Toe Dusting

We met a Barn Owl this week. We liked him, but he didn’t care for us. As a matter of fact, when your author walked in to our store where the local animal rescue people had brought it for educational purposes, the owl lowered its head and shook it in the universally recognized shake of disapproval. The rescuers of the owl told me not to take it personally, but I knew better. That owl was rescued after an encounter with a high voltage electrical line which it would not have encountered were it not for humanity’s insatiable desire for electricity. He had no use for me or any other of my fellow Homo sapiens, except possibly for those who rescued him and now care for him.

The rescuers assured us the owl was “toe dusting.” Fairly new to its role as a teacher of humans, the owl was stressed and toe dusting was the physical sign of that stress. Ornithologists hold that Barn Owls lower their heads and shake it over their talons, either as an aggressive signal or as a defensive behavior.

Toe Dusting

I don’t believe it. They do it as a message of disapproval, just like that herbaceous Mountain Goat on the Olympian Peninsula in Washington State a few weeks ago when it gored a man in the leg and then stood over the man until he bled to death. The animals are getting angry with us and who can blame them?

But even if it was threatening me, that owl has the softest eyes of any bird I’ve ever seen up close. Mind you, if I were a field mouse or a vole scuttling across a snow field on a cold, crystalline night and looked up when that owl’s shadow crossed the snow I doubt that I would find anything soft about those eyes. I would see the eyes of a minister of death. And that shadow I would see the instant before my death would be the first clue I had that an owl was anywhere nearby: Owls are about the only land-dwelling animals who never make a sound they don’t intend to make.

But I was in no danger from the owl, and I loved his eyes. They reminded me of Edward Howe Forbush springing to the defense of Barn Owls in his magisterial Birds of Massachusetts and Other New England States. Defending them from unjust persecution, he called them “benefactors to mankind.”

Like Forbush, I may be susceptible to emotional projection and may have mirrored my own consciousness when I looked in those eyes, but I don’t believe that either. Those were the wise eyes of an old soul looking out at me.

Merlin

The rescuers also brought a Merlin with them. Nothing soft about a Merlin’s eyes I can assure you. Falcon eyes put one in mind of Yeats’ horseman,

Cast a cold eye

On life, on death.

Horseman, pass by!

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Here is our post on identifying Barn Owls and here is more on Barn Owls and Halloween. George Orwell also wrote about Barn Owls.

The Mockingbird Problem

We’re back from a birding/fly-fishing trip and will now finally address The Mockingbird Problem. Northern Mockingbirds – and about twenty percent of other passerine songbirds – are mimics. They steal their songs from their environments. Imagine the smartest student in class unnecessarily cheating on tests by going around the room and copying little bits of every other student’s answers.

That makes no sense. Instead of getting an “A” on the test, the student would get an “F” because her answers would be gibberish. Yet mockingbirds – obviously the star students in avian music class – do precisely that. Rather than develop their own unique songs, they just copy bits and pieces of the songs of other species.

Why?

Wouldn’t it be easier and less costly to invent their own songs and pass those down to their offspring? Less brain power would be required and learning would be simpler. Besides, the mockingbird isn’t fooling any other birds. They all recognize that the mockingbird isn’t one of them.

Nobody knows. We think we know that they sing for the same reasons as other birds: the males are seeking, stimulating, and keeping mates and they are competing with one another for mates and territories. But no one knows why they evolved singing songs of other birds. The same question can be asked about other mimics such as Common Starlings, Marsh Warblers, Australian Lyrebirds, bowerbirds, scrubbirds, and African Robin-chats.

Chihuahan Desert Mockingbird Locale (Otero Mesa)

We’ve learned a lot about Mockingbird song in the last century though. We know, for instance, that both males and females sing, although females sing only in the summer and only when their mate is off their territory. The males sing most in Spring, less in summer, still less in Autumn and hardly at all in winter. Unmated males sing more than mated males and will, in spring, sing all night long. (I’ve camped on the Chihuahuan Desert and listened to one sing all night long. That mockingbird may have been lonely, but he provided me with one of my favorite backpacking memories.) Unmated males sing in all directions, while mated males tend to sing inward toward their own territories.

