HawkWatch Update Archive - 2008

Discover what happened during the 2008 HawkWatch on Cadillac Mountain. Below are the weekly Riding the Winds updates written by the 2008 Raptor Intern, Sarah Kebler. The earliest entries are at the bottom and the later entries are at the top.

October 15, 2008. Sadly, our season is coming to an end on top of Cadillac Mountain: HawkWatch officially ends today. But our birds are still going strong! Northern goshawks and rough-legged hawks will begin to pass through soon. We recently observed more than a hundred birds on Sunday and Monday.

Just for a quick recap, we have seen numerous raptors here in Acadia this season, including a few hundred sharp-shinned hawks, ospreys, northern harriers, Cooper's hawks, American kestrels, merlins, peregrine falcons, bald eagles, and turkey vultures. We have had some memorable moments, with close views of ospreys, small raptors, and two immature bald eagles playing together in the air. As of Tuesday, the total for the season is 2,592 birds, which puts us just above our 13-year average of 2,555.

Now you may wonder what we do with the data we collect. Well, every afternoon hawk-watchers throughout North America enter their data into a large database at www.hawkcount.org. This database is administered by the Hawk Migration Association of North America (HMANA). (Staff that participate in our HawkWatch at Cadillac Mountain have the guilty pleasure of constantly checking this website to see how other sites are doing.) The data are then complied for long-term regional and national studies, allowing ornithologists (bird geeks like me) to see trends in their populations. For example, the number of peregrines and bald eagles is on the rise, but the number of American kestrels is on the decrease at most sites across the United States. Kestrels are possibly on the decline due to loss of habitat. They nest in tree cavities bordered by fields. In recent years, there are fewer fields, and private land owners often cut down dead trees leaving less habitat for kestrels.

In the end, do keep in mind that when spring nears, the raptors are on the move again. They will begin their journey to the north in a hurry to set up a nest site and raise their young.

Before saying goodbye, I just want to say a quick thank-you to the park rangers at Acadia National Park who have spent countless hours watching for birds in the sky. And here is a big thank-you to all of the "regulars" who attend HawkWatch on the north-wind days! They are truly a huge help and good company. And most important, thanks to all the visitors who have attended HawkWatch and have learned something new. See you next year!

- Sarah Kebler

October 8, 2008. Hello, fellow hawk-watchers! We continue to see migrating raptors from the north to the south on top of Cadillac. This past Monday we saw more than 230 raptors, including 89 sharp-shinned hawks and 89 American kestrels! We saw so many birds because the weather conditions were just right: the sun was hitting the rocks and pavement, creating thermals for the birds to ride on, and a north wind was blowing.

This week's Riding the Winds is focused on the northern harrier and the osprey. It is common to have very good views of both birds on Cadillac as they are going south. The osprey is headed toward Florida and the Caribbean, and the harrier is headed to the southeastern U.S. I enjoy seeing the northern harrier since we typically only see one or two a day if we are lucky-but on Monday we saw 18! They have really good hearing since they have an owl-shaped face with feather discs that help capture sound. By listening for prey, the harrier can find food in the marshes and open grasslands. I have seen ospreys flying right overhead and attempting to fly around us without us knowing. But since they are such a large bird, visitors help us in spotting them so we can count them.

Northern Harrier: Length (18-20"); wingspan (40-46"). This "marsh hawk" is one of the medium-sized birds that we see on Cadillac. The bird appears lean and lanky, and it has narrow wings and a long tail. The males are a known as the "gray ghost" since they appear gray-silver. In reality, they are white with black wing tips. The females are a tawny color, and the immatures are a cinnamon color. Their wings are uplifted in a sharp dihedral or "V" shape. The wing beats have a unique cadence and are "lazy." The bird flies with a slight rocking motion. Hint: These birds have a bold white spot on their rump.

Osprey: Length (21-24"); wingspan (54-72") These "fish hawks" have a five-foot wing span and are a larger raptor version of a gull because they have long gull-like or "M"-shaped wings that droop down. This bird has bold black and white patterning on its underside and dark eye stripe. Ospreys have gray feet and yellow eyes. They have waterproof feathers since they catch fish in the water, but they are not able to swim and must exit the water as soon as possible. Hint: Stiff wing-beats and an "M" shape!

