NPS/Chris Wiebusch

Park staff and state biologists banded three peregrine chicks at the Precipice this year.

Each week during the nesting season, Acadia's raptor intern shares information about the park's peregrine falcons in this View from the Aerie. Check back weekly from early June through mid-August for news about our peregrine pairs.

June 3 | June 13 | June 17 | June 24 
July 1 | July 8 | July 15 | July 23 | July 29

If you are interested in seeing what's happening in person, join park rangers and volunteers for the daily (weather permitting) Peregrine Watch program. For more information, check the schedule of events.

June 3, 2008. Hello, and welcome to the 2008 edition of the View from the Aerie! My name is Sarah Kebler, and I am the new raptor intern for the summer. I am a graduating senior from College of the Atlantic in Bar Harbor, Maine. While at school, I took numerous courses in biology, and I have a new found love for birds!

This article will be a weekly event to inform you of the goings-on of the peregrine falcons. The term peregrine means wanderer, which is a fitting name for the birds that are known for their long wanderings during migration. So why the title View from the Aerie? Simply because an aerie (EYE-ree) is the nest site of a large bird of prey that is inaccessible because it is on a high cliffside. Unlike most birds, falcons do not build a nest from sticks and found materials; instead the female lays her eggs on sand, soil, or gravel. These sites are called “scrapes” since the falcons will scratch the surface before the eggs are laid.

This year we have very exciting news: We have three peregrine falcon chicks on Champlain Mountain. In recent days, the chicks have wandered close to the edge of their cave, which means we can see them. The chicks are white balls of fluff and adorable! Lately, we have seen the chicks stretching their wings almost in preparation for flight. This provides great viewing pleasure for the raptor staff and visitors to the park. The chicks are roughly 26 days old and will be taking their first steps to flight around day 35–40.

The adult peregrines are great parents! Often the female is seen perched and on the lookout for predators. The peregrines see any large bird, such as bald eagle, hawks, gulls, osprey, and turkey vultures, as possible predators (the last two, however, would most likely not eat a chick). Lately the male is hardly at home since he is searching for food for the family. The lunch menu varies for the chicks on a daily basis. Dinner ranges from birds the size of songbirds to red-winged blackbirds to tasty pigeons. Often the female calls when the male is in view, and the exchange of food occurs in flight. The female then enters the nest site to feed the chicks. 

Now you may wonder why the male is sent to search for food while the female remains at the nest site to protect the young. Well, the female is larger than the male, and the male may be able to catch prey faster due to his small size. This size difference often occurs with birds of prey and is called reversed sexual dimorphism. The female’s wingspan is 40 to 42 inches, and the male’s is 36 inches. A male weighs 1.25 pounds, and the female weighs about 2 pounds. There are different theories about why a female may be larger. One theory is that females need to be larger due to the huge energetic cost in producing and incubating eggs. A second theory is the female and male will not have to compete for the same food source because of their different sizes. A female will catch larger prey (pigeons and gulls) while the male will catch smaller birds (songbirds such as goldfinches).

The park has three other peregrine falcon sites: Beech Cliffs, Valley Cove (near Flying Mountain), and Jordan Cliffs. Recently we learned that Valley Cove and Jordan Cliffs have young.

Please note that the peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and to answer any questions. Please remember that peregrines vigorously defend their territory and that there are several trail closures to protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail.

- Sarah Kebler

June 13, 2008. Greetings everyone! I hope you enjoyed last week’s issue of the View from the Aerie. For this second issue, the topic is banding.

About two weeks ago an attempt was made to band the peregrine chicks. As the interpretative staff set up for the day, they were unable to find the adult peregrines. After a few minutes the male and female were spotted flying high in the sky, circling, and then they disappeared. As the rangers began to climb the trail leading to the nest, both birds began to fly around the rangers. It was a marvelous sight to behold! As the rangers continued climbing, the parents became more aggressive by screeching in an attempt to scare away the climbers. As the chicks get older, the parents become more protective because of the time spent raising them.

Back at the parking lot, the interpretive staff kept busy teaching visitors about banding. There are several different reasons why scientists band birds. The most important is confirming how many eggs were laid and how many chicks hatch. It also allows scientists to learn the sex of each chick. In the long term, scientists can learn how long falcons live and how far the birds travel.