Darwin's Mockingbirds

The males possess two entirely different repertoires, one for the spring and another for autumn. One had 203 songs in his mind. Somewhere between 90 and 150 seems about average. They continue to learn new songs for as long as they live. Older birds have larger repertoires than younger ones. Males with the most varied songs may get the largest territories. They may also mate earlier. And they sing all the time during breeding season, warbling away while copulating, eating, and foraging.

And probably they sing silently while dreaming. We know that Zebra Finches dream in song; no reason to suspect a bird that devotes as much of its cranial capacity to learning and remembering complex songs wouldn’t also dream in song.

They sing more during full moons.

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For more on Northern Mockingbird song see:

Derrickson, K. C. and R. Breitwisch. 1992. Northern Mockingbird (Mimus polyglottos), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/007

doi:10.2173/bna.7 (Subscription Required)

Frank Gill, Ornithology (3^rd ed.), pp 230-231 and 237.

For a sample song, try this: http://www.birdjam.com/birdsong.php?id=4

The photo of the Northern Mockingbird at the top is by Manjithkaina, used via a Creative Commons license.

Why Do Birds Sing?

The short answer is, they sing to live. But that doesn’t tell us much. It is not a testable hypothesis and is at too high a level of generalization to be helpful.

And before we go any further, we pause to note that we are talking about bird song today, not bird calls. Calls are the comparatively simpler sounds made by birds to stay in contact with one another, to call for mobbing behavior, or to sound alarms. (Alarm calls, by the way, tend to be high-pitched calls which make the source of the sound harder for a predator to find.) Today we are talking about the more complex, difficult, and – to our ears, anyway – melodious songs of the passerines and other birds that sing.

Birds produce song by forcing air through the syrinx, a bony structure at the bottom of the trachea. The syrinx resonates sound waves generated by the vibrating membranes of the syrinx. Changing the force of the air controls volume while pitch is controlled by both the force of the air and the muscular tension applied to the membranes. Some birds can even produce two separate notes at the same instant because they can control both sides of the syrinx independently.

The two leading bird-song hypotheses of our time are that male birds sing to attract mates and to establish and protect territories. Those hypotheses are at least testable, have been tested, and look to be correct – as far as they go.

But even they don’t get at the root of the question. Bird song evolved along with birds. As far as we know, the dinosaurs from which birds evolved didn’t sing. (Maybe that’s the reason they died out! Nothing to do with volcanoes in Asia or a meteor strike in the Yucatán: They couldn’t sing! Of course, neither can I, so I am not fond of my new hypothesis about dinosaur extinction. If true, it doesn’t bode well for my continued survival nor that of my children, who can’t sing either.) The first dinosaur-birds probably didn’t sing and certainly did not have the highly developed language of many current bird species.

But at some point we must assume the male birds that croaked out rudimentary songs had a sexual advantage over their competitors who hadn’t figured out anything more than avian karaoke. Otherwise, they wouldn’t be singing today

Said differently, why weren’t the ordinary, simpler, and easier-to-learn bird calls enough?

For that matter, why did the males of so many species develop their brilliant colors? That too takes more evolutionary effort than dull and drab. Moreover, brilliantly colored birds are easier for those predators which have color vision to spot. The same is true for song. A robin singing away in pre-dawn light is easier for a predator to find than if the robin was emitting only an occasional high-pitched call. Why does the robin take the risk? Natural selection, after all, destroys without fear or favor. Why is a noisy robin more likely to pass along his genes than one sitting quietly hidden two feet away?

The possibility exists that beauty plays a role. Maybe the bird that sings most beautifully is the one most likely to breed in spite of the danger? For those of you with a scientific/materialistic frame of mind, nothing excludes such a possibility: Beauty may be adaptive. How else to explain the Elegant Trogan? For those readers of a more spiritual/religious framework, why would beauty not be a survival requirement? How else to explain the Elegant Trogan?

But before we can go further we have to deal with “The Mockingbird Problem.” We’ll be back next time to discuss mockingbirds and their songs.

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The photo of the fossil dromaeosaur  at the American Museum of Natural History in New York was taken by Dinoguy2.

Lesser Prairie Chickens

Perhaps you’ve never been to the eastern plains of New Mexico. I can describe the scene for you in one word: Flat. Sparsely populated, sparsely vegetated, and sparsely sparse, it is a land of big horizons. Once, before courageous, stubborn, and perhaps misguided farmers and ranchers tried to wrest a living from it, it was all short-grass prairie. But Euro-Americans plowed it for dry-land farming and brought cattle to graze it. One look at it today, especially on a windy spring day when the dust blows, tells you that even if a cow once could have made a living on its over-grazed vastness, those days are long gone.

