Category Archives: Mammals

Because the wolves are shot

coyote

What do you really know about coyotes? Maybe you’ve heard the official line about the economic consequences of coyotes killing livestock. Maybe you know of a neighborhood cat that was taken. Maybe you’ve heard conservation groups protesting inhumane treatment of these animals, or recall Mark Twain’s “slim, sick, and sorry-looking skeleton…a living, breathing allegory of Want.” In reality, these animals are neither good nor evil, but are simply trying to survive the best they can in a world that is changing around them.

And as the coyote turns the cat to sweetness
in its mouth, a month-long stint of apricot
pit-, ant-filled scat, a month before of
birdseed, cricket, crappy sandwich; so,
 
don’t turn your back; befriend them; grab
and wave a stick; the twenty doses meant to still
their little ones were killed inside coyote,
and outcome: snapping infant death: your indoor
 
dogs, and bitten, squalling children
 

Karen Leona Anderson’s poem “Coyote” begins with a list of found items a coyote has eaten. Coyotes are omnivores and scavengers, meaning that they can and will eat just about anything.  Though they have a bad reputation as killers of sheep, chickens, and deer, coyotes also eat snakes, foxes, rodents, pet cats, sandwiches, and garbage, for a start. This could be the key to this species’ success in a country where the large predators are either killed outright or squeezed out by human population growth.

Which isn’t to say the coyote isn’t targeted. They are one of the most vilified animals in North America. The Wildlife Services division of the US Department of Agriculture specializes in “predator control,” killing thousands of predators to protect livestock and big game. The most common predator killed (at an estimated 512,500 between 2006-2012) is the coyote. Outcry by biologists and the public as well as a series of articles by Pulitzer-prize winning journalist Tom Knudson led to ongoing investigations into this organization.

The problem with killing coyotes is that in some systems they act as keystone predators. Remember ecology: everything (plant, herbivore, carnivore) is connected to everything else in the food web. When part of the web is removed, it affects every other organism that was connected to it. A keystone, literally, is the stone at the top of an arch that holds up the entire structure. A keystone predator, then, is at the top of the food web. When it is removed, the delicate balance between interacting species is destroyed.

edu_food_web

Removal of coyotes has an effect on smaller predator (mesopredator) populations; in the absence of coyotes, populations of animals such as raccoons and foxes (and housecats!) increase dramatically. These mesopredators then consume far more eggs, birds, mice, voles, and other small animals than they should, and the populations of these prey organisms plummet. (Housecats in particular decimate bird populations. More information here.) In a cascade effect, whatever plants or insects the birds or mice feed on are then released from predator pressure, and they, in turn, multiply. Replace the keystone predator in the system, and order is restored. This is called top-down regulation: maintaining the balance of the food web below and around the top predator.

dens
in rainpipes, basements, crawlspace, tenants’ dumpsters:
a fed coyote is a dead–what? Since they ate
even the stinging sugar-eaters, since when
 
they couldn’t eat they bred into your pets
a coyness, slipped behind the fence, endorphins,
dopamine sweeter than the kibble
                                                   –so what’s to want?
 

Whereas in the west, wolves, bears, and mountain lions act as apex predators, these animals have been almost entirely extirpated from the eastern US. In response, the sly coyote, omnivorous and adaptable, has taken the role formerly held by wolves. Genetic studies have shown that quite a few eastern coyotes are, in fact, coyote-wolf hybrids. As a result, they are larger than their western counterparts, and are behaviorally more wolfish. Unlike wolves and other large predators, however, coyotes aren’t picky about forests and open space. They easily adapt to live in suburban and even urban areas where food is abundant. Chicago, for example, has tracked hundreds of coyotes living in the city for the past 14 years, thriving off of the rodent population.

Though originally pushed out of rural areas by human expansion, biologists say that coyotes are equally at home in the city. They pose no danger to us so long as we allow them to remain wild. This means not feeding them, being sure to pick up your garbage, and taking pets inside at night. Don’t be so quick to judge an animal that is only surviving. Remember that every species has its part to play, and that designations of good or evil are restricted to those of us with morals and a conscience.

With eyes like lanterns out by the latticed gate,
a future soft-tanned pelt pulls up
and moves to the city, deceitful little trot,
about to whelp and, honey, because the wolves
 
are shot and wildcats museumed and moth-torn,
the city, hareless, knows it’s gone to them; omnivorous
I tell myself, so make yourself their home.
 
