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Writer's pictureRyan Dibala

Eagles of Catalina

Never before in my life have I felt so alive – so squeamish to the pinch, so calmed by warming zephyrs. Often, I’ll close my eyes in hopes of forming sensory memories dominated by smells, sounds, and feelings, neglecting my sense of sight that so often overrides all other perception. For now, it’s only the errant wind on my face, the subtle smell of blooming buckwheat, and the long rapid trill off towhees.


View from the promontory near the Twin Rocks nest looking along Santa Catalina's northern coastline towards Goat Harbor and beyond


Life is calm and collected here; if I were to have the audacity to bring with me the slightest worry or concern to this spot on top of this ridge, I should well deserve the harsh rebuke of those enduring quotidian routines behind four walls.


A remote area on the southeastern corner of Santa Catalina island known as the Palisades


Santa Catalina Island is located about 29 miles southeast of Long Beach off the coast of southern California and is part of the eight-island Channel Island archipelego. This map was taken from the Catalina Island Conservancy website: https://www.catalinaconservancy.org/userfiles/files/Hiking%20Map%202017%2011x17.pdf


The hills roll down from all directions around the little town of Avalon, where I lived for three months working as an intern with the Student Conservation Association (SCA). I later accepted a position with the Institute for Wildlife Studies (IWS) working as a wildlife research technician in Channel Islands National Park


The romantic maritime town of Avalon and the many boats moored in Avalon Bay. The circular building is the Catalina Island Casino. Built in 1929, the Art Deco and Mediterranean Revival building is not actually a casino at all. The main floor is a theatre and the upper floor is a ballroom and promenade

My work schedule this year has been surreal, allowing ample time to explore the plains, foothills, and mountains of life – literally and figuratively. I have an 8 days on, 6 days off schedule working on Catalina Island as a field biologist tracking the movements and nesting behavior of bald eagles (Haliaetus luecocephalus) that were reintroduced here in the early 1980’s. Ever since the 1950’s, the pesticide Dichloro-Diphenyl-Trichloroethane - better known known as DDT - has had detrimental impacts on many marine-dependent birds, including the bald eagle. Here in southern California, the Montrose Chemical Corporation discharged an estimated 1700 tons of DDT into the Pacific Ocean between the late 50's and early 70's, contaminating ocean sediments on the sea floor off the coast of Los Angeles. Through the process of biomagnification, the pesticides worked their way up the food chain and affected predators occupying the highest trophic levels the greatest. Brown pelicans (Pelicanus occidentalis), peregrine falcons (Falco peregrinus), and bald eagles are a few of the species that were hit the hardest. DDT directly affects the birds by depleting them of their calcium reserves, resulting in the production of thin-shelled eggs that break when they are incubated by the adults.


A recently returned eaglet at the Seal Rocks nest on the southeastern corner of Santa Catalina Island


In 1978, Dave Garcelon founded the Institute for Wildlife Studies (IWS) in an attempt to restore the bald eagle to the islands of southern California. For over 25 years, biologists with IWS have been removing the contaminated eggs from wild nests and replacing them with dummy eggs. The real eggs are then brought back to a facility where the eggs are cared for in artificial incubators, the chicks are hatched and then fostered back into the nests. These nest manipulations have been done only on Santa Catalina Island where historically DDT levels have been the highest. Many birds have successfully fledged from the five nests on this island and have dispersed northward to the islands of Anacapa, Santa Cruz, and Santa Rosa in Channel Islands National Park. These are the birds I routinely monitor.


The female of the Twin Rocks nest soars high above us


Fog would regularly blanket the ocean, obscuring it entirely from my view. In this photo, you can appreciate the island's dry, Mediterranean-like chaparral vegetation


This year the program on Santa Catalina was extremely successful with a record-setting 11 hatched chicks. Seven of the eaglets hatched after being incubated in the lab and the remaining four hatched in the wild. This was the first year biologist Peter Sharpe refrained from removing eggs from the two nests that have been consistently showing lower levels of DDT within the past few years. As a result, both Pinnacle Rock and the West End nests were naturally successful for the first time in over half a century! This certainly is indicative of lower concentrations of DDT in marine sediments around Catalina.


Bald eagle eggs collected from island nests are kept in an incubator and regularly candled to monitor the development of the embryo. Note the tracings of the embryo's development in pencil


A newly-hatched eaglet in the hands of IWS veterinarian Winston Vickers


I couldn't resist having my photo taken with the little fluff-ball


The eaglets are fed quail meat for four to five days, upon which point they are taken back to their natal nests. This amount of time is not long enough for the eaglets to physically imprint on their caretakers, so we did not need to use puppets when feeding


The eaglets on parade a day before their return to their natal nests


Giving the eaglet one last feed before returning it to the nest


Returning the eaglet to its nest involves carefully carrying the fragile bird along precarious cliff-edges and precipices. Once at the nest, the dummy eggs (seen to the right) are collected and the eaglet is left to be discovered by mom and dad. The adults readily accept the chick and begin feeding it right away


While we were at the nest, the adults often made uncomfortably close swoops in our direction


This past week the eaglets had reached the age of 8 weeks. At this age, they have grown nearly the size of their parents and are still unable to fly. It is the perfect opportunity for biologists to band and mark the birds in order to keep track of their future movements. First, we attach a leg band that includes a personal identification number. Two patagial wing-markers are then clipped into the upper wing (an orange tag is used for Catalina birds and a blue tag is used for Santa Cruz birds) and a GPS transmitter backpack is mounted around the neck. Lastly, measurements are taken and blood is drawn for later sex determination.