Before 1880, it was covered with buffalo grass and bison. Buffalo grass, and its cousins, blue grama grass and little bluestem grass, sustained the great bison herds of the southern plains for more than ten thousand years.

Capable of surviving all but the most extended droughts, short-grass prairie could survive neither the cow nor the plow.

Bison, on the other hand, helped the short grasses. They fertilized it, churned the soil so seeds could germinate, and they moved the seed around. In return, the grass, even with its low load of carbohydrates, provided succulent new shoots for the bison to eat.

The grass, evolved to a perfect fit for semi-arid land, could hold moisture a foot below the surface, even during hot, windy days and long dry summers. Timothy Egan wrote of it:

As long as the weave of grass was stitched to the land, the prairie flourished in dry years and wet. The grass could look brown and dead, but beneath the surface, its roots held the surface in place; it was alive and dormant. . . In turn, the grass nurtured pin-tailed grouse, prairie chickens, cranes, jackrabbits, snakes, and other creatures that got their water from foraging on the native turf.”

Contending Male Lesser Prairie Chickens

Only small islands remain and some of those small islands are home to the few remaining Lesser Prairie Chickens. We’ve destroyed about 92% of their habitat, killing about 97% of their population. Nobody knows for sure how many are left, but they once numbered, like the bison, in the millions. Today only thousands remain. Not only did we destroy their habitat, we hunted them like grouse. Of course, they are grouse.

They needed a nobler name.

Once they lived throughout western North America. Fossil remains from the Pleistocene Glaciation have been found in from Oregon to New Mexico. Today they live only in isolated pockets of sand sage or shinnery oak rangeland in extreme southeastern Colorado, southwestern Kansas, the eastern edges of the Oklahoma and Texas Panhandles and eastern New Mexico.

The males attract their mates – and hardy human watchers – on traditional display grounds known as leks. Often on knolls or ridges and always in areas of sparse vegetation, the males gobble and hop and display, raising their tails, erecting feathers, drooping wings, enlarging their eye-combs, stamping their feet and “booming” by expanding esophageal air sacs. The show starts an hour or so before sunrise and continues for two or three hours. The successful males copulate with as many females as possible before retiring for the day. Sometimes, they return for an early evening encore performance. The females retire to nests, which are usually within a mile or so of the lek, to brood and raise the young.

Lesser Prairie Chickens eat grasshoppers, leaves, flowers, and seeds, especially shinnery oak acorns. They, in turn, are eaten by hawks, eagles, Prairie Falcons, coyotes, badgers, snakes, and humans. Like other grouse, they burst into flight when startled and often fly when moving to and from their gobbling grounds, feeding areas, roosting sites, and loafing sites. Most flights are short-distance, low-level affairs with alternating wing-flapping and gliding.

But mostly they are gone now, victims of a human culture that produced a mind-set enabling Phil Sheridan, General of the U.S. Army to say,

The hide hunters will do more in the next few years to settle the vexed Indian question than the entire regular army has done in the last thirty years. For the sake of a lasting peace, let them kill, skin, and sell until the buffaloes are exterminated. Then the prairies can be covered with the speckled cattle and the festive cowboy, who follows the hunter as the forerunner of civilization.

It would have been better for the prairie chickens had Euro-Americans adopted a different attitude when we arrived on the short-grass prairies:

What is life? It is the flash of a firefly in the night. It is the breath of a buffalo in the winter time. It is the little shadow which runs across the grass and loses itself in the sunset. (Crowfoot, Blackfoot Indian.)

That little shadow might have been a prairie chicken.

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The photos of the Lesser-Prairie Chickens were taken last week by friend Linda Rockwell, who has a new blog showcasing her bird photography. You’ll find it here and many more photos of prairie chickens.

The bison photo is by Jack Dykinga of the USDA.

For more on the bison, short-grass partnership, see The Destruction of the Bison: An Environmental History 1750-1920, by Andrew Isenberg of Princeton.

