Why the ‘Obsession’ with Urban Biodiversity Could Be a Fatal Distraction
Published as part of an environmental storytelling partnership with the Laboratory for Environmental Narrative Strategies (LENS) at UCLA, with extensive contributions from faculty and MFA students in UCLA’s documentary film program in the Schoolof Theater, Film and Television. The second storyline considers how Los Angeles has inadvertently become a sanctuary city for non-native animal species that are sometimes endangered in their native habitats. Find more Urban Ark stories here.
“They’re here!” We craned and shuffled and peered, and — there they were: maybe six or eight parrots, perched in pairs at the top of a tree in Pasadena’s La Pintoresca Park, lit up by the last few minutes of sunset. But they had not truly arrived. Not yet.
Within a few minutes, there were a hundred parrots in the tree, then hundreds, then hundreds more in all the trees around us. Every branch of every tree for blocks was thick with parrots. The sky darkened faster than the sunset accounted for, as huge flocks of hundreds of birds obscured the San Gabriels in the distance and converged on the trees at the Pasadena intersection of Fair Oaks and Washington Boulevard. And they were all screaming, sharing the day’s gossip with a sound that drowned out the traffic and made us shout at each other: “Ok, they’re here!” And more came, and then they truly were here. Then, they were quiet.
Every day at sunset, Pasadena’s population of red-crowned parrots returns to roost here overnight. It’s an incredible show — Austin has its bat bridge, Seattle has its fish ladder, and Pasadena has its parrot park. The birds are a thrilling example of urban biodiversity. These parrots are endangered in their home range in northeastern Mexico but are thriving here. They are also an opportunity to experience a concept not yet as widespread as biodiversity: “bioabundance.” The term refers not to the number of species in an area but, more simply, to the number of individual creatures. There’s a big difference between a species being present and a species being abundant: a lone bird of a rare species may be an exciting find for birders, but a thousand of a more common species become part of the landscape, in terms of both ecology and experience. Experiences of bioabundance can be uniquely enriching, even overwhelming. Unfortunately, they may be harder and harder to find.
Several pieces in this series explore the ways in which scientists have come to appreciate and catalogue the biodiversity of cities like Los Angeles. Citizen science efforts, such as the Natural History Museum’s BioSCAN project, have revealed the incredible diversity of undiscovered species waiting to be found in urban areas. Another example is the city’s Sustainable City pLAn, which outlines the L.A.’s goal to “protect and support biodiversity.” Policies designed to support biodiversity — including expanding the city’s green spaces and developing non-toxic alternatives to pesticides — will likely lead to increased bioabundance as well.
Recently, though, some environmental thinkers have argued that adopting “biodiversity” as our standard measure for the health of a natural system can distract us from losses that drastically impoverish ecosystems even if they don’t kill species. Simon Barnes worries about the “crashing numbers of ordinary everyday creatures” that go unnoticed when we focus on the plight of rarer endangered species. Hugh Warwick has suggested that our “obsession with biodiversity” leads us to ignore evidence of catastrophic drops in the population of, for example, insects — citing a study showing a decline of insect biomass in Germany of 80 percent over less than 25 years.
Other unflashy creatures are suffering as well. A 2010 study suggested that the number of microscopic phytoplankton in the world’s oceans has declined over 40 percent since 1950. These tiny plants are the ultimate source of food energy for every animal in the ocean. They also help convert carbon dioxide in the atmosphere into oxygen, so their decline will likely contribute to global warming — and global warming, in turn, means less phytoplankton. Even if this cycle never causes plankton species to go extinct, the decline in abundance means a decline in fish, whales, dolphins and other charismatic megafauna we think of when we think of ocean biodiversity:. It also means a decline in the wealth and sustenance that people pull from the sea. In the same fashion, declines in the populations of bees, which pollinate our crops, could have many of the same effects on land.
Learn about how urbanization is contributing to the abundance of certain species (or lackthereof) in this segment of "Earth Focus."
But beyond the loss of the “ecosystem services” that we depend on, the shrinking number of plants and animals in the world around us — Michael McCarthy calls it “the great thinning” — is also the loss of a certain, remarkable kind of experience. McCarthy’s book “The Moth Snowstorm” is named for a memory from McCarthy’s childhood: when “moths filled the summer nights … in such numbers that they would pack a car’s headlight beams like snowflakes in a blizzard, there would be a veritable snowstorm of moths, and at the end of your journey you would have to wash your windscreen, you would have to sponge away the astounding richness of life.” As in Germany, insect populations in Britain have dropped by over 50 percent since midcentury, and the moth snowstorm is only a memory for people old enough to have lived through the experience. McCarthy describes a version of what marine ecologist Daniel Pauly has called “shifting baseline syndrome”: each generation's understanding of what constitutes a normal natural world is set by their experiences in childhood. And so, if we only measure an ecosystem’s biodiversity, we might miss the lost opportunity to experience what McCarthy calls “astounding richness of life.”
But nostalgia for such experiences remains. Maybe this is why the passenger pigeon is such a popular example of the possibility of de-extinction: when you read people’s descriptions of what it was like to see their flocks, which numbered in the billions and could take hours to pass, it’s hard not to yearn for that kind of biological immensity. Passenger pigeons seem to be a kind of charismatic megaspecies — a symbol for the fragile abundance of the natural world.
Luckily, there are opportunities for experiences like this — at least a little like this — available in California today. Every fall, thousands of Vaux’s swifts migrating south along the West Coast stop over in L.A. for a few nights. Some years, huge flocks have roosted in abandoned chimneys in downtown L.A. (Making sure there are always chimneys for the swifts might be a good application of biophilic design principles.) On the coast in the spring and summer, thousands of six-inch silver fish — grunion — wriggle out of the water in the moonlight to spawn. After wet winters, superblooms drench the desert in color. Santa Monica Bay is home to a booming shark population — although it may be best not to go see that example in person.
And butterflies. One of the most remarkable instances of bioabundance I’ve experienced was at the Pismo Beach monarch grove in November 2017. Monarchs spend their winters here and at other points on the coast to rest. In the gray light of an overcast fall day, they can be hard to see among the leaves of the trees. Until you lean in close, or a gust of wind blows through the grove, and you realize all those shaking leaves are the monarchs, and suddenly the whole grove is shimmering black and orange around you. The monarchs cover the trees and hang from them in long, fluttering strands. There can be hundreds of thousands at once; it’s like being surrounded by the species itself.
But local abundance does not always indicate a healthy species — monarch populations have declined 90 percent in the last 20 years, due to the destruction of milkweeds, the only plant the monarch caterpillars feed on.
The importance of bioabundance should direct our attention to the sturdy but sometimes ailing creatures that surround us — for example, to the fact that the number of trees in parts of L.A.’s urban forest has declined by more than half in the past 10 years, thanks to the ever-increasing construction of ever-larger houses. It takes effort to sustain these populations. If you’d like to help the monarchs, for example, you can create a mini migratory stopping point in your yard by planting milkweed. More broadly, essays in this series explore choices that we could make to make Los Angeles a friendlier place for bioabundance. I think these efforts are clearly worth it. The plankton and the bees sustain us. The butterflies and the parrots offer the chance to give ourselves over to the nonhuman world for moment. Our lives would be poorer without theirs.