These are just two of the birds you might see soaring over us at HawkWatch. Join us 200 yards down the North Ridge Trail of Cadillac Mountain from 9 a.m. to 2 p.m. through October 15. Of course, weather permitting! Please bring your own pair of binoculars (don't worry, we have some if you don't) and together let's watch the journeys of migrating birds!

- Sarah Kebler

October 1, 2008. Hello, again! After a few rainy days we are ready to start watching for birds again! In the past weeks, I have written about how to identify some of our most popular birds, including the sharp-shinned hawk, Cooper's hawk, broad-winged hawk, red-tailed hawk, peregrine falcon, merlin, and American kestrel. The next few weeks will focus on some of our more unique birds. This week's Riding the Winds will focus on the bald eagle and the turkey vulture.

The bald eagle is one of our raptors most sought-after by visitors. We have about 12 pairs nesting near or around Frenchman's Bay. It is the one bird that most visitors hope to see because it is the national symbol. The bald eagle is the national symbol due to their long life span of about 20 to 25 years, amazing strength, and large and majestic appearance. As it was then and still is today, the eagle represents freedom. However, did you know that the bald eagle was not everyone's choice for the national symbol? Our very own Benjamin Franklin wanted the wild turkey. He mentioned the bald eagle was not of moral character and was a lazy bird, since eagles are notorious for stealing food from osprey. Also, eagles are often picked on by smaller song birds. Ah, it is true-I have seen, with my very own eyes, crows, herring gulls, and peregrine falcons attacking a poor bald eagle. Benjamin Franklin claimed that is was the wild turkey that had the courage to find its own food and could defend its own territory.

This past week we observed two immature bald eagles playing with each other. The two birds flew side by side and, at times, dropped in the air while holding onto each other's talons! This was quite the site to see. We believe the young ones were practicing courtship displays, which will come in handy when they are ready to mate.

The turkey vulture, on the other hand, is not a type of raptor. These birds are often mistaken as raptors but are more closely related to storks. Who would've guessed? Turkey vultures lack a few qualifications. First, they do not have talons and are unable to catch their own food. Second, they have a great sense of smell, which helps them find carrion or dead animals (most birds lack a well-developed sense of smell). Often this means snacking on road kill. I have seen a turkey vulture eating a raccoon on the side of the road. (It was a sight to see until the people behind me began to honk!)

Bald Eagle: Length (28-38"); wingspan (79-90"). In case you're wondering, the wingspan really is between 6 and 8 feet! Bald eagles are large blackish birds with yellow bills. Adult birds have white heads and tails. The young, however, are completely brown from head to toe with various white spots and are often mistaken for golden eagles. It takes immature eagles about four to five years before they display the white head and tail and become sexually mature. Bald eagles appear to have large heads, long wings, and short tails. When flying, the wings are solid and as flat as a board. These birds rarely flap, and when they do, it is in a slow, robust fashion. Bald eagles can be found near the sea coast, lakes, rivers, and marshes. Hint: Look for the white head and tail!

Turkey Vulture: Length (23-28"); wingspan (63-71"). Turkey vultures are large birds with dark bodies. They appear to have small heads with long, broad tails. Their bills are whitish, and their heads are red! The wings are held in a dihedral, or a strong "V" shape. These birds very rarely flap, and when they do, it is usually because they are readjusting their wings. Their flight pattern is rocky, almost tipsy! Hint: Think "V"!

These are just two of the birds you might see soaring over us at HawkWatch. Join us for HawkWatch 200 yards down the North Ridge Trail of Cadillac Mountain from 9 a.m. to 2 p.m. through October 15. Of course, weather permitting! Please bring your own pair of binoculars (don't worry, we have some if you don't) and together let's watch the journeys of migrating birds!

- Sarah Kebler

September 24, 2008. HawkWatch is coming along! This past Thursday we had more than 200 birds, and we are still waiting for our biggest day yet. Our biggest day in past years consisted of more than 700 birds. Today we had a close look at two different ospreys. One flew around us, giving us an excellent view of its side. Later in the day, one flew right above us, showing us its underside in detail.

Today, I am going to focus on the accipiter family, which consists of the sharp-shinned hawk, Cooper's hawk, and northern goshawk. These hawks mostly live in the forest; they are built for moving quickly through the trees. They are able to fly around the trees because their wings are short and rounded. Accipiters also have long, narrow tails. They hunt in the forest, along forest edges, and also in open woodlands. When these birds are hunting in the forest, they make short flights and will perch to look for prey. When they find food, they will extend their talons away from the body to grab it, protecting their head and eyes.

