Is the behavior of sports fans explainable?

 (Aaron Rodgers, quarterback of the world champion Green Bay Packers.  Hang out with this guy to really enhance your status.)

I warned you in my first blog about 18 months ago that we would eventually get to some gritty topics about human behavior.  Up to now, we have been mostly just messing around with the humorous aspects of the human condition.  But I want to tackle some fascinating elements of our species (at least they are fascinating to me, and this is my blog, and you are not the boss of me).  And although I am not a professional card-carrying behavioral ecologist, or sociobiologist, or evolutionary psychologist, I have followed this literature for nearly 40 years.  It is about the most interesting non-fiction reading there is, in my opinion.

My closest colleague at Cornell, Paul Sherman, does carry a valid card of the type listed above, and I have been strongly influenced by his thinking.  He proved to me that asking questions about animal behavior (humans are animals) and then posing possible answers by thinking about how natural selection works can be productive and stimulating.  I think it is a fun type of thought experiment.

I have been in wonderment for decades about the motivation of those who so passionately root for and idolize their favorite football or baseball team.  I just don't get it.  Sure, I supported my teams in high school, and hoped they would win the regional or state tournaments.  I wanted the football team to win rather than lose when I attended Ohio State University.  But as those years passed, I found that I couldn't care less if any particular team won or lost and, in fact, I got to the point where I can't stand to watch any sports on tv.  So I am naturally curious about this conspicuous human behavior displayed by tens of millions of people worldwide, and which enables a relative handful of star athletes to become famous and fabulously wealthy.

In particular, it is curious how a person can become so emotionally vested in a team on which you have never been a player, or excited about the outcome of a team from a school you never attended, or remain overtly loyal to a team from a city in which you have never even lived.  To a behavioral ecologist, this is all extremely interesting.  (Realize that this little essay is not about the person who loves the game of baseball or football or basketball so much that they could watch any two teams play and love every minute of it, and not even care who wins.)

I don't have a lot of data on which to build a little theory about this fascinating behavior of humans, but there are some observations about which we can probably all agree.  Here they are:

1.  the majority of fans that follow most teams are men; most of the most passionate fans are men

2.  the most avid male fans are of prime reproductive age (15-50)

3.  the passion is so elevated that in many (or most ??) cases, fans of one team literally hate other teams and/or hate the fans of opposing teams, hurl incredibly insulting epithets at them, etc. (for spine-chilling evidence of this, check out the numerous Facebook fan pages of sports teams, but don't let your young children read them)

4.  in many (or most ???) cases, fans advertise their commitment to their favorite team by wearing jerseys, jackets, ball caps, or belt buckles, and put team bumper stickers on their car

This behavior is interesting, because we ecologists are always analyzing what organisms do in terms of cost-benefit analysis.  So in this case, how do fans benefit from supporting their favorite team?  They must get more than it costs them in terms of time and money, or it seems unlikely they would continue their support?  Aside from the fan who bets money on the outcome of a game, most fans stand to receive no immediate material benefit from their team doing well.  So where is the reward?

Now, most of you are not students of natural selection, I assume.  So, you are probably saying that people follow their teams because "it feels good", "it is enjoyable", or "I feel a sense of pride when my team does well". But the behaviorist wants to know why it feels good.  If it is enjoyable, then it almost certainly serves some other purpose biologically.  Why do we like sugar?  Because it is sweet.  But biologists then ask why does it taste sweet?  The biological answer is that it tastes good to us (and probably to most mammals) so that we will seek it out and ingest certain foods that contribute to our nutritional well-being and, thus, our survival.  The same kind of answer follows the question about why sex feels good.  If sex were painful, humans would have intercourse less often and, presumably, have fewer children on average compared to a group of humans where the act was pleasurable.  I am simply asking the same question about why so many humans follow their favorite sports teams so passionately.