 

REFERENCES:

“Agriculture’s Misnamed Agency.” 2013. The New York Times.  Link.

Cart, Julie. 2014. “Congressmen question costs, mission of Wildlife Services agency.” Los Angeles Times. Link.

“Coyote: Canis latrans” by Karen Leona Anderson, from the collection Punish Honey. Buy it here.

The Humane Society. 2013. “Why Killing Coyotes Doesn’t Work.” Link.

Knudson, Tom. 2012.  Wildlife Services’ deadly force opens Pandora’s box of environmental problems.  The Sacramento Bee.

Stolzenburg, William. 2008. Where the Wild Things Were. Bloomsbury.

“Urban Coyote Ecology and Management.” The Cook County, Illinois, Coyote Project. Link.

USDA Publication. 2011. “Coyotes in Towns and Suburbs.” Link.

Way, J G. 2007. Suburban Howls: Tracking the Eastern Coyote in Urban Massachusetts. Dog Ear Publishing, Indianapolis, Ind.

THANKS:

Special thanks to Karen Leona Anderson for permission to use her work.  Please check out her lovely collection of poetry, Punish Honey, available here.  More information on Dr. Anderson is available here.

They flutter, shake like mystics. They materialize.

bat

Few creatures have attained the ability to evoke utter terror like the bat.  What is it about this flying mammal that has resulted in such a stigma of filth, disease, and horror?  Paisley Rekdal’s poem, “Bat,” begins by depicting a bat at rest, but by the final lines, the nightmarish language has drawn the reader into a paranoid fantasy.  The title acts as the first line in this work, which begins:

“Bats
 
unveil themselves in dark.
They hang, each a jagged,
 
silken sleeve, from moonlit rafters bright
as polished knives.  They swim
 
the muddled air and keen
like supersonic babies, the sound
 
we imagine empty wombs might make 
in women who can’t fill them up.”
 

So in the opening stanzas alone, bats have evoked moonlight, knives, “supersonic babies,” and infertile women.  This rich, dark symbolism had to have begun somewhere, but where?  Why is the bat often feared and hated by humans?

Bats are the only mammals capable of true, sustained flight.  Their wings are unlike birds’ wings; in fact, the bones in a bat wing are homologous to those in a human hand, which means they are alike in structure because they descended from a common ancestor.  Between the “hand” and body of the bat, and between each finger bone, is a thin membrane of skin called the patagium.  The “thumb” of the bat projects from the top of the wing in a claw, allowing bats to climb.  As a result of these features, bats belong to the order Chiroptera, which in Greek means “hand-wing.”

Most bat species are only active at night, and spend daylight hours hidden away in caves, under bridges, in chimneys, or in trees.  Because of their nocturnal habit, most bats have evolved a system called echolocation, which uses soundwaves to navigate and find prey.  In brief, the bat produces ultrasonic sounds and listens for the echos bouncing off of objects in its path.  By interpreting the speed and intensity at which the echos return, the bat creates a detailed image of its surroundings.  With echolocation, bats can judge the size, distance, and direction of movement of small objects like insects.  Some bats make these sounds with their mouths, while others use their noses.  It is thought that the strange nose structure (called a leaf) in some tropical bats serves to help focus the sound for accuracy purposes.

"Chiroptera," from Ernst Haeckel's Kunstformen der Natur, 1904.

“Chiroptera,” from Ernst Haeckel’s Kunstformen der Natur, 1904.

“A clasp, a scratch, a sigh.
They drink fruit dry.
 
And wheel, against feverish light flung hard
upon their faces,
 
in circles that nauseate.”
 

It seems likely that the mistrust and fear of bats stems initially from their appearance and behavior.  They only come out at night, can fly, emit strange noises, and some even drink blood!  European cultures have long associated bats with witchcraft, black magic, darkness and evil, and this animal has suffered negative connotations in works from Shakespeare’s Macbeth to Bram Stoker’s Dracula.  In Mesoamerica, bats symbolized the land of the dead, destruction, and decay.   A fear of bats even has a title: chiroptophobia.

