Posts: 35

1. Would you like to write and publish on the internet?

   10.Feb.10, 09:21 EST
   
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   If you would like to write about anything you want and get reactions to your ideas, click on the link below:
   
   http://hubpages.com/_writesalot/profile/Life+at+DrTom%27s
   
   
   You can join HubPages for free.  No pressure; no obligations.
   
   

2. Life at DrTom's

   17.Jan.10, 13:13 EST
   
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   See DrTom, former Cornell University professor, for a humorous, and sometimes super-serious perspective on life, gardening, nature, wildlife, aging, cigars, scotch, stocks, retirement, and family at http://lifeatdrtoms.blogspot.com/. DrTom is blogging as part of his “Old and in the Way” project. The site now contains more than 80 original essays, and it is growing every week.
   
   I spent the past 30 years in a room full of 20-year olds; I need to talk to adults now. For reflections of a retired baby boomer, or if you just need to smile, please check it out.

3. Firewood gardening

   16.Nov.08, 08:31 EST
   
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   For the past few weeks I have been “bringing in” the firewood that will heat our home for the next five months. Cutting down trees, sawing them up, and moving the pieces to the house from the woods is a laborious process that I work on from spring to fall, whenever the weather is not too hot and not too cold. This is really hard work, but I enjoy it for two reasons: my wife and I benefit from the “harvest” in the form of inexpensive heat from November to March, and it is gardening at its best. How can this be gardening?
   When gardening, we normally think of starting with a bare patch of earth, adding some seeds or small plants, and then nurturing them until they produce something usable. When I cut firewood, I am selectively removing individual trees from an already crowded palette. When this old cattle pasture was abandoned about 50 years ago, wind-blown seeds of maple, ash, and aspen wafted onto the site from the old forest across the road and took hold. Decades later the stem density of trees was so high that it was difficult to walk through this woodlot in places. So I have been reducing this density by removing trees that are misshapen or diseased, or trees that after removal will open up much-needed space for adjacent trees that I have decided are more valuable. Sun is limiting in such an environment, so opening up the canopy on two sides of a tree you hope to encourage is sufficient to hasten its growth. This is essentially like thinning a row of carrots or radishes that is too dense to allow these root crops to develop to a decent size.
   What is really interesting is that my forest garden has been changing. Originally populated by maple, ash, and aspen, whose seeds blew in from adjacent older forest, I now have hundreds of nut tree seedlings and saplings that have appeared since I moved here in 1980. Gray squirrels and probably blue jays have moved those nuts from mature oak, hickory, and beech from my neighbor’s forest to mine, and I didn’t pay a cent for them. It certainly appears now that my woodlot canopy will be dominated by these species several decades into the future, and I am helping this process along with my thinning. I always leave oak or hickory trees over red maple or white ash when I decide what to cut, because I have so many of the latter compared to the former. In other words, my gardening is helping Mother Nature move in the direction she “wants” to go anyway, and I benefit by obtaining thousands of British Thermal Units (BTUs) of heat.
   But what about the global warming/carbon footprint aspects of woodlot gardening? I am burning wood, which releases carbon into the atmosphere. But I am thinning my forest, which increases the growth rate of trees left in the woods that are sucking carbon out of the atmosphere to support that growth. If the pounds of wood added to these trees due to my thinning exceeds the pounds of wood that I cut and burn, then there would be a net gain in reducing carbon. But to determine if that is true would require measurements I have neither the time nor expertise to make, so I can not be sure. On the other hand, if I were not burning wood, I would be heating my house with electricity, which also contributes to carbon inputs. My colleagues who know more about this than I do say that I am doing about as well as one can. And so, I continue to garden in the forest, to heat my house, to stay physically fit, to enjoy the changes I witness in bird populations, to admire my garden, to endure bruised shins, to marvel at the changes, to justify it to students, to fight off leg cramps, and to sit with a scotch and a cigar in its midst. It is all good.
   DrTom
   www.drtom.tv

4. September regrets

   16.Nov.08, 08:27 EST
   
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   This fall is the first time in almost 30 years that I am not teaching in the university classroom, due to my pending retirement on November 1. It is a bit strange not to be in a room full of students as the weather begins to change here. My feelings are mixed about this “vacancy” in my life. The field biology course I have taught at Cornell since 1980 is still being taught by a colleague in the room immediately next to my office, so I can see and hear the activities with which I was so associated for half of my life. Students still stop by my office when I am there, and we discuss the usual matters of importance to undergraduates. But in just a couple of years, my name will have been forgotten as ever having anything to do with a course that I shaped and molded over all that time. This is just the way life is.
   I have said from the moment I decided to retire that what worried me most would be the lack of daily contact with young, vibrant students. They kept me thinking, they kept me current on what 20-somethings think about, and they validated what I became professionally all those decades ago. Next weekend I am having 6-8 of these young rascals out to my house for dinner and a bonfire just to get my September “fix” of youth’s enthusiasm. But that event is temporary and fleeting, and it will not fill the void that comes from leaving what you always took for granted. Can my work on this site be a replacement for all that interactivity between student and mentor?
   The challenge of this portal is to try to reach more people than I ever could before with messages about how the natural world works and why we should care about that. There is no way to reproduce the personal contact that comes in the classroom or in the field, but I will try as best I can. After all, it is that personal contact that makes learning and teaching both fun and rich. Anyone who thinks that “distance learning” can or should replace classroom instruction is dead wrong, in my opinion. This portal will not replace the vitality of the classroom that contains live bodies and active minds, but with your help we can close the gap. Don’t be afraid to show us who you are. Don’t be afraid to express your opinion. Don’t be afraid to criticize the opinions you see here, including mine. The time to speak up is now. Finally, I repeat my personal motto, which can serve as advice to the timid: the wrong hypothesis is better than no hypothesis at all.
   DrTom
   www.drtom.tv