At this point, I need to introduce the concept of "status", which has a special meaning in biology.  There are many factors that can contribute to an elevated status in humans: wealth, notoriety, physical beauty, intellectual acumen, physical prowess.  Status is important, especially for males, because females are attracted to men with high status.  High status males have more mates during their life, copulate more, and leave more children (or at least they did before the era of easy access to contraceptives in developed societies), which is the all-important currency that drives evolution.  Thousands of scientific studies show this relationship for non-human animals.  The data for humans are more difficult to obtain, but if you search Google for scientific studies by P.W. Turke and L.L. Betzig 1985 (Those who can do: Wealth, status, and reproductive success on Ifaluk), E.A. Smith 2004 (Why do good hunters have higher reproductive success?), or R.L. Hopcroft 2006 (Sex, status and reproductive success in contemporary United States), you will find convincing evidence that status matters a great deal to humans.  But you already know that status is important to humans, and that we try to raise ours all the time.  This is true of humans in every culture and society everywhere in the world.  And if I asked you why we seek status, you would probably say something like "because it feels good".

There is little doubt that professional athletes have high status.  The Super Bowl that I watched Sunday exhibited some of the elements that contribute to the status of the participants, aside from the obvious financial payoff.  The President of the United States watched the game at home, and a former President was in attendance at the game along with numerous high-status movie stars.  Then, there is the presence of the U.S. military, which I have never understood.  Regardless of how that association ever got started, the military pageantry just before the game, the singing of the National Anthem, the military fly-over, and the segues to our soldiers in Iraq who watched the game lend credence to this football game as an important event in America.  That is, the Super Bowl is a really big deal, watched by more than 100 million viewers.  As Michael Douglas stated in that somewhat emotional segment before the kickoff, "This is so much bigger than just a football game."  If you think that the "head man" or chief of a Paleolithic village of a couple hundred people had high status among his villagers, then the status of the quarterback of the winning Super Bowl team must be off the charts.

What then about the fans?  I have long thought that the idolization of celebrities that is so common among humans is a status-enhancing behavior.  Or, at least it is a behavior that is a vestige of an age-old desire to be close to the source of power, wisdom, or wealth.  Perquisites that enhanced survival and/or reproductive success must have flowed to those who were confidants of the clan or tribe's chief throughout most of human history.  Today, if I were a close friend of Warren Buffett or Bill Gates or the Queen of England, I would likely obtain some tangible benefits.

And so we are strongly attracted to famous, wealthy, and powerful people, even if it is from afar.  We celebrate them, idolize them, dream about being with them or at least seen with them-------of somehow having our lives and our fortunes touched by theirs.  To help prove this point, imagine that you flew from New York to LA, and you happened to sit next to Angelina Jolie on the plane.  I will bet you my next three Social Security checks that the first words out of your mouth when you joined your spouse or friend at the terminal would be: "Guess who I sat next to on the plane?"  It would probably be the most significant event that happens to you all month, and you would talk about it with whomever would listen.  Importantly, your status would be enhanced, at least for a little while, because of this experience you had with the famous celebrity.

We may not be conscious of the possible enhancements to our well-being if we were to be befriended by one of these high-profile people, but that lack of awareness does not lessen the potential benefits of such an association.  Anyone with higher status than ours is a person with whom it is worth fraternizing, so in a global world the number of such people is extremely high.

It should be obvious by now that my hypothesis is that our tendency to follow a sports team, and to advertise that fact to others, is just another example of attempting to enhance one's social status.  It is a cheap and easy tactic to use; being a sports fan is the poor man's approach to bettering your position.  But there are certainly other explanations for this behavior.  For example, maybe people (essentially men) become a visible fan of a team because nearly everyone else in their social group or community is already a fan.  By NOT being on board, you could be viewed as a weirdo and, of course, your status would suffer accordingly.  But that is essentially the same idea; namely, maybe your status will not soar because you became a fan, but it might decline if you do not.

I have not discussed how we might test this idea or other predictions we could make based on it, but this blog is already too long.  Another time. I could be dead wrong about all of this, and I strongly invite your alternative explanations.  However, as I have long believed, the wrong hypothesis is better than no hypothesis at all.

On mowing the lawn

(I doubt these guys are saving any gas.)

I've been mowing lawns since I was about 7 years old.  We would never let our young kids use dangerous power equipment like that today, but that was a different time.  The yard had to be mowed, my father worked long hours away from home, and my mother was busy with two younger siblings.  I've mowed lawns of houses in which I have lived in Ohio, Idaho, Oregon, Washington, Arizona, Oklahoma, and New York, so I have given the activity a great deal of thought.  In fact, thinking is mostly what one does while mowing the lawn.