For more on the Lesser Prairie Chicken and its relationship to short-grass prairie, see Hagen, Christian A. and Kenneth M. Giesen. 2005. Lesser Prairie-Chicken (Tympanuchus pallidicinctus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/364 (Subscription required)

White meat or Dark? (Part II)

I hope no one told our chickens that I am blogging about white meat and dark meat this week. They seemed a little slow out of the gate when I opened the chicken coop this morning; leery and suspicious, I thought.

Each morning I talk to the chickens as though we were all in the Royal Navy. “Good morning and I hope I find you well. Some eggs, if you please.” Then, in the evening when putting them to bed, I give them some Shakespeare, “We are such stuff as dreams are made on, and out little life is rounded with a sleep.” Although, come to think of it, last night I gave them something different. “For God’s sake, let us sit upon the ground and tell sad stories of the death of kings.” Perhaps that disturbed them and made them wonder.

Or maybe it was the Border Collie puppy, who seems to me to take an unhealthy interest in the chickens. As I said last time, the chickens are in no danger from the humans around here, but they worry some about the dogs. Dogs don’t discriminate between dark and white meat.

No dark meat here

Unlike chickens and turkeys, most birds can’t afford the luxury of white meat.

What we call “meat” is, in fact, muscle tissue. To be precise, skeletal muscle tissue. Composed of cells that contract when they receive an electrical impulse, these are “voluntary” muscles and are the prime movers of birds and mammals. Attached to bones, they literally move the animal world by contracting and relaxing.

Two types of voluntary muscle tissue do all this work, “slow-twitch” and “fast-twitch.” Dark meat, actually red meat, is slow-twitch muscle tissue, full of red blood cells and mitochondria which ensure a rich supply of blood and oxygen. These are the muscles that contract more slowly and less often, but are responsible for all sustained muscular effort, such as flying.

Birds that fly a lot haven’t got room for much fast-twitch (white) muscle tissue. Hummingbirds, for instance, have no white meat at all. Only ground dwelling birds (Mostly ratites) and birds like chickens, turkeys, and grouse which fly rarely and only for short distances have the luxury of a lot of white meat, because fast-twitch muscle tissue has many fewer red blood cells and cannot provide the oxygen necessary for sustained effort.

That is why ducks and geese have little white meat; even their breast meat (the pectoralis muscle) is dark. Ducks and geese have to fly for long distances and need slow-twitch, endurance muscles. Besides, it kept them safe from my parents who, like I said last time, didn’t care for dark meat and lied to me about it.

Wild Turkey

One thing that fast twitch (white) muscles are good at is sudden movement. Gallinaceous birds (turkeys, grouse) are capable of sudden bursts of flight. (What birder hasn’t been startled by a grouse exploding into flight in front of her?) Birds that don’t do sustained flying don’t need as much of the heavier, redder muscle tissue which is why the pectoralis muscle tissue(breast meat)of chickens and turkeys is white.

In wild turkeys, about one-fifth of the muscle tissue is white. And we humans fool with the genes of domesticated birds just to increase the amount of white meat. But even domesticated chickens and turkeys use their legs and thighs for sustained muscular effort and that is the reason their legs and thighs contain dark muscle tissue.

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For more, see Evans and Heiser “What’s Inside:Anatomy and Physiology,” Chapter 4 of The Home Study Course of Bird Biology, 2^nd ed., Cornell Lab of Ornithology.

For more on my childhood, see my autobiography, Bleak House, which I self-published under a pseudonym.

Dark Meat or White?

Psst! Don’t tell our chickens about this post. We don’t want them to know that the people who bring them food and water are chicken cannibals. We are, but not of our own chickens. We find them much too humorous and endearing to actually kill and eat one. Besides, we want the eggs.

The Araucana Chicken

And speaking of the chickens’ eggs, a week ago the Araucanas began laying again which is a sure sign that spring is on its way again. The Araucanas quit laying entirely, usually in late October and don’t start again until the end of January or early February. That wouldn’t be true if we artificially controlled the length of the photoperiod in which they live, as do commercial egg operations. Even the chickens which continue to lay in the winter do so at a slower rate than the rest of the year, because of the extended hours of darkness.

But our purpose today is to discuss the age-old question among humans who eat chickens and turkeys, “White meat or dark meat?”

Your author grew up believing that he preferred dark meat, the result of lies told him by his parents. When I was a young boy they told me that the dark meat was the best and, because they loved me so much, they would let me eat the legs and thighs. It wasn’t until adulthood that I discovered that they told me about the dark meat so they could have the white meat to themselves. And the gizzards. I never got a gizzard. Not until I was a grown man did I get a gizzard.