5. Does the existence of New Orleans make ecological sense?

   12.Sep.08, 10:03 EDT
   
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   As an ecologist and an environmentalist I have often wondered whether New Orleans makes any sense at all. This major city is located on the Louisiana coast 2-6 meters below sea level. Using the U.S. Army Corps of Engineers, we try to build structures that block the waters of the Atlantic Ocean from flooding this historic metropolitan area of about 1,000,000 people. I have concluded that given the costs of rebuilding the city�s structures and housing, and the probability that future disasters due to hurricanes and flooding are probably 100%, that it does not make sense to continue supporting this endeavor. My argument goes like this. When we know that a particular disaster has a high probability of occurring, we should minimize our investment of resources in that location. We know the following with virtual certainty at this point: polar ice caps are melting, sea level is rising, and cyclonic storms that arise over the warming oceans of the world are likely to be more common and more intense than in the past. This means that Katrina-like events will occur again along the Louisiana coast. The question is whether humans can design and build structures that will hold out against these powerful natural events. Maybe we can learn something from a place in the world that has been fighting this battle for centuries: the Netherlands. From Wikipedia, we find that �After the 1953 disaster, the Delta project, a vast construction effort designed to end the threat from the sea once and for all, was launched in 1958 and largely completed in 2002. The official goal of the Delta project was to reduce the risk of flooding in the province of Zeeland to once per 10,000 years. (For the rest of the country, the protection-level is once per 4,000 years.) This was achieved by raising 3,000 kilometres (1,864 miles) of outer sea-dykes and 10,000 kilometres (6,200 miles) of inner, canal, and river dikes to "delta" height, and by closing off the sea estuaries of the Zeeland province. New risk assessments occasionally show problems requiring additional Delta project dyke reinforcements. The Delta project is one of the largest construction efforts in human history and is considered by the American Society of Civil Engineers as one of the seven wonders of the modern world.� In other words, given 2,000 years of experience with trying to keep the ocean at bay in a country where 27% of the land is below sea level, the Dutch have developed a system that is so extensive and so elaborate that it is considered one of the seven wonders of the modern world. The jury is still out as to whether even this will continue to work against rising seas. Now, I am not an expert on this topic, but it appears that the storms that pound the Louisiana coast are more powerful in terms of wind than what typically comes from the North Sea, and the Caribbean storms occur more frequently. In other words, the chances of Americans designing a system that can prevent the kind of disaster we saw in 2005 from occurring again and again seem remote to me. I realize it is not politically correct to talk about abandoning a city with a 300-year history. And New Orleans is an important conduit for oil, natural gas, and other products entering through that deep-water port. However, I am sure that some kind of elevated housing could be constructed for those who choose to remain there to work in those industries, which are vital to U.S. commerce. I envision that something like an oil rig structure could be devised that would serve the purpose. But to spend billions of dollars and to squander thousands of tons of physical materials to rebuild repeatedly seems like folly, not to mention the future human suffering that this encourages. I have often admonished my children that the future is not likely to look like the past, and to behave accordingly. This is particularly true in a world that is so populous that we are even changing the climate. It is time that global planners incorporate more ecological thinking into their repertoire. Southeastern Louisiana was once a vast wetland at the mouth of the Mississippi River, and I suggest we let it revert to its natural state. DrTom www.drtom.tv

6. 

   Curious behaviors of animals: American toad

   04.Sep.08, 07:44 EDT
   
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   Every summer I have an American toad (Bufo americanus) that usually spends some time in my garage. Insects accumulate in one corner, and I suppose this becomes a sort of toad luncheonette. For a few days in early July, I found an adult toad sitting during the day behind the open door to the garage. I assume it went outside to forage at night, when toads are most active, but I never really followed him at that time.
   
   Completely separate from anything to do with the toad, we have always had a deer mouse (Peromyscus sp.) problem at our house. Deer mice regularly enter the house somewhere, and they end up under the kitchen sink. So, for years I have kept metal box traps, known as Sherman live traps, set in the kitchen and along a raised wall in the garage. The garage is my first line of defense, where I capture many mice before they even break into the house. This trap has a spring-loaded door, so that once an animal enters the trap, it steps on a treadle on the floor of the trap, which causes the door to snap shut, trapping the animal inside. It is a valuable tool of biologists who study small mammals. (By the way, deer mice love dark cavernous places, so I never even bait these traps with food. Just open the trap door, set it in a likely runway, and it functions like a deer mouse magnet).
   
   So in July, when I noticed that the trap in the garage was closed, I assumed I had another deer mouse to release far from the house in the woods. But when I opened the trap, a large American toad was inside. I released the toad on the floor of the garage, reset the trap, and had a good laugh about it with my wife. But to my amazement, the next day, the same toad was in the closed trap again. This time, I took the photo you see below, and released the habitual prisoner again. I never saw that toad again.
   
   Now, this toad’s behavior is somewhat endearing, and it reminded me immediately of the “Frog and Toad” series of children’s books by Arnold Lobel, which I have read to my children and grandchildren many times. But the most interesting part of this anecdote is yet to come. Notice in the photo below where this trap was located. It is on a ledge about two feet above the floor of the garage, much higher than toads can jump. But also notice the lumber, stacked in stair-step fashion adjacent to this wall. The only way this toad could have reached the ledge is to have hopped up each level of lumber to get to that ledge and the trap. And, it performed that maneuver two nights in a row.
   
   Why did this toad go to so much trouble to get to that ledge, and then enter that metal box? To get to the other side? To explore worlds unknown to other toads? To get featured in a DrTom blog? I have no idea. But it proves how entertaining nature can be, even in your very own garage.
   
   DrTom
   www.drtom.tv

7. After, then before

   10.Aug.08, 10:29 EDT
   
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   I spent last week in one of my favorite places, the Las Cruces Biological Station in southern Costa Rica. The station is one of three research stations operated in Costa Rica by the Organization for Tropical Studies (OTS). The director at Las Cruces, Zak Zahawi, had invited a few of us to present a summary of our research there in a workshop/conference format. I was accompanied by two of my students, Viviana Ruiz-Gutierrez and Martin Schlaepfer (now a professor at Syracuse). Vivi prepared most of the material that I presented, and Martin gave an overview of his fascinating work on lizards and frogs. Our collective work focused on the effects of forest fragmentation on understory bird populations and on herps.
   
   My graduate students and I began doing research in and around Las Cruces in 1993, a project that ended earlier this year. It represents the end of an era for me, because this was the last research project with which I will be involved as Cornell faculty, given my pending retirement. My students and I employed an intensive mist-netting program to capture and mark birds permanently with aluminum leg bands. In total, we logged about 15,000 captures of about 200 species during the project. Many individuals were recaptured many times in this rugged landscape. Sophisticated quantitative techniques are then used to estimate annual survival rate, population size, and the probability that birds will move from one forest fragment to another. We have published several scientific papers on this work, with more to come.
   
   When I started the project, I usually described it as a study of the effects of forest fragmentation on bird populations. But after a while, I realized that was incorrect. The clearing of forests that had resulted in the fragmentation we witness today was done by Italian immigrants in the 1950s. Presumably, many of the “effects†of this event already had occurred way before I arrived there in the early 1990s. Some bird species probably had gone extinct before our study started, for example. So, I began describing our research as “how birds live in a fragmented landscape.â€
   
   But now, something very exciting may happen. LCBS is interested in purchasing privately-owned land along the ridge between LCBS (260 ha) and the Guaymi Indigenous Reserve (7,000 ha) about 7 km further west. This would create a corridor that would connect these two important pieces of primary forest. From this researcher’s point of view, this is extremely important, because if this corridor area is allowed to regenerate forest from its current state as cattle pasture, our study fragments would eventually become part of a large contiguous forest again. I was not able to do the “before and after†study that I would have preferred, but someone would be able to do the “after and before†study, if you catch my drift.
   
   Stay tuned for more developments on this interesting issue.
   
   DrTom
   
   www.drtom.tv

8. The love and hate of it all

   07.Aug.08, 10:06 EDT
   
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   I am an avid gardener. My wife and I nurture flower gardens, a large vegetable garden, fruit trees, blueberry bushes, and ornamental shrubbery around the foundation of the house. I am also an ecologist and a lover of wildlife. The problem develops when the objects of these two loves come together. This “coming together” is better known as herbivory.
   
   The problems for the home gardener are nearly endless. But in my case, it is certain herbivorous mammals and insects that receive the bulk of my wrath. Woodchucks eat almost anything leafy in the vegetable garden. White-tailed deer feed on fruit trees up to the lowest branch they can reach, damage rhododendrons and viburnums, and eat the high protein crops among the veggies. Eastern chipmunks dig up tulip bulbs and create a burrow system through the “hilly” flower garden next to my house. Eastern cottontails, which I have not had on my property for many years until this year, eat all manner of veggies and girdle fruit trees in the winter. Meadow voles eat the cote d’azur that I am using to “tame” a slope near the house. Eastern gray squirrels dig up flowers in our pots to plant their acorns. Eastern tent caterpillars feed on the leaves of apple and plum trees, and Japanese beetles seem particularly fond of plum leaves. How the early pioneers actually produced enough food to stay alive two centuries ago astounds me.
   