I mow about a half acre here in Ithaca.  Until 5 years ago, I used a walk-behind mower and it took 3-3 1/2 hours to complete the job; after I got a riding mower, the job was reduced to a third the time, so it gave me less time to think than doing it the old way.  Now I feel rushed.  I have to cover a lot of mental ground in only an hour or so.  I used to have time to outline my classroom lectures in my head while on the mower.  Now, I can barely enumerate the names of my kids and grandkids before I am finished.  When we rented a farm in Monteverde, Costa Rica years ago, the peon who worked the place mowed our lawn by hand, with a machete.  Wow!  He must have gotten a lot of thinking done.  He always seemed like he had life pretty well figured out, and the abundant time he had cutting grass probably contributed to that.  We modern North Americans can cut the grass lickety-split with our fancy machines, and we are clueless about almost everything.  See the correlation?

One of the first issues in mowing is exactly how you are going to do the cutting.  What pattern will you adopt?  Most of us mowers probably go around in a square, shooting the cut grass to the outside of the mowed area.  That means you are going counter-clockwise, because the outlet on the mower is on the right side.  I have seen some mowers simply go back and forth, first shooting the grass to the outside, and then shooting it to the inside of the mowed area.  That seems bipolar to me.  Some of the vegetation gets cut once, some gets cut twice.  Some aficionados have recommended that I mow my lawn using swaths that are diagonal within the yard, rather than horizontal or vertical.  Pretty fancy, so it would look good from a Google Earth photo.  But I stick with the counter-clockwise square, so I can easily determine that the geometric shape remaining to cut is diminishing in size as I go.  I need that positive reinforcement.

I have learned a great deal of ecology while mowing lawns for five decades in half a dozen states.  I apply no chemical spray to my lawn, so it is a bit rough with all sorts of herbaceous biodiversity that tell me something about what is under my feet.  One learns where the wet areas and the dry areas in the yard are located.  This often comes in handy later if you want to plant flowers or trees in the yard.  I learn where the yellow jackets have their hole in the ground, after they find me first.  I know where the pickerel frogs, which like wet meadows, live in my yard.  I enjoy the beautiful orange hawkweed blooms, just before I whack their little heads off, and I have followed the health of the same patch of buttercups for years.  I am aware of when crickets hatch in August, and I then anticipate the female turkeys that bring their brood through the yard to feed on the abundant insects.  I see deer droppings, and dog poop, and the occasional raccoon pile.  I know where moles like to dig their tunnels, and I know where they never dare to try.  And I see the non-sentient seedlings of white ash trees that are forever trying to find a home in a yard that is cut to the ground repeatedly.

So I think and I examine and I reduce the height of the vegetation. I accomplish mental work, I learn some ecology, and I make the yard look better simultaneously.  It's multi-tasking, the manly way.  When the mower is put away in October for the winter, I feel like I have closed up my mobile office or my lab for the season, and I truly look forward to all the mental stimulation that next May will bring.  Next time you have this chore to do, focus on nature's classroom that is all around you, and try to enjoy the relative solitude the job provides.  And remember, don't drink and drive, or try to send text messages as you negotiate that counter-clockwise square.

Tree planting programs: another form of greenwash?

(Is embedding tree seeds in cardboard a good idea, or just another round of greenwash?)

We hear a great deal about programs to encourage us to plant a tree.  It always sounds good, because most of us love trees, appreciate their value to us emotionally and ecologically, and understand the importance of wood and paper products that come from trees.  But when I scratch the surface of the suggestion to plant more trees for the environment, I find it is more confusing than amusing.

The supposition in these tree-planting programs seems to be that by planting a tree seedling or tree seed that we are rebuilding our forests.  But for this to be correct, it matters where you plop the baby tree, and what species it is that you are plopping.  Most ecologists are completely convinced that we should encourage vegetation native to a particular region to grow in that region.  I have often lamented in this blog the invasion of our local habitats by non-native plants.  So when someone gives you a tree seed and tells you to plant it, you need to know what species it is and if that species is indigenous to your area.

