Girdling the Maple

Consider the consequences if your largest blood vessels were coursing under surface of the skin instead of deep inside the body. I know it’s hard to imagine. But if the aorta ran the length of your back, branching out to limbs and major organs, the pulse wave might be visible and certainly palpable over the spine. The vena cava would return blood along the midline from belly to chest where it would plunge inside to the heart.  In a lean body this great vein would look like a bluish canal through the skin. Such a vascular anatomy offers no obvious advantages but there are several disadvantages, including a greater risk of hemorrhage. It wouldn’t take a deep wound to release a fatal gusher from either of these vessels; even a bruise might cause enough swelling to seriously affect returning venous blood.

sapsucker bore holesMy crazy musing began when I noticed rows of shallow, neatly-drilled holes encircling the trunk of our prized Japanese maple tree. This was the unmistakable signature of a yellow-bellied sapsucker which visits us in winter. Besides licking the sap, the bird finds insects that are attracted to the weeping holes so that its work generates carbohydrates and proteins for its diet. By springtime the sapsucker had left for its northern breeding grounds and the holes had dried up, but the fresh foliage was far less luxuriant than in previous years. Since I couldn’t find any signs of the tree being attacked by insects, molds or viruses I assumed the woodpecker had damaged its conducting vessels which, like the vascular anatomy in my imaginary person, lie just under the surface.

Yellow-bellied sapsucker by John James Audubon: Birds of America
Yellow-bellied sapsucker by John James Audubon: Birds of America

Although there is no circulatory system in plants the vascular tubes are somewhat analogous to blood vessels. Xylem carries water and minerals up from the root system, while phloem shifts the products of photosynthesis in the foliage to other parts. Between these two great highways lies the cambium consisting of a stem cell type (meristem) which generates new xylem and heartwood on one side and new phloem and tree bark on the other.

Trees could not have evolved conducting vessels deep in their boles because the inert heartwood would prevent their girth from increasing. But the price paid for this superficial distribution under the bark is a greater vulnerability to traumatic injury and infection. Where the sapsucker had been drilling the xylem and phloem was permanently damaged because cambium is not replaceable. Fortunately the harm to our tree is not fatal or as serious as lesions to

Frost damage in tree
Beech tree with frost lesion

others in our yard caused by frost or insect borers which expose heartwood to the elements and disease. Only by complete girdling, as American pioneers often did when clearing the eastern forests for farming, is a tree condemned slowly to an early death.

One day while hiking in l’Estrie when I lived in Quebec I came across a tiny shack with a lopsided metal chimney poking out of its roof.  I could have easily missed it deep in the maple forest, but curiosity forced by legs to follow the snow tracks of someone who had branched off from the beaten trail. I ended up at the front door, and because it was unlocked I stepped inside.

It was a dream house for a child. Every surface I touched felt sticky like cotton candy (candy floss). It was a sugar shack where maple syrup was still being made in the traditional way. There was a huge boiler in the corner standing over an open fireplace from which a chimney pipe ascended to the ceiling. This was where sap would soon be slowly evaporating to produce one gallon of amber syrup from every 40 gallons of thin fluid tapped from maple trees outside.

I didn’t have to look far to find those trees. Many of those more than nine inches in diameter had holes now vacant but which in previous seasons had held a spile from which sap would drain into a bucket. Some of them had multiple holes a few inches apart and often arranged in a spiral pattern. The harvesters had been more careful than my sapsucker to avoid harming the trees, but I can’t blame it when pancake days come round.maple syrup

Next Post: Doc Bamboo

Candid about Cats

When a gray cat started prowling around our yard I assumed it was a new neighbor. I was wrong, she was a new resident!

I stumbled on her nest by chance a few days later. It was sheltered against the brick side of our house, and after scooting off from under my feet I noticed there were three tiny kittens in the nest. I guessed because their eyes were open that they were over ten days old, but not much more. The cutest kitty was tabby, another black as soot, and the third gray like their mother. She had chosen a safe place to nurse and hadn’t left a trail through the groundcover to attract attention.

cat nest
Nest of kittens

Soon afterwards a lady arrived from a non-profit rescue service with a pet carrier and a trap in the back of her SUV. She gets calls most days to abandoned cats, so collecting my family was routine. I greeted this dedicated volunteer with a cheer.

