Peregrine Watch Update Archive - 2005

August 4, 2005. The peregrine falcon viewing season is coming to an end. The Precipice Trail opens today, August 4. The past few weeks the interpretive falcon staff has been watching the falcons closely to see how dependent the young are to the cliff face. This information helps the park biologist determine when to reopen the trails. Typically, around week five or six is when the young birds disperse and begin to journey off on their own.

What do we look for? The falcon team tries to keep close observations on the birds (while interpreting for visitors) and write down exactly when and what is going on with the birds. Observations to look and listen for include screaming (if from a young bird, it could mean it is hungry); defensive behaviors towards other raptors (chasing off osprey and bald eagles); adult falcons bringing in dead birds for the young to eat; and playing with other falcons. Over the past week, the falcons have not been very visible, except for one young female who is continuing to beg for food from mom and dad.

If you still have not gotten out looking for the falcons, you should come quickly before there is not much to see! The three young birds at Beech Cliffs are still around and have been flying for approximately four weeks. Sitting on the beach of Echo Lake or hiking the trail can provide a great view—when they are around!

This will be the last View from the Aerie, but stay tuned for the next raptor event: Hawkwatch (atop Cadillac Mountain) will be starting August 22.

- Lora Haller

July 18, 2005. This year, the peregrines at Acadia National Park have been dealing us many surprises. Just this past week, it was established that the peregrine pair at Valley Cove was not successful this year in raising chicks. Although the adults are seen there regularly, the nest may have failed because of the cold, wet spring; predation; human disturbance; or some other factor. The north section of the Valley Cove Trail has therefore been reopened because of the failed nest, as was the case with the Jordan Cliffs pair several weeks ago.

To summarize Acadia’s peregrine falcons for 2005, there were four resident pairs on the island. The pairs at Valley Cove and Jordan Cliffs were not successful in raising chicks this year. At Echo Lake, there is a pair on Beech Cliffs that have three young, which fledged around July 8. The famous Precipice family is still somewhat active on Champlain Mountain, although they may shortly disperse from the area. The four chicks hatched around May 6-10, and fledged around June 18-21. We believe there are three males and one female.

The Precipice and East Face trails are the only trails closed for the peregrines, and they will open around the beginning of August. We may be monitoring the Echo Lake peregrines for a few weeks before we (Interpretation staff) migrate up Cadillac Mountain for Hawk Watch in late August.

-Todd Larsen

July 11, 2005. As the summer at Acadia progresses, the number of visitors grows and the peregrines’ activity levels wane. This is not caused by increased disturbances, but merely because the young ones are becoming more adventurous and expanding their home range beyond the east face of Champlain Mountain.

There is one quote that really personifies the natural history of peregrine falcons such as those on Champlain Mountain:

The Peregrine Falcon is, perhaps, the most highly specialized and superlatively well developed flying organism on our planet today, combining in a marvelous degree the highest powers of speed and aerial adroitness with massive, warlike strength. A powerful, wild, majestic, independent bird, living on the choicest of clean, carnal food, plucked fresh from the air or the surface of the waters, rearing its young in the nooks of dangerous mountain cliffs, claiming all the atmosphere as its domain and fearing neither beast that walks nor bird that flies, it is the very embodiment of noble rapacity and lonely freedom. It has its legitimate and important place in the great scheme of things, and by its extinction, if that should ever come, the whole world would be impoverished and dulled.
- G. H. Thayer, 1904

The most remarkable and ironic part of this quote is the last line about the possibility of extinction, although this was written forty years before the worldwide decline in peregrine populations.

In other peregrine falcon news, the young falcons at Echo Lake have left the nest! On July 8, two juveniles were observed flying around the nest site as the last nestling was trying very hard to make the leap. As of July 10, all three are flying and can be easily seen from the beach at Echo Lake. The two adults at Valley Cove are still being seen high on the cliffs, but have given us little indication of the location and progress of their chicks. The Flying Mountain Trail along the water is still closed, as well as the Precipice and a section of the East Face Trail.

Keep an eye on the sky and pass on the words of the birds!

- Todd Larsen

July 4, 2005. This week the juvenile Peregrine Falcons at the Precipice are celebrating their two-month birthday. They have now been flying for about two weeks (first fledged around June 18), and they are becoming quite the acrobatic aerialists. We believe the four fledglings are comprised of three males and one female (size differences indicate the sex, with males being slightly smaller than females). This past weekend the fearless fliers were observed chasing off an osprey and some turkey vultures that may have been perceived as a threat or simply could have been a large, slow-moving target to play with. The siblings are often seen high above Champlain Mountain playing tag with each other, grappling with their talons, or just perching on the rocks at the top of the ridge.