   So what do I do about this onslaught of herbivores, in addition to complaining. I have a large black Labrador retriever that I taught to chase deer out of the yard. Not sure that was a good idea, because it sometimes seems as though he might break through the living room window to get at them. As far as I can tell, all those remedies to keep deer away from your gardens are a joke, unless you install a deer-proof fence or actually spray a substance that is distasteful on the plants you are trying to protect. I have live-trapped woodchucks and meadow voles and moved them down the road. (The neighbors should be able to have as much fun as I’m having). I have placed wire cages around certain fruit trees. I even spray apple and plum trees to attempt to reduce insect damage. The battle has become a part-time job, so it is fortunate I retire later this year.
   
   Now, don’t misunderstand. All of these organisms are really interesting in their own right, and I enjoy them and appreciate their ecological value. My dilemma is probably a very common one, where we try to do the “right” thing environmentally or ethically, but where there is a conflict between long-term concerns and our short-term needs or desires: I worry about global warming, but I drive too much; I worry about the human population problem, but I had three children; I worry about plastic waste and the longevity of my local landfill, but disposable diapers are so convenient. And, of course, I love wildlife, but I don’t want it interfering too much with other loves that I have.
   
   The summer continues, my battle rages, and the amount of edible produce I harvest hardly seems worth it. But in some strange way it seems that the struggle to eke something usable from the land is as important as whether I am successful or not. And I learn a lot of ecology along the way.
   
   DrTom www.drtom.tv

9. In Denver, and I’m homesick

   23.Jul.08, 08:16 EDT
   
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   For the past week, my wife and I have been in Denver, Colorado visiting our sons. Denver is large and growing rapidly, as is the entire Front Range of Colorado from north to south. Driving on the highways is reminiscent of driving in southern California. The area is full of young people who immigrated here from Ohio, Illinois, New York, and other places where life has ceased to be exciting enough. They come here for skiing, snowboarding, mountain biking, hiking, and camping in the Rocky Mountains nearby, and when in Denver there is plenty to do. The city boasts professional teams in baseball, basketball, football, and ice hockey, plenty of parks, bike and jogging paths, restaurants and bars of every stripe, interesting museums of art and history, and a good zoo. But I’m bored stiff. What the heck is my problem?
   
   I’m bored because my primary activity in life, aside from this portal, is learning about the organisms that live on my land, writing about those organisms, and tweaking that habitat to make it a bit more interesting. In short, I miss my forest in upstate New York and the “backyard ecology” that I practice there. Normally, an ecologist loves to travel to new places, because there are new habitats to explore, new birds to observe, new trees to appreciate. But in the city of Denver, that is not very satisfying. Oh, there are trees everywhere, but almost none of them should be here. Denver was built on the short-grass prairie of central Colorado—the native vegetation was only a few inches tall. Trees would have been limited to the banks of streams and rivers, and they would be cottonwoods and willows. The trees in the city now are mostly native to some other region of the U.S. or to another country: ash, Russian olive, Chinese elm, and Tree of Heaven, that native of China that I absolutely detest outside of its homeland. An irony is that we drove around a neighborhood yesterday with street names like Ash, Birch, and Cherry. Rub it in my face!
   
   My issue here is that there is vegetation everywhere, but it does not constitute a “habitat”. Most homes have attractive green lawns, scattered trees planted in the yard and along the sides of the house, and a variety of flowering plants in gardens. All of this takes nearly daily watering, of course. But that is another complaint I have, for another blog. Nothing I criticize about Denver is any different than what I would say about almost any city n the world. We reconstruct a cheap facsimile of what we took away when we built the city in the first place. For most, this is apparently just fine. In my case, I can’t wait until I go to the airport on Sunday.
   
   DrTom

10. Round two: Bird report, June 22, 2008

    09.Jul.08, 20:26 EDT
    
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    Singing of male songbirds increased during the past week. This is correlated with an increase in hormones that signal reproductive readiness. During the past few days, I have witnessed the fledging of black-capped chickadee, American robin, and Eastern phoebe nests. This evening I saw a chestnut-sided warbler feeding a fledging in the aspen grove in my forest. Singing of all these species, as well as tufted titmice, brown creeper, ovenbirds, dark-eyed juncoes, and veery, has increased noticeably. The males, at least, are ready for round two.
    
    In April I wrote here about the return of the phoebes from their wintering grounds in Latin America. The pair near my house usually nests on the light fixture next to the front door. However, this year they nested on the ledge above a basement window on the back of the house. A few days ago, they fledged five young from that nest. I know this because I was checking the contents of the nest almost daily. When I walked past the nest last week, the babies, which were now over-sized for the diameter of the cup nest, exploded in flight in all directions into the woods. The adults followed them immediately and I am sure they have been feeding them ever since. Within a day, the male was singing again, new eggs started to appear in that same nest, and today a female was incubating four eggs. Second clutches are almost always smaller than the first clutch of the season. Remember that starting today, day length begins to shorten. Winter is right around the corner (well, you know what I mean), so adults need to get those young fledged and grown. The big question is whether the female phoebe is the same female that raised the first clutch. Without having marked birds, I can not be sure, but I have to assume she is the same. Phoebes are a bit atypical in reusing the same nest during the breeding season.
    
    And so it goes. Produce as many young as you can. The forest is noisy again, with the singing of adult males, and the baby-like begging of fledglings of a half dozen species. I measure the season of the year by this never-ending cycle that keeps me alert for the cues that signal where the earth is in its orbit around the sun. And it keeps me going outside to look and to listen.
    
    DrTom

11. Homage to Amelanchier

    22.Jun.08, 21:11 EDT
    
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    One of the required trees to learn in my field biology course was a relatively insignificant species (from a timber perspective) called Juneberry, or shadbush, or serviceberry. It has several common names, but I am referring to the genus Amelanchier. The common species in our area is Amelanchier laevis, or smooth Juneberry. This shrub or small tree is in the rose family, and rarely gets more than 10 meters high. It flowers in May, when the American shad used to run up the eastern coastal rivers to spawn, and it bears ripe fruit in June (thus, Juneberry).
    
    The tree was always difficult for students to identify in autumn when it contained neither flowers nor fruits, so I made a big deal of how much I loved this tree. During the semester, I often heard students say in discussing the trees they were required to know from their list, “you know the one, Gavin’s favorite tree.” I thought that by exaggerating my admiration for this species that they would more easily remember what I wanted them to know. But I really do love this species; it really is one of my favorite trees in the eastern deciduous forest. But why?
    
    First of all, everything about Amelanchier is attractive. The gray bark with weaves of green running through it, the finely serrated leaves, the abundant white blossoms, and the purple fruit that resemble blueberries offer much. But many open-grown specimens have a growth form that reminds me of a small tree you might see in a Japanese garden, almost like a giant bonsai tree. Based on my observations, they are slow growing, adding only a few centimeters of new growth per year. Although I have never worked the wood, it is supposedly hard and durable and was used in former times as tool handles.
    
