JIM CONRAD'S
NATURALIST NEWSLETTER
Written at Hacienda San Juan Lizarraga
one kilometer east of Telchac Pueblo, Yucatán, MÉXICO
and issued from Hotel Reef Yucatan 13 kms to the north

November 30, 2005

JETTY BOOBY
Walk up the beach about half a mile from Hotel Reef Yucatan and there's a structure jutting into the sea made of car-sized blocks of concrete piled atop one another. I think the structure serves to block waves from the channel on the other side used by fishermen from Telchac Puerto as they go to sea.

On my weekly visits to Hotel Reef I visit the jetty because there's always a large number of Brown Pelicans perched there as well as Laughing Gulls, Royal Terns, and cormorants. It's a good place to sit just watching waves come in, and Telchac's fishermen going to sea in their brightly colored boats, with nets heaped in piles in the boats' centers.

Right after Hurricane Wilma brushed us, one day a new kind of bird perched on the jetty. They were large, dark, snaky-necked birds. At first I thought they were cormorants but then I saw that their long bills were sharply pointed, not hooked like a cormorant's. Also, up closer the birds' upper bodies were brown, unlike any cormorant. They were immature Brown Boobies, which you can see at http://www.gos.org/sightings/10-boobies/brbo-20020824-6895.jpg.

That word, booby, by the way, comes from the Spanish "bobo," which means "stupid person or slow bird." Bobo probably derives from the Latin "balbus" meaning "stammaring," relating to the stammaring sounds of barbarians.

Anyway, there's a whole bird family for the boobies, the Sulidae. All boobies are large, long-bodied seabirds with long, pointed wings and tapered tails. They are all tropical and they are all truly oceanic birds, more at home far at sea than along shores. Apparently Hurricane Wilma sent these jetty boobies ahore. Brown Boobies, unlike the average songbird with its regional distribution, are found on all the Earth's tropical seas.

Over the weeks since Wilma's visit the jetty boobies have gradually diminished in number. This week only one remained. During the hour I was there he just sat in a sheltered, sunny spot, hardly moving at all. Who knows why he tarries there when the open sea stands right beside him?

*****

PULSATING OWLS
We have our share of owls at San Juan. A pair of Great Horned Owls keeps a nest atop one of the hurricane ruins next to my lodging, and I hear them every day and night hoo, h-hoo, hoo, hooing. Great Horned´s are found all the way south to Tierra del Fuego.

Even more commonly heard is the pulsating, one-toned, ±3-beats-per-second, easily imitated whistle of several Ferruginous Pygmy-owls. Our weedy scrub must be exactly what pygmy-owls like because they are very common both on the hacienda and in surrounding fields. Sometimes in early mornings so many Ferruginous Pygmy-owls are monotonously, even hypnotically calling from so many directions that it's comical, the whole world seeming caught up in pulsating pygmy-owl whistles.

A Great Horned Owl is 19-22 inches long, while a Ferruginous Pygmy-owl is only 6.5-7.5 inches long. An American Robin is larger, at 9-10 inches. Even in broad daylight it can be hard to spot Ferruginous Pygmy-owls because they tend to perch unmoving as they call, often obscured by a leaf.

"Ferruginous" refers to the owl's rusty-red, dominant color. A remarkable feature of all six Mexican species of the pygmy-owl genus, GLAUCIDIUM, of which the Ferruginous Pygmy-owl is one, is that on the backs of their broad, rounded heads they bear "false eyes" consisting of feather markings. At a distance they seem to be looking exactly at you, even if they're staring in the opposite direction. See can see a Ferruginous Pygmy-owl looking away at http://www.schmoker.org/BirdPics/Photos/Owls/FEPO15.jpg .

These false eyes surely help protect pygmy-owls from predators larger than themselves, though when you see what aggressive hunters they are you wonder whether they need them. Pygmy-owls are known to take birds up to the size of the American Robin, which we've seen is a good bit larger. Pygmy-owls also eat reptiles and insects.

Ferruginous Pygmy-owls are distributed from southern Texas and Arizona south to northern Argentina.

*****

ALLSPICE
Each morning I greet Roberto the gardener with a "¿Qué hay de nuevo?" or "What's new?" and one day this week he had something new. During his machete work on the hacienda's grounds he'd come across a 20- ft-high tree he couldn't recognize. Roberto knows a lot, so I figured he had a good find.

The tree's leathery, six-inch-long leaves were simple, unlobed, with smooth margins, and with typical pinnate venation. In other words, they were about the most ordinary-looking leaves imaginable. However, then I began noticing details.

First, the leaves arose from the stems in pairs, not singly, which by far is the most common state. The tree's buds were not covered with scales -- they were "naked." Holding a leaf up to the sun, its surface seemed to be densely set with almost-microscopic pinpricks -- botanists would call such a leaf- surface's condition "pellucid-punctate." The punctations consisted of translucent glands embedded in the leaf matrix, filled with aromatic oils. Because my fingers were crushing some of the glands a delightful fragrance suffused the air around me, an effervescently fresh scent very like clove.

It was an Allspice tree, PIMENTA DIOICA, a member of the fabulous Myrtle Family, in which we also find such spicy-smelling trees as the eucalyptuses, the Clove-tree and the classic Myrtle, as well as guava trees. You can see leaves exactly like ours at http://www.nybg.org/bsci/belize/Pimenta_dioica_2.jpg.

