I see another beautiful, old tree is suddenly gone from my street.

The caprice, perhaps, of a building management company or landlord may be responsible. Whatever the reason, it's gone, for good.

And although here in San Francisco so many do pride themselves on what they conceive as their respect for the natural world, I never saw such a place for hacking down Nature whenever it dares to do something on its own.

No matter how many bowls of granola they may virtuously consume, I'll swear some of the inhabitants out here on the Left Coast often seem as opaque to the charms of the living creation as any Philistines in Arizona or Texas who, doggedly and unreflectively, will bulldoze the life out of a square of ground to pour concrete for a parking lot or business park.

Behind my present apartment, where, permanently fixed by rent control, I have lived for thirty years, there was once another such huge, perfectly healthy tree.

At night, the wind sighing in the rustling branches was a familiar sound. Two owls lived in it. Its presence blocked the view, now unshielded, of the unsightly walls of retrofitted buildings and other structures.

But one day I came back from an out of state trip to find hard-hatted workers with chainsaws in it, tearing it down. From my back balcony I called out to one of them who was working in the denuded crown, asking why. "The property owner says it's too big for the yard," he shouted back.

The property owner, in this case, was, in fact, a foul, old alcoholic, a red-eyed harridan who used to cuss out passing pedestrians, including me, just on general principles, as they passed by her front stoop.

She survived the tree for a little less than a year and a half before they carried her out.

Others, city planners conspicuous among them, are righteously engaged in a crusade to tear out all "non-native" vegetation. Eucalyptus trees, for example, fall victim to these selective, fair-weather stewards.

Actually, though Eucalyptus was re-introduced in historic times and is today considered an interloper, it was, as I understand it, authentically native back around the time of the end of the Pleistocene, a mere ten or eleven thousand or so years ago, an eyeblink in the long history of the Earth.

That was when the area was populated by various elephants-- mammoths and mastodons, as well as saber-toothed big cats like Smilodon and Homotherium, giant, elephantine sloths and Dire Wolves. Horses and camels, too, were here, before becoming extinct on this continent where they originated. The horse had to be re-introduced from the Old World. In the 19th Century, the U.S. Army tried to bring back the camel, here in the West, but it didn't take.

Oh, yes, this part of the world has seen 'em come and go.

And there's a lot still left, unexperienced by most, right here.

Even within the densely populated city, other lives than ours go on. Unseen and unknown by people, non-human creatures also share the metropolis, following through the cycles of their being. Beneath the superimposed human world, the realm of natural life proceeds as it may, unperceived by the urban dweller.

When I first came to live in this building, there was a family of raccoons living below it.

A bewildering series of basements and subbasements underlie the house, a pre-1906 structure which easily weathered the 1989 Loma Prieta Earthquake with a few protesting creaks, and the '06 shaker before that. The lowest of these opens into a subterranean, dirt-floored space, and there these masked, ring-tailed procyonids kept house, just as their kind had in that spot since long before the currently standing Victorian was put up.

Once, years ago, while it was raining, I heard peculiar sounds from the small enclosed space my window overlooks between my apartment and the one next to it. A rapid series of thumps, followed by a swishing, sliding sound, and then a concussion. A sort of thump-thump-thump-thump, ssshhh... bang! Quite a bang, too, shaking the walls.

When I looked out, it was the raccoons, enjoying the wet weather. Two were alternately charging forward (the thumps of the short-leggéd run), then sliding along the wet surface (the swish) and finally fetching against the far wall (the emphatic thump). Quite in the spirit of play, the full-grown creatures did this as I watched, charmed.

But this was, as I say, years ago. There is no raccoon family here now.

A woman, a tenant on the first floor who had moved in with her two small children, was "nervous" about the 'coons being there. They might, she was worried, somehow harm her offspring.

So the exterminators came and killed the animals.

Residents there from before the time of human occupancy, they were now seen as inconvenient and to be disposed of.

Nothing has lived in that dirt-floored space since. Nothing, that is, but a homeless man about fifteen years back, whose habit of lighting fires under the building inspired the rest of us to prompt him to shift his operations elsewhere.