This week on Treehugger I read about a new "invention" where tree seeds are embedded in cardboard boxes.  When you are finished with the box, you bury the cardboard and a tree grows in that location.  Apparently, the company, which is called Life Box, has chosen tree seeds that are native to every major region of the country.  They think this has covered any criticisms about non-native species or invasive plants getting where they should not be (see comment by MycoKat here).  But it is not as simple as that.  For example, white birch is native and common in forests about 150 miles east of Ithaca, NY, where I live, but it is not found in the forest around Ithaca. If those seeds were used in their boxes, would those boxes only be used for shipping to eastern NY and not central NY?  I doubt it.  Humans have this tendency to superimpose their mental image of a map on the landscape, and it rarely matches the ecological reality that has been in place for centuries.

Let's assume you now have the seed of a tree species that is truly native to the exact location where you live.  But then, where do you put the darn thing?  You can always plant a tree in your front yard.  Nothing wrong with that.  That tree can be appreciated for its beauty for decades, and it produces oxygen and sequesters carbon dioxide during its life just like the next tree.  But this has nothing to do with regenerating a forest.  If you were interested in helping out our forests, I guess you might plant the thing next to or inside an existing forest.  But that is really unnecessary.  Forests produce plenty of seeds from the trees that are already there and don't benefit from our putting one more seed in the ground.  Evidence of the abundance of forest tree seeds can be found in your gutter every year, when you clean out the maple, ash, and elm seeds that have blown in there.  Squirrels and blue jays are moving nut seeds around the forest and planting them all the time.  Let nature do its thing.  It knows more than we do anyway about where to put these propagules.

So where should you put tree seeds if you have them?  I suggest putting them where they are really needed; put them where there is absolutely no forest at present, but in a location where there WAS once a forest that contained the species of trees you are about to plant.  An abandoned lot in a city would be a great place to undertake such a project, assuming there is still viable soil there.  That is, create a forest, however small, where there was not one before (or, at least, not in a very long time). Or what about an area that was once mined for some commodity, where the vegetation was skimmed off the surface of the earth for miles around?  That area needs help.  These examples would be true efforts at restoration.  Abandoned hayfields or meadows rarely need this kind of help; seeds from trees in nearby forests will find their way there.

My point is that planting a tree sounds as American as apple pie.  What could be wrong with a wholesome activity like that?  But this "movement" has all the characteristics of a program that makes us feel good without accomplishing anything substantive for the environment.  As a conservation biologist, we don't need more trees, we need more habitat.  And habitat, whether it is forest, or prairie, or marshland, mostly needs protection to develop on its own.  Only then will it contribute to viable populations of biodiversity, as well as provide all those "ecosystem services" like carbon sequestration that are so important.

Natural mortality in deer: the inescapable comparison to humans

(An adult female Columbian white-tailed deer marked with an ear tag and a plastic collar for identification in the field.)

For my Ph.D. research I studied a population of white-tailed deer located on a national wildlife refuge in southwestern Washington.  The refuge was situated on the north bank of the mighty Columbia River and this particular subspecies of deer is called Columbian white-tailed deer.  They were placed on the Endangered Species List in the early 1970s, which led to my research project on this rare form of North American deer.  The only other form of white-tailed deer that is considered endangered is the diminutive Key Deer of Florida.

As you all know, most populations of deer in North America are subjected to sport hunting every fall.  Historically, hunts allowed for male-only kills, but this has been greatly liberalized in recent decades to allow hunting of females to reduce the size of this now abundant (= too abundant) species.  One of the demographic observations about deer populations is the sex ratio of adults---it almost always favors females significantly.  Sex ratios among adult deer typically are 3-4 females for every male, and this is generally attributed to the fact that males are hunted and females are not.  That is, more males were removed from the herd every year due to legal hunting than were females, and this resulted in a skewed sex ratio favoring females.  Reproductively speaking, this is not a problem because most species of cervids (which include elk, moose, and caribou) have a promiscuous breeding system, where each male breeds with as many females as possible.  An adult male white-tailed deer can breed with 10 or more females during a single breeding season in the fall, so the skewed sex ratio does not inhibit reproduction at all.  Essentially, all females get pregnant every year regardless of the sex ratio.  Larger, older, and more experienced males probably obtain more copulations than younger, smaller, and less experienced males and, therefore, the larger bucks sire more offspring.