Allspice spice is made from this tree's small, dried, unripe berries. It's said that the odor of allspice spice is like a rich blend of cinnamon, nutmeg and cloves. While the Myrtle Family does produce cloves, trees providing cinnamon and nutmeg belong to the Laurel Family in which our eastern US Sassafras also is found.

Why would plants evolve smelling so good? If you could have seen the leaves of our Allspice tree maybe a good answer would have occurred to you as it did to me. Those leaves were practically unblemished by bug munchings and fungal infections. All surrounding trees bore leaves that now at the end of the rainy growing season were tattered and spotted, but the Allspice's leaves were still in mint condition.

The aromatic oils in those pellucid punctations must taste awfully bitter to bugs.

*****

THE CHINCHE HOCICONA & CHAGAS DISEASE
Katharine, who owns Hacienda San Juan, had mentioned that at the Social Services Building in town they'd hung up a poster showing the insect that transmits the dreaded Chagas Disease. The other day she pointed out a bug climbing a windo screen in the Big House and said that that might be the Chagas bug. Or maybe not. Hard to say.

It was a brown Hemiptera, a member of the "True Bug" Order, the kind of bug that as a kid in Kentucky I would have called a stinkbug without a second glance. I nudged the critter with a finger, smelled the finger, and it stunk like stinkbug.

The insect carried below its thorax a stiff, strawlike proboscis, however, and Katharine assured me that that proboscis could be used to puncture skin and suck blood, and that she'd squashed bugs just like these at the window and found them full of blood. Also, I remembered that some bugs in this order were called assassin bugs. I figured I'd better hike to town and look at that poster.

The poster showed a bug very similar to our window visitor, except that bright red spots marked its wing margins, which, happily, wasn't the case with our window bug. The poster gave only the insect's Spanish name, which was Chinche Hocicona, which translates more or less to Snouted Chinchbug. With that name and knowing that it was a vector for Chagas Disease, it was easy to Google up the rest of the story.

Our Chinche Hocicona's scientific name is TRIATOMA PALLIDIPENNIS or T. INFESTANS. The disease-causing organism it transfers from one victim to another is a flagellate protozoan called TRIPANOSOMA CRUZI. The disease organism is evolving into various strains, so symptoms for the disease vary from region to region.

Chagas Disease proceeds through three stages. The first stage begins the fourth or fifth day after being bitten and the main symptom is fever and a headache. The liver, spleen and heart begin enlarging. At this stage it's possible to cure the disease completely, but the symptoms are easy to misinterpret.

The second phase can last ten to thirty years, during which the walls of various body organs deteriorate.

In the last phase the central nervous system is affected, no cure is possible, and death may result.

Chagas Disease is bad in some places in Mexico but we're unclear as to how common it is around here.

You can see the disease's geographic distribution here.

You can see the disease's bug vector at http://www.port.venice.it/sanimav/triatoma.jpg.

*****

DEW
I've been thinking what a fine thing dew is, and how lucky I am that most of my days begin as dewy ones.

An hour before dawn I'm stiffly walking through the grass toward the highway where I'll jog for half an hour. "Stiffly" because at age 58 it takes a while for my joints to loosen up. At that hour I'm still glowing with deep-seated warmth after a good night's sleep in a toasty sleeping bag, so the morning's chill is a sharp freshness playing on the skin. Once I'm running, the body heats up even more, and what a pleasure to feel the night air streaming around my body as I run watching the stars.

Walking across the grass, that's when I feel the dew. I try to lift my feet high to keep my expensive running shoes dry, but they get wet anyway and I feel sprays of cold dew on my ankles as I walk. Somehow the stars in the black sky and the cold dew in the black grass mingle in my mind. Well, quantum mechanics says that they're pretty much the same thing, anyway.

Dew forms when moist air cools. Rising, cooling currents of sky air produce the vapor of white cumulus clouds, and hot air escaping from a boiling teakettle forms steam as it cools. At night the land radiates energy, or warmth, into space, cooling, so relatively warm night-air, when it touches a relatively cold blade of Earth-rooted grass, condenses dew. It's all the same mechanism, as if the Universal Creative Force were so pleased with Her concept that She wanted to see it expressed again and again in different ways.

Dew carried to its extreme is fog, and we have both good dews and good fogs here. The fogs at dawn lie in puddles on this flat land and as I jog I run into and out of them. When I'm inside a fog-puddle my glasses whiten and I feel condensation on my moustache, run my tongue there, and it's amazing how something so cold and wet can make a warm body feel so alive.

When the sun comes up, I'm out there with the birds and somehow it seems to me that birdsong is the same as dew and stars, though I can't say whether quantum mechanics goes that far.

When the dew or fog is heavy, droplets of water coalesce on the undersides of horizontal twigs. Tropical Mockingbirds here know how to angle their long beaks over a twig's edge and run it along the twig. Then they raise their dew-wet bills and drink what trickles into their throats. I think these fogs and dews during the dry season must keep many things alive.

Several bird species also take dew-baths, fluttering against wet leaves again and again until their feathers are wet. Then the birds go perch in the sunlight preening themselves.

How beautiful is a bird wet with star-song-dew just being itself in morning sunlight.

*****

Best wishes to all Newsletter subscribers,

Jim

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