The sun made its long-awaited appearance this Monday! After a foggy week of rest, the raptors are on the move again through clear skies with the winds at their backs. A cool northern breeze seems to have inspired some of the later migrants to set south. This week was a bit chillier on top of Cadillac Mountain, and we spotted a few of the first Red-Tailed Hawks on their migration.

Maine’s largest bird of prey, Bald Eagles, were flying over Hawk Watch nearly all week. They dwarf all the other raptors over Cadillac with their nearly 7-foot wingspans! Bald Eagles are opportunistic, so they eat whatever prey is available to them. Northern Bald Eagles, which we see migrating through Acadia, often live near water and mostly eat fish. They don’t tend to migrate until late fall when lakes and rivers start to freeze over, restricting their access to food. This makes sense with what we’ve seen so far; cooling temperatures have pushed more Bald Eagles south as Autumn progresses in Acadia.

A bald eagle perches on a dead tree near the summit of Bernard Mountain in 2022. (Photo by Lily LaRegina/Friends of Acadia)

Raptors typically migrate individually, but we saw a group of four adult Bald Eagles flying over the Hawk Watch site together on Monday. They were likely taking advantage of the good weather after such a rainy week. We heard them before we saw them, loudly whistling at each other as they soared away. Just when it seemed like the sky couldn’t get any more crowded, the four Eagles attracted a territorial, local Peregrine Falcon to fly through the group and attempt an attack. When the Peregrine grew weary of the Eagles, it continued flying north and eventually dove towards a local Turkey Vulture over Frenchman’s Bay.

Also on the move this week were the Turkey Vultures. Although they aren’t true raptors, their migratory behavior is still recorded on Hawk Count because of their important role as carrion feeders. By consuming dead animals, they prevent the spread of diseases and harmful bacteria, so they’re key in sustaining ecosystem health. Interestingly, though, Turkey Vultures weren’t always included in the Cadillac Mountain Hawk Count, because when the program first began, no Turkey Vultures were migrating as far North as Acadia.

Didn’t capture photos this season, but here’s a turkey vulture soaring over Acadia a few years ago. (Photo by Ashley L. Conti/Friends of Acadia)

Since the early 2000s, Turkey Vultures have been spotted migrating south over Cadillac Mountain, and some breeding pairs have even been found as far north as Quebec. Their shifting range and breeding presence are among the many environmental changes that we’ve been able to track as a result of Hawk Watch!

Though my time with the raptors is ending, migration season is far from over, which is made clear by the well over 300 migrating raptors we spotted this week. Volunteers will continue to monitor the site until early November, and their continued efforts will contribute greatly to this fantastic, collaborative, community science project. You can continue to stay up to date with Fall migration on the Hawk Count website for the rest of this season and in years to come! It’s been an amazing experience to spend my days observing the raptors, both local and migratory.

Contributing to the public’s knowledge about the behavior and importance of these winged apex predators has only grown my appreciation for birds of prey and Acadia’s amazingly interconnected ecosystems.

Just as fantastic has been the wealth of community and perspectives I’ve encountered as a result of Acadia’s interpretive programs! There’s truly no replacement for being immersed in natural resources with people from all different places, backgrounds, and enthusiasms. Thank you to all the collaborators, partners, organizations, and visitors who granted me this opportunity and for shaping my wonderful season at Acadia National Park!

The wet weather had the raptors’ feathers ruffled this week, so we spotted fewer than 10 migrants at Hawk Watch. A layer of fog has been hanging over Cadillac Mountain for the last few days. The fog reduces visibility, making it difficult for migrating birds to identify crucial landmarks, food, or safe resting spots. Many days this week were rainy, giving the raptors another reason to lie low. Wet air increases drag, and wet feathers reduce lift, both of which make flying more strenuous.