    Second, starting about mid-June, the fruits ripen and the show begins. So, my evening ritual (you know, scotch, cigar, binoculars, and folding chair) is often spent sitting several meters away from my favorite Juneberry. Every fruit-eating bird in the area is attracted to this offering, which, of course, is how the tree disperses its seeds. Birds swallow the fruits while they are in the tree and defecate the seeds elsewhere several minutes later. American robins, gray catbirds, American goldfinches, veerys, and cedar waxwings are the most common visitors on my property. Today (June 14) the fruits are not yet ripe, but the waxwings started feeding on these fruits a couple of days ago. (Are those seeds ready to be dispersed yet? Are they yet viable? Are waxwings seed predators rather than seed dispersers?) This is really curious to me and it deserves further investigation. In a few days, the branches of the tree will be moving constantly with the shifting of bird bodies intent in harvesting as much as they can as rapidly as possible.
    
    The most interesting visitor is the yellow-bellied sapsucker, the fruit-eating woodpecker with a sweet tooth. Remember that this is the species that drills small holes in a neat horizontal line in certain species of trees (like red maples), and then visits these holes later to lick up the sweet sap that oozes from them; it may also feed on insects that are attracted to the sap. For several years, I have had a pair of sapsuckers visit my Juneberry trees as long as there is ripe fruit available.
    
    Gray squirrels and eastern chipmunks also love these fruits and, although I have yet to witness this, I am betting that deer mice in the genus Peromyscus climb these trees at night to eat the fruits. George Petrides writes that foxes, skunks, raccoons, and black bears also relish Juneberry fruits. They are also quite edible by humans.
    
    I have described my hobby of thinning my woodlot for various purposes. One of the objectives has been to release this sun-loving tree to fuller sunlight along my driveway so that it flowers more profusely. There are now 14-15 specimens lining my long driveway, which provide a beautiful show of flowers in May. I usually proclaim that spring has really arrived when Juneberry is in flower. Oh, I did not mention this, but an old etymology of the third common name, serviceberry, is consistent with my proclamation of spring arrival. Pioneers are said to have used the flowering of Juneberry to know that the ground had thawed sufficiently to bury those who had died during the winter—funeral services could be held at that time.
    
    My enthusiasm for Amelanchier has not changed over the years. About all that has changed is what used to be called “Gavin’s favorite tree” is now referred to as “DrTom’s favorite tree.” Same tree, different name.
    
    DrTom

12. Political candidates and unintended consequences for the environment

    14.Jun.08, 12:41 EDT
    
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    It is nearly impossible to be a blogger and not comment at least once on the presidential race that has enfolded in front of us. For starters, I will put my cards on the table and tell you that I am for Barack Obama all the way. My wife and I first got excited about Obama in February 2007, I heard him give a speech in the Jewish synagogue in downtown Denver, Colorado in March 2007, and later that month my wife and I put “Obama for President” bumper stickers on our car. By the way, that car is a SUV, so you now see all my cards.
    
    But the question here is which candidate, McCain or Obama, would be better for the environment. The answer to that important question is not abundantly clear to me and, in thinking about it, I realize how complicated and convoluted the answer could be. Traditionally, we environmentalists tend to think that Democrats are more favorable for the environment than Republicans. However, the Endangered Species Act of 1973, the conservation legislation that many tout as the single most important environmental law ever written, was enacted under the Republican Richard Nixon. On the other hand, President Reagan (a Republican, who is quoted as saying “If you’ve seen one redwood tree, you’ve seen them all”) appointed James Watt as Secretary of the Interior, which most environmentalists considered a disastrous choice for such an important position as the manager of the nation’s natural resources. Generalizations seem to have low predictive power in this kind of analysis.
    
    Here is a brief and highly simplistic analogy to demonstrate how there can be both intended and unintended effects on the environment. Let’s consider two families in the U.S., the Greens and the Slobs. Mr. and Mrs. Green read Al Gore’s book on global warming and they took it seriously. They turn off the lights when they leave one of the rooms in their house, they run their major appliances at off-peak hours, and they bought a small car (their second car) that gets 35 mpg. They built their 3,500 square foot house, well-insulated, in the woods from which they drive 10 miles to get to work everyday. They take a winter skiing vacation in Colorado and a summer vacation to Europe or Costa Rica most years that, of course, involves flying. Did I mention that the Greens have three children and two cats?
    
    The Slobs haven’t read a book in a decade (the last was a Danielle Steele romance novel), they keep their electric home really warm in the winter and really cool in the summer, and they even throw trash out of their car when driving down the road. The Slobs live in a 1,500 square foot house in a run-down suburb of a major city. The Slobs drive an SUV, but they live only about 1 mile from their jobs. Their vacation in the summer involves driving to the beach about 50 miles away and staying in a cheap rental for a week with their only child.
    
    If we were to do a carbon footprint analysis of these two families, it would surprise no one here that the Greens contribute much more to climate change than the Slobs. In fact, the two additional children that the Greens have will, alone, result in a much greater impact on the environment over the roughly 75 years in which those two humans live in the U.S. than any energy the Greens could possibly save while those children are still living in their home. During those 7-8 decades, those two additional humans will consume tons of raw materials in the products they buy, use millions of joules of energy, and generate hundreds of tons of waste. In the short run, the Greens are also responsible for permanently eliminating a chunk of habitat from the forest in which they built their house, reducing and/or degrading biodiversity in the process. In short, although the Greens “intend” to reduce their impact by watching their energy consumption and their waste generation, their “unintended” impact is much greater than the Slobs, who are basically clueless about the whole issue. And if we compare the Greens to almost any of the 4-5 billion people living in developing countries, their relative impact is enormous.
    
    Obama and McCain both intend to cut carbon emissions by 2050: Obama wants an 80% reduction over 1990 levels and McCain wants a 60% reduction. Both of them have opposed drilling for oil in the Arctic National Wildlife Refuge. The League of Conservation Voters has graded each senator’s lifetime voting record with regard to environmental issues—McCain got 24%, Obama got 86%. Overall, Obama seems to be the candidate likely to be better for the planet, a conclusion also reached by others who are examining this issue (http://www.observer.com/2008/obama-vs-mccain-environment-opening-bell).
    
    What about the unintended consequences? What if Obama, who has written a book about being hopeful, engenders enough optimistic feeling in the U.S., or even the world, that the birth rate ticks up .1%-.2%? Sounds far-fetched, but birth rates historically increase when people feel the future is going to be bright. Or, what if McCain is able to stimulate the housing market to the extent that several million more houses are built than would otherwise have been the case? All economists think this would be a good thing, but try to estimate the increase in energy consumed, habitat lost, and materials used if two million new houses are built. Both candidates promise to stimulate economic growth and lower gas prices, but this tactic is almost certainly bad for the environment. For example, lower gas prices stimulate greater use of that resource and contribute more to climate change. These are enhancements that might be “good” for most of us in the short term, but be “bad” for us all in the long term. Isn’t this the classic dilemma?
    
    Most of us do not engage in very deep analysis of environmental issues, even with a general election coming in a few months. We take at face value what each candidate says they are going to do, compare what they say, and make a decision. My argument here is not that they may be lying, or naïve, or simply misinformed about what is possible to accomplish. That may be true. I am arguing that evaluating the consequences of having one man as President over another is pretty complicated because of the probable chain of interactions and unintended consequences of policies that may have nothing directly to do with the environment. But, then, isn’t that an incorrect statement? Doesn’t everything we do have an effect on the environment?
    
