Bald Eagles Soar to New Heights
Reintroduction project in Channel Islands National Park has been a success for the iconic raptors
As I kayaked into the cove at Cluster Point on the southwest side of Santa Rosa Island, part of the Channel Islands National Park in California, I witnessed something few had seen for at least 50 years. Two bald eagles, one mature, the other a juvenile, were lurking on the periphery of a northern elephant seal rookery. A big bull elephant seal appeared to be dead, lying motionless in the wind-whipped sand. The mature eagle hopped in closer and went to peck at the colossal marine mammal. Besides catching fish, the majestic raptors are known to scavenge on marine mammal carcasses. Just as it went for a bite, the 3,000-pound seal lurched skyward, startling both bald eagles. Their wings opened up and the howling northwest winds carried the hungry raptors eastward beyond the next bluff, the dramatic scene best observed from the seat of my kayak.
Bald eagles had virtually vanished from the Channel Islands National Park by the early 1950s due to poisoning from the pesticide DDT. Montrose Chemical Corporation, which manufactured DDT beginning in the 1940s, dumped hundreds of tons of it into the Southern California Bight near Santa Catalina Island, placing the local food web in great jeopardy. Exposure to the pesticide caused birds like the peregrine falcon, the California brown pelican, and the bald eagle to lay thin-shelled eggs lacking in calcium. Before chicks were born, eggs would crack and the chicks would be crushed by their parents. Generations of birds never left the nest.
Ten years of litigation followed, and in 2000, Montrose was ordered to cough-up $140 million in restitution, with $40 million set aside for the recovery of wildlife like the bald eagle, as well as seabird habitat restoration.
Beginning in 2002, the National Park Service, The Nature Conservancy, and the Institute for Wildlife Studies embarked on an aggressive recovery plan, releasing 12 bald eagle chicks a year through 2006, all on Santa Cruz Island in the National Park. The chicks, hatched in captivity, were brought to the island at just 8-week-old. Eaglets are not capable of flying until around 12 weeks, so they were firstplaced in hack towers, large elevated structures where they have a nest, a perch, and a view of their new surroundings. Before the eaglets were ready to fledge, biologists would go in and give the birds a checkup. Blood work was done, and the eaglets were fitted with GPS to track their comings and goings. When the chicks reached 12-weeks-old, the hack towers were opened and the birds could leave at their leisure.
Though reintroduction efforts ended in 2006, biologists have continued to monitor eagles born naturally on the island, giving check-ups when the eagles are 8-weeks-old, and fitting them with tracking devices. The hack towers are now used for sick and injured eagles.
Since the recovery project began, bald eagles have reclaimed historic nesting habitat in the National Park, and today there are at least 70 bald eagles on the volcanic isles. The success of the Channel Island eagles when it comes to nesting on their own, without human intervention, has also been a victory. In 2014 and 2015 alone, close to 20 chicks successfully hatched in the park. For example, a pair of bald eagles have successfully reared eaglets the last two years on Anacapa Island, the first successful nest on that narrow islet since 1949.
By comparison, on nearby Catalina Island, where eagles have also been reintroduced, biologists have had to repeatedly remove viable eggs from nests, swap them out with pseudo eggs, and incubate the eggs in a lab before returning eaglets to the nest for the parents to rear.
Of course, there have been challenges along the way. Some of the eagles attempted flying across the treacherous Santa Barbara Channel, and didn’t make it. (A few did make it – one flew all the way to Idaho.) One bald eagle was observed attacking two eaglets in their nest, severely injuring both. The young eagles were rescued by biologists, rehabilitated, and set free once again. Additionally, one nesting pair took the unusual step of making a nest to the ground. Previously, biologists from IWS had only seen this nesting behavior among bald eagles in the Aleutian Islands.
Santa Cruz Island has a webcam that offers a unique view of the breeding and nesting behavior of bald eagles on the Channel Islands National Park. Now anyone can experience the recovery of these apex predatory birds in one of the most remote National Parks in North America.
Chuck Graham has been documenting the recovery of bald eagles on the Channel Islands National Park since the reintroduction program began in 2002.