Last updated: October 31, 2024
Article
Riding the Winds: Hawk Watch in 2024
NPS photo by Brady Richards
My name is Sara, and I am here with the SCA (Student Conservation Association) as the Raptor Intern at Acadia National Park.
Earlier this season, I assisted the Peregrine Falcon Watch program. With the seasons changing, it is now time for the Hawk Watch program! Just as with the View From the Aerie blog, I will be providing updates on our 30th season of Hawk Watch as I write the “Riding the Winds” blog.
Migration season is upon us! During the raptor migration season, Acadia National Park and Schoodic Institute partner to record counts of these migrating raptors, and educate visitors about these birds. The Hawk Watch site is located 200 yards down the Cadillac North Ridge trail from the summit of Cadillac Mountain. Schoodic Institute volunteers collect data with help from Park Rangers and visitors. Weather permitting, Park Rangers and I will be at the site Monday, Thursday, and Friday, from 9:00 AM – 12:00 PM. Schoodic volunteers will be at the site 9:00 AM – 2:00 PM on most days of the week.
NPS photo by Molly Mays
A vehicle reservation is required to drive up the Cadillac Summit Road. No reservation is needed for hiking up to the site. Any and all are welcome and encouraged to stop by. It has been so exciting spotting raptors flying across the landscape. You can help to point out birds and we can help identify and add it to our data collection! We hope to see you soon to look for and learn about the raptors migrating through Acadia National Park.
To check our daily counts, visit www.hawkcount.org to see the data we have collected this season, explore other sites, and past seasons records.
NPS photo by Molly Mays
September 2 – 6, 2024
We are just a few weeks into counting and have seen over 300 raptors! What is a raptor anyway? Certain characteristics determine what we call “birds of prey”. They are meat eaters and are properly equipped to catch their meals! This includes sharp talons, sharp beaks, and good eyesight. The term raptor covers the birds we look for during the Hawk Watch Program which includes, hawks, falcons, eagles, osprey, and harriers. You may notice that we count Turkey Vultures as well. While they aren’t exactly raptors, they are still common sightings as migratory species. These birds rely mostly on smell to find their food (already dead meat that doesn’t need to be caught), therefore they lack the sharp talons and keen eyesight. We have quite a few local Turkey Vultures, keep your eye out for some while you are out exploring in Acadia.
September 9 – 13, 2024
On days without ideal wind conditions, our sightings may be few and far between. This week, Monday only had 15 raptor sightings. On slow days, we look out for local Turkey Vultures and Bald Eagles. We may also see migrating hummingbirds and monarch butterflies!
When we talk about ideal wind conditions, this can vary depending on the location of the Hawk Watch site. At Cadillac Mountain, the best winds for migrating raptors will typically be North winds. This gives them a tail wind, making it much easier to fly longer distances. These birds prefer to conserve their energy and oftentimes won’t be seen flying into harsh conditions. They also like to catch a ride on thermals. Thermals are updrafts created by the heating up of the land. This causes the warm air to rise, making for a great elevator for these raptors to catch a ride on!
NPS photo
The rest of this week had good wind conditions bringing our weekly total to over 400 raptors! You can see a more detailed report of each day at Hawk Count. We saw many birds utilizing thermals and rising into our view. Our most sighted bird this week was the Sharp-Shinned Hawk. These are often recognized by their rapid wingbeats and glides, their longer tails, and their tendency to dive after other raptors in their way.
Adobe Stock licensed image
A frequently asked question is “how do these birds know where they are going?” Our coastline makes for a great map to follow. The coastline is a great landmark for birds in the area to follow South. This, along with the thermals and updrafts created by the nearby mountains such as Cadillac, help make conditions for a great migration path.
September 14 – 20, 2024
This past weekend, on Saturday, brought the highest daily count so far this season with 288 raptors! The following week was slow, with just 5-20 raptors each day due to South winds. But that Friday came with brisk fall temperatures, a strong North wind, and over 60 raptors by noon! Don’t forget to keep up with the official raptor count at www.hawkcount.org.