    DrTom

13. The scorpion house

    09.Jun.08, 06:02 EDT
    
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    I find all organisms absolutely fascinating, from elephants to the malaria parasite. Their morphology, behavior, and physiology are incredible manifestations of natural selection. They are all interesting, often beautiful, and sometimes obnoxious. In my book, scorpions are one of those animals that cause immediate repulsion, with their pair of claws at the front of their brown or black body, and that stinger that they hold over the body in strike readiness. For about a year, my wife and I and our three children rented a farmhouse in Monteverde, a small community in the Tilaran Mountains in Costa Rica. Months after moving there, we passed a local resident on the dirt road who asked where we lived. After describing the location to him, he immediately said without fanfare, “Oh, you live in the scorpion house.”
    
    Of course, by that time we had already discovered the fact that the house had a healthy population of a species of black scorpion about three inches long. Why was this fact not advertised by the landlord? Why did the multiple listing book not inform us of this? Why wasn’t the house cleared of this hideous looking invertebrate by Acme Pest Control before our arrival with a 5-year old child? Answer: because Dorothy and the Gavin family were not in Kansas anymore.
    
    This stingy occupant of our home could be found almost anywhere in the house, but scorpions like to be in a dark place during the day, and then to move about after dark. We regularly checked the cushions of the sofa, our shoes, the shower curtain, bed pillows, clothes, and closets for the sneaky critters. We acquired a house cat during our stay there, and the best thing about this feline friend was his proclivity to hunt down scorpions in the house. In fact, on Christmas morning 1986, we found a freshly killed scorpion placed carefully on the white sheet beneath the tree where there were precious few gifts that year. Just what I always wanted! But what about the biology of this 8-legged arachnid? From the DesertUSA website (http://www.desertusa.com/oct96/du_scorpion.html ): “Scorpions are nocturnal. They often ambush their prey, lying in wait as they sense its approach. They consume all types of insects, spiders, centipedes, and other scorpions. Larger scorpions may feed on vertebrates, such as smaller lizards, snakes, and mice if they are able to subdue them. They capture their prey with their pedipalps, paralyzing them with their venom as well if necessary. The immobilized prey is then subjected to an acid spray that dissolves the tissues, allowing the scorpion to suck up the remains”.
    
    Scorpions often appeared at night and would crawl on the wooden ceiling or open rafters of this rustic house. One night, my wife and I retired to bed, turned off the light, gave each other a kiss, and then turned our heads in opposite directions to settle in for the night. At that very instant, I felt a light “thump” on the pillow between our heads, in the exact location where we had kissed about 10 seconds before. I jumped out of bed, turned on the light, flipped up the pillow, and there was a large scorpion that had already hidden itself beneath the cushiony refuge. I just knew it. I was happy it had not fallen from the ceiling a few seconds earlier. Damn, this is disturbing.
    
    Several weeks later I was taking a shower. I always checked the shower stall thoroughly just to make sure that it was free of “friends”. All clear. I started the water, shampooed my head, and while I was scrubbing away with my eyes closed due to the soap, I felt something crawling up my leg. You guessed it, and I knew it again. I opened my eyes to see the forward progress of a large scorpion, now at knee level and moving rapidly. Another 18 inches higher and, well, I think you can understand the cause of my concern. The thing must have been in the drain, and when the water began to flow, it crawled out of the drain and up the nearest vertical structure, which was my left leg. I flicked it off quickly. Is nothing sacred?
    
    During all these close calls, only my wife ever got stung. She was folding clean clothes and patted a scorpion she did not see. The sting is much like a wasp sting, but has a burning sensation that lasts for several hours. Other scorpion species in Arizona and New Mexico are apparently more toxic than this Costa Rican relative. About 10 years after we returned to the states, I visited friends who were living in the scorpion house in Monteverde. In the morning, I put on my jeans hastily and was immediately stung on the inside of my thigh. I ripped off the pants, which I had left on the floor overnight, to find a scorpion inside the leg. I had forgotten what had become a daily routine when we lived there—the vigorous shake of the clothes before you put them on.
    
    I often say that bad memories are better than no memories at all. I am, of course, overstating the case, because our year in Monteverde was truly magical, and it changed our family forever in many ways. But I can do without the daily vigilance that comes with living with an unwanted guest that can inflict pain. Now, when a mosquito or black fly lands on my arm in upstate New York, I look down at the puny wimp and think to myself, “You’re nothin”.
    
    DrTom

14. DrTom bird report-May 30, 2008

    03.Jun.08, 08:53 EDT
    
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    I spent an hour this morning appraising the avian situation in my forest. Male singing has changed over the past month in an interesting way. Species that were quite vocal earlier in May are now fairly quiet, but others are singing constantly. Dark-eyed juncos, chipping sparrows, song sparrows, black-capped chickadees, wood thrushes, all the woodpeckers, white-breasted nuthatches, eastern phoebes, American robins, gray catbirds, blue-headed vireos, black-throated green warblers, mourning doves, and broad-winged hawks are relatively inconspicuous now. I assume that the frequency of bird song is correlated to the stage of the nesting cycle. Males sing to keep other males at arm’s length and to attract females. When the male or female (usually the female) are incubating eggs or tending nestlings, males tend to be quieter. I am sure this is to avoid attracting predators to their territory, where the nest is located.
    
    But other species are quite vocal. Ovenbirds, red-eyed vireos, mourning warblers, chestnut-sided warblers, indigo buntings, great-crested flycatchers, and veerys are still waking me up early in the morning. Because they returned from migration later than the group of silent species, some of whom are year-round residents, these late arrivals may not even have mates yet. If they are mated, then they must be at an earlier stage of the nesting cycle.
    
    Some of this can be documented. The phoebe nest hatched five nestlings yesterday. By the way, I covered this bird in a blog several weeks ago. It turns out that this pair nested on a window ledge on the back of my house rather than on the light fixture on the front. The chickadees that I described last week are now incubating eggs. And I found a nest yesterday of an American robin in a Syringa shrub next to the house with four eggs. (I will add images of these nests to the Photo section of this site in a day or two).
    
    But let’s review songbird nesting chronology a bit. Males establish territories, sing, and, if fortunate, acquire a mate. One or both adults build a nest, which is distinctive to that species (i.e., mud, moss, grass stems, twigs). Bird nests are truly marvels of the animal world. How birds actually build these structures amazes me constantly. During this stage, they copulate, which is done by the male hovering in flight above the female; their cloacas touch, sperm is transferred, and voila. When the nest is complete, the female will start laying eggs. Egg-laying occurs early in the morning, and the female lays only one egg per day. Even the famous while leghorn chicken, which has been bred to do nothing but produce and lay eggs, can only lay one egg per day.
    
    Clutch size varies from about 3-6 in temperate species, but the number is relatively fixed within a species. One of the parents, usually the female, then begins incubating the clutch after the next-to-last, or penultimate, egg is laid. Eggs do not begin developing until the heat from the female’s body is applied during incubation. The last egg laid, which occurs one day after incubation starts, will hatch about 24 hours after the rest of the clutch; this “runt” of the litter is often the one not to survive because it is always one day smaller than its siblings. Incubation takes about 10-14 days, depending on species, and then the real work begins.
    