So, I had at my fingertips a non-hunted refuge population of deer to study, and I was free to choose the research questions that were of interest to me.  I decided that this was an opportunity to study natural mortality and demography in this population of about 200 deer found on a somewhat contained (i.e., surrounded by water or habitat not used by whitetails) piece of land of about 2,000 acres.  I lived on the refuge and worked on the population daily for two years.  At the end, an interesting demographic pattern emerged, which informed my view of what makes male mammals tick.

My primary method of studying this phenomenon was to systematically search the refuge with my assistant, Bill Half Moon, for dead deer.  When we found a carcass, I estimated the month in which it had died, its location on the refuge, and I collected the skull for later analysis.  This analysis involved removing a tooth, and staining and sectioning the tooth to reveal cementum annuli that can be counted to determine the age of the animal at time of death.  It is sort of like counting tree rings.  Of course, the sex of the deer was easily determined from the skull as well.  If the carcass was fresh enough, I took it to Oregon State University to be necropsied, and to determine the cause of death.  I also cracked open a femur to examine the bone marrow, which can be scored subjectively for fat content, which is a crude method of evaluating the nutritional health of the deer at time of death.

It turned out that in this population the sex ratio among adults was still 3-4 females for every male.  However, we knew that the sex ratio at birth was nearly 1:1; in fact, there were probably slightly more males born than females, a typical pattern in mammals.  That is, the sex ratio started out about equal, but by the time males and females were two years old or older, there were many more females than males in the population.  We knew that males were not leaving the refuge, or emigrating, so the only other explanation for the skewed sex ratio was mortality.  Between birth and adulthood, males died at a younger age than females.    Males, on average, were living about 3.5 years, while females were living an average of about 6.5 years.  The oldest male skull I recovered was 7.5 years old; the oldest female skull was 13 years old.  In other words, males were cycling through the population at a faster rate than were females.

To put it bluntly, males are just more reckless than females. They get hit my cars, they get caught in barbed wire fences, and they drown in ponds more often than females.  But the most common cause of death in males was their poor physical condition immediately after the rut, or breeding season.  In this population, the rut began in November and lasted about two months.  At the end of the rut, we are in the middle of winter when conditions are not conducive to recovering body condition, and males paid the price.  It is known that adult male deer spend so much time and energy locating and tending females in heat during the rut that they lose significant body weight.  They increase physical activity during this important process and they decrease the time they spend feeding.  The result is that males are worn out and emaciated come January, all because they want to make love to as many females as possible.  In fact, you could say that many males literally mate themselves to death.

The similarities to other mammals including humans is inescapable.  The mortality rate of male humans is higher than females, especially among those just entering age of reproduction.  Males take dangerous chances, largely in an attempt to increase their status in the eyes of females, whether they know it or not.  The winners can win big, with multiple mates during their life and the possibility of siring many offspring.  Of course, modern contraception has changed the outcome of this male behavior somewhat, but our behavioral tendencies produced over the past 4 million years of human evolution continue to play out regardless.

(See full citation and an Abstract of the monograph produced from this research.)

Does touching a bird's nest cause the female to abandon it?

(Male Bobolink.  The male usually helps at the nest, but the female does most of the work.)

Did you grow up with your mother telling you not to touch that robin's nest because the mother would not come back and the babies would die?  Most of us did.  This has to be one of the most frequently uttered adages in all of nature lore.  The fact is, this is mostly myth.

During the 1980s, Eric Bollinger and I studied Bobolinks in upstate New York.  Bobolinks are a polygynous (i.e., males commonly have more than one female mate) species in the blackbird family.  The males have an incredibly long, bubbly song and their appearance is described as having  a tuxedo on backwards.  They are about the size of a sparrow.  Bobolinks build their grassy nest on the ground.  The female lays one egg per day until she has completed a clutch of five, begins incubating with the laying of the penultimate egg (next to last), incubates the eggs for 10-12 days, and then feeds her nestlings for another 10-12 days until they fledge.  Males usually help feed nestlings, but they are not as attentive as females.