It’s exciting that the Cadillac Mountain Hawk Watch has been counting migrating raptors for 30 years! That’s a lot of birds! While looking for raptors is exciting and educational, what do all these counts mean? When you join us at Hawk Watch and spot a raptor, it gets added to our data sheet. Now you have actively participated in science! These numbers are a more accurate way to determine how raptor populations are doing throughout the entire continent. Many raptors will nest in remote areas and can go undocumented. Counting them during their migration is a better way to estimate how they are doing and gives us an opportunity to look for trends in their populations to compare to past years.
NPS photo by Molly Mays
Understanding population trends can help aid in raptor conservation. To see if there are notable shifts, we need these data sets. Without them, there wouldn’t be an understanding of changes to their populations over such a large period of time. Being able to see when a raptor population is in decline or rise can give us information about their environments.
Raptors are at the top of the food chain. This makes them environmental indicators to the overall health of their ecosystems. This was seen in the 1950s with the use of the pesticide chemical known as DDT. This chemical began to build up, or “bioaccumulate,” in other organisms. Then, as the smaller organisms like insects were eaten by other organisms, and these organisms were eaten by raptors, they were getting even higher concentrations of these chemicals through this process known as biomagnification. Bald Eagles and Peregrine Falcons were two well-known species that were negatively affected by this chemical use. Their populations crashed. Thankfully, due to the Endangered Species Act and a variety of conservation efforts, these species have made a great recovery. This recovery can be seen in our Hawk Watch counts.
September 23 – 27, 2024
Easterly winds this past weekend brought some movement with ninety birds on Friday, just over sixty birds Saturday, and twenty-four birds Sunday. But, as we moved into the week, fog and rain has impacted bird movement. As raptors wait for those ideal conditions mentioned last week, they spend time hunting and refueling. While there may not be as many raptors to see flying overhead, keep your eyes out for more activity in other areas of the park where they may be looking for their next meal!
What are these raptors looking to eat anyway? As discussed in a previous blog post, raptors are predators and eat meat. Each species has different specializations that allow them to hunt different prey. Their prey can be a variety of things depending on the raptors size and hunting styles.
For example, Osprey are adapted to hunt for fish. Oftentimes, once successfully caught, they will hold the fish in a forward direction to fly efficiently. Raptors such as sharp-shinned hawks and other accipiters are built for flying quickly through forested areas. Here, they can search for small mammals (mice, chipmunks, etc.) as well as songbirds to prey on. Their long tails and shorter, wide wings make it easy for them to quickly maneuver through these forested areas.
Others look for more wide-open spaces. This includes falcons such as the American Kestrel. As the smallest falcon, their diet consists mainly of insects and other invertebrates.
NPS photo by Molly Mays
Many species under the buteo category also look for open habitats. If you’ve ever seen a hawk perched on the side of the highway, there’s a chance this could have been a Red-tailed Hawk. These are a very widespread species can be found in Acadia and within the majority of the United States. They are larger raptors that mostly eat mammals such as mice, rabbits, and squirrels.
There are many helpful tools to help you identify raptors. Paying attention to their hunting behavior and environment is a great way to narrow down the possible species. During your visit in Acadia, or wherever you are, see if you can determine what raptor you may be observing!
September 30 – October 4, 2024
We have seen lower numbers this season overall, including a much lower count of Broad-winged Hawks. This often catches visitors’ attention when looking at our board’s seasonal counts compared to the average over the past 30 years.
Without this season's data, across multiple hawk watch sights, we cannot say that there is a decrease in their population. This could just be due to birds following a slightly different flyway.