The myth of the vampire is based in fact.  There are, however, only three species of vampire bat in the world, and those live in Mexico, South and Central America.  In addition, two out of these three species only drink the blood of birds (the third drinks mammalian blood, but prefers cattle to humans).  Unlike the movies, they do not suck their victim’s blood: rather, they prick the animal and lap up the blood.  The bats’ saliva contains an anticoagulant that prevents the blood from clotting.  This enzyme is useful to humans, as well: it is used to treat human stroke victims.

Another major fear inspired by bats is of rabies.  While it is true, that some bats carry rabies, only a very small percentage do, and it is impossible to contract rabies by merely seeing a bat or being in the same room as one.  That being said, if you are bitten by a bat (or by any other wild mammal, ever) tell your doctor.  If the animal can be captured and tested for rabies, it will provide peace of mind.

Fear of rabies has caused a lot of unnecessary destruction of bats and bat colonies.  This does not only disrupt the ecosystem, but affects us as well, since the presence of bats is quite beneficial to humans.  Most species are insectivorous (eat insects), and consume some very damaging pest species.  Many others act as pollinators for both wild and cultivated plants, including bananas, peaches, durian, cloves, and carob.  Fruit-eating bats play a role as seed dispersers, and in some clear-cut forests, up to 95% of first new growth can be attributed to bats.  Bats have also been shown to disperse the seeds of avocados, dates, figs, and cashews.

So bats may look scary, and they may act strange or unnatural, but in truth they are generally harmless, beneficial animals; animals that continue to be incredibly misunderstood.  As with many other wild animals, bats are more afraid of you than you are of them.  The next time you’re out at night, try to remember this when, without a sound, those silent wings swoop downward toward you before you can react.  Enjoy your fear, but don’t allow it to guide your actions in the waking world.

“Imagine one at breast or neck,
 
Patterning a name in driblets of iodine
that spatter your skin stars.
 
They flutter, shake like mystics.
They materialize.  Revelatory
 
as a stranger’s underthings found tossed
upon the marital bed, you tremble
 
even at the thought.  Asleep,
you tear your fingers
 
and search the sheets all night.”
 
 

REFERENCES:

Harris, Tom.  2001.  “How Bats Work.”  Howstuffworks.com.  Link.

“Learning about bats and rabies.” Centers for Disease Control and Prevention.  Link.

“Myths and Facts.” Bat World Sanctuary.  Link.

Rekdal, Paisley.  “Bats.”  Read it here.

Tuttle, Merlin D.  2011.  “All About Bats.”  Bat Conservation International.  Link. 

THANKS:

My personal bat guru, Laura Cisneros, provided fact-checking and proofreading of this post.  Any mistakes or inaccuracies are my own.  Laura is a PhD student researching the effects of human-modified landscapes on different aspects of bat communities.  Results of her research identify characteristics of these landscapes that maintain a diversity of bat species and increase the probability of maintaining vital ecosystem services (e.g. pollination) provided by bats.  As she writes,

“Have you ever looked out of an airplane window and noticed the intricate patchwork of forest, cropland, pasture, and urban areas below?  These human-modified landscapes occupy over 75% of the Earth’s land surface.  In other words, habitats available to most species are embedded within a mosaic of land that has been converted for human use.  When we alter ecosystems by reducing them in size and fragmenting them, we lose species that play important roles that maintain a working ecosystem.  One such group of species is bats.  In the tropics, bats are very abundant and have a diverse diet, including fruits, nectar, pollen, insects, frogs, fish, and blood. As a consequence, bats play an important role in seed dispersal and pollination as well as in regulating animal populations (some of which are pest species to agriculture).”

For more information, please check out her webpage, located here.

There are wonderful holes in my brain

madcow

One of the more terrifying diseases to appear in the last few decades is mad cow disease, scientifically known as bovine spongiform encephalopathy (BSE).  Unlike some other diseases in which the more you understand, the better able you are to cope with the concept, the more you understand about mad cow disease, the more terrifying it becomes.  This disease is a fatal brain disorder that is neurodegenerative, meaning it causes degeneration in the brain and spinal cord.  The incubation period for BSE ranges anywhere from 30 months to 8 years, and it is transmissable to humans, though the form of the disease humans contract is called “variant Creutzfeldt-Jacob disease” (vCJD).

