by Christian Shepherd
photography by Jaysin Brandt
Near a small hill accessible only through an unpaved road of loose dirt and gravel, there is a modest hiking trail that traverses Sycamore Canyon in La Verne. Normally, the hill is sparsely covered in weeds and a few wildflowers, but this year, an unusually fertile spring has sprung forth new fruit: a superbloom of yellow, blue and pale wildflowers, some standing at least six feet tall that blanket the hillside. Kaleidoscopes of butterflies known as the Painted Lady burst forward from the flowers, like slag from a volcano, gorging on this buffet of nectar in numbers so large that new hope for butterfly population numbers has been fostered.
But the decline in butterfly populations, which has been noted for more than 100 years and widely accepted to be caused by problems such as global warming and mass development, is not so easily fixed; the Painted Lady is a particularly resilient species, and the likelihood of seeing a renaissance of this species of butterfly is slim to none and even less likely for other butterflies who do not have the same flexibility as the Painted Lady.
Like any other spring season, these orange and black butterflies have migrated to the greater Los Angeles area from their winter homes in the Mojave, where they go to escape the notoriously frigid 65-degree California winter. Since they can travel at around 25 miles per hour, Sycamore Canyon is just a small part of the Painted Ladies’ home, but the insects are more than happy to stay in the area as long as there is an available food source.
The canyon’s ecosystem is rich; it houses more than one type of reptile — notably the Rattlesnake, which can be heard regularly in the canyon’s quiet as hikers trek. The trail is adjacent to a training ground for unbroken horses, which are taken on walks along the hiking path. The horses keep the trails fertilized as they trot through the canyon with much less effort than the people on the trail. The wildlife here is thriving, but the higher hikers find themselves climbing, the more they are exposed to the human impact on the environment.
About halfway up the canyon, there is a lookout point that directs your attention directly toward the Interstate 210 Freeway and the hundreds of thousands of people who are driving or residing in what used to be the home of more than 150 species of California-indigenous butterflies. Now, track homes, highways and paved roads have cleared most of the fields that support the flowers that feed the butterflies.
Ecologists like David Bickford, a University of La Verne biology professor, have watched for decades as butterfly counts around the world have dropped at alarming rates. “We’ve turned former decent habitat and a lot of natural areas into real estate, into places that people love. The Mediterranean climate that we enjoy here in Southern California is awesome for us, and it used to be awesome for all the other organisms that were here before us … I think there is a direct correlation between the habitat loss that we’ve experienced at our own hands and our own benefits … somebody has to lose; it’s a zero-sum game,” David explains.
David Bickford lived in Singapore for 12 years, where he spent the majority of his time teaching at the National University of Singapore, a research-intense institution. He has been working in and around Southeast Asia for 25 years, focusing most of his adult life on conservation biology. “Butterflies really exemplify this slow, steady decline that’s been happening ever since we became more urbanized. We’ve seen the loss of species and the loss of individual populations leading to widespread decline,” David says. “When people say there is 80% loss of butterflies, 90% loss of things like Monarch butterflies, that’s really indicative of, yes, those animals are gone, but the reason those animals are gone is because the habitat is gone.”
David points out that we need to figure out the solution now, while the effects on the environment are not as dire, so that we can avoid problems like the complete collapse of our climate system. He says that the mission of reversing what has been done and staving off the worst possibilities is part of what scientists are studying today. “If we are thinking about restoration, we’ve got to put all the pieces back. What are the thresholds that we need to really be careful of, humanity’s kind of safe zone before things get past a threshold and become a nonlinear change?”
David also emphasized that the problems we have had are not linear degradations to the environment. When you combine them all, the effects become exponential. “It’s not just one thing, it’s this composite, and the unfortunate and highly probable situation is that they act in synergy. They don’t just add up to be some kind of net loss. It’s actually more than all those parts if you put them together. We have two or three human generations, so less than 100 years.”
David is only one of the countless scientists who is looking at the research and pushing for humanity to take direct action to reverse the issues it has caused. According to NASA, increased carbon dioxide and other man-made emissions in the atmosphere have caused the Earth’s average surface temperature to rise 1.62 degrees Fahrenheit since the late 1800s. The same study shows that the five warmest years on record have taken place since 2010. While a degree or two may seem like a minor change in places in Southern California, where we can experience heat as high waves breaching 110-degree Fahrenheit, one or two degrees of fluctuation in global temperature has devastating effects on environmental systems.
