A Primer on Hawks

[Terry Suchma]

A Primer on Hawks, Part 1

(For Cheryl and Asop)

Yes, hawks are a problem for colonies, but unless you have a small colony, I don't think that hawks will cause you to lose all the existing birds of your colony.

For landlords worried about hawk predation on a small colony, the real problem is that you don’t have many birds in the first place. When you have a few pairs at your colony during a breeding season, you actually have a colony in decline. In order for you to perpetuate your colony into the future, you, the landlord, must attain and sustain at least 12 pairs of martins annually. With at least 24 birds in every season and taking into account natural attrition of Purple Martins, you should hopefully realize the reappearance of, at least, half of those birds in the following season.

Not all the migrating martins travel together. Martins do not migrate in large flocks of birds like you see with many types of other migrating birds. Instead, martins only migrate in small aggregates from one staging place to another and roost together with other arriving martins and/or swallows. Then, they leave the roost and travel again to the next stop in a small aggregate of birds.

While storms, like hurricanes, do annihilate a good number of migrating bird, including martins, they do not wipe out the entire numbers of martins since martins depart from various exiting venues across the Gulf coastal areas and leave on different days, etc.

So, not all your martins will have been lost in a colony of 12 pairs or more from one year to the next. You should have the return of a few birds, or, at least, one bird.

As for hawks, they hit everyone's colony, big or small. Bird eating hawks are the Sharp-Shinned Hawk and one similar to the Sharpie, but larger, the Cooper's Hawk. In the far northern tiers of our country and in southern Canada, there are Goshawks which are quite large birds.

Here are bird species graphics and info on these bird eating hawks which technically are called "Accipiters." There are also falcons that eat birds.

Bird eating hawks or Accipiters

1. Sharp-Shinned Hawk

2. Cooper's Hawk

3. Northern Goshawk

Falcons

Peregrine Falcon

American Kestrel


It should be noted that Kestrels take both flying insects, like cicadas and dragonflies, as well as birds relative to its own size. They would not be considered common predators of Purple Martins. Favorite food targets of Kestrels would be House Sparrows and other small sized birds.


Many may note that I also did not include the Red Tailed Hawk or the Red Shouldered Hawk. This is because the bird eating hawks, whether small or large, are endowed with narrow wings and are capable of high flight speeds and excellent maneuvering skills through dense forested areas in pursuit of their prey. Accipiters can turn on a dime in pursuit of their prey. The Red Tailed and The Red Shouldered Hawks have large, rounded wings, which makes them anatomically unable to successfully pursue the swift-flighted martin. These hawks, called Buteos, or the broad wing hawks, cannot reach the great speeds and acutely sharp turns in flight as the Accipiter Hawks and Falcons can. I say most of the time because as I have documented from landlord accounts, over the years, that “opportunistically, if a martin zigs and a Red Tail zags in the same air space, they may intercept each other and the martin can be taken. In the martin world, there have been “opportunistic” takes of martins by such birds as Red Tails and even Great Blue Herons, both of which are not known as serious predators of Purple Martins.

The Sharp-Shinned and the Cooper's Hawks look quite similar with the following two exceptions:

1. The Sharpie is smaller and, the Cooper's Hawk is as large as a Red-Tailed Hawk.

2. The Sharpie has a squared-off tail and the Cooper's tail is rounded.

Both hawk species have the same coloration and horizontally-barred (black and white) tails.

The largest Accipiter, the Goshawk, is completely different in both coloration and size. It is blue-gray with a white eye stripe. While the Cooper’s is about the same size as a Red Tailed Hawk and being about 14-20” in length, the Goshawk is about 21-26” in length. Again, the Goshawk is found in the most northern tiers of our country and southern Canada.

The differences in the above sizes relate to the fact that the females are larger than the males.

