The islands of the Californias are precious gems strung along a section of the coast of western North America — stunningly beautiful and home to unique plants and animals found nowhere else in the world, like the diminutive island fox, the cobalt blue Island Scrub-Jay, the iconic island oak (Quercus tomentella), and brilliant island mallows (Malva spp.). However, these unique ecosystems are particularly vulnerable to introduced species. In fact, 75% of bird, mammal, and reptile extinctions have occurred on islands. On these islands along the coast of California and Baja California, Mexico, a suite of nonnative, invasive animals were introduced between around 150 to 100 years ago. Fenced in by the ocean with no animal predators, populations of sheep, goats, deer, and more reached unsustainable densities. Having evolved without any herbivores larger than a rodent, the naïve island plants had lost their defensive spines and chemicals, and were targeted like baby salad mix. Voracious rats, cats, and mice plucked baby seabirds from the cliffs. Argentine ants did more damage than creatures many times their size and biomass, inhibiting native insects, rodents, and reptiles. Without the native vegetation to hold it together, bare soils eroded in sheets off of the landscape, leaving tree roots exposed up to an adult human’s hip. Whole new sandspits were formed from the eroding soil — enough to alter topographic maps. Fisheries suffered from the influx of sediment.
Fortunately, indomitable conservationists stepped in across the archipelago — from both federal agencies and nongovernmental organizations — to do the near impossible job of removing these invaders. Against steep logistical, legal, and political headwinds, these conservation heroes stayed firm in their knowledge that the islands couldn’t recover without this crucial action. And they made it happen. In February 2023, Santa Barbara Botanic Garden will celebrate three of the many conservation heroes who have led these efforts: Peter Schuyler from The Nature Conservancy and Catalina Island Conservancy, Kate Faulkner from the National Park Service, and Grupo de Ecología y Conservación de Islas in Baja California. We’ll be celebrating their work and the recovery that followed: vegetation transforming from a sea of invasive grasses to diverse native shrublands, rare birds recovering and recolonizing, and pollinators going about their work unhindered. We’ll also applaud the other efforts that were made possible through the recovery process: the planting of thousands of oaks, pines, manzanitas, and more; the fastest removal of a mammal (the island fox) from the endangered species list in history; and the recovery and delisting of six endangered plants. In addition, we’ll discuss how we can continue this work until the longevity and resilience of the islands’ unique flora and fauna are secured.
At our annual Conservation Symposium, we bring conservation heroes and engaging experts together with students, land managers, conservation practitioners, and educators. We examine issues from various angles and then follow with a panel discussion to illuminate how we can all contribute and what we can do even better moving forward. Our participants leave with the knowledge and energy to further the mission of conserving native plants and habitats for the health and well-being of people and our planet.