As for the woman and her two kids, they moved away soon after, having been there a total of less than a year.

On walks late at night, when most of the neighborhood is asleep, I have seen families of skunks moving cautiously in single file. And they saw me, too. Skunks show no fear.

I have been on the radio-- an early morning program called the Puzzling Evidence show, for the last three decades, on KPFA 94.1 FM in Berkeley. Sometimes I have had to take the last B.A.R.T. train to the East Bay and wait at the station for a number of quiet hours for the others to arrive (we begin at 3 AM). Once, during this period of killing time, as I stood surveying the street on the front balcony of the station building above Martin Luther King Jr. Way, I watched as a simply enormous opossum, the size of a medium-sized dog, tentatively moved from his place of concealment, the shrubbery bordering some small stores on the other side

This ghostly, white-furred creature, trailing its long, hairless tail, waddled out under the steet light, its whiskered, pink nose twitching, its eyes glittering. No dreaded human being was up (except me, hidden in my perch above), and the marsupial beast began trundling along the sidewalk. It pattered across the street to my side in its foraging search.

Eventually, though I made no sound, it became aware of me somehow, looked up, hissed audibly and rapidly retreated to its place of cover. I felt privileged to have seen it, though.

Today, however, those little stores are long gone, uprooted to build a huge, towering apartment complex now rearing above and confronting the radio station on the west side. Gone too must be that venerable 'possum, since not even ornamental vegetation now remains at the site. So it goes-- à bientôt, Pogo.

What can one do? The human presence is antithetical, toxic to even urbanized wildlife. Even if I wanted to, I couldn't adopt a 'possum or a 'coon into my home. They also would not care for the arrangement.

And often you can't interfere. You will just make things worse, whatever your good intentions. The curse of the Damned Human Race.

Not at an esoteric hour, but at the approach of twilight, another time I was a number of blocks away from home, walking there. As I crossed a major street and started up the hill, something white fluttered out of the nearest tree and landed near my feet.

Looking down, I saw that it was an immense, white Praying Mantis, almost as long as my hand. It was a slightly greenish, almost luminous white. Parts of the body, the head and abdomen seemed to shade to a rose pink, though in the light it was difficult to tell.

I had never seen one that size or color. But as it was now walking in the street, I resolved to try to move it to a place of safety.

Easier said than done. I couldn't pick it up with my fingers; I had no card or even leaf to try to slide under it.

Moreover, it aggressively resisted, striking at my hand with its claws. It hissed at me, too. Unusual for any kind of an insect to make a noise, but I distinctly heard it.

The Jerusalem Cricket (Stenopelmatus nigrocapitatus), a large (four-inch-long) and massively armored desert-dweller, which I've also encountered nonetheless within the confines of San Francisco, at the foot of my friend's staircase in Diamond Heights, makes a sharp, distinct cry if you pick it up. I wouldn't recommend doing that, though, as they can really bite.

But I never, ever, heard or suspected that a mantis could make a sound.

It was a formidable creature, and I was running out of time. For along the street toward me ambled a loud group of young men, who had clearly emerged from a nearby bar. I didn't wish them to see what I was doing-- I suspected they'd stomp the arthropod flat out of sheer bravado.

I had no choice but to continue on my way, the mantis unrescued, hoping it was unseen by the others -- not left to the tender mercies of Man.

Hal Robins is a renowned underground comic artist and his work has appeared in Last Gasp’s Weirdo, Salon Magazine’s Dark Hotel and many other publications. For decades he has been the co-host of KPFA-Pacifica Radio’s “Puzzling Evidence” program. Reverend Hal is the Master of Church Secrets for The Church of the SubGenius. As Dr. Howland Owll, he has served as MC for many unique San Francisco events, and is the principle of The Ask Dr. Hal Show, still currently running both as a live staged event and in-studio on Radio Valencia (radiovalencia.fm) Friday evenings. Hal contributed his unique vocal talents to the award-winning interactive game Half-Life.