Sharp-Shinned Hawk: Length (10-14"); wingspan (21-26"). The sharp-shinned hawk is a slender, dove-sized bird. It has small, stubby wings with a long, narrow tail. In a distance, the bird appears dirty chested, but the adult birds have a blue-slate color on their back with orange barring on their underside. These birds fly in an erratic line, with a quick and snappy wing beat. The flight pattern has been described as flap, flap, glide. Hint: These birds will often harass larger birds.

Cooper's Hawk: Length (14-21"); wingspan (27-34"). The Cooper's hawk is a crow-sized bird that is easily confused with the sharp-shinned hawk. The wings are straight along the leading edge (the front part of the wing when the wing is extended). The tail is as long as the body and has a longer rounded tip. The flight is more sustained and powerful than that of the sharp-shined hawk. The Cooper's hawk appears slower and stiffer. Their pattern is a flap, flap, g-l-i-d-e. Hint: The terminal band on the tail is broader and whiter then the sharp-shinned hawk's.

These are just two of the birds you might see soaring over us at HawkWatch. Join us for HawkWatch 200 yards down the North Ridge Trail of Cadillac Mountain from 9 a.m. to 2 p.m. through October 15. Of course, weather permitting! Please bring your own pair of binoculars (don't worry, we have some if you don't) and together let's watch the journeys of migrating birds!

- Sarah Kebler

September 17, 2008. Hawks are on the move as we enter into our fourth week of HawkWatch! We have seen more than 700 birds. Our most seen bird continues to be the sharp-shinned hawk at 290; last year we had a total of 1,003. We have seen 184 broad-winged hawks, 105 American kestrels, 55 osprey, and 20 red-tailed hawks.

This week's Riding the Winds will be focused on the most familiar hawk family-the buteos. This family includes the red-tailed hawks, broad-winged hawks, and red-shouldered hawks. These birds tend to be excellent fliers in the wind due to their broad wings and short, fanned tails. They are able to fly thousands of feet above us without even flapping once using thermals and creating kettles. Buteos tend to hunt from a perch and will sit and wait for their food to appear. They often use their talons to catch their prey.

Here are some details about two species of buteos:

Broad-Winged Hawk: Length (13-17"); wingspan (32-39"). These hawks are crow sized and have a chunky body. Broad-winged hawks are pale with a white throat. They have a short tail and broad wings, which are curved and held flat almost horizontally. Their wing beat is stiff and choppy. When soaring, their wings are angled downward. These birds tend to be found in the forest searching for frogs, snakes, small birds, and other small animals. It is not uncommon to see hundreds of these birds swarm up in a kettle at Hawk Mountain or farther down south. Broad-winged hawks have a long journey when traveling to Central and South America. A typical journey is 4,000 miles. A recent study showed these birds traveling roughly 70 miles per day, making their trip last almost two months. Hint: Adults have a wide white tail band and are seen in kettles.

Red-Tailed Hawk: Length (18-21"); wingspan (45-52"). The red-tailed hawk weighs about 2.5 to 4 pounds and is often seen perched along the highway. This bird has a chestnut coloration and a white underside with bold black markings. The shoulders are rusty looking, and the wings are extremely muscular with distinct commas on the underside. These hawks use heavy flaps when flying and soar with a slight dihedral (v-shape). When flying a red-tailed hawk often makes wide circles without flapping. Hint: The red-tailed hawk can hover.

If you would like to participate in HawkWatch, please join us 200 yards down the North Ridge Trail of Cadillac Mountain from 9 a.m. to 2 p.m. Of course weather permitting! Please bring your own pair of binoculars (don't worry, we have some if you don't) and let's watch together the journeys of migrating birds!

- Sarah Kebler

September 10, 2008. HawkWatch is beginning to pick up as more birds begin heading down south! Here is a quick update of the birds we have been seeing. Our most-seen bird is the sharp-shinned hawk; we have watched 214 fly by us. We have had 20 red-tailed hawks already, and last year our total was 48. We have seen 102 broad-winged hawks, 25 northern harriers, and 33 ospreys. The season is just beginning, and we hope to see many more in the next few weeks!

One question I have pondered these past few days is how raptors and other birds decide when to migrate. Is it due to the upcoming cold weather, or is it the lack of food available during the winter? A more complicated question is how they know what route to take. We have state highways and road signs, but these birds don't.

