Merlins And Accipiters Attacking Flocks Of Birds

[Steve Kroenke]

Merlins And Accipiters Attacking Flocks Of Birds…Hammer Of The Gods

One of the most spectacular predator/prey interactions involves a fast flying raptor that is pursuing a flock of birds which forms a tight “ball” in an attempt to elude the predator. Many birds of prey will not penetrate the tight flock because this could be dangerous to the raptor, particularly at high speeds. The hawk or falcon could injure itself when hitting multiple birds. Also the shifting pattern of the tight flock is confusing to the raptor and makes it difficult to select a victim. The prey knows this and a flock of birds when under threat by a merlin or Accipiter instinctively coalesces into a “single organism”. The tight flock weaves, dives and climbs through the sky as the merlin or Accipiter closes in. When the raptor is almost at contact, the flock tightens incredibly close and all you may see is a “black mass”. And the raptor usually breaks off its attack but may still continue chasing the flock. However, on occasion a raptor will try to pluck a single bird from the flock or break the unity to force several members out to make the prey more vulnerable.

Over the years I have observed a few high speed pursuits involving merlins and Accipiter hawks and flocks of red-winged blackbirds, cedar waxwings and cowbirds. Several of the attacks were breathtaking as the flock tightened and weaved through the sky at high speeds while the merlin or Accipiter closed in for the kill. It was Hammer of the Gods!

Here are three examples involving a merlin, Cooper’s hawk, and sharp-shinned hawk attacking a flock of birds.

Merlin Attacks Flock Of Cowbirds

Living on a major bird migratory flyway has its pros and cons. Our area in northwest Louisiana is apparently the interstate highway for both songbird and raptor migration. March, April and early May are the big times for Accipiter hawk and merlin migration north and we are right in their pathway. This has created a major threat to our large martin colonies and the martins and I must constantly be vigilant and prepared to react in an instance the moment danger arrives.

In March of 2006 a female merlin had been hunting in our area for some time and she terrorized our purple martins. However, the martins saw her every time and they always managed to escape higher in the sky while emitting blood curdling screams though there were some hot pursuits. With more eyes watching for predators, our huge numbers of martins were not easy targets in our open location.

The merlin is a small but robust falcon that eats primarily birds and has a speed that few birds can exceed. I have seen a female merlin pick out a fast flying martin that was over 100 yards away and trying its best to distance the enemy. The merlin pumped her wings strongly and within seconds overtook the twisting martin, but was unable to make contact due to the martin’s superior agility. From what I have seen, martins nearly always escape when they KNOW the merlin is after them. The martin may not be able to out fly the merlin by speed alone but can often do it by out maneuvering the falcon.

However, the merlin would often pursue other prey and a favorite was a flock of cowbirds or red-winged blackbirds twisting and turning through the sky. Nothing is more spectacular to watch than a merlin chasing a mass of cowbirds or redwing blackbirds that behaves as a single organism and tries its best to elude the Grim Reaper. I am spell bound as the merlin follows the meandering flock of birds and then tries to pick off a straggler or scatter them. The flocking behavior of the prey is designed to confuse the predator with the constant shifting of flight patterns. Each bird becomes lost in the mass and this helps to protect the individual from predation.

One afternoon in March the female merlin wanted cowbird. I was in my yard watching my martins when suddenly every martin in my colony and my next door neighbor, Bob’s colony emitted screams of terror and bolted upward. Martins were streaking through the sky like a herd of gazelle fleeing at the approach of a hunting cheetah.

I figured it was the merlin but I had no idea where she was or even if she had managed to enter Bob’s colony. I rushed to the open area between our colonies and just stopped dead in my tracks.

About 100 yards to the north of Bob’s colony and about 200 feet up was a flock of cowbirds that were performing their gyrating flight and behaving as one entity. They writhed back and forth as each bird blended inside the mass and lost its identity. Their flight was tortured as they fled for their lives.

But they were not alone and the Grim Reaper swung its grisly scythe. A female merlin was flying at a terrific speed and following every maneuver of the cowbirds. They turned; she turned. They climbed; she climbed. They dived; she dived. The mass was being hunted down by a spot with a hunger for fresh cowbird.