This subject may seem an unlikely one for poetry, but then again, what is poetry if not a medium for discussing your deepest fears or exploring something from a new angle?  In her poem, “The Mad Cow Talks Back,” Jo Shapcott writes from the point of view of the mad cow herself, relating what Shapcott imagines the disease might be like:

I’m not mad.  It just seems that way
because I stagger and get a bit irritable.
There are wonderful holes in my brain
through which ideas from outside can travel
at top speed and through which voices,
sometimes whole people, speak to me
about the universe.  Most brains are too 
compressed.  You need this spongy 
generosity to let the others in.
 

This first stanza describes the main effect of the disease: an infected brain is so filled with holes that it resembles a sponge.

A section of brain from a BSE-infected cow shows the many sponge-like holes.  Photo by Dr. Al Jenny of the USDA.

A section of brain from a BSE-infected cow shows the many sponge-like holes.
Photo by Dr. Al Jenny of the USDA.

But what causes this disease, with its bizarre manifestation and fatal diagnosis?  Why is it transmissible to humans at all?  What can we do to prevent it?

Unlike most other illnesses we are familiar with, this one is not caused by a bacterium or a virus, or even a parasite.  Rather, the cause of mad cow disease and all other diseases of this type (called transmissible spongiform encephalopathies, or TSEs) is a prion.  A prion is, believe it or not, a misfolded protein that causes other prions to fold incorrectly.  That’s right: an infectious protein.  The strangest thing about a prion is that, unlike all other known infectious agents, it does not contain any nucleic acids (DNA or RNA).

Infection occurs when a prion enters a healthy organism and there induces normal proteins to fold into prion form.  The resulting structure is extremely stable and resistant to denaturation, a term used to describe a protein unfolding and losing structure as a result of chemical or physical agents.  Misfolded proteins aggregate into plaques, which cause the infected cell to die (leaving a hole).  The prions are then released to infect surrounding cells.

Since they don’t have any genetic material, prions are not alive, and so cannot be killed.  Measures to sterilize contaminated meat are extreme: incineration at 1000 degrees C (1832 degrees F!), autoclaving at 134 degrees C, boiling in lye for 15 minutes, or exposure to concentrated bleach for over an hour.  Since you can’t “kill” or inactivate prions by cooking or freezing, the best prevention is to completely avoid potentially contaminated meat.  To this end, the USDA has tightened restrictions on tissues known to carry mad cow disease (brain and spinal cord tissues) and bans “non-ambulatory” cows (those that can’t walk) from being processed for human consumption.

So, the progression of disease: a cow becomes infected by a prion, most likely through its feed.  Prions get into the bloodstream and cross into the nervous system.  Once in the nevous system, clumped prions kill the nerve cell, and the prions are released to infect surrounding cells.  Numerous nerve cell deaths lead to loss of voluntary muscle movement and abnormal behavior, including increased aggression and excessive reaction to noise or touch. Eventually, the cow can no longer walk, and dies.  Perhaps, as Jo Shapcott envisions in her poem, the brain goes so quickly that the cow doesn’t realize the horror of its situation.  Maybe the infected cow simply experiences things in a different way.  Though hard to imagine, we can allow this poem to give us hope that these unfortunate animals don’t go so harshly.  The cow tells us in no uncertain terms:

I love the staggers.  Suddenly the surface
of the world is ice and I’m a magnificent
skater turning and spinning across whole hard 
Pacifics and Atlantics.  It’s risky when
you’re good, so of course the legs go before,
behind, and to the side of the body from time
to time, and then there’s the general embarassing
collapse, but when that happens it’s glorious
because it’s always when you’re travelling
most furiously in your mind.  My brain’s like
the hive: constant little murmurs from its cells
saying this is the way, this is the way to go.  
 

REFERENCES:

“The Basics of Mad Cow Disease.”  WebMD.  2013.  Link.

“The Brain Eater.”  NOVA Online.  1998.  Link.

Freudenrich, Craig.  “How mad cow disease works.”  Howstuffworks.com.  Link.

“The Mad Cow Talks Back.” by Jo Shapcott.  Read it here.

Max, D.T.  2007.  The Family That Couldn’t Sleep: A Medical Mystery.  Random House.  Buy it here.

Tenenbaum, David.  2004.  “Mad cow comin’ home.” Whyfiles.org.  Link.