    One or both parents must then find food, and I mean a lot of food, to feed the hungry nestlings. These morsels usually consist of insects or other invertebrates, which are high in protein. Nestlings fledge from the nest after 10-12 days. If you have never found a nest and followed it, you should do so. The rate at which nestlings grow is truly astounding. You can see the difference in size and feather development every 24 hours. But here is a puzzle. Those nestlings have to defecate several times per day, and yet you will see no feces in the nest. Where is it?
    
    Will you cause the adults to abandon the nest if you find it and check on it up close once or twice a day? It depends. If the adults are only at the nest-building stage, they may abandon that effort and relocate because they “think” a predator has found the nest. Why continue if something is going to eat your eggs? But once they have reached incubation stage, they will usually not abandon the nest. Too much time and energy have now gone into that nest to just walk away. So find an active nest, observe it until the babies fledge, and report to us here. There are worse family activities in which you could be involved.
    
    Once the young have fledged, many males will begin singing all over again in the hopes of attracting a new female who wants to nest. And on it goes, throughout the ages—the stuff of which poems are made.
    
    DrTom

15. Of invasive plants and Big Macs

    30.May.08, 14:46 EDT
    
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    One of the first-hand observations I have made over the past few years is the tendency to homogenize the world’s biota, especially plants. Jacaranda trees native to Brazil are common as ornamentals in Nairobi, Norway maples native to Europe are common on the streets of eastern U.S. cities, and the bird of paradise flower native to South Africa is found in nearly every city in the tropics worldwide. The botanical situation reminds me of the proliferation of franchised fast food restaurants, where you can now find Kentucky Fried Chicken outlets in Cairo and Kampala as easily as in Louisville, Kentucky. And both trends disturb me, perhaps for similar reasons.
    
    I tend to bond with habitats like most people bond with their friends or their pets. I also bond with humans and dogs, so I am not totally weird. But I have a close affinity to every place where I have spent considerable time: the meadows of upstate New York, the riparian habitat along the San Pedro River in Arizona, the sagebrush community in Idaho, the rainforests of Costa Rica, and, of course, the forest around my home in Ithaca. When a real estate agent is asked to name the three most important aspects of a home’s value, they usually say “location, location, location.” Similarly, we biologists often say when asked to name the three most important elements in conservation, “habitat, habitat, habitat.”
    
    Very simply, habitat is where an organism lives. It is comprised of the plants, animals, and microorganisms in a particular location. The species composition of a habitat is determined by many factors, but it includes the climate, the historical path leading to species’ colonization or evolution in that location, the interaction of species over time, geology, soils, and more. Each habitat on earth is absolutely unique—they each have their own physical appearance, their distinctive sounds of birds, frogs, and insects, and their complex blend of odors. I am convinced that if I were blindfolded and dropped into any habitat where I have ever spent any amount of time that I could identify where I was by simply smelling the air. The ponderosa pine forest of the Kaibab Plateau and the rainforest of Costa Rica come to mind. The sounds would make it even easier—vermilion flycatchers along the San Pedro River, bellbirds and black-faced solitaires in Monteverde, cicadas (different species) in Ohio or Las Cruces.
    
    Now, before my ecology friends jump all over me, I realize fully that habitats are not static. Habitats change over time. The habitats I love will not be the same a century from now. During that amount of time, some ecologists would say that the habitat has changed or matured; some would say that it has become a different habitat altogether. I am not interested in that debate. I just do not want readers to think that I think these entities are unchanging. I have watched the woodland around my house change dramatically in 28 years. Therefore, I am not arguing that we do whatever we can to prevent habitats from changing. That would be folly, and would be an unwise strategy biologically.
    
    But I am arguing that we do what we can to allow habitats to develop along a more or less “normal” path. We can also argue for a week about what is meant by “normal” or “natural.” I am bored with that argument. Simply put, there are certain events or conditions that I define as “unacceptable”, and which I think are an impediment to following a normal path to change.
    
    One of the unaccepatables is the invasion of a habitat by plants or animals that are native to some other part of the world. That is a no-brainer for me, and a reason I spend many hours per month eliminating Tartarian honeysuckle, multiflora rose, autumn olive, and common buckthorn from my woodland, four species indigenous to Eurasia. I know they were not here a century or so ago, so when I see them it offends my sensibilities. From a conservation perspective, I am not even sure there is a practical reason to eliminate them. Certainly, if they became superabundant, they would exclude other native plants from growing there, with the result that some ecological interactions between those native plants and other organisms would be disrupted or extinguished. But when they are in limited abundance, their greatest danger may be that they will not remain at such low densities. I eliminate these plants because I can; the large Lumbricus earthworms that are so common in my part of the world are not native here either, but there is little I can do to diminish their numbers.
    
    So I pull and cut and sometimes spray and my students think I’m that crazy prof who would rather declare war on invasive plants than talk on a cell phone. How weird. But there is a certain parallelism to all of this. When I am in a foreign country, the last place in the world I want to eat a meal is in a Pizza Hut or a McDonalds. And when I am in a forest near Ithaca, NY, the last plant I want to see growing there is a European or Asian species. In both cases, something is being lost and, although I can not put to words exactly what that loss is, I believe it is important.
    
    DrTom

16. Denial, conspiracy, and the state of things

    28.May.08, 13:38 EDT
    
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    We have all done it. We want to blame someone for nearly everything bad that happens to us. In the case of oil prices, there are several likely suspects. Exxon-Mobil is making huge profits, speculators are driving the price up because of their trading in oil futures, there is too much oil in the U.S. Strategic Petroleum Reserve, and China is hoarding oil. In fact, a CNBC poll this morning showed that respondents believed that only 15% of our oil problem was due to consumers; the remaining 85% believed it was due to speculators, OPEC, President Bush, Congress, or big oil companies. It could not possibly be the case that demand exceeds supply, because that would mean that they, or we, or I am using too much oil. If we are using more than can be produced, that might mean that economic growth has a limit of some kind, and that is nothing we have ever had to contemplate.
    
    In fact, we still reject the notion that there is a limit to growth, because, if true, it would adversely affect all types of measures of our “quality of life”: the creation of new jobs, the increase in the value of my stock portfolio, the nation’s GDP, same store sales this year over last year, and so on. We reject this unpleasant scenario and replace that specter with an attempt to find out who is doing this to us. Once we identify the criminals, we can alert our government who will punish the offenders or pass new legislation and, thereby, fix the problem, or so the thinking goes.
    
    On the other hand, this week I heard three “experts” on financial markets, all of whom I have come to respect over the past 8 years, come down on the side of basic supply and demand as the fundamental cause of high oil prices---Warren Buffet, Jim Cramer, and Boone Pickens. Pickens, the legendary oil man from Texas, actually said that the world can produce 85 million barrels of oil per day at present, but the global demand is currently 87 million barrels per day. And the International Energy Agency report released earlier this week estimated that by 2030 we will be able to retrieve about 100 million barrels of oil from the ground per day, but the demand then will be about 116 million barrels per day. If the latter number is greater than the former, then there will be demand pressure on the price of oil. Of course, this is not to say that speculation has nothing to do with the exact price of oil at any given moment, but as the adage goes: “Speculation gets the price of a commodity to where it was going anyway, only faster.”
    