Suddenly the merlin’s afterburner kicked in and she literally plowed into the periphery of the flock of cowbirds. This can be a dangerous mode of attack for a bird of prey because of the possibility of injury from plunging into a mass of birds. But this merlin attacked with reckless abandon!

The cowbirds shifted abruptly downward and all, except one, then climbed higher. I couldn’t believe it! The merlin had apparently hit one of the cowbirds and it dropped down, perhaps stunned or even dead. I watched the dark shape spiraling toward the ground!

The merlin quickly banked downward and caught the falling cowbird and carried it over an open pasture. But not so fast!

Bob’s martins were wild with rage it seemed and they launched a vigorous mobbing attack on the laden merlin as she labored to carry her prey across the pasture. Martin after martin attacked and emitted their anti-predator mobbing call, ACCCK.

I finally lost track of the merlin as she probably descended to the ground to consume her meal.

This merlin was a pro at hunting flocks of birds and not intimidated by the shifting flying patterns and bunching up actions.

Cooper’s Hawk Attacks Flock Of Red-winged Blackbirds

We often see large flocks of red-winged blackbirds in our area as the birds migrate through during the winter/spring. Sometimes these flocks are literally hundreds of feet wide and when the birds land on the ground it literally turns black.

These large flocks of blackbirds become tempting targets for bird eating Accipiters, like the Cooper’s hawk. The Cooper’s hawk is a medium size Accipiter and the female is about the size of a crow. But with so many prey items the hawk can become overwhelmed and unable to select a specific victim. However, on occasion a Cooper’s hawk will be able to separate a single bird from the flock during an assault on the entire group. Then the fun really begins!

Several years ago huge flock of red-winged blackbirds landed in a group of trees located about 200 yards from my purple martin colony. Since it was late winter, many of the trees were still leafless. It was early March and the martins were here.

I was watching the blackbirds when all of a sudden they bolted as one from the trees and formed a thick black cloud that started twisting over the treetops. I knew there had to be a raptor after them.

The entire flock climbed up and directly under them was a male Cooper’s hawk in full hunting mode! His body was sleek, his wings turned back and beat rapidly, and he was going after the “black cloud”! Hammer of the Gods!

The blackbirds twisted and turned in a huge tight mass just above the trees. As they shifted up and down and to the side, the hawk stayed close to them but would not plunge into the mass. I just held my breath and waited for a blackbird to get separated from the flock.

The hawk was not giving up and continued to harass the huge flock until several birds fell behind. This was exactly what the hawk wanted.

The hawk exploded in speed and latch on to one blackbird that streaked just over the tops of the leafless trees. I watched the blackbird flying for its life as the hawk’s sleek body now looked like a missile and his wings beat ferociously.

The hawk was only about a foot from the fleeing blackbird which turned and weaved between the tree tops. The hawk had no difficulty following every banking action of the blackbird as the hawk used his long tail as a rudder to guide his quick banking actions. The blackbird appeared doomed unless he could somehow dive down into a thicket and get deep inside.

For about 200 yards the hawk pursued the blackbird which jerked from side to side in attempt to escape the talons of death. The hunter and hunted were about 50 feet above the ground and at the edge of the woodlot with the leafless trees. I watched in awe as the hawk followed every move of the blackbird like a giant flycatcher.

When the hawk was about to pluck the blackbird out of the sky, the prey suddenly went straight down in a blinding burst of speed. The hawk matched the maneuver and both predator and prey violently plunged into a thicket that borders the road in front of my house! Surely they had committed suicide with such a Kamikaze dive! At this point, I didn’t know the finally outcome.

In a few minutes, I saw the Cooper’s hawk fly up from the thicket without his meal! The blackbird had apparently managed to elude the hawk deep in the thicket.

This high speed pursuit was one of the longest chases I have ever observed by a Cooper’s hawk. Most Accipiters, which includes the sharp-shinned hawk, typically pursue prey for about a 100 yards or less and that is what I have usually observed.