Darkness thickens our feathers

cat-caught-bird

One of the greatest dangers to wild birds worldwide is predation by the domestic cat, Felis catus.  This issue has gained more attention recently with the proposed ban on cats in New Zealand.  In response to data that New Zealand cats had succeeded in killing off nine native species and endangering 33, economist and environmentalist Gareth Morgan suggested that cats should eventually be eliminated from his country.  New Zealand isn’t the only country with a problem, however: in a study of cat predation in the United States, kill rates were found to be two to four times higher than previously thought, with a median estimate of 2.4 billion birds killed each year.

Caleb Parkin’s poem “The Angry Birds,” addresses the threat of the housecat and the willful ignorance of its human owners.  Written from the point of view of a bird observing a hunting cat, a sense of dark foreboding hangs over each word:

Dusk.  The swish of the tear
in the door.  Silence.  The sky a cage
of black-blue branches.  Breathing.
 
A darkness thickens our feathers,
sticks to the points of our beaks.  
We petrify.  By the table of bait, 
it waits.  A first screech flickers
life into the street-lights.  Then–
reflected on narrow green eyes–
a manicured lawn of limbs.
 
The baby ape takes in tiger cubs.  
We watch you through the glass,
face alight, twiddling your thumbs.
Playing games in the night,
with our heads.
 
From up here, we look down on
the pastel television-picture within:
Kitty returns, is named, tickled under the chin:
delicately purrs at an opening tin.
 
And you, unwitting napkin,
with blood all over
your hunter’s hands.
 

In this poem, the human is “the baby ape” who has taken in “tiger cubs.”  This language emphasizes the ferocity of the cat, and the human’s position as unwitting ally.

The numbers involved from the previously-mentioned study suggest that cats are very likely causing population declines in some species of birds.  So why are we surprised that so many birds are being killed?  Most likely, this is because cat owners only see a small fraction of their cat’s prey.  A recent study by the University of Georgia with National Geographic obtained estimates of domestic cat predation by attaching video cameras to cats in order to investigate the cats’ activities.  They found that 44% of the cats they studied killed wildlife.  Of these predators, only 23% brought captured prey home, while 49%  left prey at the site of capture, and 28% consumed what they caught.  These results support that previous studies (and owners!) have been significantly underestimating the effect of cats on native wildlife.

So if even well-fed domestic cats are indicated in the decline of local bird populations, what’s a cat owner to do?  Obviously, keeping a cat indoors is the best solution to the problem.  If, for whatever reason, you need to allow your cat outdoor access, there are still steps to curb bird predation.  Never praise a cat that has caught a bird, since positive reinforcement will only enhance this behavior.  Keeping claws trimmed will hinder a cat trying to climb trees or catch wild birds, and a bell on the cat’s collar may warn birds of its approach.  Finally, never feed feral or stray cats.  The instinct to hunt is independent of hunger, and, simply, a well-fed cat has more energy to catch birds.  Report stray cats to a no-kill shelter or humane society.  Remember that, technically, cats are an invasive species, and it is within our grasp to control their effect on the environment.

REFERENCES:

Angier, Natalie.  2013.  “That Cuddly Kitty is Deadlier Than You Think.”  New York Times.  Link.

“The Angry Birds.”  by Caleb Parkin.  Read it here.

Loyd et al.  2013.  Quantifying free-roaming domestic cat predation using animal-borne video cameras.  Biological conservation 160: 183-189.  Link.

Morelle, Rebecca.  2013.  “Cats Killing Billions of Animals in the US.”  BBC News.  Link.

Mullany, Gerry.  2013.  “A Plan to Save New Zealand’s birds: Get Rid of Cats.”  International Herald Tribune.  Link.

THANKS:

Special thanks to Caleb Parkin for permission to use his work.  Please check out his blog, Skylab Stories, for weekly science poems, as well as various other creative writings.

Alive beyond compare.

tumblr_mgnktljy9K1qijl35o1_500

“…the heart, exposed exactly for what it is: homelier
than we’d like to imagine.  And alive beyond compare.  
Here, the heart is the heart, and isn’t
a fist or a flower or a smooth-running engine
and especially not one of those ragged valentines
someone’s cut out, initialed, shot full of cartoon arrows:
the adolescent voodoo of desire.  Here, nothing’s colored
that impossibly red.”  
 