    I hear this same conspiratorial sentiment when discussing global climate change with the man in the street. It is all a scam perpetrated by ivory tower scientists and left-wing liberals like Al Gore and weirdo environmentalists. Someone is lying to us because THEY want US to behave differently, so THEY can benefit from our changed behavior. THEY are making up this grand story so THEY can become rich and famous. If THEY were correct that humans are causing climate change and this change is going to be bad for us, then WE would have to do with less, WE might have to curb our growth as a society, WE would have to drive less or drive smaller cars, or WE would have to turn off the lights frequently. THEY are doing something to US!
    
    It should be obvious at this point in this little tirade that I believe as Pogo stated several decades ago: “We have met the enemy and he is us.” There is really no one else to blame for this state of affairs but us: our individual consumption and, likewise, the collective consumption and waste of a huge and growing human population currently numbered at about 6.6 billion. Remember that there is a net annual increase in the human population of about 80 million people per year; a decade ago, the net increase was about 100 million people per year. Currently, that means that every year there are about 100 million new people reaching driving age, regardless of what the driving age is in the country in which they reside. Now, most of those people will probably never drive a car, but I think you get the idea. It is tough to increase the supply of oil, or to reduce the effects of anthropogenic climate change, when the demand is increasing inexorably.
    
    Supplies and prices of commodities or other necessities of life will not be resolved easily or quickly. And neither will global environmental problems like climate change or conservation of biodiversity. But I continue to believe that no problem is likely to be solved unless we understand the true cause. Pogo was a wise opossum.
    
    DrTom

17. Hay fever and the evolution of pollination

    24.May.08, 05:54 EDT
    
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    April and May are my favorite months in upstate New York, because overt biological activity returns to the landscape. It is also my most miserable time—I suffer from allergies to pollen. My eyes water and itch, my nose tickles and runs, my throat is scratchy, and I sneeze a lot. I can take medicine but it makes me sleepy, and if I have to drive, being drugged is a bad idea. I am not alone. Approximately 20-30 million Americans suffer from outdoor allergies, mostly plant pollen. Although I have never been tested for the specific pollen to which I am allergic, I am pretty sure that maple, oak, ash, and possibly pine cause my problems, based on which flowering trees are in abundance near my house every year. I am also very allergic to grass pollen, so I simply stay out of meadows and hayfields during mid summer.
    
    The enemy of those of us who suffer from allergies to plant pollen is “anemophily”. We all learned that flowering plants produce pollen, which is equivalent to sperm in vertebrates. The pollen must reach the plant carpel, or female part, of the plant so that the DNA in the pollen grain can join the DNA from the female gamete found in the ovule to produce a seed. We know that some plants are self-fertile, but others require that the pollen from the male structure get to a female flower elsewhere on the same plant, or to another female flower on another conspecific individual in the landscape. In some species, like aspen, you have male trees that produce only pollen, and female trees that produce only female flowers. So pollen often has to find a female flower of the same species somewhere in the landscape many meters or even hundreds of meters away. Most plants rely on insects, bats, or birds to move pollen from point a to point b, but about 20% of plant species rely on wind for pollen transport; this form of pollen dispersal is called anemophily. And those plants are the problem for hay fever sufferers, because their pollen is in the air to enter our eyes and nose.
    
    Plants with showy, colorful flowers are always used in those television commercials that advertise an allergy medicine. You know the ones. The woman wants to garden, they show her walking through a yard full of black-eyed susans, Echinacea, lupine, and penstemon, and the scene implies that all those flowers are causing her itchy eye problem. Wrong! Plants that have large, or colorful, or aromatic flowers evolved those structures to attract some animal that can see or smell those characteristics. Those tend to be the plants we put in our gardens, because humans simply enjoy the sight. Plants did not evolve those beautiful structures for our enjoyment. Natural selection has responded to the potential suite of pollinators that existed out there. In fact, the tremendous diversification of flowering plant species coincides with the diversification of insect species during the Jurassic about 190 million years ago, although there is controversy surrounding the cause and effect of plant-insect evolution.
    
    The plants that cause our problems are wind-pollinated, and they have small, inconspicuous flowers. How many of you know what a grass flower looks like? You need a compound scope to see them. But when they are at their peak flowering, if you hit the spike that contains those flowers, a small dust cloud of pollen will billow into the air. If I walk through such a field for 10 minutes, I need to reach for the Benadryl.
    
    I have never suffered from hay fever in the tropics, however. This is curious, because there are many more plant species near the Equator than in upstate New York. But maybe that incredible diversity is part of the explanation as to why I am symptom-free in Costa Rica. There are many species, but it seems that the number of individuals in each of those species in any given location is not so great. The chances of a wind-blown grain of pollen landing on the female flower of another individual of the same species would seem to be low, or even remote, and not very efficient. If plants were selected naturally to develop a flower that attracts a particular species of fly or beetle or hummingbird, which visit to collect nectar or even pollen itself, that mobile organism is much more likely to visit another flower of the same species, probably within minutes. Many, but not all, of these animal pollinators are real specialists, and tend to visit only one species of plant. This is a much more focused system than relying on wind, which works just fine in the forest around my house where I have dozens of maple and ash and pine trees per acre, for example. (The story gets a bit more complicated. Red maple, which I have always thought caused my allergies, has small, red flowers. They are wind-pollinated, but they are also visited by bees. The fact that they are red suggests that they are not strictly wind-pollinated).
    
    So now you have something to think about. It is fun to look at a flower and attempt to hypothesize what pollinates it (see link). But also, the next time someone complains about their hay fever symptoms and points an accusing finger at the large yellow flowers growing along the side of the road, you can give a little fake sneeze and smile knowingly to yourself.
    
    DrTom

18. Our feline “friends”

    19.May.08, 11:38 EDT
    
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    About a decade ago I had a student in my Conservation Biology class named Scott Boomer. We were discussing the problem of non-native organisms that week, and Scott told me he had kept some interesting records on the behavior of three cats that he and his wife had at that time. The cats (one male, two females, and all neutered) had access to food and water in Scott’s apartment around the clock. The three natural predators had the habit of capturing prey outside and bringing it back to Scott, often dropping it at his feet or putting it in their bathtub. Scott is a biologist and he was able to identify all the prey items returned to his apartment over a 2-year period. The list included:
    
    Mammals: 5 deer mice, 2 woodland jumping mice, 5 Eastern chipmunks, 4 meadow voles, 1 gray squirrel, 6 star-nosed moles, 4 short-tailed shrews, 1 cinereus shrew, 2 little brown bats, 1 Eastern cottontail
    
    Amphibians: 2 green frogs
    
    Reptiles: 1 Eastern painted turtle, 3 Eastern garter snakes
    
    Birds: 3 common yellowthroats, 2 black-capped chickadees, 1 house wren
    
    Total: 43 animals
    
    Now, there are about 90 million cats in the U.S., according to the 2005-2006 National Pet Owners Survey. A certain percentage of those cats never go outside. But anyway you run the numbers, the collective mortality on native wildlife by U.S. cats must total millions of individuals of dozens of species. In some places in the world, feral cats, those that have gone completely wild, are responsible for the demise of rare species of birds. The Stephens Island wren (a flightless species) in New Zealand went extinct in the late 1800’s due to the island’s cats, or so that story goes. The wedge-tailed shearwater in Hawaii is also impacted by cats. Conservation biologists actively control cats (as well as non-native rats, mongoose, etc.) in such places today, especially on oceanic islands.
    
