The phoebe and the porch light

 (An Eastern Phoebe with an insect.  Is it the same bird nesting on my porch light year after year?)

Each year in late March, Eastern Phoebes (Sayornis phoebe) return to my property from having spent the winter as far south as Mexico.  Today, they returned.  I can always tell, because the male sings incessantly when he returns, and his favorite song perch seems to be at the corner of our house next to our bedroom.  The singing starts just before it is light, so spring phoebes and DrTom are on the same schedule, fortunately.  I love early morning.

Bird migration has always fascinated me.  I have been more interested in why birds migrate, than in how they do it.  The answers to the how question are truly astounding, and there are many good summaries of this.  Much of the early pioneering work on this topic was done at Cornell University by Bill Keeton, who used homing pigeons as his model.  And the Germans Kramer, Sauer, and Wiltschko are important.  Depending on the species, they might use visual landmarks like rivers during the day, or they use the sun’s location, or they navigate at night by orienting to the stars, or they use the earth’s magnetic field.  Bobolinks (Dolichonyx oryzivorus), for example, contain small deposits of an iron compound called magnetite in their skulls.  This is presumably used to detect the weak forces of the earth’s magnetic field to help them migrate between North and South America.

Eric Bollinger and I published a number of papers in the 1980s on Bobolinks and the behavior known as breeding site fidelity, or breeding site faithfulness.  This is the tendency of individuals to return to the exact location where they bred the year before.  It turns out that this is a common phenomenon in migratory songbirds: adults often return to the exact location where they bred the year before, but their babies rarely return to the place where they were born.  In Bobolinks and most songbirds where this has been studied, adults tend to return to the site where they bred the year before if they were successful in producing babies at that location.  If the nestlings had been eaten by a snake or a skunk, for example, or the nest was destroyed by farming equipment, then those adults tend not to return to the same location the following year.  It appears there is a simple Darwinian algorithm operating in those pea-sized brains: if I was successful in producing offspring, return; if I was unsuccessful, do not return.

So, every year since 1980 we have had a pair of Eastern Phoebes near our home.  But the observation is more remarkable than that.  Phoebes originally nested on ledges beneath an overhang, probably rocky cliffs.  Houses, however, are a great substitute, because of the overhanging eaves and the existence of some kind of platform beneath that overhead protection—like a window ledge.  At our home, phoebes almost always use the light fixture next to the front door.  (They also use a window ledge on the back of the house.) This is convenient for me, because every morning during the breeding season, I step outside, reach my hand up and into the nest, count the number of eggs or nestlings by feel, and then resume drinking my Cafe Britt coffee (which, by the way, you can buy on this site).  Although I have never formally studied phoebes, this would make for pretty easy field work.  The bottom line is that nearly every year, the nest over our light fixture successfully fledges 4-5 young.

Now, I have never banded the phoebes at my house, and this is unfortunate.  I am missing a lot of the biological story, because I do not know if these are the same individuals that return to my property each year.  But for 28 years, phoebes have nested on this light fixture and yet these birds probably live only a few years—they can not be the same individuals during all of that time.  This means that new birds sometimes settle near my house, start looking for a suitable nest site, see the light fixture under that overhang, and a “CFL light bulb” goes off in their little head.  (Research has proven that light bulbs in bird heads are fluorescent and not incandescent).  Each succeeding generation of phoebes spots that nest location and simply can not resist it, in spite of the fact that every time we enter or leave the front door, the attending adult is flushed off the nest.

As you can see, my original interest in site fidelity has blended with a fascination for this incredible innate focus by the bird on a suitable resource, in this case a nest site.  I am sure that exactly the same consistency and skill go into locating and capturing food—phoebes mainly eat flying insects like moths.  Many thousands of years of natural selection have honed these abilities into a razor-sharp performance, which ensures their survival and successful reproduction.  For me, spring has not really started until I hear that simple, yet distinctive song of the phoebe.  My coffee is ready, so all I need now is this year’s nest.

Is life better with cell phones or is it just different?

(Electronic stuff.  Is life better or just different?)

My previous blog criticizing cell phones caused me to reexamine a question about which I have long pondered.  Are we better off with the invention of modern conveniences like cell phones or is life just different?  This is an extremely complex question, and one should not answer this glibly.  It seems to me that the only way to approach this problem is by using a cost-benefit perspective.  Let's return to the cell phone example. 

Cell phones allow us to communicate with other people and their electronic devices from almost any place at almost any time.  We can not only make voice calls, but we can send text messages that sit there until the receiver responds, and send photos.  With the "smart" phones, you can connect with the internet, and there are thousands of applications that can be downloaded that provide music, games, other forms of entertainment, and tools that range from determining what elevation you are at to helping you identify birds in the field.  Basically, you can send more information faster than ever before.  Very kewl, and extremely useful at times.

