delighted to receive over 40 entries from kids. They were all in Ms. McManus’ seventh grade science class at Miller Middle School. It was difficult to decide which was most deserving of the two prizes. Perhaps the most unexpected is Mikayla Montoya’s description of European nightcrawlers (Eisenia hortensis). This worm, an exotic from Azerbaijan, is ideal for fishing. Mikayla seems to be on her way to being a nature writer or biologist with her description of worm hunting with her dad in their neighbor’s yard! Unfortunately, she did not include the conservation status in her essay.

Some of the animals students described are pretty exotic—and endangered. My mother and Charly Cooper would agree that the golden lion tamarin (Leontopithecus rosalia) is both beautiful and threatened by human expansion. I was amazed to learn from Mady Ward’s essay that the longhorn cowfish (Lactoria cornuta) likes to be scratched between its eyes! Eli Kopp-DeVol’s description of Osteoglossum bicirrhosum, also known as the silver arawana or water monkey is intriguing. He explains that this fish can jump out of the Amazon onto the limbs of trees when the river floods. The seeds it eats are dropped on the river below, where they grow into new trees. These essays all deserve honorable mention.

It was difficult to choose winners in the kids’ category because of the wide variety of species and the obvious interest that the writers have in their choices of animals. The first place winner is Nick Tarpley who notes that the leaf-cutter ant (Atta cephalotes) has amazing abilities, including lifting three times its own weight. ”They don’t eat leaves, unlike popular belief. Instead they use the leaves to help grow fungus, which is their main diet.”

Second place goes to Hannah Smith for her description of Przwalski’s Horse (Equus ferus przewalskii). I learned that the wild population of this precursor of modern horses is fewer than 300! Fortunately there are a few more of these animals living in zoos and reserves. The species is endangered, of course. Hannah wrote: “I love horses for their beauty and movement. The Przewalski horses are not as beautiful as the domestic horse but are an important part of living history.”

There was only one adult entry, from Diane Trembly. She has friends in high places—western scrub jays (Aphelocoma californica) who have trained her to provide peanuts. Diane is impressed by their intelligence, writing “If I toss out multiple peanuts, the birds “weigh” them to see which is heavier, returning later for the lighter peanut.” Smart birds! And smart Diane, who gets a gift certificate to For the Birds.

Awarding the adult second prize is easy. It took an enthusiastic teacher to motivate all of the seventh graders. This is Jackie McManus’ second year teaching in Durango. She writes: I love teaching 7th grade – the kids are so funny! One day, after reminding the kids that fair isn’t always equal and equal isn’t always fair, one of my students blurted out, “Yeah, because if life was fair and equal, horses would be riding US half the time!” I love it!

I would like to finish with a quote from Kevin Brinkley, who chose to write about the Adelie penguin (Pygosecelis adeliae). Although his entry didn’t win a prize, I like his closing: “Thanks for reading. I hope you learned a lot.”

Published in the Durango Herald 12-2008

The article above may be copied or published but must remain intact, with attribution to the author. I also request that the words “First published in the Durango Herald” accompany any publication. For more information, please write the author at:

More About Wild Species

Saturday, February 21st, 2009

The article below may be copied or published but must remain intact, with attribution to the author. I also request that the words “First published in the Durango Herald” accompany any publication. For more information, please write the author at:


More About Wild Species

© Richard Grossman MD, 2008


The library of life is burning and we do not even know the titles of the books.

Dr. Gro Harlem Brundtland, former Prime Minister of Norway


            September’s article announced a contest to write about your favorite species of animal. It gave hints about my favorite animal, and promised to reveal what it is. Although the contest’s official deadline is past, I welcome submissions at:

            Why am fixated on wild species? Because they make up our most precious treasure, biodiversity. Biodiversity, or biological diversity, refers to the huge number of different plants and animals that have developed over the ages. Almost two million different species have been described and cataloged. Biologists suggest that the actual number of different species is many times this great. There may be another eight million animals and plants that haven’t been described yet!

            My friend, Al Schneider, just found a new species of plant in the sunflower family north of Cortez. Gutierrezia elegans has just been given its common name, Lone Mesa snakeweed. For more information and pictures of this pretty plant you can go to Al’s website: Just think, there may be many more undescribed species right where we live!

The tragedy is that we are losing biodiversity faster than species are being described. Our era is dominated by humans, and we are causing species to go extinct at an alarming rate. The last time that there was such a rapid loss of biodiversity was the end of the epoch of dinosaurs.

There are several ways humans cause species to die off. One is by direct killing, such as the dodo, a flightless bird that was hunted to extinction. Another is by introduction of exotic species. Australia had no proper mammals except for the dingo, (Canis lupus dingo, probably brought by the first aboriginal settlers) until Europeans arrived. They introduced foxes, rabbits and other domestic animals that out-competed and wiped out many of the more primative marsupials.

Pollution threatens many living things, including whole species. The bird with the largest wingspan in North America is an example. The California condor (Gymnogyps californianus) was headed toward extinction from lead poisoning. They would feed on carrion that had been shot with lead bullets. An aggressive program of limiting lead shot and hatching chicks in a laboratory has reestablished these amazing birds.

In most of the world, including the USA, the largest threat to biodiversity is habitat destruction. People in our country are living in larger homes on larger lots with larger lawns, competing with wildlife. Roads and highways block migration routes of many animals, thus creating killing zones for many who attempt to cross. As the human population grows and we consume more, our impact on the natural world is exploding.

Dr. E.O. Wilson, the famed Harvard biologist, made a superb video in which he pleads for preservation of biodiversity. Search for it at: Wilson uses the acronym HIPPO to help remember the causes of loss of biodiversity: Habitat destruction, Invasive species, Pollution, Population growth (human), and Overharvesting. There is also a beautiful book in the Durango Public Library titled Sustaining Life: how human health depends on biodiversity. This book shows the many ways we depend on species that we might not even be aware of.

The growing human population—and our extravagant consumption—are the primary factors that threaten biodiversity. The Living Planet Report 2008 tells it like it is. Prepared in part by the World Wildlife Fund, this is an account of the state of our natural world. It is available at: The report describes the economic value of biodiversity and the many services that the natural world performs for us. The report compares our use of resources with what is available.

Oh, yes; my favorite species is Hyles lineata, the white-lined sphinx moth. Like most sphinx (or hawk) moths, it has a wide body. It is usually seen in the evening or night, although I have seen them in broad daylight.

One of this species’ endearing qualities is its vision. H. lineata can discriminate colors when the light is very dim. Whereas humans need sunlight to see colors, and some animals perceive them even in dim moonlight, my favorite (other than H. sapiens) species can discriminate colors by faint starlight! Even on the darkest night these moths can find their favorite flowers to sip nectar.

There is amazing diversity in the natural world. Unless we slow our population growth and our consumption, we will leave scant resources for our progeny.


Published in the Durango Herald 11-2008

Creative Commons Attribution 3.0 United States
This work is licensed under a Creative Commons Attribution 3.0 United States.