    We hear a lot these days about our “ecological footprint”, or the impact that a human has on the earth’s natural resources and ecosystems. I doubt that our pet ownership is included in these calculations. Remember that I tend to think in terms of quantity and quality of habitat for biodiversity. I usually think of our “habitat footprint” as defined by the boundaries of our house and the lawn surrounding it. But the effect of that living space penetrates further depending on the chemicals we use on the property, how far away we or our children trounce on the environment, and the influence of our pets, of which cats are probably the worst offenders. There are zones of concentric circles beginning with the epicenter of the house itself, which include areas of decreasing influence on the fauna and flora that is there now, as one moves respectively outward. Cats probably have an effect in each of those zones, but they may represent the only threat in the outermost circle, which is perhaps several hundred meters from the edge of the house.
    
    This blog post is meant to increase awareness of an idea that perhaps you have not thought much about. I do not intend to explore a detailed solution to this problem, although attaching a simply bell to your outdoor cat would probably reduce its kill rate. You might be thinking that cats kill organisms that people do not like very much anyway, so what the heck. But I can assure you that every one of those species listed above that was killed by Scott’s cats are really interesting vertebrates, behaviorally and ecologically. Remember that not so long ago, nearly everyone thought it was fine to shoot wolves and eagles.
    
    DrTom

19. The evening ritual

    15.May.08, 11:04 EDT
    
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    I have an evening ritual this time of year. I take a glass of single-malt scotch and a good cigar and I go to a place in the forest around my house and sit there for an hour or so. (Today it was a 12-year old Glenlivet and a La Gloria Cubana). Vertebrates are breeding here this time of year, so I watch and I listen. I always take my binoculars with me. Tonight was good.
    
    A gray squirrel was building one of its summer nests. I had never actually seen them to do this, even though the leafy nests, or dreys, are obvious in the forest during the summer. This nest was in the top of a dead white pine about 7 meters off the ground. The squirrel climbed to nearby red maples, nipped off branchlets with leaves, and carried them rapidly back to this nest. The branch was somehow placed in the nest, but I could not see the details of that. It is amazing how much energy must be expended scampering up a tree vertically, over and over again. I never thought that squirrels have their babies in these nests; females use tree cavities for that important purpose. But some literature indicates they do use dreys for birthing.
    
    I also found a tree cavity being readied for nesting by a pair of black-capped chickadees. I knew they nested in cavities, but I never actually saw them excavating one. Chickadees are considered “weak” excavators. Woodpeckers usually start the cavity, and then chickadees take it from there if the wood is soft enough. Chickadees are sexually monomorphic, so you can not tell which is male and which is female. In this case, the pair took turns entering the cavity, with tail stuck partly out of the opening. I was not sure if they scraped the interior with their mouth or their feet, but they left the cavity with a mouthful of woody debris that they dropped to the forest floor several meters from the hole. I am sure they will line the nest with some soft material once this initial process is completed. This cavity was in a dead red maple, about 3 meters off the ground. Note the importance of dead trees that can be used for cavity excavation in the forest. I will follow the progress of this nest through the spring. At one point a third chickadee appeared, but was promptly ushered away by one of the residents.
    
    A point I have been making for many years to students is that none of us has seen it all. Tonight, I observed two behaviors, one by a gray squirrel and one by a pair of chickadees, which I had never witnessed before. This is what keeps me going back day after day. It is great entertainment, and it is free.
    
    So here is your assignment, should you choose to accept it. Find some natural or quasi-natural area near where you live this week. If you live in New York City, you have Central Park, for example. Then, go there! Spend at least 60 minutes there and just watch and listen. Especially listen. Go alone. And do not take a cell phone or one of those darn iPod thingies with you. Come back here and tell us what you saw or heard. It does not matter if you know the names of the birds, or mammals, or insects. Describe them. If you do not see or hear something you have never seen or heard before, I will be amazed. Some people sit in their apartment and meditate or do yoga, and that is great. But outdoor, natural approach works also, and you may learn something new in the process. (Use of the scotch and cigar as props are optional). Happy listening!
    
    DrTom

20. Fretting about my forest

    08.May.08, 19:14 EDT
    
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    I am a purist when it comes to thinking about habitats for plants and animals. I want it to be the way it used to be. I wish I could go back and see North America 500 years ago. I wish I could live another 300 years to see what the forest around my house will become. But there are many factors that cause a natural habitat to deviate from what it could be, or to be different from what it once was. In most of the world, we cut down whatever was there originally and planted food crops, built houses, or just abandoned the land after we harvested the original inhabitants.
    I guess we are pretty lucky in the northeastern U.S., from a naturalist’s perspective. After the massive clearing of those fantastic deciduous forests, humans attempted agriculture and most of it failed economically. That process has allowed that vast area to regrow itself over the past six or seven decades in a process known as secondary plant succession. For example, the hill on which I live was a cattle pasture until 1960, so I now own a forest that is about 48 years old. This old pasture is developing as a forest mostly on its own. The trees are getting bigger and older, they flower and produce seeds, new seedlings appear and grow, develop into saplings, and so on.
    
    So why am I on edge all the time about the biological process I am witnessing every day around me? For starters, we have a major mammalian herbivore living here—white-tailed deer. Deer eat many of these tree species, as well as various non-woody plants, and deer, therefore, influence the species composition and relative abundance of tree species in the future forest. In my forest, they seem to prefer maple, oak, magnolia, and tuliptree, and avoid ash, cherry, aspen, juneberry, and hornbeam. Given that deer densities in this region may be about 10 times their original density, they can have a significant impact on what our future forests become. Realize that I love deer; after all, I conducted my Ph.D. dissertation on Columbian white-tailed deer in the Pacific Northwest. But they have become the bane of my existence as a conservation biologist in upstate New York.
    
    Second, there seems to be a new tree disease in the region every time I ask an expert. Chestnut blight decimated American chestnuts decades ago, Dutch elm disease pummeled American elms, and beech bark disease infected American beech; more recently we have to worry about the woolly adelgid on hemlocks and the emerald ash borer in ash trees. All of these have the potential to significantly reduce populations of these tree species and every tree disease listed above has something else in common—none of them are native to North America. The pathogens all got to this country from Europe or Asia. Introduction of non-native or exotic organisms is a major problem for the conservation of biodiversity globally (one of the so-called “Four Horsemen of the Environmental Apocalypse”).
    
    And finally, there is the “invasion” of non-native shrubs in the forests of the U.S. In my area, the offenders are usually Tartarian honeysuckle and multiflora rose. I have both of them in abundance in my woods, or at least I did until I declared war a few years ago. I have spent many hours walking and pulling, or walking and clipping, or even walking and spraying the tough ones with the herbicide “Roundup.” And with the elimination of every individual comes that feeling of satisfaction that I am putting the system on the right track. We may not know all the species that were in this habitat centuries ago, and we may not know the relative abundances of the various native species back then, but we know that Tartarian honeysuckle and multiflora rose were not part of it.
    
    For what it is worth, I continue to patrol for deer with my Labrador retriever, pull up exotic shrubs, and monitor my trees for any mysterious death. I’d have to live until 2308 to see if I made any difference at all. And most of the time, I feel I am just spitting in the ocean, because the forces of degradation are enormous and the majority of the public will never know the difference. It sure is getting lonely out there.
    DrTom