Bald Eagles Thriving and Maintaining Island Balance for Island Foxes

Across the Channel Islands, 2019 has been the best year for bald eagle reproduction since recovery efforts began 35 years ago. This spring 24 bald eagle chicks successfully fledged from nests. (That means they survived to fly.)

According to a press release from Channel Islands National Park: "This year there were 19 breeding bald eagle pairs on the Channel Islands producing 24 chicks, including 10 on Santa Cruz Island, 9 on Santa Catalina Island, two each on Anacapa and San Clemente Islands, and one on Santa Rosa Island."

Orange wing-tags mark Catalina-hatched bald eagles

Bald eagles are a vital part of the Channel Island ecosystem. As fishing eagles, they prey primarily on fish and other birds, as well as consuming carrion. Bald eagles do not typically eat mammal prey and therefore are not usually a threat to island foxes.

On occasion island foxes climb up into bald eagle nests. For the most part the foxes act as a clean-up crew picking up tidbits of food left behind by eagle chicks. Eaglets are typically either protected by a parent when very young or too large for island foxes to prey upon.

blue wing-tags mark no. island eagles

Bald eagles therefore help transfer vital nutrients from the marine environment up onto the island. They help provide marine resources to island foxes, deer mice, and the island ecosystem. Nitrogen and calcium from fish are dropped on the land or eaten and deposited via scat. Marine resources can then help to fertilize island plants.  

Island foxes and bald eagles lived in balance on the Channel Islands for thousands of years. The oldest bald eagle fossils found in Southern California are 35,000 yrs old and from the La Brea Tar Pits. Bald eagles declined between 1945 and 1960 because of the insecticide DDT which had been introduced by people into the surrounding marine environment. DDT and bald eagle.

Bald eagles historically kept golden eagles from colonizing the Channel Islands and, in doing so, protected the island fox. Though they are both called "eagles," bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos) are not closely related. They come from two distinct evolutionary branches of predatory birds that separated and became competitors more than 12 million years ago. (By comparison, humans and chimpanzees diverged from a common ancestor just 7 million years ago.)

Golden eagles are mammal predators; they specialize in hunting small mammals about the size of a football (rabbits, ground squirrels, deer fawns, marmot, etc.) . Golden eagles hunt island foxes. They also eat carrion. Because both species will eat something that is already dead, they are known to take food from each other. There have been accounts of a bald eagle taking a dead island fox body from a golden eagle.


These two large birds have evolved to specialize in different food, but they compete for territory and nesting sites. Around the world fishing eagles and mammal-eating eagles are in competition with each other. You might think of them like dogs and cats–they share an ancestor, both are predators, but they have different specializations. They put up with each other at times, they will steal food from each, and in a confined space, like the islands, they just don't get along.

Though both bald and golden eagles are similar in size, resident bald eagles on the islands are frequently in mated pairs. Golden eagles encountering the islands are typically migrating individuals. This two-on-one situation gives bald eagles the upper hand.

When the Channel Islands' bald eagle population is thriving, there is no room for golden eagles and the habitat is safer for island foxes. Check out live bald eagle nest cams on the islands: http://www.iws.org/livecams.html

More Connections Between Bald Eagles and Island Foxes

courtesy of P. Sharpe; bald eagle catching fish off the islands

The recovery of bald eagles on the California Channel Islands has played an important role in island fox recovery. Bald eagles prey on fish and marine birds. They are not mammal predators and do not actively hunt island foxes. Because bald eagles nest on the Channel Islands, they chase away migrating golden eagles and do not allow them to colonize the islands.

With 50-60 bald eagles now living across the eight Channel Islands, no island foxes are known to have been killed by golden eagles for several years. Bald eagles definitely make a difference in the ecosystem for island foxes. But what benefit do island foxes provide bald eagles?  