The Araucana Egg

Back to red meat versus white meat. You didn’t come to hear about my parents or my childhood. Which wasn’t bad, you understand; just full of parental lies about white meat. Oh, and that time my mother promised to buy be a new package of M&Ms after she spilled a bag on the kitchen floor, but never did. And one of my parents threw away my Mickey Mantle rookie baseball trading card which, if I still had, could sell for enough money to retire on.

I’ve forgiven them for all that though, so let’s get back to white meat and dark meat. I do wonder though,from time to time, what happened to my first model train . . . And my favorite childhood pillow. . . .

As you know, when someone serves you turkey or chicken at a dinner party, they will politely ask you whether you prefer dark meat or white meat. Or at least they will if they are not my parents who will lie to you about the whole thing but, like I said, I’ve forgiven them for that and so won’t say anything more about it. Whether you choose white meat or dark meat is largely a matter of personal taste, at least assuming you were raised by honest people, who didn’t warp your childish perceptions by deliberately misleading you and depriving you of the joy of white meat smothered in gravy on your plate.

Most birds don’t have any white meat so it wouldn’t have been an issue if my parents served duck, for instance. Ducks don’t have white meat. But I never got duck growing up. No. All I got was the thighs and legs of chickens and turkeys. But let that go.

Geese too. They don’t have any white meat either, but do you think my parents ever served geese? Not when I was around, they didn’t. They didn’t like dark meat.

Wild Turkey in Golden Gate Park - NPS Photo

One time, I remember, my father went turkey hunting with some friends and he came back with a wild turkey. That turkey had fed on Prickly Pear cactus and it had lovely streaks of light purple running through the breast meat. Or at least that is how that turkey remains in memory. I wonder how it tasted. All I got was a leg. Not that it matters now. I don’t hold a grudge.

So, besides taste, what is the difference between white meat and dark meat? All of it is muscle tissue, after all. The answer lies in what the bird uses the muscles for and how often it uses them.

By the way, I only learned this as an adult, after getting interested in birds. My parents certainly didn’t tell me. And I am going to tell you all about it, but it is going to take longer than I have room in this post to tell you. Somebody, probably one of my parents, told me that blog posts shouldn’t be longer than about 800 words or people won’t finish reading them and I just exceeded that limit for today, so you’ll have to wait for the next post to find out why some meat is white, some dark.

I know you are disappointed, but it’s not my fault. Blame my parents.

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For more, see Evans and Heiser “What’s Inside:Anatomy and Physiology,” Chapter 4 of The Home Study Course of Bird Biology, 2^nd ed., Cornell Lab of Ornithology.

For more on my childhood, see my autobiography, Bleak House, which I self-published under a pseudonym.

Pardon out fonts today. We’re not sure what happened, but we don’t know how to fix it. Probably my parents’ fault.

Brown Pelicans

From this morning’s Washington Post comes news that some Brown Pelicans have recruited humans in Maryland to feed them during the winter. The pelicans forgot to migrate, a mistake from which they would not normally recover. Brown Pelicans belong on the Gulf Coast in winter, not the northern Atlantic seaboard.

The pelicans are causing consternation among the wildlife officials in Maryland who know that a Brown Pelican who forgets to migrate has no business passing along its genes. Natural selection has no patience with that kind of oversight. But nobody wants to watch pelicans freezing to death and buried somewhere in humanity’s genes lies an urge to help individual animals in trouble.

Still, it isn’t nice to mess with Mother Nature.

Bald Eagle Surveys Its Domain

As David Farenthold writes, “In the wild, after all, evolution doesn’t give mulligans.” (Not only is Farenthold’s article full of good information, it is quite well written. It is worth your time to click through and read it. It’s better than what you’re reading here. Not all nature journalism is as good which is why I go out of my way to praise the piece.)

Taken as a whole, of course, we spend more time destroying animals’ habitats and rendering the planet unsuitable for them than we do caring for individuals.

That there are forty or so Brown Pelicans in Maryland which need rescuing is a success story of sorts. We almost killed the entire species because of our aversion to vampire bugs, a/k/a mosquitoes.