The differences in sizes between the Sharp-Shinned Hawks (10”-14” in length) and the Cooper’s Hawks is that the smaller Sharp-Shinned female may be as large as the larger male Cooper’s Hawk. So, in a fast attack in your backyard, you might not be able to distinguish that the hawk reconnoitering your colony is a female Sharp-Shinned or a male Cooper’s Hawk. Though there is a difference in their tails with the squared tail of the Sharpie and the rounded tip of the Cooper’s, you may not have enough time to distinguish size of the bird or identify which of the species is going for your martins. But, I would say, that most raiders of the backyard feeder are the Sharpies.

All Accipters can be identified from below by focusing on their tails. A Red Tail has a shorter and fanned out rounded tail while the Accipiters will have a long narrow tail trailing from their bodies in flight. Think cigar shaped tails!

Cooper's and Sharpies take birds relative to their size, hence the terms, sparrow hawks, chicken hawks and duck hawks. These terms indicate the size of the individual hawk’s prey birds. These are Old World terms but are still used commonly by people today. But, with the Sharpies and Cooper's, they will both take Purple Martins. Goshawks’ life sustaining requirements make it a bird that must take a larger bird for sustenance. Purple Martins would only fill their eye teeth if Goshawks had teeth.

Over the years, I have heard it all about hawk harassment from landlords. But, is it truly harassment if we, ourselves, are luring hawks into areas with large martin colonies? What about the playing of lure type martin sounds? Isn’t it a no-brainer that the predator knows the sound of the prey? When sane minds think about it, the answer is yes. We are somewhat responsible for setting the martins up in the middle of our yards. The martins become like “sitting ducks.” Doesn’t it also seem as though we are providing the opportunistic moment for the hawks to take our martins?

(Go to part 2, next posting)

Terry

[Terry Suchma]

Alert! Alert! Please note! High Horse Editorial Ahead!

So, why take it out on the hawks? They aren’t the bad guys. We aren’t either. This is why we need to wrap our heads around the big picture. We should definitely take preventative measures to save as many martins as we can but this does not involve a rifle with a sharp spotting scope or a horrifically painful and deadly leg trap as some shameful landlords have been known to use. Some landlords with enormous martin numbers at their site have been known to resort to breaking the laws. And, they brag about it. I pride myself on not being so specialized in martins that I have lost sight of the big picture of how wildlife works. For me, I love my martins and other native bird species so much that I will not tolerate abuse of the state and federal wildlife laws that protect both martins and hawks.

While this is a subject for another time, I will touch on it lightly. Purple Martins are really not our birds as we refer to them. I, myself, am guilty of referring to the martins as my martins. But, while we endearingly call them “our martins,” we know, or should know, that the martins are not property that we own. We are Purple Martin stewards, and as such, the martins are in our temporary stewardship. It is a privilege to host martins—not a right! Much of what we do in the PM interest is against the wildlife laws (US Fish and Wildlife (USF&W)) but USF&W knows what Purple Martin landlords and Bluebird managers do to perpetuate these birds. They governmental agency looks aside because they think we are helping to perpetuate and conserve the Purple Martins and also that we are obeying the laws. Those that abuse the laws at their backyard colonies are blackening the eyes of all of us who abide by the laws and maintain our colonies in abeyance of the laws and threaten our privilege of hosting martins in our yards.

Please read the following from the Migratory Bird Treaty Act and apply it to both martins and hawks:

Sec. 703. Taking, killing, or possessing migratory birds unlawful

Unless and except as permitted by regulations made as hereinafter provided in this subchapter, it shall be unlawful at any time, by any means or in any manner, to pursue, hunt, take, capture, kill, attempt to take, capture, or kill, possess, offer for sale, sell, offer to barter, barter, offer to purchase, purchase, deliver for shipment, ship, export, import, cause to be shipped, exported, or imported, deliver for transportation, transport or cause to be transported, carry or cause to be carried, or receive for shipment, transportation, carriage, or export, any migratory bird, any part, nest, or eggs of any such bird, or any product, whether or not manufactured, which consists, or is composed in whole or part, of any such bird or any part, nest, or egg thereof, included in the terms of the conventions between the United States and Great Britain for the protection of migratory birds concluded August 16, 1916 (39 Stat. 1702), the United States and the United Mexican States for the protection of migratory birds and game mammals concluded February 7, 1936, the United States and the Government of Japan for the protection of migratory birds and birds in danger of extinction, and their environment concluded March 4, 1972 (FOOTNOTE 1) and the convention between the United States and the Union of Soviet Socialist Republics for the conservation of migratory birds and their environments concluded November 19, 1976.

