We’ve reached that point in the school year when my biology students have learned about Gregor Mendel, his experiments with pea plants and the general concepts of genes and heredity. We’ve also taken a look at the structures and basic functions of DNA and RNA and the roles that they play in the process of protein synthesis. Next week we will be looking at the concept of genetic mutations and their important role in the general process of evolution. In short, we are about to get into my favorite part of the year when we can consider the existence of life on Earth and how it has changed over the last 500 million years.

During the lectures on evolution we will explore the concepts of the struggle for survival and its place in the broader concept of the “survival of the fittest.” The general concept of genetic “fitness” is sometimes an interesting one for students because it is not always as simple as it might seem. In preparation for the lectures to come in the next few weeks I am rereading certain books on Charles Darwin, including his autobiography. My particular copy of this book (which has been printed and reprinted many times over the years) has an entry on the inscription page that reads, “It is not the strongest of species that survives, not the most intelligent. It is the one that is most adaptable to change.”

This brings to the deliciously complicated concept of time to the forefront. Suddenly we aren’t talking about the survival of a single individual, but rather the survival of a species. We are forced to think of the concept of “fitness” not as simple physical fitness, but as the overall ability of an organism to survive and reproduce. The day-to-day struggle of the individual is important because it is potentially going to shape the future of the entire species in question. Who survives? What does that mean (if anything) for the future path of the species as a whole?

We spend a lot of time thinking about Mendel’s experiments so that we can bring an understanding of genes and alleles into the discussion of evolution and with those ideas comes the inevitable contemplation of reproduction. In the world of wild plants and animals, but especially in the animal world, we must acknowledge that any particular individual has only a limited opportunity to reproduce. Thus, when and with whom you reproduce is quite important. And, for wild animals and humans alike, there is also the question of “if” you will reproduce at all. In order for the long game to play out, the short game must be played over and over. The two are inseparably intertwined with one another.

And just as I am starting to prepare for discussions on this topic I happen to have come face to face with the realities of the struggle for survival right outside my kitchen window. Last month I wrote columns on red squirrels and gray squirrels and discussed some of the characteristics of the two species and some of the behaviors that I have observed. I rarely re-visit a species so quickly, but in this circumstance I think there is merit, for I have seen the result of conflict, of “struggle” between individuals.

There are several red squirrels that visit my feeders and their “antics” are quite entertaining. These animals tend to be in a constant state of irritation, consternation and exasperation with almost everyone around them and I think we find it endearing because they are so small. To think that such a tiny creature would have the audacity to give a human such a sound and thorough dressing down just makes us laugh, but that somewhat diminishes the seriousness of their attitudes. If red squirrels were the size of raccoons they would be absolutely terrifying creatures.

Red squirrels really put on a show when they are in close proximity to one another and there is no habitat feature more likely to create such situations as neatly as a birdfeeder. Such an abundance of food made available in such a small pinpoint of a location will bring many individuals together and sometimes the seriousness of their “humorous” dispositions comes to light. Over the years I have seen certain squirrels that are missing part of a tail, but this year I have seen what is certainly the most extreme evidence of conflict — a squirrel that is missing an entire ear.

Completely healthy, this squirrel is a male and he has clearly been involved in a physical altercation. The upper portion of his right ear is completely gone, but it is difficult to immediately determine if this makes him a loser, or perhaps a winner. Only time will tell for sure. At present I can only identify four red squirrels by sight. Two are completely intact, one is missing half of its tail and then this male is missing an ear. His continued presence will suggest that he is a winner. If he disappears, then I won’t really be able to say what happened. This is one of the most agonizing parts of science; the not knowing.

So keep your eyes peeled for any evidence of survival at your own feeders. Do you see hints of predator attacks? Do you see any evidence of conflict between members of the same species? Do you see any examples of courtship behavior? Pay close attention to northern cardinals for that particular tidbit. As you sip your tea, or your coffee, don’t just look at the birds; try to see them as well.

Bill Danielson has been a professional writer and nature photographer for 25 years. He has worked for the National Park Service, the U.S. Forest Service, the Nature Conservancy and the Massachusetts State Parks and he currently teaches high school biology and physics. For more in formation visit his website at www.speakingofnature.com, or head over to Speaking of Nature on Facebook.

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