The history of peregrines at Acadia is interesting and inspiring. Peregrines were known to have last nested at Valley Cove in 1947 and at the Precipice in 1956, before the ill-effects of the pesticide DDT caused the populations of falcons and other raptors to decline. In 1970, peregrine falcons were placed on the Endangered Species List, and a hacking program was initiated to reintroduce the birds. Five years later, a U.S. Fish & Wildlife survey revealed that the eastern subspecies had gone extinct, and only 50 wild pairs remained in the continental United States!

At Acadia National Park, an evaluation of historic and potential aeries (release sites) revealed Jordan Cliffs as a suitable site because of its location between two historic aeries, accessibility for the attendants, low hiker traffic, absence of great horned owls (main predator), and local interest. From 1984-86, 23 peregrine juveniles were released from this site. In 1987, one of the hacked birds returned and in 1991 set up his first successful nest on the Precipice. This was the first successful nest in Acadia since 1956. Peregrine falcons were removed from the federal Endangered Species List in 1999, but they are still endangered in the state of Maine.

Although peregrines are making a slow comeback, they still need protection from human disturbances and pesticide use. Monitoring these raptors tells us more about their behavior, and education will let people know how they can help prevent another near-extinction.

- Todd Larsen

June 27, 2005. If you’ve been by the Precipice lately, you might have noticed a lot more airborne and vocal birds. The four juveniles have left the nest and are most commonly seen at the top of the cliffs. Young peregrines have a high-pitched, scratchy, whiny call (rehk, rehk, rehk) that they use frequently when communicating with their siblings and especially when the adults are nearby. They are constantly playing with each other: playing tag, grappling with their talons, and catching objects in mid-flight. The adults are still bringing food in for the fledglings, but don’t tend to stay around the cliff for too long because the young always want food. They are also beginning to go hunting on their own.

With the warm weather, the birds are most active in the mornings and often find shade to avoid the heat of the midday sun. Birds do not have sweat glands, so they use other methods to prevent overheating. They may compress their body feathers in order to retain as little body heat as possible, or increase circulation to unfeathered body regions such as the legs or face to facilitate cooling. On hot days the falcons regularly rest under a rock ledge or tree and may use evaporative cooling by releasing vaporized water from the lungs by panting, much like dogs do.

Park staff are on duty at the Precipice everyday from 9 to noon. The best time to see the Peregrine Falcons is earlier in the morning, when they are most active.

- Todd Larsen

June 20, 2005. They grow up so fast! This past week was a very exciting one at the Precipice. We were fortunate enough to watch two of the juvenile peregrine falcons take their first flight! On Saturday morning, the young birds were exercising their wing muscles (winnowing) and one of the birds decided to take the plunge. The juvenile rapidly flapped its wings and landed ungracefully on a ledge a few hundred meters away from the nest. A short time later, one of its siblings also made its first flight, leaving one nestling at the nest-site. The adults rewarded the fledglings with some food and attempted to coerce the third juvenile into flight by flying close to the nest with food, but it just was not ready yet. The last juvenile took to the air this morning around 8:30 a.m.

Despite recent reports that one of the juvenile peregrines at the Precipice fell from the nest and died, it is in fact alive and well. This was confirmed when all four juveniles were seen flying along the cliff face. Juvenile peregrines have different plumage and typically flap their wings more often than the adults, which gracefully soar and glide through the air.

The fledglings will stay around the East Face of Champlain Mountain for 5-6 weeks as they quickly learn to become expert aerialists and hunters on the wing. The adults may fly above the fledglings and drop a piece of meat, which the juveniles will try to catch in the air. It is quite exciting at the Precipice now, as we never know where to look or what to expect from these conspicuous birds.

Come by the Precipice and watch the juveniles as they learn to fly, hunt, stoop, soar, glide, and more!

June 13, 2005. As the temperature has increased, so has the activity of the Precipice Peregrine Falcons. The four chicks are over five weeks old now (between 32 and 36 days old as of Monday), and they are almost the same size as their parents. Most of them have attained their full juvenile plumage, which is tan/brown with vertical streaking, compared to the white/gray and horizontal barring of the adults. The chicks are being fed almost once an hour unless the weather is unfavorable, such as too hot or raining. During these times the adults will seek shelter for themselves (out of view from the parking lot) and bring food to the young as needed. The adults stash dead birds in crevices along the cliff for those rainy or hot days when hunting is more difficult.