Across the Channel Islands bald eagles are hatching out their 2018 chicks. Channel Island National Park reported that there are 13 active bald eagle nests across the islands this year and at least 22 known eggs.  

courtesy P. Sharpe

Three eaglets hatched in the Sauces Canyon nest last week on Santa Cruz Island. You can watch them 24 hrs a day via a webcam https://explore.org/livecams/bald-eagles/channel-islands-national-park-sauces-bald-eagle

Tonight, close observers saw some unexpected visitors to the bald eagle nest. Along with fish, the parent bald eagles have brought scavenged seal placenta back to the nest to feed their chicks. But with the darkness, something else stole up into the nest to eat the placenta bits. Circled in green, do you see the surprise scavengers? island deer mice.

captured image from the webcam 3/20/18

Who would have thought that hungry deer mice would come up into the bald eagle nest to eat meaty placenta. The eagle does not have night vision, it is a daytime hunter. It could hear the munching mice and would occasionally drive them off. Island deer mice are known to eat songbird eggs, and possibly chicks, when given the opportunity, (like when island fox populations were very low). The eaglets are small and without their parent's protection, would they be prey for the gang of deer mice? At one point six deer mice were visible.

Island foxes play an important role in controlling island deer mouse populations. 

Other bald eagle parents on the islands are sleeping soundly tonight, but the bald eagle with the messy nest is wide awake in the rain. It has two jobs tonight: keeping three eaglets warm and dry, and keeping the deer mice at bay. It will be a long night for this bald eagle, it needs an island fox.

Island foxes sometimes clean leftover food out of bald eagle nests. Island fox in a bald eagle nest.

New discovery of house mice attacking albatross chicks and nesting adults. 

Bald Eagle Recovery Spreads Across Channel Islands

Channel Islands National Park reported in July that 60 bald eagles are currently living across California's Channel Islands. In spring 2014 there were sixteen known breeding pairs and fourteen chicks successfully fledged or flew from the nest.

As bald eagles reestablish their population, they help protect island foxes by reducing the probability that golden eagles will colonize the islands. Bald eagles primarily prey on fish and seabirds, while the golden eagles prey specifically on mammals. In the late 1990s, golden eagles nearly caused the extinction of the island fox on three islands: San Miguel, Santa Rosa and Santa Cruz.

Milestone bald eagle birth in 2013.

A landmark this year was the return of bald eagles to San Clemente Island. It is believed this is the first time bald eagles have attempted to nest on this southern island in approximately 50 years. The U.S. Navy manages San Clemente Island and they have been successful in protecting island foxes and other island endemic species. The bald eagles are evidence of recovering habitat on the windswept island. 

The newly established pair was unsuccessful in nesting in 2014, but hopes are high that the pair will find success in the future.

According to the National Park Service the pair of bald eagles combine the successes found on the other Channel Islands. The female was hatched near Juneau, Alaska, in 2004. She was relocated as a juvenile to Santa Cruz Island as part of the efforts to reestablish bald eagles on the National Park islands.

The male eagle is a young adult, hatched in 2007. He began life in an incubator on Santa Catalina Island and was placed in a bald eagle nest on the island, where he was raised by foster eagle parents. 

With a number of active bald eagle nests on Santa Cruz and Santa Catalina Islands, the young pair looked south for territory of their own. Biologists hope that eventually all of the Channel Islands will have resident bald eagles. The recovery of the bald eagle and the island fox is dramatically interconnected. Success for the bald eagles supports island fox recovery and stability.


See Current Island Fox Recovery, island by island.

Bald Eagle Recovery on California Channel Islands

courtesy of Peter Sharp

The return of bald eagles to the California Channel Islands has been a slow but steady effort that has aided the Channel Island fox recovery on the northern islands. A robust bald eagle population keeps away golden eagles, island fox predators.  