Banding chicks is a tricky operation. The chicks must have adult-sized legs, and this occurs around day 20. Banding also needs to occur before the chicks are able to fly and are nervous about humans. Therefore, banding must occur between day 21 and day 25 when the chicks are still curious about their surroundings. That day, we were able to confirm that the Precipice has three chicks, and there was an egg that did not hatch. Due to technical difficulties and the aggressiveness of the adult peregrines in protecting their young (including skimming the climber’s helmet), the banding attempt was aborted.  The unhatched egg was collected to test for heavy metals and contaminants. The chicks will begin to fly around day forty (which will be next week)!

Please note that the peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and learn their story. Please remember that peregrines vigorously defend their territory and that there are several trail closures to protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail.

- Sarah Kebler

June 17, 2008. Hello, and welcome back to the View from the Aerie! We have good news about the peregrine falcons! In the past two week, the chicks have lost their white down feathers and have grown bigger. Since the young are older, sometimes it is difficult to tell the adults from the young. One way to tell the difference between the birds is the young have brown plumage with vertical barring, while the adult birds have gray plumage, a black hood, and a white breast with black horizontal barring.

In the past few days, the young have been extremely active. Yesterday, two chicks walked out of the nesting cave and climbed a few feet to the left of the site. There the chicks found food left by the female peregrine and brought the food back into the cave. It was a sight to see! One chick held onto the food and stood at the ledge for a few minutes. The chick then began to flap its wings continuously as if it wanted to fly and soar through the air. In the end, the chick opened its wings again and hopped into the cave. These are the first baby steps toward flying. Peregrines fledge, or begin flying, between 4.5 to 6 weeks, so the chicks should be flying very soon.

Peregrines are very good at flying. They have earned the gold medal for being the fastest bird living today! These birds cruise at 65 mph in flapping flight and can dive at 200 mph; in comparison the bald eagle has been recorded to dive at 100 mph.

The parents will help ease the chicks into flying. They will stop feeding the young continuously and instead will fly with food back and forth in front of the young until the youngsters chase their parents for the food. The young need to eat constantly throughout the day, as it allows them to grow healthy and strong in a timely manner. An adult needs roughly five ounces of meat a day, which equates to approximately one pigeon, blue jay, red-winged black bird, or black guillemot, or eight chickadees. The adult birds also store food at a cache site on the cliffside for a mid-day snack.

In other top stories around Acadia, biologists were able to band two healthy male chicks at Jordan Cliffs, high above Jordan Pond. We are happy to say there are a total of five confirmed chicks in the park (and we are fairly certain Valley Cove has young too)!

The peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and learn their story. Please remember that peregrines vigorously defend their territory and that there are several trail closures to protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail.       

- Sarah Kebler

June 24, 2008. We have exciting news–the Precipice peregrine chicks started flying last week! The chicks are new at flying and are struggling. While the adults fly with ease and grace, the chicks have to constantly flap their wings to stay in the air. In a short time the chicks will learn to fly in a graceful manner.

Since the chicks are flying they are rarely seen at the nest anymore. It becomes increasingly difficult to find the chicks because they hidden on the cliff. The birds blend in with the rock surface.

In a few weeks the adult birds will encourage the chicks to find a new home. This happened to me when my parents sent me off to college and told me to never come home again… expect for the holidays! But like the adult birds, my parents taught me how to work hard and earn my dinner. Once the chicks get kicked out, they may travel far, or they may stay near. Some will fly to others places in Maine, New Hampshire, Rhode Island, and New York. Others may venture to Venezuela, Belize, and other places in South America for the winter.

While looking for the chicks on the cliff, visitors often ask if the peregrines are still an endangered species. Today peregrines are no longer on the federal endangered species list; however the breeding population is still considered endangered in the state of Maine. There are roughly nineteen pairs nesting in the state of Maine. The last nesting pair in Acadia before the reintroduction program was in 1956. The last peregrine seen in Acadia was in 1965. This bird was looking for a mate but never found one.

Peregrines began to sharply decline in the 1950s for numerous reasons. Farmers shot them because they believed peregrines were a threat to their poultry; some peregrines were shot during World War II due to the fear they would eat messenger pigeons; and wild eggs were given to falconers. These factors impacted local populations, but a widespread destruction of peregrine falcons began with the use of DDT and organochloride pesticides.

DDT was first produced in 1874 by Othmar Zeidler, a German chemist, but it was not until 1939 that Dr. Paul Muller learned how quickly DDT killed flies and mosquitoes. Insects at the time were a serious threat to humans: mosquitoes can carry malaria, and lice can carry typhus. At the time it appeared that DDT did not harm animals. Today we know that the break down of DDT, DDE, is harmful to animals. After DDT was used as an insecticide, it spread through the ground and into the rivers, ponds, and streams. DDE was then absorbed by plants and animals, eventually reaching peregrines falcons through the food chain. A female bird with a large concentration of DDE produces thin egg shells. Therefore when she attempts to incubate the eggs, they break.