Peregrine falcons are very well adapted for fast flight and a carnivorous lifestyle. Peregrines have excellent vision. Some reports suggest that their eyesight is up to eight times stronger than humans. When a peregrine is soaring, its long, tapered wings and spread-out tail feathers are noticeable, increasing the raptor’s surface area and subsequent lift as it rides on thermals or wind currents. When the peregrine stoops, or dives, at its prey, it will tuck its wings against its body to minimize surface area and decrease friction, resulting in faster flight. Being one of the fastest birds in the world, peregrines have been recorded at speeds in excess of 100 mph in a stoop; some researchers estimate their maximum speed to be even higher. There is a system of tubes called ‘baffles’ in their nostrils that alters airflow and is believed to improve breathing as the bird dives for its prey. The large feet of peregrines each contain four sharp talons (claws) that are used to capture or strike prey in the air. The falcon has a hooked beak for tearing flesh, as well as a notch on the upper part of their beak which is used to sever the spinal cord of their avian prey. All of these traits have played a role in their success as hunters.

As for the other peregrine pairs in the park, the Beech Cliffs pair has three chicks, the Valley Cove pair also has young (number currently unknown), and the adults at Jordan Cliffs are still being elusive. Come to the Precipice this week and you may see a juvenile peregrine falcon take its first flight as it learns to become one of Earth’s aerial creatures.

- Todd Larsen

June 6, 2005. What is an Aerie? (Pronounced EYE-ree) An aerie is the nest of a large bird of prey which is generally inaccessible due to its proximity high on a cliffside. Peregrine falcons will not build a nest out of sticks, but lay their eggs on sand- or gravel-covered ledges that have been scratched in preparation. These types of nests are called scrapes. Sometimes a pair of falcons will choose to use an abandoned nest such as an old raven’s nest, as they did for the last five years on the Precipice and last year on Beech Cliffs.

We have some new and exciting news! We have just confirmed that there are four chicks at the Precipice site. On June 6, as the female was feeding the chicks, all four of the young were seen at the same time. By using an age growth chart containing pictures of peregrine plumage at different ages, it is possible to estimate their ages. Since the female lays the eggs on different days, the chicks do not hatch at the same time (usually around a day apart). There is an obvious difference between the siblings on the Precipice. The oldest appears to have hatched around 31 days ago (May 6) and the youngest is about 27 days old (hatched May 10).

The next couple of weeks will be the most exciting at the Precipice because the young are becoming more visible and active. They should start to fly around June 20, and will stay near the nest for over a month after that.

There is still little information on the peregrine pairs at the other three nesting sites. Peregrines have been spotted near Jordan Pond, but nesting activity has not been observed. Keep reading the Aerie to stay informed, or stop by the Precipice any day from 9 a.m. to noon; where the sun always shines and black flies are uncommon.

- Todd Larsen

May 30, 2005. Welcome to the first installment of the View from the Aerie. My name is Todd Larsen and I am the Peregrine Intern at Acadia this summer. I am from Port Perry, Ontario and I graduated from Bishops University in Quebec last spring. I am looking forward to observing these interesting raptors and educating people about their natural history.

The Precipice site is truly a grand location to view the birds; it seems that if the peregrines are in the right mood, they will put on a show for visitors. However, the falcons can easily conceal themselves against the peregrine-hued granite, forcing interpreters to go beyond behavioral analysis and instead discuss the evolutionary adaptations of raptors, or the history of peregrine conservation. There is much to be said and learned about these birds.

This year, the Precipice peregrine pair has been quite active as they are constantly on the lookout for potential threats to the nest including bald eagles, osprey, turkey vultures, and the occasional hiker. The larger female seems to be the one most often guarding the nest, making frequent vocalizations “reh, reh, reh,” and waiting for the male to “bring home the bacon,” birds ranging in size from warblers to ducks. They have chosen a new nest site, just up the cliff face from the old raven’s nest they have used for the last five years. The eggs are believed to have hatched around May 9th and we have spotted three chicks, but there may be four. When an adult brings food to the nest you can see it feeding the chicks. Before long the nestlings will be more visible on the ledge as they become more active.

There are other peregrine pairs on the island, on Eagle Cliffs at Valley Cove and on Beech Cliffs above Echo Lake. Although these couples are more reclusive, we believe they are still incubating eggs. The status of the pair on Jordan Cliffs above Jordan Pond is unknown at this time. As a result, regular trail closures remain in effect (East Face and Precipice Trails, north section of Flying Mountain Trail (between the Valley Cove and Man of War Brook Fire Roads), and Jordan Cliffs Trail). I look forward to meeting park staff and enjoying all of Acadia. Please stop by the Precipice site (staffed daily from 9 a.m. to noon – weather permitting) or the interpretation office for more information from Raptor Ranger Lora Haller, VIP Anne Smallidge, Jonathan Gormley, and myself (Todd Larsen).

- Todd Larsen

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