Sharp-shinned Hawk Attacks Flock Of Cedar Waxwings

The sharp-shinned hawk is the smallest member of the Accipiter family which includes the crow-size Cooper’s hawk and even larger goshawk. The sharpie is an active bird eating hawk and specializes in small species, including purple martins.

Though sharpies often make surprise attacks on their prey at low altitudes, sometimes they will attack higher flying flocks of birds and pursue them. But the sharpie is not like the merlin and is not a marathon hunter under most conditions.

I remember one spectacular attack by a female sharp-shinned hawk on a flock of cedar waxwings that was as enthralling as the merlin hunting the cowbirds and the Cooper’s hawk pursuing the red-winged blackbirds.

Migratory cedar waxwings form flocks and they stay together. There is safety in numbers with more eyes looking for danger and if you are part of a flock then your chances of being eaten is lower because of more other opportunities for a predator.

A number of years ago, I was in downtown Quincy, Florida which is a small town that is west of Tallahassee where I previously lived. I was watching a flock of cedar waxwings flying overhead when they suddenly started weaving erratically. They tightened and swerved from side to side. I knew there had to be a hawk after them.

Sure enough, a female sharp-shinned hawk was approaching the cedar waxwings from a higher altitude. She was is a hunting mode with her body profile sleek and wings turned back.

Then down she came in a blistering burst of speed. She was going directly for the cedar waxwings which now were a tight ball and violently banking up and down and to the side.

The hawk was only feet away from the cedar waxwings and was apparently attempting to separate one from the flock. The cedar waxwings’ flight was tortured as they tried to escape this highly maneuverable hawk that matched every banking action of her prey.

After several violent turns, the cedar waxwing flock lost some of its cohesion and one bird became separated from the others. This was what the hawk was waiting for. She could now concentrate on this lone cedar waxwing. Hammer of the Gods!

Both hunter and hunted were maybe a hundred feet up in the sky above buildings, cars and street lights. I gasped as the little cedar waxwing twisted violently downward with the sharpie right behind her prey. The twosome streaked toward the heart of downtown Quincy, Florida!

With incredible aerial gymnastics, the cedar waxwing and sharpie twisted and turned and I was never sure which bird would prevail in this encounter. They flew around street lights, over cars, and along the side of a building! The hawk seemed to be only inches from the cedar waxwing which was flying for its life.

And the hunt finally ended for me when the cedar waxwing and sharpie disappeared behind a bank. I never knew what happened. Both predator and prey were determined to win!

Over the years I have observed numerous interactions between raptors and their prey. The most common has been Accipiter hawks and merlins attacking purple martins in my colonies. But bird eating raptors also hunt other species and one of the most exciting hunts of all is a merlin or Accipiter pursuing a flock of birds that transforms into a single organism. The shifting flying patterns of the flock and the determination of the predator to capture a victim from such situation is one of the wonders of the natural world. You never know what is going to happen.

Steve Kroenke

[Donnie Hurdt MN]

Good reading as always Steve I really diddent feel sorry for the Cowbird that got caught and glad the Blackbird got away and I hope the Waxwing made it too. One always has to pull for the little guy dont they?
I have a little story along the same lines to share, yeaterday as I was walking by the birdfeeders a Northern Shrike came out of nowhere and hit a House Finch in mid air but only got feathers. The finch took off for the protection of a row of evergreens with the Shrike close behind they both dissapeared in the evergreens dont know the outcome of that one either. This Shrike has been hanging around all winter bothering the birds at the feeders.

[Steve Kroenke]

Hey Donnie,

We have way too many cowbirds over here! They do cause many problems for some species. I have never seen one bother any of my martin colonies but I did have one enter a bluebird box once and lay an egg in the bluebird's nest. I have seen Accipiter hawks pursue cowbirds at my feeders when I lived in Tallahassee.

Thanks for sharing your interesting observation of the shrike attacking the house finch. Those shrikes can almost be like an Accipiter hawk around a bird feeder. We have several loggerhead shrikes in the area right now and they will try for goldfinches at Bob's feeders when the weather is real cold.