DDT was banned from use in the United States in 1972. There are still traces of DDT and DDE but in smaller concentrations. Today, through reintroduction programs, we can watch peregrines soaring in the sky or chicks flapping their wings to stay in the air—like at the Precipice lately!

The peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and learn their story. Please remember that peregrines vigorously defend their territory and that there are several trail closures to protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail.

- Sarah Kebler

July 1, 2008. The young falcons or eyases (from the Middle English word meaning "nestling") are growing so quickly! Soon these chicks will be off to explore the world on their own. After the eyases leave the nest they may travel thousands of miles looking for unoccupied territory. Around the age of 2 or 3 they become sexually mature. They live on average 7–10 years in the wild, but may live to be 15 or 20 years old! 

Along the way there are many dangers that they will face. It is believed that 1 out of every 4 chicks will make it to adulthood (age 2). A common danger is flying into the wrong thing; many chicks fly into buildings or cars in the cities. In natural areas, they may have trouble flying and be pushed around by the wind. The peregrines also have some predators, including the great horned owl.

Before the juveniles leave the Precipice, they need to strengthen their flying skills. They are still working on these skills and are starting to soar and dive. They dive and chase each other around the cliff side, and sit perched together at the top of the cliff. They seem to like playing on the right side on the cliff; it is fun to watch the juveniles run along the ledge because it appears they are playing peek-a-boo with visitors. At the same time, we find it difficult to find these birds on the scope since they are constantly on the move!

By playing together, the juveniles are developing life skills that will help them chase away real predators, enable them to find food on their own, and later choose a suitable mate. Finding a healthy mate is an important step in having and raising a family of peregrine chicks.

The past couple days were extremely foggy days at the Precipice, and we did not see any peregrine falcons. We did hear the little ones scream for a short period, though! A few days ago, when the sun was out and the sky was blue, we saw the juveniles play. Let's hope for sunnier and warmer days along the coast of Maine!

The peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and learn their story. Please remember that peregrines vigorously defend their territory and that there are several trail closures to protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail.

- Sarah Kebler

As we watch the birds play, we can see the differences between the female and male juveniles. The female is larger than her brothers and has darker feathers on her face. Today one of the males and the female juvenile were perched on the same rock. It was a sight to see, but soon the chicks were off playing again. They played all morning until about 11 a.m., then they decided to rest in a shaded area. The parents also brought food twice to the young, but continue to hide on the mountain from their chicks. Imagine three hungry chicks with large talons that have started flying, like a teenager learning how to drive. Scary!!!

As mentioned before, peregrines are a type of raptor. The term raptor traces back to Latin, meaning one who seizes by force. There are 34 species of raptors in North America; 12 species are often seen in Acadia National Park. Characteristics that all raptors share include having sharp talons and beaks, eating other animals, and often possessing an ability to soar. (Join us starting in late August for HawkWatch, where you can see and learn more about these other types of raptors.)

Peregrines are part of the falcon family, which also includes the American kestrel and the merlin. This group of birds is known for their incredible speed. They can fly quickly because they are small birds with long pointed wings and a good-sized tail.

The peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and to answer any questions. Please remember that peregrines vigorously defend their territory and that there are several trail closures in place to protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail. And, as always, Junior Rangers are welcome to visit! Come visit the peregrine juveniles before they leave the Precipice!

- Sarah Kebler

Raptor intern Sarah searches for peregrines on the cliff.

A day or two later, a ranger noticed a juvenile bringing food that appeared to be gray and furry to the cliff. We believe it was not a bird, perhaps a gray squirrel. Still, it means that the birds are learning to hunt and eat on their own. Falcons will tear apart some of their food but also eat some whole. Like owls and other birds of prey, falcons regurgitate pellets of bones and feathers. 

We have also seen the young chase off a northern harrier, which is slightly larger than the peregrines. Two of the young quickly sprung into action and began mobbing the northern harrier. The juveniles know how to defend their home; they learned excellent defensive and aggressive behaviors from their parents.

