June 14, 2011
By Sabrina Lawrence-Gomez
Today we traveled from Middle Ranch to the City of Avalon to take part in the Naturalist training given by Frank Hein, the Manager of Education for Catalina Island Conservancy. Frank gave a lecture on the natural history of the island including its formation. The island was formed when the Farallon oceanic plate subducted under the North American continental plate at a shallow angle, forcing crust to scrape off, creating the Sierra Nevada and the Channel Islands. Catalina then rose up out of the ocean about 5 million years ago. Because of its unique tectonic history, the island is composed of metamorphic and igneous rocks that can normally only be found beneath the surface of the ocean. Additionally, Catalina’s ecosystem is so unique because it has never been connected to the mainland continental crust; all of the plant and animal life here has had to cross 20 miles across the Pacific from the mainland. Some species did this on their own, native species, while some species were brought by humans, introduced species.
Frank talked about many of the introduced species on Catalina, including the American bison and the now eradicated feral goats and pigs. The management of the bison on Catalina is a great example of the Conservancy’s ingenuity in balancing the interests of the ecosystem and the community. The bison are a tourist attraction and an adored member of the community (they aren’t used in the bison burgers that star in many local menus!) however they are not adapted to living on an island where there isn’t enough food to support a large herd. As a result Catalina bison are not as robust as those in their native Great Plains grasslands, not to mention they place grazing pressure on the island plants. In order to solve this problem, the Conservancy conducted a study and determined the optimum herd size to be between 150-200 individuals then transferred nearly 300 individuals to the Rosebud Lakota Reservation and the Dakotas to meet that quota. To maintain that low population the Conservancy placed the female bison on birth control (using a projectile syringe to administer injections!) in order to reduce the population of the herd and reduce the pressure that yearly child rearing places on the females.
This program has been very successful and a supported by the community, unlike the program that eradicated the feral goats and pigs of the island. A large part of the tension between the locals and the Conservancy is due to the removal all of these small game animals (except for one lone pig affectionately named Ninja Pig) from the island. Hunting goats and pigs provided a source of food and recreation for many on the island but these grazers were extremely detrimental to the ecosystem, encouraging erosion and preventing many plants from reaching maturation. Since these animals have been removed erosion has decreased and many native plants have bounced back, but there is now a distrust of the motives of the Conservancy. Frank mentioned how the Conservancy acts as a fulcrum, balancing public interests with its mission, to be a responsible steward of its lands. This is clearly a difficult balance to strike and there is much to be learned from the successes and flaws of these conservation efforts.
After the lecture, we explored the Conservancy’s Nature Center. Although this wasn’t my first trip to Avalon, it was my first visit to the Nature Center. At the front desk we saw the Eagle Cam! Eagle Cam is a live camera that films three bald eagle nests 24/7, two of which are on Catalina, as a part of the Bald Eagle Restoration Project. With the help of the Conservancy, the U.S. Fish and Wildlife Service, the Institute for Wildlife Studies, and the California Department of Fish and Game initiated a program to reintroduce bald eagles to Catalina in 1980. In 2007, two bald eagles hatched on the island, the first two to do so in almost half a century! The Conservancy has had great success with the program, and has set the bar for endangered species restoration programs.
Our next activity was an interpretive hike, a guided hike focused on natural and cultural history, behind the Wrigley Memorial up to the ridge divide road, led by Frank. We learned some new plant species and practiced our identification skills along the way. Some of the species we identified included: the Catalina endemic St. Catherine’s lace, sow thistle, laurel sumac, scrub oak, cucumber vine, the invasive genista, white and black sage, and the native sticky monkey flower. Creating and leading an interpretive hike is one of our main goals for this internship, and the hike with Frank provided a great example of one. Hopefully, we can incorporate all that we’ve learned today into our trail!