Exploring the bird-tree connection
Noticing a nest in a tree can motivate the mind to wonder about many things.
Is it a bird nest or a squirrel nest? If a bird built the nest, what kind of bird was it? Why did the bird build its nest in that tree, and what kind of tree is it? And what materials did the bird use to make that nest? Will the bird use the nest more than once? Will the bird use the same nest this year that it built last year?
The questions can be many, but one particular question stands out: Why that tree?
A German botanist who studied various interactions between fungus and plant, Heinrich Anton de Bary published in 1879 an academic paper resulting from his research into lichens. Discovering that lichens are a combination of an alga and a fungus, de Bary coined the word “symbiosis,” which he defined as unlike organisms living together.
Prior to de Bary’s coinage of symbiosis, Belgian biologist Pierre-joseph van Beneden — known for his expertise in marine biology and parasitology — published the book “Animal Parasites and Messmates” in which he defined two new words: “commensalism” and “mutualism.”
He defined commensalism as a relationship between two species, one of which acquires needed survival benefits from the other and the other of which remains largely unaffected by the relationship. He defined mutualism as “mutual aid among species,” meaning all species involved derive essential benefit. Some sources cite his terms being used earlier than his 1876 book.
Regardless of dates of first usage, the three terms — commensalism, mutualism and symbiosis — collectively energized a long-sluggish aspect of biological science now known as “ecology.” Ernst Haeckel introduced that term in 1866.
As science-based research has expanded our knowledge and comprehension of Life on Earth, various scholars have redefined the terms and added a few new words. Some ecologists contend that “mutualism” and “symbiosis” mean the same thing and so are redundant.
I prefer to regard symbiosis as a large-scale encompassing term that sets the stage, so to speak, regarding how different species interact with each other. Other terms explain specializations in the way different species live together.
So, “symbiosis” means “living together”; and “mutualism” means living together in a way that benefits all species involved.
Looking up at that nest in the tree indicates something meaningful. That tree lives unaffected by either the presence or the absence of the bird’s nest, but the bird that built
Monthly nature programs at Loveland Public Library, 300 N. Adams Ave., continue in the Gertrude Scott Room. The year-long series “How Life Lives” focuses on the many different connections among living creatures and the various connections they all have to the nonliving world. The program, “Commensalism: One Way of Living Together,” will be presented at 10 a.m. Wednesday, April 3. The free program sponsored by Friends of the Loveland Library will explain how different wildlife species live together in a one-way benefit relationship.
that nest needed a protective place above ground to raise its offspring.
The bird benefits from the tree though the tree is neither benefitted nor harmed by the nest. I regard the bird-tree connection as Commensal symbiosis.