Several weeks ago, a reader said it seemed there were fewer birds around this year, and asked if that were true. Here’s my answer.
One might think that this is a straightforward question, but it’s not. There are fewer birds in the world now, and their numbers have been diminishing yearly for over a century. But for our local area, the best answer is: yes and no, it depends.
First, the global situation: We live on a planet that is what is called an ecosphere, a closed system that has finite resources. Larger non-single-cell animals, with very few exceptions, depend on green plants to fix the sun’s energy and make it available for use by living things. In the process of photosynthesis, the chlorophyll in green plants takes carbon dioxide and water and, using the sun’s light energy, converts them into carbohydrates (glucose) and oxygen. The carbohydrates not needed by the plants themselves, and the oxygen, is available to animals and provides food for conversion into energy.
Chemical conversions such as photosynthesis produce byproducts that scientists term waste. It is ironic that the waste products released by green plants are essential resources for most other life on earth.
Within the ecosphere, there is the biosphere, the total of all living things. In this essay, I am focusing on the larger animals (birds, elephants, snakes, humans, etc.) in total. What may not be obvious is the constant competition that is happening within this part of the earth’s biosphere. All these larger animals are competing for the food that plants provide. For millennia, we humans and other animals, including birds, competed on a relatively level playing field. Humans were expanding our reach and abilities, but we were held in check by various limiting/negative factors.
However, for the past 200 years or so, humans have dominated the competition and expanded our numbers rapidly. Humanity reached one billion in the mid-1800’s, three billion by about 1960 and now there are over 8 billion humans. We now make up about 32% of the mammal part of the biosphere (that is, 32% of all mammal animal cells on earth belong to humans). If one adds in all the animals that are propagated to serve humans (domestic animals like cattle and sheep), this number approaches 90%. And for avian part of the biosphere, domestic birds make up about 70% of the total.
This means that we humans, directly or indirectly, take in a huge proportion of the food/energy that plants produce. We also produce abundant waste products (the portion of food and other kinds of waste that are not turned into energy). We humans are very successful competitors, and we now dominate all the habitable earth.
Side-by-side and driving this domination is the increased ability of humans to exploit energy captured by past plants – fossil fuels – and the inventions of myriad machines to expand our domination of the ecosphere. We humans think of all this as progress and a growing economy, but it has serious consequences.
The first consequence is pollution. This growing economy has provided the food we need to survive and the energy we need for various forms of work. It also produces abundant waste products that oftentimes pollute the ecosphere.
Climate change driven by more carbon dioxide in the atmosphere is another consequence that comes to mind, but it’s not alone. Other major implications are desertification and ocean acidification (actually elements of climate change), the collapse of ocean fisheries, soil depletion, deforestation, food shortages, and many more.
How does this impact birds? Throughout the world there is less habitat and food/energy available to birds (and other non-human, non-domesticated animals) and as a result there are simply fewer birds. Some of these reduced numbers are well-known (for example, the Passenger Pigeon and Carolina Parakeet, common in the mid-1800’s but extinct by the early 1900’s), but others are more obscure.
Birds exist in a hugely-wide variety of locations and habitats, including parts of Antarctica, the only land mass not dominated by humans. But Antarctica’s remoteness has not lessened our human exploitation of its nearby marine waters. Humans now venture far and wide on the oceans, harvesting all types of food.
In fact, sea bird numbers have declined some 70% since 1950, due to both competition from humans for food and to pollution. In the late 1980’s, there were single flocks of Sooty Shearwaters (a seabird that nests on South Pacific islands) along the Washington Coast, numbering 1.5 million. Now, a flock of 100,000 is rare.
But what about locally? In many ways, we in Thurston County have been shielded from the worst of bird reductions. We are relatively underpopulated and wealthy; we do not need to exploit every niche for food. In fact, acting both publicly and privately, we have set aside important bird habitat areas for protection. These places are called refugia – habitat refuges for birds to breed, winter, eat and simply survive.
Almost all our residential species are not reduced significantly. American Robins, Song Sparrows, Winter Wrens, Spotted Towhees, Tree Swallows, Chickadees, Kinglets, and many more resident species are doing O.K. These include the species that you see at your seed feeder each winter. And, as long as we have sufficient refugia (and avoid the worst impacts of significant climate changes), we likely will not see big changes. It’s likely that our area will continue to be an avian refugia for many decades.
In fact, for some species, Scrub Jays and Anna’s Hummingbirds for example, we are seeing increased numbers. And, ironically, there are some bird species that seem to thrive on humanity’s waste. Think of crows and gulls – even with the closure of our local landfill, we still see them exploiting wastebins and the like. Rock Doves (City Pigeons) seem to thrive in conjunction with humanity and their numbers may make them a food source for avian predators like Peregrine Falcons.
My biggest fear for the near-term future of our local birds is for the species that migrate for breeding to our area from the global south. The loss of wintering habitat no doubt is diminishing their winter survival rates, and habitat changes along their spring migration routes will have impacts. These changes likely will come slowly, year by year, but in some future spring you may find that those Olive-sided Flycatchers you used to hear are no longer visiting us.
For the far-term, however, and beyond my lifetime, my biggest concern is the inability of humans to address the issue of ecosystem limits. We humans cannot continue to expand in both our numbers and our economy. We are exceeding the carrying capacity of the ecosystem. Exploiting fossil fuels has masked the full potential of our excess of habitat exploitation, but that cannot succeed for much longer.
Here’s a fundamental but unrecognized truth – you cannot make something out of nothing. Everything, from a walk around the block to a bird’s song, requires energy and that requires food. And the ecosystem’s ability to produce is finite. There is no “magic bullet” by which we will invent our way out of this dilemma.
I don’t know the answer – if I had one, I would be shouting it from the rooftops. But I do know that we (including our political and economic leaders) must step up and address this fundamental long-range question – what do we need to do today to ensure a viable ecosphere for all of us, including the birds, 200 years into the future?
George Walter is environmental program manager at the Nisqually Indian Tribe’s natural resources department; he also has a 40+ year interest in bird watching. He may be reached at george@theJOLTnews.com
Photos for this column are provided by Liam Hutcheson, a 16-year-old Olympia area birder and avid photographer.
ENDNOTE: If you are interested in this column’s topic, you might like to read an article recently published in the journal WORLD, “The Human Ecology of Overshoot: Why a Major ‘Population Correction’ Is Inevitable,” by William E. Rees. It is available as a shared file at open access publishing resource MDPI, click here.
EDITORS NOTE: This article was updated for clarity on 8-25-2023 at 8:05 p.m.
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PegGerdes
This is absolutely the fundamental question of our times. Superb article. Thank you.
Friday, August 25, 2023 Report this