Migratory bird flyways in North America., North Dakota Game and Fish Department, Public Domain, https://www.fws.gov/media/migratory-bird-flyways-north-america
Acadia’s coastline is apart of the coastal route of the Atlantic flyway. While the birds along this route follow the coastline as a map for their travels, other birds follow landmarks such as the Appalachian Mountain ranges. It is possible that some of these birds have just been following a route further inland than what we can see at our sight.
Broad-winged Hawks specifically prefer routes that don’t include flying over large open water, which would explain them being sighted in larger numbers in states such as Vermont. This could also be due to the weather and wind that we’ve experienced this season. There are many factors that can influence these flyways. This is one of the reasons we are collecting data. Looking at weather conditions and migration patterns can help us better understand these correlations as well as keep track of the raptor’s populations.
October 7 – 11, 2024
Last week, we discussed the numbers we see on a daily basis. Today, let’s look at how patterns can be observed over multiple seasons. For example, Bald Eagle numbers have increased after their recovery from the use of pesticide chemicals known as DDT. This is something we can see through our Hawk Count observations. Over the course of our 30 years of counting, many visitors recall when seeing a Bald Eagle was a rare and magnificent sight. It may not be as rare anymore, but it’s still quite magnificent! We have several local Bald Eagle pairs that we often see soaring by at our Hawk Watch site. These can be tricky to decide if they are to be recorded as locals or migrants. We can usually decide if we see them soaring around in front of us with no intent on moving South. Otherwise, if they are coming from ahead of us and soaring over and continuing, they can be counted as migrants.
A few weeks ago, we had an adult and a juvenile Bald Eagle riding the winds directly above us, giving an exceptional view of their flight for an extended period. These two ended up flying back into the gorge and towards the shore in front of us, which allowed us to determine they were locals. While we did not see them migrating then, they could still migrate later in the season. On Friday this week, an adult and a juvenile Bald Eagle were recorded migrating. Some Bald Eagles may stay in the area year-round. They are opportunistic hunters, meaning they sometimes hunt, sometimes scavenge, and are able to survive on a wide variety of prey. If there is enough food availability, they’ll stick around and maintain their territory.
Photo courtesy of John Branciforte, Used with permission.
A few weeks ago, we had an adult and a juvenile Bald Eagle riding the winds directly above us, giving an exceptional view of their flight for an extended period. These two ended up flying back into the gorge and towards the shore in front of us, which allowed us to determine they were locals. While we did not see them migrating then, they could still migrate later in the season. On Friday this week, an adult and a juvenile Bald Eagle were recorded migrating. Some Bald Eagles may stay in the area year-round. They are opportunistic hunters, meaning they sometimes hunt, sometimes scavenge, and are able to survive on a wide variety of prey. If there is enough food availability, they’ll stick around and maintain their territory.
With rainy weather and poor winds earlier this week, there have been few raptors sighted. While we are past the peak migration period, there’s still more time to see movement depending on those conditions. The end of the week brought more raptors with the strong northerly winds. Remember to keep up with our daily counts at www.hawkcount.org and keep a look out for those later migrants!
October 14 – 18, 2024
Although our Hawk Watch program is ending, that doesn’t mean there are no more migrating raptors! Some species are later migrants, more tolerant of colder temperatures, or traveling shorter distances. For example, we saw our first migrating Red-Tailed Hawk this past week. They may only be traveling to areas as close as Southern Maine for the winter. We’ve also started to see an increase in migrating Turkey Vultures and Bald Eagles instead of just the locals that we often record. Our daily counts are much lower numbers now that we have passed the peak of the migration period for the Cadillac Mountain site. Even so, volunteers from the Schoodic Institute will continue to record these raptor counts through the end of October and possibly into early November.
I would like to thank our volunteers at Schoodic Institute, my fellow Acadia National Park Rangers, and our visitors! Every bird spotted this season has enabled us to continue our 30 years of raptor counting here on Cadillac Mountain. Thank you all for helping to support this research, sharing your interest in raptor migration, and your love for Acadia National Park. It has been a wonderful season, and I look forward to following the counts next year.