The word migration is based on the Latin migrāre, meaning to move from one place to another. Birds exhibit three different types of migrations. The first is a complete migration: all members of a species leave the breeding grounds. The second type of migration is a partial migration, where some members of a species leave the breeding grounds, but some remain. Last of all is irruptive migration. This movement is not seasonally or geographically based, and it is not predictable. There are theories that irruptive bird migrants are mostly food specialists and move based on food supply. This year on top of Cadillac we have seen many white-winged crossbills (a small songbird), which is an irruptive species and normally an uncommon find!

Hawks and other birds realize it is time migrate when the sun rises later and sets earlier. They become restless and get the urge to fly. Just as we often prepare by packing our car with food, clothes, and maps before hitting the road for a long trip, birds also need to prepare. First on the list is a new set of clothes-or in their case, feathers! Since changing old feathers for new ones is a hardship on birds, most raptors do an interrupted molt, meaning half of the feathers are exchanged for new ones. So every fall, half of their feathers are new, and the other half are old.

After molting is over, the birds have little energy reserves left, and they need to "pack the car" (their bodies) with tons of fat. Raptors will begin eating as much food as they can within a short time period. They will build up subcutaneous fat and fat in their body cavity that will keep them going on their long migration. They will certainly be eating along the way, but the extra fat will provide some extra fuel for the road and ensure that if food is hard to find they can still make it to their winter grounds.

Raptors also need a way to find their way down south. They have various tools to help them along the way. As humans we have roads signs, maps, and GPS units, but raptors have built-in tools. The most important tool for the bird is their ability to see. Most simply follow geographical clues such as the ocean coastline, mountains, and rivers. They may also use the position of the sun, and songbirds, which migrate at night, may use the stars. It is also believed that birds can sense and use magnetic fields to their advantage. Although scientists are unsure how well raptors can smell, perhaps they use their sense of smell as well.

Join us for HawkWatch 200 yards down the North Ridge Trail of Cadillac Mountain from 9 a.m. to 2 p.m. Of course weather permitting! Please bring your own pair of binoculars (don't worry, we have some if you don't) and let's watch together the journeys of migrating birds!

- Sarah Kebler

September 2, 2008. HawkWatch has had a great start, and we have seen numerous raptors migrating through! Today I will explain how hawk-watching began, and in upcoming weeks I will provide helpful hints on how to identify raptors on your own.

Hawk-watching began on Blue Mountain, located along the Kittatinny Ridge of eastern Pennsylvania on the Appalachian Trail. But our story begins when hawk shooters appeared on the Kittatinny Ridge in the early 1900s to shoot down the birds as they flew past on windy days. These hawk shooters thought they were protecting local wildlife and their own poultry. In Pennsylvania around 1929, shooters were paid five dollars for every northern goshawk shot between November 1 and May 1! Time passed, and a man named Richard Pough, a recent college graduate, visited Hawk Mountain (as the locals called it) and was shocked to see the mountain covered with dead hawks. He photographed the dead birds and began lecturing to end the shooting. A woman named Rosalie Barrow Edge became aware of Pough's distress and vowed to end the shooting along the ridge. She raised more than three thousand dollars to purchase Hawk Mountain in 1933 and founded the Hawk Mountain Sanctuary. The mountain was closed to shootings, and the hawks flew in peace.

Since then, Hawk Mountain has flourished as one of the top places to see hawks moving south (but we are still a happening place in Maine!). The mountain itself receives visits from more than fifty thousand people annually! Since then other places have started their own hawk-watching; in fact, in New England (excluding Pennsylvania and western New York) there are more than 45 places to go see hawks. If you are unable to join us in Maine, there may be a place near you!

If you ever find yourself on top of a mountain and raptors are flying past, you can use these helpful hints to identify them. The first tool you need is a set of binoculars to help you see raptors in the distance, and warm clothes will be welcome on top of a windy mountain with a north wind! The first step in identifying raptors is to look at their appearance. How long are the wings and size of the tail compared to the body? As the bird moves in closer, take notice of their behavior. How does the raptor fly? How often and how fast does the raptor flap it wings? If the raptor comes nearer, you may also be able use color to pinpoint what species you are seeing.

This week's focus is on the family Falconidae or the falcons. On top of Cadillac Mountain, we normally see American kestrel, merlin, and peregrine falcon. These birds are built for speed and are generally smaller then other raptors. The have long and tapered wings that are pointed at the tip.

