Catalina Island Conservancy

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Established to protect and restore Catalina, the Conservancy seeks a balance between conservation and public interest. Catalina's native plant community is central to the ecosystem of the island, providing habitats that offer shelter and food to the island's endemic and native animals like the Catalina Island fox, Catalina quail, and bald eagles among many other species. But years of importing non-native plants to feed grazing animals and landscape homes, has introduced to Catalina more than 76 highly invasive plant species.

Due to so many efforts in the past to capitalize on the island, many invasive flora and fauna were introduced. The Conservancy removes invasive plants to protect and restore the island. The Conservancy's Catalina Habitat Improvement and Restoration Program (CHIRP) is designed to ensure long-term conservation of species richness and habitat integrity in one of the world's biodiversity hot spots. Three species of highly invasive plants have been nearly eradicated from the island: tamarisk, pampas grass and fig. CHIRP has targeted 27 other species for eradication and another 36 to be managed to limit their presence on the Island.^[3]

By eliminating and managing invasive plant species, the CHIRP program has encouraged native species to grow and flourish.^[4] It contributed to the discovery of new species and the rediscovery of species following years of fear that they were extinct. Among those rediscovered are Catalina grass and Lyon's pygmy daisy, which had previously not been seen for 80 years. The James P. Ackerman Native Plant Nursery at Middle Ranch provides plant and seed material for re-vegetation of the island.

The Conservancy also operates the Stop the Spread program, a partnership between the Conservancy's naturalists, CHIRP staff and the many youth camps on the island.^[5] The program is focused on invasive plant control in and around each camp. Campers are taught about the value of native species, the problems posed by invasive species and how to help eradicate invasive species. Campers also learn how to restore and improve native environments. Stop the Spread has given nearly 15,000 campers tens of thousands of hours of education from 2009 to 2013. Campers manage about 450 acres for 75 different invasive species, logging more than 7,000 hours of invasive plant removal a year.

The Catalina Island fox is found on Catalina Island and nowhere else in the world. An adult fox weighs 4 to 6 pounds (1.8 to 2.7 kg) and is about 25% smaller than its mainland ancestor, the gray fox. Its diet includes mice, lizards, birds, berries, insects, and cactus fruit. It is Catalina's largest terrestrial predator.^[6]

In late 1999, an outbreak of distemper virus caused the fox population to plummet from about 1,300 to just 100 animals. In 2000, the Catalina Island Conservancy and its partner, the Institute for Wildlife Studies, implemented the Catalina Island Fox Recovery Plan. The plan combined relocation, vaccinations, captive breeding and release, and wild fox population monitoring.^[7]

Due to this outbreak The US Fish and Wildlife Service declared the Catalina Island fox an endangered sub-species in 2004. After 15 years of work by wildlife biologists, the Conservancy announced that the Catalina Island adult fox population had rebounded to pre-crash numbers.^[8] The Conservancy's biologists counted 1,850 foxes on the island, 350 more than the year before, in one of the fastest recoveries ever of an endangered species.^[9]

The Conservancy has worked with the Institute for Wildlife Studies in a successful program that brought bald eagles back to Catalina and the other Channel Islands after DDT contamination decimated their numbers.^[10]

The Conservancy is also actively managing a herd of bison on the island with a novel contraceptive program that is attracting the attention of wild animal managers on the mainland.^[11] The bison were first brought to the island in 1924 for a movie.^[12] Over the years, they became an iconic symbol of the island's culture. But with no natural predators, the herd grew to as many as 500. The Conservancy had previously conducted studies that found the island could support only about 150 to 200 bison. To control the herd's size, the Conservancy had been periodically conducting roundups and shipping bison to the mainland.

Shipping the bison to the mainland was costly, and it raised concerns about the stress on the animals during shipment and the expansion of the herd beyond ecologically sustainable numbers between shipments. Beginning in 2009, the Conservancy's scientists injected the female bison with porcine zona pellucida (PZP), a contraceptive that had been used for fertility control in zoos, wild horses and white tail deer.^[13] In addition to substantially reducing the number of new calves, the PZP had no apparent effect on pregnant females or their offspring. A peer-reviewed study published in 2013 reported that the contraceptive program was effective in controlling the herd.^[14] Previously, more than two-thirds of the cows delivered calves every year. After receiving the contraceptive, the calving rate dropped to 10.4%^[15] in the first year and 3.3%^[16] the following year.

The Conservancy's scientists, and their collaborators at California State University, Fullerton, continue to study PZP to determine if the female bison can regain their fertility^[17] after a period of time without the contraceptive. They are also evaluating the timing of ovulation in response to PZP application. After several years without bison births on the island, Catalina Island Conservancy had plans to bring two pregnant bison to Catalina at the end of 2020.^[18]

The deer are an invasive species, and they have a significant impact on native plants due to over-grazing.^[19] In 2023, the Conservancy created a plan to reduce the impact that invasive deer have on native vegetation. After consulting with wildlife experts, capturing and sterilization were eliminated as options, and a culling (killing from helicopters) approach was adopted. Some residents of Santa Catalina Island were opposed to the cull, and asked the Conservancy to reconsider.^[20]