Steve

[Scully]

Early one late August morning I was walking my dogs along the power line right of way behind my house. Below one of the tall pylons I was puzzled to see an arrangement of black grackle feathers sticking up from the mowed grass. As I stood there puzzling another feather spiralled down from somewhere above and planted itself in the grass too. I looked up and there was a big female peregrine falcon looking back at me from the top of the tower, midway through plucking a male great-tailed grackle.

She stayed at that place behind my house for about a month. All day long she would sit quietly on the pylon, ignoring the birders that came to see her, and ignoring the many other people who passed by, entirely oblivious of her presence.

When I came out at night the peregrine would invariably be awake and looking around, once I even saw her make a short flight at night, flying towards a tree in which apparently birds were roosting, before restlessly returning to the pylon.

Why she chose that place was the fact that there is a large grackle/starling roost only a quarter of a mile away, at that season already filling up with birds. She apparently made a kill every morning, perhaps in the dark, however early I got out there she had already made a kill, and would be plucking it in the same manner as that first morning. Sometimes a big male great-tailed grackle, sometmes a white-winged dove.

She also hunted every evening at dusk, I would see her stirring and looking intently towards the streams of grackles heading for the mall. Then she would take flight with an unhurried, steady wingbeat.

The best I can describe it was like turning up a dimmer switch; her flight would be slow for the first few seconds, but then it was like she had afterburners, accelerating steadily with hardly a change in her wingbeats.

At her approach, thousands of grackles would literally fall like rain from the sky, flying vertically straight down. I had never seen anything like it. I never did witness an actual kill, but I did see her once in the failing light blitzing low over the heavy traffic in front of the mall, grackles falling everywhere.

One day in September she was simply gone, and never did return.

Of interest is the fact that I have read descriptions of wintering Arctic Peregrines in the major cities in Brazil, these peregrines also speeding low over the conjested lanes of heavy traffic, but down there in association with the big martin roosts.

Mike Scully

[Steve Kroenke]

Hey Mike,

Thanks for sharing your interesting observations of the hunting behavior of a peregrine falcon.

Though many folks think of peregrine falcons as patrolling the open skies, these predators will result to low level attacks on the concentrations of birds. They almost act like Accipiters though the falcons do not fly through trees or dive into vegetation as they chase prey. The long wings of the falcon could be damaged, plus such wings are not suitable for close maneuvering inside forests and trees.

Every year I see several magnificent peregrine falcons fly over our martin colonies and I have seen several attacks on the martins. The falcons make relatively low level attacks and their stoops are not from way up in the sky. The martins have managed to out maneuver these large falcons every time one dives on our colonies.

I have only observed one successful attack by a large female peregrine falcon on a solitary martin that made no effort to escape. I watched this falcon "stalk" a high flying martin that was just "floating" in the sky. The falcon slowly flew toward the martin and the martin didn't try to escape and never emitted any alarm cries. The peregrine simply flew over to the martin and grabbed it! I could see the martin hanging from the falcon's talons. Perhaps this martin had "its mind" elsewhere and was not watching. Or maybe the martin "went into a kind of flight shock" and froze up when this large menacing falcon started approaching. Sometimes prey animals when attacked by predators "go into shock" and make no effort to escape or defend themselves.

I have seen the migratory peregrines come over late into May on occasion and when they circle our colonies the martins climb up high above the predator. Other martins stay put on the housing and still others go inside their cavities.

The big female peregrines are noticeably larger than the males and this sexual dimorphism is common among birds of prey. It is very pronounced with Accipiter hawks.

Thanks again for sharing your observations of the peregrine falcon. They are truly magnificent birds of prey.

Steve

[Julio]

Steve as always your posts are fantastic.

[Steve Kroenke]

We have wintering Accipiter hawks in our area now and large flocks of red-winged blackbirds are coming through. There are also many robins.

These hawks will often attack the blackbirds and robins and when they go after a huge flock it is incredibly exciting and awesome.

I am re-posting this older article dealing with Accipiters and a merlin pursuing flocks of birds. I wonder if other folks have seen this!

Steve