DDT was the culprit and it did exactly the same thing to Brown Pelican eggs as it did to the eggs of Bald Eagles and Peregrine Falcons.  DDT doesn’t kill honestly, it eliminates calcium from the birds’ egg shells which then break under the weight of the incubating parent. The parent doesn’t die, it just can’t reproduce.

Peregrine Falcon Eggs

In the United States, despite howls of protest from the insecticide corporations, we got rid of DDT in time and the Brown Pelican, like the eagles and falcons, are recovering and have been removed from the Endangered Species list.

That is not true for other places in the world, even in the Americas. Friends flew to Mexico some years ago and, before being allowed to deplane, had to stay in the plane while someone came through spraying DDT. They tried to hold their breath.

We take no position on the conundrum involved in feeding animals that forgot to migrate.  We’re not allowed to. We kept Chuck, the Greater Roadrunner alive, and are now helping one of his offspring get through the winter. The youngster comes around about this time every day; in fact, the writing of this post was interrupted while I took him a mouse.

Those rescuers in Maryland are in for a busy winter. I see no reason to think that a Brown Pelican eats less than a seagull which puts me in mind of E.B. White who once raised a baby seagull. He wrote about that bird which, White said, “. . . eats twice his own weight in food every ten minutes, and if he doesn’t get it he screams.” And Brown Pelicans can live for twenty years. Hopefully, they will learn from this experience and move south next year. Otherwise, many more busy winters loom for the rescuers.

Pelicans like anchovies. Maybe the people can order lots of anchovy pizzas and share with the birds.

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The Brown Pelican photograph is by Kevin Bercaw. The other photographs are ours. You can find E.B. White’s story of the baby seagull in his essay “Hot Weather” republished in One Man’s Meat.

For more blogging about the Brown Pelicans and the issues raised by helping them, see this post.

Cats, Birds, and Bird Feeding

Recently, we had two customers in the store who are cat lovers.  Seeing the cat bib we sell, designed to passively interfere with cats’ hunting, one of them seemed offended that someone would put that on a cat and she remarked, “ Cats kill birds, it’s nature!”

Egyptian Cat Mummy

That’s wrong, at least in all the world except North Africa and the Near East.  Cats are indigenous there but nowhere else. In North Africa and the Near East birds have been evolving defenses against cat predation since the Pleistocene. Elsewhere though, cats are newcomers, brought by humans; instead of having hundreds of centuries to evolve defenses, birds have had only a few hundred years. Birds in places like North America have not had time to develop defenses against cats’ deadly effective hunting skills.

So, it is not “nature” nor is it “natural” for cats to be killing birds in North America, South America or Europe. Humans interfered with nature when we brought the cats.

And have we brought cats.  In the United States alone more than   150 million cats are alive as you read this, their ancestors brought here by humans. More than 82 million are kept as pets and the number of feral cats probably exceeds 70 million. And all of them are killing birds whenever they get the chance.

Here is the grim fact:  Cats kill millions of birds every year.  Pet cats don’t kill them for food, they kill them because cats are hunters.  Their hunting instinct is independent of their urge to eat and they hunt whether they are hungry or not. Feral cats kill many more.

Kitten Eating a Rabbit

We’ve written in this space before about the well-intentioned efforts of cat lovers to trap, neuter, and return feral cats.  (TNR) Now comes yet another piece of scientific evidence that it doesn’t work.  Biologists recently studied a feral cat colony in Tucson, Arizona, and discovered that local coyotes were eating them. And, another anecdotal piece of evidence arrived in our in-box:  At one feral cat colony in Southern California, coyotes discovered the cats and killed most of them.  Then, the coyotes kept coming back to eat the cat food set out by the people maintaining the colony.

We doubt that our customer who thinks that cats are just being true to nature when they kill birds would be as blase if a coyote kills one of their pet cats.  But, just as cats hunt birds, coyotes hunt small mammals. And the coyotes are indigenous.

Bird-Saving Cat Bib

Because this slaughter of birds by cats is human-caused, we ought to do as much as we can to lessen the impact on wild bird populations.  Here are some suggestions:

1.  Keep your cats indoors.  This is the most humane solution, indoor cats lead longer and healthier lives.

2. Hang birdfeeders out in the open and far enough away from trees so that cats can’t hunt them from underneath or inside  a tree.