Today I spent two hours searching for the peregrines along the cliff, and I did not see a single bird. Sometime around 11 a.m. I heard the peregrines call to each other, coming from the opposite direction of the parking lot. I turned around and looked into the sky, and sure enough the juveniles were finally coming home! The birds flew over the parking lot and back toward the mountain. Then they took to the wind and climbed higher into the sky where they appeared to be black dots moving in the clouds. And that’s when I lost sight of the birds. Anytime now the birds will be leaving the cliff and making their own way in the world!

While standing in the hot sun on concrete pavement, I can only imagine how hot and tired the peregrines must feel after flying and hunting all morning. In the late morning, we often see the chicks take cover in or at the base of trees and in shaded rocky areas—anywhere there is plenty of shade to cool the birds. Typically peregrines nest on east-facing cliffs, where the sun keeps the cliff warm in the morning. These cliffs are cooler in the afternoon when the sun is at its hottest point.

In other news, there are sightings of a juvenile flying around the Jordan Cliffs!

Please note that the peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and to answer any questions. As always, junior rangers are welcome to visit! Please remember that peregrines vigorously defend their territory and that several trail closures protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail.

- Sarah Kebler

Today there was some action at the Precipice. We heard a youngster calling all morning for food from the parents, and toward the end of the program, we watched this peregrine attempt to hunt. Unfortunately he began to scream while trying to hunt; his prey, therefore, knew to leave the area or to hide! Normally peregrines will sneak up on their prey.

Besides learning how to hunt on their own, juveniles need to learn how to protect their territory from intruders when they have their own nest. Birds can be territorial for different reasons, such as protecting their hunting ranges. This is seen with peregrines: as the only larger bird that nests there, the Precipice cliff “belongs” to the peregrines. Smaller birds, such as indigo buntings, American robins, blue jays, and eastern phoebes, do nest on or near the cliff.

To protect their territories, birds use aggressive behaviors such as mobbing. Mobbing occurs when an unwanted intruder enters their territory—in this case, close to the cliff. These intruders at the Precipice have included bald eagles, osprey, and northern harriers. The adult peregrines will see the bird coming in from a distance and fly above the intruding bird. While gaining speed, the peregrines will swoop down at the intruder and may even hit or physically attack the bird. Mobbing may also be a form of cooperatively attacking or harassing another bird to ensure protection from its aggression. I have seen a flock of crows harass a bald eagle—of course the bald eagle thought nothing of it!

The peregrine falcon staff are available at the Precipice parking lot from 9 a.m. to noon (weather permitting) to help visitors see the peregrines and to answer any questions. Please remember that peregrines vigorously defend their territory and that several trail closures protect the chicks from disturbance. These trails include the Precipice Trail, part of the East Face Trail, the northern portion of the Flying Mountain Trail in Valley Cove, and the Jordan Cliffs Trail.

- Sarah Kebler

July 29, 2008. It is that time of the year, folks! It is almost time to say goodbye to our family of peregrines. Just to recap this season, it has been an interesting season with the peregrines. At the Precipice, the adults have done extremely well. We have three juveniles this year; remember, compared to last year this is a huge success! Many of the early-nesting raptors, including peregrines and eagles, failed last year due to two huge storms in the spring. The juveniles this year are two males and one larger female. (With most birds of prey, the female is larger.) As we end our journey with the peregrines, please keep in mind that the adults are still using the Precipice as their home. In fact, this past winter the adult birds remained at the Precipice throughout the entire winter! Talk about withstanding the cold!

Our juveniles will soon be leaving the cliff. They are able to hunt on their own and fly at incredible speeds. They have become aggressive. Here at interpretation we will miss our young, but it is with love that we say goodbye. It is their ability to fly that will keep us coming back every year, and we hope to see you again next year, too!

I have truly fallen in love with these birds. I remember the first time I saw a peregrine. It was my junior year of college when I walked down the Park Loop Road with my ornithology class at College of the Atlantic. We stood in front of the mountain and watched the male and female interact with each other. There my two teachers gave a short speech about the peregrines and their struggle for survival these past few decades. Little did I know that in two years I would return to the site as the raptor intern. I have fallen in love with their aerial displays and, yes, their screaming. I am also drawn to their mysterious ways. You never know where you may find the birds or how long they will be around.

As our season comes to an end over the next week or so, we are looking forward to the beginning of a new season: HawkWatch. Please join us at the top of Cadillac Mountain starting August 21, from 9 a.m. to 2 p.m. on the North Ridge Trail. On the summit we will be waving goodbye to a large number of birds of prey as they begin their long journey to warmer weather and wintering grounds.

- Sarah Kebler