Island fox recovery has been incredibly rapid. More typical of efforts to save endangered species, bald eagle conservation has spread across decades: 

• 1967 bald eagle listed as endangered species
• 1970s bald eagles become extinct on the Channel Islands
• 1980 - 1986: 33 young bald eagles are reintroduced to Catalina Islands 
• 1987: eggs laid by bald eagles on Catalina Island fail to survive because of continuing high levels of DDT in marine ecosystem
• 1989: bald eagle eggs taken from Catalina Island nests and incubated. Later hatchlings or foster chicks are returned to nests. 
• 2000 - 2002: juvenile bald eagles reintroduced to the northern Channel Islands 
• 2006 first chick hatched without human assistance on the Channel Islands in 50 years; female A-49
• 2007 bald eagle eggs hatch on Catalina Island without human assistance
• June 2007 bald eagle taken off of the Endangered Species List
• 2012 Female A-49 nests for the first time on Santa Cruz Island, but first chick does not survive
• 2013 MILESTONE EVENT - Female A-49 and mate become the parents of female chick A-89 the first second-generation bald eagle chick successfully fledged on the Channel Islands since the beginning of the recovery effort

According to the biologists managing the bald eagle recovery program, fifteen pairs of bald eagles attempted to nest on the Channel Islands last year. See a photo of A-89 and the full accounting of bald eagle nesting on the Channel Islands in 2013 at the Institute for Wildlife Studies.

As a large predatory bird, the bald eagle plays an important role on the California Channel Islands. For more about bald eagle recovery SEE Video: Return Flight: Restoring the Bald Eagle to the Channel Islands by the Filmmakers Collaborative 

Celebrating Island Foxes, Bald Eagles and the Endangered Species Act

courtesy of NPS, Island Fox Recovery Group

December 28th is the 40th Anniversary of the Endangered Species Act (ESA). This vital legislation was implemented during President Richard Nixon's administration, along with the Migratory Bird Act, the Clean Air Act and Clean Water Act. Both political parties came together to improve the environment. Forty years later, there is much to celebrate.

Channel Island foxes were faced with extinction on four islands between 1998 and 2001. In 2004, island foxes on San Miguel, Santa Rosa, Santa Cruz and Santa Catalina were granted Endangered Species status resulting in additional protection and financial support for conservation efforts.

courtesy of P. Sharp, IWS, Island Fox Recovery Group

The ESA also played a vital role in protecting the bald eagle and restoring it to the Channel Island ecosystem. The interconnection between the island fox and the bald eagle meant that the survival of the island fox was dependent on the bald eagle's recovery. The role of the bald eagle on the Channel Islands.  

Protection under the ESA and conservation efforts have helped the bald eagle return from the edge of extinction. Island foxes are similarly benefiting. In less than ten years since their listing as an endangered species, island populations have shown dramatic increases and three populations have reached recovery levels. Early reports from Santa Rosa Island this fall suggest that the island fox population on Santa Rosa is now climbing toward recovery as well.

A major factor in saving the island fox has been the collaboration between government agencies, scientists, non-profit organizations and private individuals like you. Each year representatives from all of the Channel Islands, with island foxes, meet to share information and problem solve together. 

This December as we celebrate the Endangered Species Act and the success of island fox recovery, financial support to continue the annual Island Fox Recovery Group Meeting is in jeopardy. FIF knows that nothing is more important for the future of island foxes than bringing all of the people who work with the island fox together to share information. When everyone is in the same room, we save money, time and island foxes.

Help us raise $3,000 to support the annual Island Fox Recovery Group Meeting. It is a small investment, sure to reap conservation rewards. Please donate at the "Special Funding Need" donation button on the right.  

Find out more about the Endangered Species Act http://www.fws.gov/endangered/laws-policies/

Channel Island Foxes and Golden Eagles in 2013

NPS photo of a golden eagle in Denali N.P.

Between February and March of 2013, a threat to island foxes on the northern Channel Islands returned - a golden eagle.