3. If you live where cactus grows, surround the birdfeeding station with cactus.

2.    The best recent invention we’ve seen for preventing cats from killing birds is a catbib.  Invented by a backyard, bird-feeding, cat lover, the CatBib (a thin neoprene bib) disrupts the cat’s hunting skills, without interfering with any other kitty activities. It acts as a barrier between cat and prey by getting in the way just as the cat strikes out for the bird. Because birds see in color, it also functions as a colorful visual warning to the birds. Birds can see the cat coming. The best part about the catbib is that it doesn’t interfere with the cat’s ability to eat, drink, run, etc. and enjoy being outdoors. Cat owners who have used it report great success. (By the way, bells on cat collars don’t work. Cats can creep along stealthily and hunt without the bell ever ringing. Like we said, they are great hunters.)

And everybody should neuter their pet cats. Over time, that would even help reduce the number of feral cats.

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Full Disclosure: Until a few weeks ago, when his time to die finally came, we had shared fifteen years of our life with a cat.  Waldo wasn’t much of a hunter in his final years because his eyesight faded and he was content, as an old cat should be, to sleep in warm places. And we had him pretty well trained to stay in the front yard and out of the back yard where the bird feeders are.  But he no doubt killed many birds in his younger days and we didn’t always follow our own advice of keeping him indoors.  We miss him, but we’ve decided to forego further cats. Responsibility for ameliorating this human-caused slaughter of birds starts at home. Besides, our next door neighbor has upwards of ten cats so, anytime we want to hold a purring cat, we can go to her house.

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The latest TNR study, Observation of Coyote-Cat Interactions” by Grubbs and Krausman is in the July 2009 issue of the Journal of Wildlife Mangement.

The number of pet cats in the U.S. comes from  “Market research statistics – U.S. pet ownership“. American Veterinary Medical Association. http://www.avma.org/reference/marketstats/ownership.asp. Last visited November 10, 2009.

For more on feral cats see,  Mott, Maryann (2004-09-07). “U.S. Faces Growing Feral Cat Problem“. National Geographic News, http://news.nationalgeographic.com/news/2004/09/0907_040907_feralcats.html. Last visited November 10, 2009.

The photo of a feral kitten eating a rabbit is by Jake Berzon and the Egyptian cat mummy photo was taken by E. Michael Smith.

The Red-Crowned Nap-Robber

For two days I’d been pulling weeds down in the flatlands resulting in awful hay fever of the kind that prevents good sleep.  You keep waking up gasping for air if at any moment your mouth slides shut because nothing, not even a single molecule of air, can get through your nose. But now I was 3500 feet higher, at a mountain cabin and the hay fever had subsided.  It was early afternoon, the perfect time for a nap.  Warm outside, the cabin was pleasantly cool and the couch beckoned.  Tired as I was from lack of sleep, the prospect seemed delicious.
Somewhere down the hypnagogic slope to sleep, in that place just before unconsciousness where weird things happen, a great clattering began echoing around inside my head, bouncing from side to side so loudly I was certain my head was a hollow tree. The noise continued unabated as I resolutely tried to drive past it into real sleep.  I deserved a nap, or so I thought.

But the pounding continued and so I began rising back up the hypnagogic slope and came to realize the racket wasn’t inside my hollow head at all, it was inside the hollow cabin, bouncing off the walls in a cataract of noise. One rap hadn’t finished its journey before another began.  It felt like being inside one of Gene Krupa’s drums.

“Woodpecker,” I thought,  by this time fully awake.  “How did a woodpecker get inside the cabin?”

But not inside at all.  Outside.  But which way?  From the echoing, I couldn’t tell.  The din was unbelievable.

And here was the culprit.

Pounding away on 70-year-old cedar shakes on the west side of the cabin.  (I assume the bugs weren’t that old.)  The east end of the cabin is even older, 106 years and woodpeckers have been after it in the last few years as well.  I figure as long as they don’t poke holes through the walls on top of the logs, that I should let them eat whatever they want.

At first, it wasn’t clear whether the nap-robber was a Downy or a Hairy Woodpecker.  Both species look remarkably alike, from the red crown of the male all the way down to the white spots on the side.

But the Hairy Woodpecker is bigger, about nine inches long.  The Downy is only about 6.5 inches long.  I suppose that is the best way to tell them apart: Downies are smaller, more petite, and cuter.  You can tell that this bird was larger than a Downy from this photo.

