Eagles, Foxes, and Pigs – Oh My!

Oftentimes in the modern conservation movement, it feels like a lot gets said but little gets done. Lack of funding, political gridlock, social implications, logistics… there are countless obstacles that can lead to a project being proposed but never successfully implemented. This can be pretty discouraging, especially for budding conservationists (as many of us are) who are just entering the field.

I’m glad to say that this article shares a story with a happier ending than most. It’s incredibly easy to get bogged down by defeats and setbacks that hinder conservation efforts, especially under an administration that does not prioritize them in the slightest. For that reason, it’s important to continue sharing success stories like this one so we can learn from and be inspired by them moving forward.

Emerging from the depths of the Pacific Ocean, off the coast of Southern California, is an eight-island archipelago called the Channel Islands. Nicknamed the “Galapagos of North America,” these islands have evolved independently of the mainland for thousands of years and feature unique ecologies, species, and histories. Five of the eight islands now make up the Channel Islands National Park system and are protected as public land by the National Park Service (NPS), which is shown in dark green on the map below.

Santa Cruz Island is the largest member of the archipelago with an area of 96 square miles. It houses 60 of the 145 endemic Channel Island species that are found nowhere else in the world, making it a hotspot for conservation research and protection. Uniquely, the island exists under shared ownership between the NPS (24%) and the Nature Conservancy (76%), a private organization that purchases land for public use and conservation. After being struck with decades of nonnative invasions, ocean pollution, and endemic species decline, the delicate Santa Cruz Island ecosystem was in crisis. Teaming up with local experts, the Channel Islands National Park system and Nature Conservancy worked together to implement a large-scale, multifaceted, highly organized, and, yes, successful restoration project on the island. This is their story.

Santa Cruz Island

In the mid 1800s, the northern Channel Islands (including Santa Cruz) were colonized by European ranchers, bringing with them nonnative livestock animals and feral pigs whose populations grew rapidly. Pig rooting and overgrazing devastated Santa Cruz Island’s native vegetation, allowing invasive species like fennel to outcompete them and overtake a lot of the landscape. It also disturbed sacred archaeological sites of the Chumash native people, who had been inhabiting the island for millenia.

Santa Cruz Island ranch, 1869

Eggshells thinned by DDT

The destruction of native vegetation went on for decades, and eventually Santa Cruz Island was met with yet another threat. In the late 1940s, the Montrose Chemical Corporation plant in Torrance, CA began manufacturing DDT, a toxic pesticide known for wreaking havoc on the environment. Particularly, its chemical properties thin the eggshells of many bird species, including bald eagles which are native to the Channel Islands. Shell thinning often results in the eggs being crushed before chicks can hatch.

Bald Eagles

Toxic discharge with high DDT concentrations from the Montrose plant began polluting waters off the Southern California coast, which quickly made their way west towards the islands. Working its way up the food chain by bioaccumulation, DDT reached the Channel Island’s bald eagle populations as they preyed upon contaminated fish and rodents. The eagles experienced mass declines, and by the 1950s all twenty-four nesting pairs were eliminated from the islands entirely. Finally in the 1970s, DDT was federally banned and Montrose, having dispersed millions of pounds of chemical discharge into coastal waters, was shut down.

In the absence of bald eagles, another nonnative species began soaring over Santa Cruz Island. Golden eagles, without their natural competitor dominating the area, were drawn to the island in the 1990s by an abundant source of feral piglet prey. Much to their benefit, it turned out there was another source of prey available — the island fox. Island foxes are endemic to the Channel Islands, making them extremely vulnerable to extinction. Their vulnerability became shockingly apparent when, between 1994 and 2000, golden eagles reduced fox populations by 90%, leaving only 80 individuals on Santa Cruz Island.

The island’s ecosystem was in turmoil, but things were beginning to look up. Several years earlier, a lawsuit had been filed against the Montrose corporation under the federal Superfund law. Over the course of a decade, the case ended up acquiring $140 million from Montrose to be put towards DDT clean-up and ecosystem restoration. Some of these funds were allocated for bald eagle reintroduction, which sparked a new wave of collaborative efforts to restore Santa Cruz Island’s devastated ecosystem.

In the early 2000s, the Channel Islands National Park system and Nature Conservancy developed a complex restoration plan involving feral pig removal, golden eagle relocation, bald eagle reintroduction, captive breeding of island foxes, and recovery of native vegetation. With so many variables occurring simultaneously, the project was likely quite daunting. But its complexity reflects that of nature, which is probably why it was so successful!

Feral pigs were tracked down and removed from Santa Cruz Island, allowing native plants like buckwheat and sagebrush to slowly reclaim the land. Golden eagles were live captured and relocated to northeastern California, and with no feral pigs left on the island they had no incentive to repopulate the area. At this point, a captive breeding program for island foxes had been underway for several years in order to reestablish their population size. With golden eagle predators out of the picture, the foxes were gradually released from captivity onto the island and began reclaiming their natural range. The breeding program was remarkably successful, having released all foxes and restabilizing the population by 2008.

Meanwhile, Santa Cruz Island had also been selected to host the bald eagle reintroduction program as it was farther north away from the source of DDT contamination. Beginning in 2002, the program employed special tactics to ensure the survival of bald eagle chicks that were highly vulnerable due to thinned eggshells. Biologists were helicoptered in to some of the island’s highest mountain peaks (where bald eagles tend to nest) so they could take the eggs back to a research facility. There, the eggs were carefully incubated and monitored until chicks hatched. They were fed by a mock “mother eagle” and stayed at the facility for a handful of weeks, until they were juveniles old enough to attempt their first flight. They were then returned to the island where special perches had been constructed to help with takeoff.

Slowly but surely, bald eagle populations began to rise on Santa Cruz Island. The program culminated in 2006, when two bald eagle chicks were hatched naturally for the first time in over 50 years! Since then, the population has been stabilizing without human intervention. There are roughly 60 bald eagles spread across the Channel Islands today, which marks a huge success considering there were none just a handful of years ago. The eagles continue to be monitored by camera, and you can even watch the live webcam here!

Bald eagle chicks on Santa Cruz Island, 2006

It’s important to remember that fundamental change doesn’t happen overnight. Environmental issues have proven time and time again to be intricate, multifaceted, and far more complicated than we realize. Very rarely are they resolved after a first try — or second, or third, or fourth for that matter. Even this project, which received lots of institutional and public support and operated under ideal ecological conditions, took years to implement. The important part is not how many tries it takes to get there, but that we continue trying.

If you’d like to know more about the Santa Cruz Island restoration project, you can check out these videos:

Restoring Balance: Santa Cruz Island

Return Flight: Restoring the Bald Eagle to the Channel Islands

If you want to get involved with conservation efforts in the Channel Islands, there is still plenty to do! Channel Islands Restoration is a non-profit that works to restore and maintain the island ecosystems through education, research, fundraisers, and hands-on habitat restoration projects. They offer tons of volunteer opportunities and are eager for helping hands!

Ellie Pumpkin

Ellie Pumpkin is a second year student majoring in Environmental Sciences and minoring in Conservation and Resource Studies. Having grown up in a rural area on the coast of northern California, Ellie has a lifelong love for the outdoors and all of the life it encompasses. She is passionate about both writing and environmental advocacy and is excited to merge those interests in a student organization platform. Aside from trying to survive her lower division STEM classes, Ellie spends her time journaling, finding new music, making a mess in the kitchen, chasing sunsets, or planning her next camping trip. Ellie Pumpkin covers ecology.

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