Golden eagles migrate north from Mexico and the lower 48 U.S. states up into Canada and Alaska annually. Sometimes this means they fly over the Channel Islands. Historically, golden eagles have not lived on the Channel Islands for two primary reasons:

1. Golden eagles are mammal specialists. Their chosen diet consists primarily of mammals about the size of a football. The Channel Islands, prior to European settlement, did not have adequate food resources for this large predator to successfully live and breed.
2. Bald eagles historically thrived on the Channel Islands because they prey on fish, sea birds and carrion. Similar in size, bald eagles are highly territorial and dissuaded the golden eagles,  from spending extended amounts of time in the island ecosystem.

Why Did Golden Eagles Become a Threat to Island Foxes?

Beginning in 1843*, the islands were transformed into ranches. The surrounding ocean was the perfect fence.  Domestic animals (pigs, sheep, goats, rabbits (on Santa Barbara Island) and even cattle) were introduced and then allowed to go wild or feral. Mule deer and elk were also introduced on Santa Rosa Island for paid hunting trips. The young of these species, plus entrails left behind from hunting, attracted golden eagles to the northern islands.

By the mid 1950s bald eagles on became extinct on the Channel Islands because of DDT in the marine ecosystem. Without the bald eagle to drive it away, the golden eagle took up residence on the northern islands. Between 1994 and 2000, golden eagles nearly ate all of the island foxes on San Miguel, Santa Rosa and Santa Cruz Island. Island fox decline.

Positive Conservation Steps

island foxes during captive breeding, NPS

While the island foxes were protected in captive breeding facilities on the islands (2000-2008) conservation efforts helped restore balance on the islands:

• ~40 golden eagles were captured and relocated to northern California
• Bald eagles were reintroduced to Santa Cruz and Santa Catalina Islands. In 2006 they began reproducing naturally. The recovering bald eagle population is helping to stop golden eagles from recolonizing  the islands.
• Feral pigs, sheep and goats were removed and by 2012 introduced deer and elk were removed from Santa Rosa Island

Golden Eagles in 2013

On February 26, 2013 a group of bird watchers spotted a golden eagle at the Saticoy Spreading Ponds in Ventura. During this same time period, two island foxes on San Miguel Island were preyed upon by a golden eagle and a golden eagle was also seen on Santa Rosa Island.

Each year the threat posed by golden eagles flies over the endangered island foxes. Radio tracking collars are a primary means of alerting biologists that a golden eagle has killed an island fox. If predation continues, biologists can respond by trying to locate and capture the lingering golden eagle. Microchips under the skin of each island fox help biologists know the age and life history of individual foxes that are the victims of predation. Friends of the Island Fox raises funds to provide radio tracking collars and microchips for endangered Channel island foxes.

As the Channel Island fox populations recover on the northern islands, golden eagles pose less of a long-term threat. A normal population of 500 or more island foxes can withstand the loss of a few individuals to natural predation by golden eagles passing by. As the natural balance of the islands is restored with dense native vegetation, the territorial bald eagle in residence and robust island fox populations, the occasional golden eagle migrating by will become less of a threat.

*"Channel Islands National Park Timeline", Channel Islands National Park

Channel Island Foxes Celebrate Earth Day

Yippee! Channel island foxes have much to celebrate this Earth Day. Across the four islands, where island foxes were listed as endangered in 2005, pups are being born this month. The San Miguel Island fox that nearly went extinct with only 15 surviving foxes has seen a population recovery in record time. Current Island Fox Numbers 


Come Celebrate Earth Day with Friends of the Island Fox at the

Los Angeles Zoo and Botanical Gardens

Saturday, April 21 and Sunday, April 22

10 AM - 3 PM

April is pupping season! We'll be celebrating the newest generation of Channel Island foxes. Tani, the FIF Twitter fox, has gone into her den preparing for the birth of her offspring. Follow her on facebook. Across the islands wild female island foxes are doing the same thing.