The cabin was built in the old days, back when a two inch by six inch piece of lumber was actually two inches by six inches, unlike today. You see that the bird was at least 8 inches long because he covers the six inch side of one board plus the two inch side of another.

Even though the two species of woodpeckers look almost identical except for size, they are not close relatives.  Examples of “convergent” evolution, they evolved similar appearances from different lineages. The classic example of convergent evolution is the wings of birds and bats. Structurally similar, the bat wings are attached to mammals.

Pronghorn Antelope

The wild world is full of other examples.  The Pronghorn Antelope of North America is only distantly related to the true antelopes of the Old World, but looks and behaves similarly, probably because both occupy analogous positions in their respective ecosystems. None of the five species of freshwater dolphins are closely related.

Sometimes only one or two traits evolved convergently.  Platypus have something that looks a lot like a bird’s beak.  Possums have opposable thumbs. Peyote cacti of the desert and Ayahuasca vines of the Amazonian rain forest produce the same toxin, probably to deter predators.  (Although that is not always successful if the predator is human.)  The anti-freeze protein of deep-sea Arctic fish is the same as the protein in the unrelated deep-sea fish of the Antarctic.

In the world of birds, in addition to Hairy and Downy Woodpeckers, other examples include the wrens and robins of Australia which look like northern birds, but are not close relatives.  Flightless penguins of the Southern Hemisphere evolved independently from  flightless, wing-propelled, diving auks of the Northern Hemisphere. The Turkey Vulture riding the wind in our last post is not in the same family as Old World Vultures.  (In fact, no one knows for sure where Turkey Vultures came from.) Both have featherless heads, are large, flock in trees, soar for hours, and circle carrion before landing, but only Turkey Vultures use smell as well as sight in the hunt for dead flesh.

But, as far as I can tell, the The Red-crowned Nap-Robber is new to science, so I don’t know if it too is an example of convergent evolution. Personally, I doubt it.  I suspect it is a cousin of the better known Yellow-bellied Napsucker.

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Think you could have slept through the racket?  Here is what Gene Krupa’s drums sounded like. “Jungle Madness” and “Sing, Sing, Sing”

Birds and Taxes

Elegant Trogan

Absent some almost inconceivable catastrophe, humanity has made its choice: We’re going to live in cities. The advantages of living close together in large groups appears to outweigh the benefits of country life.  In most, if not all, of the developed world more people now live in cities than in rural areas.  We’ve been headed this direction since the invention of the plow.  Dividing and specializing our labor is how we’ve adapted and made it this far.

And, let’s face it: Living in a house or an apartment is a lot more comfortable than living in a cave.

As we’ve moved to cities, we’ve romanticized the country life we left behind.  The more wilderness we’ve lost, the more we’ve come to miss it.

The reason for this is not hard to spot.  The bargain we’ve made for all the advantages of city life brought stressors.  Noise, light pollution, air pollution, urban sprawl; all cut us off from nature.  But the benefits of communal life are undeniable.  In the words of the Constitution of the United States, we band together to provide for domestic tranquility, common defense, the general welfare, justice, and the blessings of liberty. To pay for all that; the highways, the police, the military, health care, education, and all the rest, we invented taxes.

Here in the United States of North America many of us are at sea in an ocean of paperwork as we prepare our tax returns due this week.  This too, no matter how much we hate it, is an evolutionary adaptation.  We don’t like it, but we endure it because the benefits outweigh the losses.

And one of the losses is the less stressful, less work-filled existence of earlier, simpler times.  It’s why we take vacations. It’s why more of us now watch birds than shoot them.

House Sparrow

So, take a short break.  Get outside and find a tree.  No matter how crowded your city, you will likely discover a bird in it.  Probably it’s a House Sparrow.  No matter; a House Sparrow is as beautiful in its perfection as a Trogan is in his.  This time of the year, that bird is likely to be singing. Take a few precious moments to watch, to listen, to breathe.

That is an evolutionary adaption too. You will hear those older, wilder rhythms and be refreshed.

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UPDATE: Natalie Angier of the New York Times wrote about taxes two days after this post.  Not only has every human society we know of taxed its members in return for admission to the group; many animal species do also, including at least two bird species.

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The photograph of the Elegant Trogan was made by Dominic Sherony and came via Wikipedia.