Eric and I and our technicians located hundreds of Bobolink nests in those years, which are built on the ground in hayfields and meadows.  Once we located a nest, we placed a bamboo stick in the ground about a meter away from the nest with some colored plastic flagging on the top of the stick so we could relocate the nest at will.  Once found, we checked the contents of the nest every day to determine its progress and success.  When the nestlings were about 7 days old, we removed each one from the nest, collected a blood sample, measured it, placed an aluminum band on one leg, and returned it to the nest.  In some years, we removed the eggs and measured them before returning them to the nest.  In other words, we disturbed the nests a great deal during their three-week life, although we were careful not to trample the concealing vegetation around the nest any more than absolutely necessary.

Nearly 1,000 nests endured this harassment, and Eric and I learned a great deal about the behavior of  females because of it.  If we found a nest while the female was constructing it, she usually abandoned the nest.  If we found the nest when she had laid only 1-2 eggs, she often abandoned the nest.  Once the female had laid her full clutch of eggs and began incubating, she almost never abandoned, and if the nest contained nestlings, she would absolutely never abandon her brood.  The same seems to be true of most other birds as well.

Think of it this way: the more the female had invested in time and energy in the whole operation, the less likely she was to give it up.  Remember also, most birds have only a limited seasonal window during which they can successfully complete the nesting cycle.  In the case of Bobolinks, it takes a total of about 30 days from initiation of nest-building to fledging of their young.  In addition, they continue to feed their fledglings after they leave the nest for some period of time.  Bobolinks do not return from South America until early May and they start moving south again in August.  If they had to start over with the nesting cycle part-way through, they would barely have enough time to get those babies to a size and age where they could endure a long migration at the end of the summer.

Realize that the patterns I have described above probably apply to most songbirds in North America.  They may not apply equally well to tropical birds, which live in an area with many predators, and which always seemed to me to be extremely wary of predation threats.  Those species might abandon their nests more readily than temperate species.

So when your mother or grandmother tells you not to touch that nest because the female will not come back to it, you can say: "Well Mom, it goes like this".  There is a danger of attracting predators to a nest that you have disturbed, and where you have presumably left your scent.  Raccoons are very good at following these clues.  But as far as the female of the nest is concerned, she has invested too much for too long to walk (well, or fly) away easily.

Hay fever and the evolution of pollination

(This woman is enjoying a good sneeze thanks to anemophily.)

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. 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.

Of invasive plants and Big Macs

(A McDonalds in Cairo.  Your order please.  Hamburger or hummus?)

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. The homogenization of biota and the homogenization of cultures disturb me.

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 rain forests 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 cloud forest 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 30 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 unacceptables is the human-assisted 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 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.

To me, there is a certain parallelism between what I observe in our native habitats and what I observe in cities around the world. When I am in a foreign country, the last place I want to eat a meal is in a Pizza Hut or a McDonalds (in fact, I guess they even kind of offend me here). 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.  But it goes something like this for me: The invasion of our landscapes with non-native plants is like a technician at the Louvre deciding to "touch up" the Mona Lisa with watercolors.  The average person would not even see the difference, but the art expert probably would.  The act of changing the Mona Lisa, the most famous painting in the world, would transform this important and beautiful object from what it was to a different piece of art.

On the other hand, are Costa Ricans or Egyptians offended when they see an American franchise restaurant in their cities?  Possibly not.  They might even think it is chic that they have this international influence.  I don't get offended to see a Chinese restaurant in Ithaca, but seeing a Pizza Hut in Alexandria bothered me a great deal.  Maybe I am uncomfortable because I fear that these restaurants, and these invasive plants, will not simply be an addition to what was already there, but that they will come to replace the original.  This creeping sameness makes the world less diverse and less interesting, but does that bother anyone else?
 
So I pull and cut and sometimes spray and my students think I’m that crazy ex-prof who would rather declare war on invasive plants than talk on a cell phone.  How weird.  And I eat rice and beans in Costa Rica instead of Big Macs, and I eat hummus in Egypt instead of pizza.  Is this what happens to us as we age?  We rebel at "progress"?  We cuss at the automobile for replacing the horse, or lament that email caused the extinction of the hand-written letter.  Or that friends were replaced with acquaintances. Or that family time was replaced with sitcoms.  I wonder, maybe I just have too much time on my hands.