Visit the FIF booth on Earth Day and see:

• the size of an island fox pup
• an island fox print that we made on Santa Cruz Island in March

Come to a Fox Talk at the island fox enclosure at Noon & 2 PM both days.

Join in a new activity to challenge your sense of smell. Can you follow a scent trail like an island fox?

Bald eagles reintroduced to the islands are thriving. A record 15 pairs are nesting across the Channel Islands. You can watch bald eagle chicks growing up on the live eagle-cams:
Channel Islands National Park eagle cams
Catalina Island eagle cams

Across the Channel Islands there is much to celebrate. You can see the recovery of wildlife yourself by joining Friends of the Island Fox on a trip to Santa Cruz Island on May 5, 2012.

Bald Eagles and Island Foxes

Tani is learning about the bald eagles on the Channel Islands and you can too. 

photo courtesy of Peter Sharp, IWS

Bald eagles went extinct on the Channel Islands following the use of DDT in Southern California. While this chemical insecticide successfully killed insects around homes and on agricultural crops, it stayed in the environment. The chemical ingredients of DDT take many years to disappear or degrade. They were washed from fields and cities into streams, rivers and eventually the ocean. 


When small animals ate the chemicals, they were in turn eaten by larger animals. Seafloor worms were eaten by fish, and the fish were eaten by the bald eagle and the brown pelican. The chemicals accumulated in top predators like theses large birds. The DDT didn't kill the eagles directly, it caused them to be unable to lay eggs with hard shells. When the mother eagle sat on her eggs they cracked. No eaglets were born and the bald eagles disappeared completely from the Channel Islands.


Today DDT is no longer legally used in the United States. Part of the effort to return the Channel Islands to their natural state was to relocate young bald eagles to Santa Cruz and Santa Catalina Islands. These reintroduced bald eagles have grown-up. They are doing well and reproducing.

You can watch the bald eagles live as they raise their chicks through the on-line EAGLECAM

As of May 1, 2011 the chicks are small gray fluffs in the nest.  They are growing up just as the island fox pups are growing up.

Watch a video from the EAGLECAM where an island fox visits the bald eagle nest.


Follow Tani's adventures as an island fox grows up on Twitter or Facebook.

An Island Fox Meets A Bald Eagle

The Institute for Wildlife Studies' EagleCams watch the bald eagle nests on Santa Cruz and Santa Catalina Islands off the coast of California. Not only do they document eagles nesting and rearing their young, sometimes they also get a candid shot of how animals on the islands interact.

This short video from Santa Cruz shows a bald eagle chick almost ready to fly (large and dark brown in the center). Notice its wing numbers placed by biologists tracking its growth and life. But the video also shows an unexpected visitor to the nest. Watch closely in the lower right hand corner and you will see an island fox climb up into the eagle nest.



Island foxes and bald eagles have interconnected lives. Bald Eagle and the Island Fox.

Because bald eagles on the Channel Islands find most of their food in the ocean or along the shore, pollution in the marine ecosystem can have a negative effect on their survival.

Your actions can have an important direct effect on the survival of the endangered island fox. When you visit any of the six Channel Islands where island foxes live there are specific steps you can take to Keep Island Foxes Safe.

Even if you can't make the journey to the Channel Islands, you can help in beach clean up to keep the marine ecosystem safe for bald eagles and to pick up debris that can be life threatening to island foxes (Island Fox and the Fishing Hook).

Join Friends of the Island Fox as we pitch in with the Channel Island Park Foundation to clean-up local beaches as part of the 26th Annual California Coastal Cleanup Day on September 25. Volunteers will meet at the Channel Island National Park Visitor Center at 9 AM. For More Information.

Island Fox Origins and the Truth Behind Eagle Diets

Are you looking for information on the origin of island foxes; how they evolved and their biology? Perhaps you’ve heard people question whether golden eagles were actually preying on island foxes. Answer your questions with information from the primary sources.

Friends of the Island Fox is honored to make information available from top researchers and biologists working with the island fox and the Channel Island ecosystem.