American Kestrel: Length (9-12"); wingspan (21"). It is the smallest and daintiest falcon. It is a jay-sized bird with a rusty-looking tail and back. The adult males have blue on their wings, while the females have a rusty color on their wings. When these birds fly they do so with a fluttery and wandering path. Their wings are constantly at work and never at a rest. Hint: These birds are also seen hovering!

Merlin: Length (9-12"); wingspan (21-27"). The merlin is a pigeon-sized bird. This bird has long, sickle-shaped wings with a broad base and appears to be squat. Male are a bluish gray; females are a dark brown. The flight of the bird is direct and fast with short wing beats. They hardly soar or glide with the wind. Hint: They are larger then the Kestrel and in a hurry to get home!

Peregrine Falcon: Length (14-19"); wingspan (39-43"). Peregrines are the largest falcon seen at the top of Cadillac Mountain. The wings are longer and slimmer and have softer angles than the other falcons. Peregrine falcons have black hoods and a white chest. Their flight is strong with powerful wing beats. Hint: The tail is relatively short compared to other birds.

Please join us again next week for more updates about HawkWatch on Cadillac Mountain and more detailed information on how to identify other birds on your own. Or please join us in person 200 yards down the North Ridge Trail of Cadillac Mountain from 9 a.m. to 2 p.m. daily-of course, weather permitting! Please bring your own pair of binoculars (don't worry, we have some if you don't) and together let's watch the journeys of migrating birds.

- Sarah Kebler

August 27, 2008. Just as children slowly begin going back to school, raptors are beginning to travel to their wintering grounds. Some only have a few miles to go, while others have hundreds of miles to travel. And this week begins the first edition of Riding the Winds! This weekly series of articles will help you learn about raptors and how to identify them.

Here in Acadia National Park, we have started HawkWatch on Cadillac Mountain. Every day we sit on the granite and watch the raptors migrate past us. We count the birds to better help us understand their population density and also because it is fun to see the birds up close. So far we have seen 12 sharp-shinned hawks, 16 broad-winged hawks, 1 northern harrier, and 1 red-tailed hawk. Other birds we expect to see as the season heats up include osprey, peregrine falcons, bald eagles, American kestrels, and northern goshawks. We also have the pleasure of seeing small migrating birds and butterflies and an amazing view of Acadia National Park.

So what is a raptor? The term raptor has Latin origins and means one who seizes by force. There are four characteristics that embody a raptor. The first and most important is sharp claws or talons. Talons are needed for grabbing and tearing food with their sharp beaks (the second characteristic). Third, raptors hunt and eat other animals like fish, insects, and, yes, other small birds. Fourth, the diurnal (active during the day) raptors are able to soar high in the sky and ride thermals.

Thermals are created when the sun heats up rocks and paved areas. The warm air rises in pockets known as thermals. Birds ride the thermals up, creating a free lift for the birds. Often, we see birds low to the ground. As we follow their movements, we see the birds fly around in circles going higher and higher until we are not able to see them any more. Eventually, the thermal ends, and the birds begin to descend using gravity. They descend downward covering long distances and will often pass right above us! At times kettles (a group of raptors) will use the same thermal at once. The other day we saw four turkey vultures using the same thermal, and they created a kettle. Turkey vultures are not a raptor but are similar (they lack sharp talons and are more closely related to storks).

So why do we use Cadillac Mountain for HawkWatch? It's the largest mountain in the park (okay, so maybe because it is all about location!). As these birds are flying south from northern and eastern Maine and New Brunswick, they come to the Gulf of Maine, a large water body they do not want to cross. They turn and follow the coastline south and will often use thermals and updrafts to go over and around Cadillac. Thermals are created in downtown Bar Harbor and also near the Jackson Lab and on the North Ridge Trail. We can see these thermals being created as we watch (with the help of binoculars) the birds being carried upward into the sky. Updrafts are created as the winds are deflected off landforms such as Cadillac Mountain. The air deflects upward and will also carry the bird toward the sky. At times these birds pass right above our heads! If you are thirsty for more, please join in next week to learn about how hawk-watching began!

Join us for HawkWatch 200 yards down the North Ridge Trail of Cadillac Mountain from 9 a.m. to 2 p.m. daily. Of course, weather permitting! Please bring your own pair of binoculars (don't worry, we have some if you don't) and together let's watch the journeys of migrating birds!

- Sarah Kebler

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