End of High Horse Editorial by Terry

Back to Hawk eating birds…

Hawks-eating birds and falcons are only doing what is natural for them to do--to cull the number of birds in the wild. The important things to remember about bird eating hawks is that unlike some humans, they are ethical hunters and only take what is necessary for them and their young to survive. In the times when they are not feeding their young, they only take a bird a day—any bird they can find and capture. And, on sharp days of winter or during weather times of rain and/or snow, the hawks, like martins, do not eat at all. Think of martins that are unable to feed for more than two days. The martins perish. So, it is no different as with hawks. Consider that in zoos, where there is a collection of many animal species, keepers do not feed animals seven days a week. This is done to simulate natural conditions in the wild as hawks experience it.

Something else to consider is that while we dearly love songbirds, like our beloved martins, the number of songbirds outnumber the number of birds of prey in the wild. It was meant to be in Nature, or the wild, that songbirds would be food for certain other birds. This is not unlike how dragonflies, damselflies and all diurnal flying insects were meant to be as foods for Purple Martins.

Interesting to think of Purple Martins as predators, isn’t it?

While flying insects, minimal as they seem to be to martin devotees, they are similar to the minimal takes of songbirds by birds of prey. While there are lovers of dragonflies, damselflies, butterflies, bees and other flying insects, these devotees are repulsed when they know that martins are taking their little gems of natures, too.

It is all relative in Nature.

One reason many of us lose our martins, both adults and young, to hawks is due to the fact that we love to see our martins from our own porches and decks in our backyards. Therefore, we or commercial birdhouse builders, build porches onto our birdhouses just so we can see the martins and nestlings come out on the porch and perform. If we all had porchless birdhouses, we would probably be more successful with fledge rates because we could keep our nestlings inside the houses longer than in porchedhouses. Martin folks don’t like to hear this but it is true. With porches on houses young martin nestlings are easily lured outside onto the porches which now make the martins easy targets for birds of prey to pick off the porches.

This is one reason why gourds enjoy a higher success rate in the martin interest. With gourds, because there aren’t porches (round holed gourds) or deep porches (gourds w/SREHs) on gourds, young inquisitive martins neither venture outside a gourd nor fledge from a gourd until they are ready to fledge. The young birds remain safely inside the gourd until they depart on schedule on their first wing. On porched houses, as young martin nestlings are clumsy and just not smart enough yet, they find more difficulty to gain an expeditious entry into their houses when there is present danger. Indeed, the little ones have no sense of danger yet to what may be hurtling toward them at break-neck speed to snatch them from the porches. Also consider that SREHs make it very difficult for adults, to quickly pass through these specialized entrances during times of attack and, they too, are easily picked off the houses as they are in the process of squeezing themselves through the SREHs.

It must be remembered by all landlords that Hawks, of all types, enjoy the protection of all federal and state wildlife laws as do our Purple Martins. They are truly beautiful birds and, unlike the appendix inside your body with no apparent purpose, there is an important reason for hawks’ existence. They have a reason to be protected under our wildlife laws. They are native species, too. And, as for their perceived greater numbers today, people have to understand that these birds are also at the peril of nature and humans. We must also remember that while songbirds are more numerous, we must also realize that it takes more time for larger bird species to fledge, survive nature, mature and reproduced in the wild.

One final word or words… The thing I want to impress on our readers here is that we should not limit ourselves to be specialized in Purple Martins but to have a general appreciation for all native bird species and their special niches in the wild. As I said previously, we must look at the big picture and wrap ourselves around this whole picture involving the relationship between one bird species and another and how we fit into this picture. How unfair it is to conserve one native bird species while causing harm to another.

Terry