Once the conditions improve, though, we’re hopeful to see more migrants. I’m especially excited to get the chance to see more raptor species we haven’t seen much of yet in 2025. Over time, Hawk Watch has taught us that not all raptors migrate at the same time. So far this season, we’ve only seen 5 Red-Tailed Hawks migrating over Cadillac Mountain. Unlike some of the raptors I’ve mentioned previously, Red-Tailed Hawks tend to migrate in higher numbers in October. Since the species migrate at different times, it’s possible that they use different environmental cues, like seasonal changes in temperature and light, to let them know when it’s time to move. Diet could also impact a bird’s motivation to migrate; raptors with cold-tolerant prey can delay moving south to find food.

SCA Raptor Intern Jaz at the Hawk Watch site on Cadillac Mountain. (Photo by John Branciforte)

In Acadia, the shifting seasons bring lots of exciting changes every year. The transition from summer into autumn is typically marked by the incredible arrival of fall foliage. Though most of the trees are still green, evidence of autumn’s approach can be seen throughout the park. For example, some animals have been spotted beginning their migration South for the winter! The fall raptor migration is underway, with birds of prey passing over Acadia as they migrate from their summer nesting sites in the North to their winter homes in the South. To get a glimpse of these migrating raptors, visit the Hawk Watch Program! The Schoodic Institute and Acadia National Park work together to monitor migratory raptors from the top of Cadillac Mountain. Visitors can help spot migrants and learn more about the birds at the Hawk Watch site, about 200 yards down the Cadillac North Ridge Trail. You can join me, the Student Conservation Association Raptor Intern, and Acadia Park Rangers at Hawk Watch Monday-Friday, 9:00 AM-12:00 PM (weather permitting). Schoodic Institute volunteers will also be at the site collecting data from 9:00 AM-2:00 PM on most days of the week. For updates, I’ll be writing weekly raptor reports throughout this Hawk Watch season here on “Riding The Winds: Hawk Watch in 2025”!

A vehicle reservation is required to drive up the Cadillac Summit Road. No reservation is needed for hiking up to the site.

Hawk Watch is one of Acadia’s longest-running citizen science projects, with this fall being the 31st season of the program. Such a long-standing project may inspire people to ask: “Why do we care about migrating raptors?” Birds of prey are apex predators, so they sit at the top of the food chain. They’re dependent on a healthy environment to support their carnivorous diets, and they naturally regulate populations by hunting. Therefore, raptor populations can inform us about the health of the ecosystems they inhabit. Because birds of prey are so widespread and can be hard to spot, the best time to monitor them is as they’re migrating. In the Eastern U.S., many birds will use the East Coast to guide them during migration along a route called the Atlantic Flyway. Acadia is lucky enough to be situated right along the raptor’s Flyway, so we’re able to spot a large portion of the migrants as they pass over. Combined with the nearly 200 other Hawk Watch sites across the U.S., we’re able to track any changes in the raptors’ population or migration behavior over the last three decades. Every day at Hawk Watch can teach us something new about the birds and their environments!

To check our daily counts, visit www.hawkcount.org to see the data we have collected this season, explore other sites, and view past seasons’ records.

Volunteers help to point out raptors at the Hawk Watch Program site.
(Photo by C. Schmitt / Schoodic Institute)

Hawk Watch has been off to a slow and steady start. The number of migrants we’ve seen has been variable, with some days having a count of 50 raptors and some having zero. This is largely due to winds coming from the South, which is typical of summer weather in Maine. To save their energy, the raptors will wait to migrate until they can ride a Northern wind to coast Southward. We’ll likely start to get more winds coming from the North as autumn approaches in mid-September. However, seeing fewer migrating birds at Cadillac Mountain does not mean that there are fewer raptors in Acadia. Migration is a long, tiring, and dangerous journey for any bird, and finding the right places to stop is a vital step.

Raptors will likely find a place to rest and hunt on days when the weather conditions, such as wind, make movement difficult. Acadia hosts a wide variety of habitats that are home to many of the animals that birds of prey feed on. This makes the park an ideal spot for raptors to stop and fuel up on their rest days! The migratory raptors in Acadia have probably been spending their time flying around at lower elevations to hunt. Depending on the species, small mammals, reptiles, and even other birds can be a good meal for raptors.