The queen was away from her nest when we returned, but the furry ball of kittens was still huddled inside. They didn’t object when we gently lifted them into the carrier.

But we had to play on their mother’s instinct to catch her. She was too shy to be enticed back while we were there, and much too wild to capture in our arms. So we set the trap back-to-back with the carrier and draped them with a cloth, leaving the entrance open. After crossing the threshold she would step on a pedal to make the door slam behind her. We waited indoors listening beside an open window.

I imagined her stealthily returning to peer through the tunnel to her babies in the carrier. Their cries would surely bring her back and overcome anxiety.  Three hours later in the gloaming we found her snarling in the trap.  Soon enough the family would be reunited in a large crate at the volunteer’s home.

queen cat
Queen in the trap

Before driving away the volunteer explained that healthy kittens are put up for adoption. Despite a rude start in life they would turn into fine home cats. But what about their mother—no one would adopt her? I presumed she would be euthanized.

Then I was told that she would be treated for parasites and tested for rabies and feline leukemia virus.  She would indeed be destroyed after weaning her litter if the tests were positive, but if not she would be spayed and vaccinated and released in our yard.

“NO…not in my backyard!”

There are many rescue organizations around the country that have a ‘trap-neuter-return’ policy. I suppose that preserving lives of unwanted animals helps to ease our collective guilt for the way that society maltreats and abandons them. Besides most people are appalled that millions of cats and dogs are euthanized, and we are moved by images of furry faces staring through the bars in animal shelters with faint chances of adoption. Who could find any satisfaction in dispatching an animal except for serious injury or chronic pain?

Tabby kitten
Tabby kitten

Some think it is unconscionable to kill any so-called feral animal that escaped from domestication or its wild descendants if a rescue shelter is available or it can be returned to a familiar place (like my backyard). I wish the same vehemence was expressed against hunting or trapping our native bobcat, because a dozen can be legally taken each year in Virginia. On the opposite side of the argument others believe it is imperative to cull cats that have gone wild, and persuade pet owners to keep all cats indoors. Municipal animal control officers have been very effective in keeping stray dogs off the streets. Roaming cats receive less attention because they rarely pose a danger to us and are better at fending for themselves than dogs. At least there is agreement between these two camps for promoting responsible ownership and sterilizing animals, apart from the genetically fittest for breeding. But because the numbers of feral and stray cats continue to soar there is a debate about culling them.

I understand that slaughtering unwanted members of a species that we chose as our companions seems a betrayal of trust. We might also feel sympathy for farm animals reared for food, but it is nothing like the bond between good owners and affectionate pets that depend on them. Moreover, it is easy for our warm feelings to diffuse over to the entire species, particularly for Anglos raised on a sentimental literary diet of Wind in the Willows and Watership Down. When I found a feral family in our yard I felt an acute conflict between as a pet owner on the one hand and a naturalist on the other, but the volunteer had no such dilemma. For her, life is always better than the alternative.

black kitten
Sooty kitten

When I protested that the gray cat would menace our wild birds, she replied: “For every fifty mice, voles, and baby bunnies brought home by my cats they only catch one bird.” There are of course many reasons why her cats are virtuous—they may prefer red meat to white or have heavy paws or the birds have plenty of cover in her yard, et cetera. But there is no longer any doubt about the national toll since the Smithsonian Conservation Biology Institute reported in a prestigious Nature journal. It found that outdoor cats killed 2.4 billion wild birds annually, including many of the most popular and beneficial species—cardinals, wrens, thrushes, bluebirds, and hummingbirds. In addition, they take 12.3 billion small mammals, but few rats. Feral animals and strays were responsible for more than half of the kills as they must hunt to eat, and domesticated outdoor cats can’t curb their instinct even on a full stomach. This stunning scale of butchery is contributing to the decline in common birds across North America and Europe and accounts for the extinction of several dozen species. The impact of cats and other introduced predators on native marsupials and flightless birds in Australasia is even better known.