NASA research from the Gravity Recovery and Climate Experiment shows that between the years 1993 and 2016, Greenland lost an average of 286 billion tons of ice per year. Antarctica’s ice loss per year has tripled in the last decade, and from 1993 to 2016, it has been losing about 127 billion tons of ice per year during that same time frame.
Pomona College Professor of Biology and Zoology Jonathan Wright has been monitoring butterflies for decades. “I have done some butterfly surveys in the UK before I came to North America in my 20s. More recently over the past three years, I’ve been doing a butterfly census in our local Bernard Field Station in Claremont where we have been monitoring the butterfly population on a monthly basis.”
The walls of Jonathan’s office are full of bookshelves stocked with scientific texts and novels about the study of biology with titles like “The Story of Life” and “The Evolution Wars.” Opposite his desk, a Granny Smith apple rests on another burly text titled, “The Biology of the Invertebrate.” A pocket guide of butterflies species rests next to his keyboard. Jonathan says that while there is an ecological crisis taking place because of factors like climate change, the Painted Lady is actually an example of a species that is less susceptible to its effects. “[The Painted Lady] is a very resilient species so I suspect more substantial data sets across the country show the Painted Lady has not fared particularly badly with climate change so far. It is a very, very adaptable species. They are the most cosmopolitan butterfly species in the world, actually.” Jonathan explains that this is largely due to its breeding cycle, which can produce offspring multiple times per year.
“Quite a few of our species here in Southern California are single-brooded species, which means that they have one generation a year. They may overwinter as adults, larvae, pupae or eggs, but whatever scenario, when the pupae choose to produce the adult butterfly, that butterfly is the only generation of the year. That butterfly has to lay eggs and then the eggs, larvae, or pupae will all be, potentially, the next generation of adults and will be responsible for overwintering and seeding the next generation. Species that are multigenerational can breed two, three, four, sometimes even more times in a year, particularly those that are highly mobile and can potentially move from one favorable food location to another, like the Painted Lady, tend to be much more adaptable.”
Jonathan and David share the same sentiment toward urbanization and its impact on the surrounding ecosystems. “Butterflies, in general, have declined, and again, it is probably related in particular to the increased use of herbicides, pesticides, insecticides and development,” Jonathan notes. “When I arrived here 20 years ago, the I-15 area from Chino all the way south to Temecula was largely undeveloped, and there was a huge amount of low-elevation grassland there, and now an enormous part of that has just become urbanized and built up. With every bit of acreage that has lost a wildflower, we’ve lost acreage for adult butterflies to feed, because they are nectar feeders as adults, and potentially the food plant species [are gone] for their caterpillars.”
Here at Sycamore Canyon, it is easy to understand the impact of urbanization. The hiking trail leads to the top of the hill, but even at about a quarter of the way up, the view becomes a picture of the effects that David and Jonathan are talking about. An endless expanse of gridded real estate connected by major highways and roads, old and new industrial development sites and thousands of ant-sized cars is in the distance, cruising together to create a quiet hum that serves as the backdrop to this small butterfly haven on the hillside that once spanned through what people have now claimed for themselves.
From here, it is easy to see why butterflies are struggling, especially for species that are not as resilient as the Painted Lady, like the famous Monarch butterfly. “Monarchs have seen a rather catastrophic decline, actually, but that probably has to do with the fact that their breeding habitats are fairly localized in Mexico, and also, their food plants are very restricted. They only feed on the milkweeds. Milkweeds tend to live on field edges where they get knocked out by herbicides. Herbicide use has really destroyed their potential food source for the Monarch caterpillars,” Jonathan explains. According to the United States Environmental Protection Agency, 6 billion pounds of pesticides were used in 2011 and 2012. Pesticides are substances that are used to kill insects or other organisms that are harmful to cultivated plants or animals. Herbicides are substances that are harmful to plant life and used to kill weeds or other unwanted vegetation. A report from EPA shows that herbicides are on a swift upward trend.
Our World in Data, an organization that provides research and interactive data, estimates that in the year 2000 there were 156,919 square kilometers of urbanized human habitat. It also reported that 4.13 billion people were living in urban areas in 2017, and expect that number to jump to 9.77 billion by 2050–approximately 2 billion more than the current population of the entire planet. If humanity intends to sustain its ecological system, then a critical eye must be turned toward current practices.
“Climate change, pollution, over-harvesting, habitat loss, invasive species … they are just products of the what we do. We don’t mean for them to happen. The transportation systems and infrastructure is devastating to natural systems,” David explains. “Nobody meant that to be devastating; it’s just that not a lot of thought went into it.” ■