Paul W. Collins, Curator of Vertebrate Zoology at the Santa Barbara Museum of Natural History recently gave two presentations from his accumulated research at an Island Fox Workshop sponsored by the Santa Barbara Museum, Ty Warner Sea Center, Santa Barbara Zoo and Friends of the Island Fox. Both of these presentations are now available through links from the Friends of the Island Fox Educational Research Library.

• Origin, Evolution and Biology of the Island Fox - looks at genetic, morphological, and archeological data regarding island fox origins and the basics of island fox biology, size, behavior, reproduction and diet

• Diet of Bald and Golden Eagles on the Channel Islands - looks at the role eagles played in the decline of island foxes on the Northern Channel Islands and compares the diet of bald and golden eagles on the islands by examining prey remains in nests.

These two slideshow presentations can be found in the Educational Research Library

Under: “Island Fox Fact Sheets & Current Research”

Under: “Links to Research Sources”

Friends of the Island Fox is endeavoring to create the Internet’s most current library of information regarding island foxes. If you are a researcher or biologist and would like us to link to or host your published work relating to the island fox or the Channel Island ecosystem, please contact the Friends of the Island Fox Webmaster at islandfoxnews@gmail.com

Fire and Foxes on Catalina Island

As of 6 PM Friday May 11 the wildfire on Catalina Island appears to be 35% contained. The current situation is an unfortunate example of the delicate nature of island habitats.

Officials from the Catalina Island Conservancy report:

Bald Eagles
The bald eagle chicks that recently hatched on the island are safe. The nests are on the eastern end of the island and not near the fire area. (more on the new bald eagle chicks)

Island Foxes
Currently the effect of the fire on wild island foxes is unknown. Radio collars on individual foxes will be vital in locating individual animals and determining if any have been overwhelmed by the wildfire.

This is another situation that highlights the importance of radio collars on the endangered island foxes on San Miguel, Santa Rosa, Santa Cruz and Santa Catalina Islands. Island foxes are currently having their pups on the islands. This new generation will soon need radio collars.

You can help make sure all endangered island foxes have radio collars.

More on the Catalina island foxes.

As details regarding the Santa Catalina island foxes and the Catalina Island Conservancy become available Friends of the Island Fox will provide updates through our Island Fox News e-mails. To be added to the e-mail list contact us at islandfoxnews@gmail.com

For photos and an article in the Los Angeles Times CLICK HERE

Bald Eagle Update: Spring 2007

The recovery of island fox populations on the northern islands is linked to the successful return of bald eagles to the Channel Islands. (Why bald eagles went extinct on the Channel Islands in the 20th century)

Bald eagles stake out territory for themselves and help to keep out golden eagles which prey on unsuspecting island foxes.

This spring has been filled with wonderful successes for nesting bald eagles on the Channel Islands.

• U.S. Fish & Wildlife reports “Two Bald Eagle Chicks Hatch Unaided on Catalina Island”
• Catalina Island Conservancy announces “Third Bald Eagle Chick Hatches Naturally on Catalina Island”
• Channel Islands National Park finds bald eagles nesting for the second year on Santa Cruz Island
• You can watch the bald eagle chicks grow up via NestCam as part of the Catalina Island Bald Eagle Restoration Project conducted by the Institute for Wildlife Studies.
• Hear the Latest Bald Eagle News from Dr. Peter Sharpe, Institute for Wildlife Studies when he talks on “Bald Eagle Restoration on the Channel Islands” at Channel Island National Park Wednesday May 9 at 7:00 PM.

Each Channel Island is a delicate ecosystem. Restoring habitat and supporting a healthy bald eagle population is vital to saving the endangered island fox.

Island foxes are presently having their pups out on the islands. Stay tuned for Updates from the Fox Conference in June and come support Friends of the Island Fox at the Los Angeles Zoo & Botanical Gardens’ Fox Festival Saturday May 19th.