The threat to so many native species should be sufficient reason for keeping cats indoors and curbing the rest, but welfare is another. Feral animals live in a shadow land between domestication and wild nature. Cats have evolved by human selection over eons and their behavior is no longer so well-adapted for life in the wild, especially far from their native range.  Given the opportunity cats wander outdoors, and often into jeopardy. The pitiful sight of a feline corpse by the highway is the most obvious reminder, but when researchers fitted cats with ‘Kitty Cams’ in suburban Georgia they were astonished at the sheer volume of hazards they face outdoors. The lives of semi-wild cats are even riskier and much shorter. They are burdened with parasites, threatened by coyotes, persecuted by people, exposed to wild weather and the threat of starvation, and lack any humane veterinary care. Pictures of a condemned animal in shelters pull our heartstrings, but there are millions of others in our cities and woods that suffer and perish out of sight.

I wonder if the consciences of people against culling feral animals could be appeased if we draw a mental boundary between them and Fluffy at home. Of course they look alike as members of the same species with indistinguishable genomes, even after generations of separation. The proof was also before my eyes since the kittens in our yard can become perfect pets. Isn’t it prejudicial to count the life of their wild mother as inferior, and call for termination? Is that a kind of catism?

gray kitten
Scary kitten

I remember as a kid worrying whether animals had souls, but grown-ups never gave me a satisfactory answer when I asked, “Do pets go to heaven?” I still think it’s a good question, though I’d frame it differently now. It would have helped if they had given me C.S. Lewis’s book The Problem of Pain. In a nutshell, he argues that if we have a personal relationship to God then our pets can be ‘ensouled’ through us. This is a strictly theological perspective and far from the biological view that humans are merely the most advanced model in organic evolution instead of a special creation. But leaving biology aside I venture some metaphysical inklings, although I admit they are speculative and our relationship to pets and their generous spirit remains deeply mysterious to me.

Lewis wrote, “in so far as the tame animal has a real self or personality, it owes this almost entirely to its master. If a ‘good sheepdog’ seems almost human that is because a good shepherd has made it so.” I too wonder if the ineffable bond with its owner gives a pet a deeper sense of its own self than their wild cousins ever have. Until recently, most animal behaviorists even denied that apes have much self-awareness, and I predict that research will challenge our thinking about other animals too.

To suggest that pets raised in a human home develop greater self-consciousness is skating on the thinnest ice and puts the writer at risk of being regarded as an anthropomorph, which is the cruelest label for a biologist. But while musing on ice a little longer I wonder if our animals can actually share crumbs of what we call ‘humanity.’  If so they might be able to share some kinds of mental suffering, like grief, that most scientists thought were strictly human. Skating even more dangerously near the melt zone I wonder if a greater sense of selfhood even increases their perception of physical pain. Pain is a subjective experience that is hard to explain to others and impossible to share compared to our five basic senses (seeing, hearing, touching, smelling, and tasting). We already know that pain is not always experienced the same by everybody: spinal mechanisms gate the ascending nervous pathways to the brain so that perceptions can be altered by states of mind. Perhaps our pets can suffer more than untamed beasts, and maybe I dismissed foxhunters too lightly for claiming their quarry hardly suffers at all. Of course this theorizing should never be used to justify maltreatment of animals which is always abhorrent and shameful.

We adopted a young stray cat. We called her Thursday and she lived with us indoors like a pampered princess for fourteen years, and for half of her lifetime in a Fifth Avenue apartment in New York. But she never returned affection, except with the threat of tooth or claw. It was my wife’s compassion that brought her home, but looking back I don’t think the cat ever had a soul!  Unlike the kittens we rescued Thursday was already too old to be imprinted by human kindliness. Taking her off the street had probably saved hundreds of birds and prevented her from making more of her kind, but it didn’t make a civil cat that deserved a place in heaven alongside our other house cat, John Henry. Cats are all the same, but are not all equal. If I see that gray mother cat prowling around our bird feeder again I will feel prejudicial, and hope my wife won’t sneak out to feed it.

Postscript: When the animal rescuer called a few weeks later we were told the cat was so ferocious that she had to be separated from her kittens. But since the viral tests were negative she had been spayed and released in our yard. We were told, not asked!

Next Post: Girdling the Maple

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