An adult bird and a camera used for a live web feed at the West End nest


All of the nests on Catalina are located on rocky pinnacles adjacent to the ocean – some are not the easiest to visit. The combination of steep approaches, loose rock, prickly pear cacti and dive-bombing adult eagles make a few of these hikes downright treacherous. Karen, another research assistant working on the project, apparently lost her footing twice while scrambling to the Pinnacle Rock nest. Luckily, her backpack broke both falls. The helmet on her head also provided ample protection. Pete actually required that helmets should be worn at a few of the nests, not because of falling rocks but because of aggressive eagles. Earlier this year, Pete was clipped in the back of the head by K-33, the male at the Twin Rocks nest. Attacks like these are extremely rare and the whole thing was kept low profile so as not to give a bad reputation to the bird we are trying to save.


Prickly pear cacti on a ledge near the Seal Rocks nest


Location of the Two Harbors nest. We approached the exposed escarpment via a rocky scramble on the far side of the ridge


Attaching patagial wing-markers on the juvenile eagles at the Two Harbors nest. Each eagle has its own personal number to identify it from afar


Fortunately, this year it wasn’t necessary for me to deal with Pinnacle Rock’s gnarly approach and Twin Rocks’ ill-tempered male. I helped with banding the chicks at Two Harbors and Seal Rocks. These two nests each have their own unique attributes: Two Harbors is up on an exposed ridge above an isthmus (some say the ridge resembles a pregnant woman lying on her back with the nest located at the tip of her chin). Seal Rocks is on an east-facing cliff, nestled in the shadow of a scrub oak (Quercus pacifica). Its approach is steep and loaded with loose rocks but upon arrival, it feels as if one is climbing into the recesses of a tree fort.


The blind to observe the Twin Rocks nest is at the top of this rocky knoll. The approach is a hike along the ridge and a steep climb up the rocks seen on the right. I brought my parents up there and they both made it to the top unscathed without a complaint



Enjoying a fun visit from my parents


The cantankerous male at the Twin Rocks nest. This was the bird responsible for leaving a five-inch gash in the back of Pete's head while returning a chick to the nest


We had safely scrambled down to the Seal Rocks nest where Pete had one of the two chicks in his arms. He quietly passed the frightened bird to me and proceeded to capture the second chick. In order to avoid scaring the eaglets off the side of the nest, Pete approaches slowly with a curved stick. He uses this stick to apply support to their backs so as to prevent them from taking a long tumble down out of the nest. This pressure also guides the bird closer to him, whereupon he uses his free hand to grab it above the talons.


The juvenile eagle's curled talons after receiving its band


Once Pete got hold of the second bird, he passed it my direction, instructing me to put my index finger between both legs while using my surrounding fingers to control each individual leg. Once I had a firm grip, Like a feathered football, I tucked the bird under my left shoulder, ensuring that both wings were properly folded inward.


Preparing to band an 8-week old bald eagle at the Seal Rocks nest. The most important thing to remember is to control the talons at all times. At this stage, the talons are big and strong enough to inflict serious injury


I immediately took a seat on the most comfortable and secure place I could find. This happened to be in the shade of the oak tree where a strong wind had recently gained intensity. Around the corner, boulders blocked the wind and a rocky slab sat in direct sunlight, so we quickly moved in that direction, walking slowly along the precarious ledge.


Jess Dooley, a biologist who has been working on this project since 2001, told me to find a spot where I’d be comfortable for a good half hour. After all, I’d have to hold this bird tight as it endured our intrusion. After I had found an adequate sitting spot (hardly comfortable), Jess began taking measurements on the bill and talons. After that, she extended the wing opposite my armpit, injected a needle into the brachial artery, and began pumping it to draw blood. She took her time stitching on the GPS transmitter backpack and attaching both orange wing markers.


Banding bald eagle chicks on Catalina Island was a new and exciting experience for me. Never before have I been that close to something so wild. However, it is unfortunate we have to taint their beauty by attaching these big, gaudy wing markers and cumbersome looking backpacks. It’s just not the same as when we first arrived at the nest to find chicks that were completely undifferentiated from the surrounding wilderness. I look forward to the day when this population of eagles no longer needs human support and can fly freely, unencumbered by man-made objects and safe from toxic pesticides.



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