In honor of the holiday, I’d like to consider the human heart.  No, not the one usually found in poetry, but the one actually inside of you; the one functioning to carry blood throughout your body, the one transporting oxygen and nutrients and chemicals to every extremity.  David Clewell’s poem “Not to Mention Love: A Heart for Patricia,” is, as the title implies, a love poem written (almost) without the word “love”.  Clewell has tried to

“keep the heart in its proper place for once.  It’s not
in my mouth or on my sleeve  or winging its way lightheartedly 
in circles over my head.  It’s more or less right
where it belongs inside of me, no small thing.”  
 

So, dispensing with hyperbole and flowery romantic language, what we have left is the heart itself.  Put most simply, the heart is just a muscular pump.  But what is its function?  And how does it work?

Inside your heart are four chambers (fun fact: while mammals have four chambers, reptiles and amphibians have three, and fishes, without the need to breathe air, have only two).  The top two are the left atrium and right atrium (plural: atria), and the lower two are the left and right ventricles.  (The “left” and “right” designation always refers to the animal/person whose heart it is: so if a surgeon was looking down a patient, the left ventricle would be on the patient’s left).  Each chamber bears a one-way valve so that when the chamber is contracting, blood can come in, but when the muscles relax, the valve is shut.

The heart works with a two-stage contraction (the contraction phase is called “systole”).  In the first stage, the right and left atria contract simultaneously, pumping blood through their associated valves into the right and left ventricles.  In the second stage of contraction, the right and left ventricles contract simultaneously to push blood out of the heart.  This two-stage process is why you hear a heartbeat as two sounds “lub-DUB”–that’s the sound of your heart valves closing.  After the contraction, the heart muscle relaxes, a phase called “diastole.”  As Clewell writes,

“There’s nothing cute about it.  The heart 
is the heart, chamber after chamber.  Ventricular.  Uncooked.  
In all its sanguine glory.  I couldn’t make up a thing
like that.  The heart’s perfected its daily making do, the sucking
and pumping, its mindless work: sustaining a blood supply
that’s got to go around a lifetime.”  
 

(This last point is not exactly true.  Blood is, in fact, produced in the bone marrow).  In their contractions, the right and left sides of the heart fulfill different functions.  Blood returning from the body is oxygen-poor and enters the right side of the heart (atrium to ventricle).  The right ventricle sends this blood out to the lungs to be oxygenated (and to release carbon dioxide).  This blood then returns to the left side of the heart (atrium to ventricle again) where the much-larger left ventricle pumps oxygenated blood out to the entire body.

But it’s Valentine’s Day!  What about love?

What we call “love” is a combination of emotional attachment and brain chemicals.  Though we may seem to feel things in our “heart”, the heart really has only one thing to do with love: it acts to circulate the aforementioned brain chemicals (dopamine, serotonin, and oxytocin) in the blood out to the body and all the rest of the organs, where they can have the physiological effects that make us feel love.  Does this mean love is all in our heads?  Not at all.  It’s everywhere inside of us, thanks to our powerful hearts.

“Sure, there’s a brain somewhere, another planet,
just seconds or light-years away, and maybe some far-flung
intelligence madly signalling for all it’s worth–
but the heart wouldn’t know about that.  It has its own
evidence to go on.  What’s convincing to the heart
is only the heart.  It doesn’t have the luxury of stopping
to weigh, to reconsider, to fold and unfold the raw data of the world
until it’s creased beyond recognition.  Some days it can’t distinguish 
a single sad note from a chorus of exhilaration, but still
the heart has its one answer down to a science: yes.  Over
and over, the iambic uh-huh.  Whatever it takes, some kind of nerve
or unlikely grace: the heart never knows what to think.”
 

REFERENCES:

Bianco, Carl.  1999.  “How Your Heart Works.”  HowStuffWorks.com.  Link.

“Biological basis of love,” Wikipedia.  Link.

Boston Scientific.  2009.  “Heart Valves.”  Link.  (Check out the cool animations on this site as well!)

“Not to Mention Love: A Heart for Patricia,” by David Clewell.  Read it here.

Wilson, Sue.  2002.  “Red Gold: the Epic Story of Blood.”  pbs.org.  Link.