What about the costs?  Most people probably pay more per month than they would for their land line, cell reception is not as clear or as reliable as a land line (we need more frickin towers on more hills?), and the recent 10-year study released by the World Health Organization demonstrates that prolonged cell use increases the chances of developing a brain tumor.  One noted neurosurgeon, Dr. Vini Khurana, believes that worldwide there will be more deaths from cell phone use than from cigarette smoking, given that 3 billion people use cells.  Children, in particular, are warned not to use cell phones for long periods of time.  There are 330,000 vehicle accidents per year due to cell phone use while driving.  But other studies do not find a link between cancer and cell use.  So, innocent until proven guilty, or should it be guilty until proven innocent, like the FDA treats prescription drugs until rigorous tests prove otherwise?

In my originally question, I used the word "better" - is life better with a modern convenience like a cell phone or is it just different?  To answer this question, someone has to define the word "better", and I will leave that to you.  Is my life better because I can listen to music on my commute to work on the train rather than reading a book, or watching people, or talking to the passenger in the seat next to me? 

I've been picking on cell phones lately as the example du jour.  But you could replace the words cell phone with plastic bags, indoor carpeting, gasoline, automobile, prophylactics, shoes, rubber bands, or antibiotics.   Many, but not all, of these items results in a short-term benefit for the individual who uses them at the cost of degrading the greater environment for everyone else.

If, in fact, we could agree that life is mostly just different, not better, with some inventions, then the cost-benefit analysis begins to take a modified form.  Is it worth this "difference" to use a cell phone but to increase your chances of developing a brain tumor?  Is it worth this "difference" to be able to carry around water you bought in a store if it increases the plastic load in our landfills significantly?

On the other hand, if everyone in your community, or neighborhood, or profession adopt this new device and you do not, are you then at a significant disadvantage relative to your peers or competitors?  Maybe these devices result in life being "better" for the individual only after nearly everyone else has already adopted the thing.  It would be tough to be successful selling real estate if you had no phone when all the other agents did. But if no one had them, maybe life would not be any worse off for anyone.

I think the original question here would be a great topic for high school or college essays.  My perspective almost always comes from thinking about the trade-off between the quality of life for individuals versus the environmental cost to society generally, and there is almost always one.  What do you think?

Walk a mile in my shoes

(These shoes now reside in Paris.  Ignore the mismatched socks; that was just an absent-minded professor thing.)

The heavy, tight-fitting leather shoes were hurting my feet something awful, and I couldn't take it anymore.  So I removed them as soon as we disembarked from the subway near our room, and set them in an obvious place on the sidewalk against a building.  I walked the remainder of the distance to our room in my socks.  I suppose this was the first time an American had ever left a pair of perfectly good shoes on the sidewalk in the 16th arrondissement (the Trocadero section) in Paris.  My feet felt better instantly and I felt liberated generally.  Nearly barefoot on a Parisian sidewalk, and I didn't give a damn.

About a year after this, I was in Kenya for an international meeting in Nairobi.  After the meeting, I went on a little safari to the Maasai-Mara, where I stayed in a small tent camp.  On this trip I took a pair of sandals, to wear around the camp, and some high-top hiking shoes for daily excursions onto the savanna.  My Maasai guide and I hit it off right away; he knew all the birds in the area, and I wanted to know them all.  But during my two days with him it was obvious that he coveted my sandals, which he saw me wear to dinner each night.  When I was about to leave on the third day, I made a gift of the sandals to this young guy, who was extremely pleased to receive them.  He promised that if I ever returned, one of his wives would fix me a nice dinner.  Sounded good to me, as long as the dinner did not consist only of cattle blood.  By the way, if you have any good recipes using this "food", please pass it along.

Then, last month in Costa Rica my feet developed a rash that would stop the bulls in Pamplona.  I was convinced it was due to the Crocs I had been wearing, and they weren't very comfortable anyway.  However, I admit that the Facebook group that I had only just discovered titled "I Don't Care How Comfortable Crocs Are, You Look Like A Dumbass" was haunting me. I seem to have a deficiency when it comes to buying footwear that works for me.  So I gave the Crocs to the cleaning lady at the Hotel Herradura in San Jose.  They were nearly new and I didn't want to just toss them in the trash.  Bon appetit, or I'd guess you'd say bon chaussures.

So, three pairs of footwear left on three continents during a 3-year period.  I had become a one-man TOMS shoes' representative.  Although I was feeling a bit like a poor-man's philanthropist, I was more taken by the kind of story I might tell about this behavior.  Of course, the idiom that came to mind was"walk a mile in my shoes".  But that is an invitation for someone to see the world from your point of view or station in life, and literally wearing someone else's shoes does not accomplish that at all.   Ironically, given that people in the countries I visited wanted to own MY shoes almost allowed me to walk a bit in their shoes, if you catch my drift.

I suppose it is not a coincidence that we focus so much on footwear.  After all, you could walk around without a shirt or pants or dress if you really had to.  You might be embarrassed, but you can physically do it.  But try walking around Paris or San Jose or the tropical savannas of Africa barefooted and your physical metal would be sorely tested.  In other words, shoes may have become a method of making a fashion statement in the modern, affluent world, but it is damned practical to have some protection on the bottom of your walking tools.  I have stated this before but, after spending time in agricultural areas of tropical America, I have never looked at a banana or a cup of coffee without deep appreciation for the human sweat it took to produce those commodities.  Similarly, I will never look again at the choices in my shoe collection with passive disdain, even if the selection of the day makes me look like a dumbass.

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.