The raptor we’ve seen the most so far this season is the Sharp-Shinned Hawk! Also known as “forest hawks,” these raptors are small accipiters that use woodlands to hunt for songbirds. Sharp-Shinned Hawks are hard to spot during their breeding season because they nest in densely forested areas. Like many raptors, the best time to count them is during migration. Sharp-Shinned Hawks have been the most frequently spotted so far, but they have also shown the largest decline of all North American raptor species in recent decades. Reasons for their decline may include habitat loss or a decrease in prey availability, such as birds and insects.

Programs like Hawk Watch are vital because they enable us to continue monitoring trends in raptor populations, such as the decline of Sharp-Shinned Hawks, which can highlight environmental risks and potential needs for conservation efforts.

Hundreds of migratory raptors flew over Cadillac Mountain during the Hawk Watch Program this week! Birds of prey can fly thousands of miles during fall migration, so they can be very picky about the type of weather they choose to migrate in to help save energy. We saw a perfect example of that this week with the shifting conditions. This Monday, high humidity prevented many birds from traveling due to the resistance or drag that comes with flying through humid air. The rest of the week had more ideal weather with dry air, North winds, and plenty of sun. Raptors were definitely taking advantage of the good conditions, because we had the highest migrating bird turnout of the season so far! Friday was the standout day of the week when we saw well over 100 individuals.

We got a great look at a female American Kestrel when it landed at the top of one of the conifer trees about 30 feet from the Hawk Watch site. After flicking her tail and resting for a couple of seconds, she flew right over our heads, then continued her Southward journey. It was remarkable to observe the significant impact the weather has on migratory bird behavior. Things will likely get even more interesting as we approach the beginning of fall and the weather continues to turn in the birds’ favor!

This week, the weather worked both for and against the migrating raptors on the Atlantic Flyway. Last week, we saw how climate conditions influence raptor migration, and one of these conditions is the amount of sunlight available each day. Raptors take advantage of the sun as it heats the land, creating thermal updrafts that allow them to soar. The birds ride the rising warm air like an elevator and then coast off the top in search of the next thermal.

Raptors are visual predators, so those that migrate during the day also take advantage of the light to help them spot and catch prey. This classifies them as diurnal, meaning they are awake during the day and sleep at night. Owls are an exception to this, as they are nocturnal and have exceptional night vision, allowing them to migrate at night. This has caused an interesting adaptation in their prey; songbirds often migrate under moonlight to avoid being easily seen and hunted.

Raptors have several other distinguishing traits that set them apart from many birds. In addition to their excellent eyesight, all raptors have hooked beaks and sharp talons for hunting all sorts of prey. Many of these fierce predators were seen migrating over Cadillac Mountain this sunny week, including hawks, eagles, ospreys, falcons, and more! Excitingly, the beginning of this week saw a decent showing of migrating falcons, a unique group of raptors known best for their speed and agility while flying. The falcon species we often see at Hawk Watch are Peregrine Falcons, Merlins, and American Kestrels. This Tuesday, we even spotted a juvenile Peregrine Falcon on its way South.

Falcons mostly eat other birds or invertebrates and use their powerful, pointed wings to pursue and catch their prey, sometimes mid-air! Clear, open territories are ideal hunting grounds for falcons to properly detect and pursue their meals. These insects and birds that falcons rely on are less abundant in Northern areas in winter, so the falcons begin following their food South in the fall. In fact, the main inspiration for fall raptor migration is prey distribution.

In the middle of the week, winds were coming mostly from the South, so any migrating raptors were probably getting some much-needed rest and food to fuel up before setting out again. Friday rounded out our falcon-dominated week with lots of sun and North winds! American Kestrels were flying by in groups of 2 or 3 nearly all morning!