JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from Mayan Beach Garden Inn 20 kms north of Mahahual
on the Yucatán Peninsula's eastern coast just north of the Belize border,
in the state of Quintana Roo, MÉXICO
(N18°53'16.36', W87°38'27" )

July 17,  2011

A NONI-EATING FOX
Not long after dawn, while the sand road beyond the northern bend was still somberly shadowed, something wandered across the lane too far ahead to make out what it was. On the bike I coasted to a stop, the critter paused, too, stared at me, and then crossed the road again. When I drew closer it became clear that here was a Gray Fox, UROCYON CINEREOARGENTEUS.

As I watched, the fox kept going back and forth across the road, slowly working in my direction. I stepped behind a roadside bush hoping he'd keep approaching, and he did. After a few minutes he arrived carrying something white in its mouth, as shown at http://www.backyardnature.net/n/11/110717fx.jpg.

The white object was a Noni fruit, which the fox deposited at a certain spot among the weeds along the road. Nonis are small, evergreen, broad-leafed trees originally from Southeast Asia and Australasia, but now planted throughout the world's tropics because of the medicinal value of their bad-tasting but edible fruits. Noni trees are common invasives here, all along this coast looking and behaving as if they were a native species. We've profiled them at http://www.backyardnature.net/yucatan/noni.htm.

The fox deposited his Noni fruit, then kept coming in my direction. Mosquitoes were swarming all over me but I didn't move, knowing that by remaining still I might be "invisible" to the fox. When the fox was about seven feet away (2m) I snapped the picture shown at http://www.backyardnature.net/n/11/110717fy.jpg.

This individual's fur shows a good bit of reddishness, so how do we know that this isn't a Red Fox? The most obvious field mark is its black-tipped tail. Red Foxes have white-tipped tails. Also, Red Foxes, though enjoying the largest distribution area of all members of the order Carnivora -- occurring in both the New and Old Worlds -- don't occur in Mexico and farther south in the Americas. Here, if it's a fox, it's a Gray Fox.

The Gray Fox similarly enjoys a large distribution area, though is absent from the Old World. It's found from southern Canada to northern Venezuela and Columbia. As you might expect for such a large distribution area, throughout the Gray Fox's domain there's a good bit of variation in fur color and other features. Sixteen subspecies are recognized. Our Yucatán foxes belong to the subspecies fraterculus.

Gray Foxes are fairly common in this area, on the average turning up along the roads I bike about once a week, sometimes more. Several times I've silently biked up close behind one trotting down the road away from me. Actually I'm surprised that they are not more wary of humans -- that one would pass within two meters of me not hidden well at all behind a roadside tree.

By the way, Coyotes, which at first glance look a little like Gray Foxes, and range from Canada and Alaska south through Mexico to western Panama, so far haven't extended their presence into most of the Yucatán.

*****

IMMATURE & FEMALE FRIGATEBIRDS
Now that migrant birds who nest up North are gone, the most conspicuous bird along the beach is the Magnificent Frigatebird. Nearly always you can see one to several sailing along the beach or hovering over the water's edge. With wingspreads of up to 7-½ feet (2.3m), these are impressive presences! Of all birds on Earth, frigatebirds have the lightest body weight (2-3 lbs, 1.1kg) in relation to their wing area.

In field guides usually mature males are illustrated inflating their female-attracting, red throat pouches. When visitors see immature and female birds without such pouches, sometimes they're not sure what they're seeing. Nowadays we have many more immatures and females than mature males. A mature female with her black head and broad, white chest band is shown at http://www.backyardnature.net/n/11/110717fb.jpg.

A picture of an immature with a fully white head is at http://www.backyardnature.net/yucatan/mag_frig.jpg.

*****

HAWK NEST FINALE
Early this week the Common Black Hawk nestling who spent so much of the previous week at the nest's edge gazing toward the horizon, no longer was there. I thought maybe for some reason he was cowering inside the nest where I couldn't see him, but neither has he shown up since then.

Usually one of the adults can be spotted perching nearby, out in the mangroves, so I'm guessing that the nestling now is a fledgling being watched over by the adult, and has spent this week down in the mangrove scrub continuing his explosive growth and education.

I'll let you know if someday Black Hawk in mature plumage comes sailing about.

*****

SCURRYING ROCK LICE
Not long after dawn and a night of intermittent showers I biked the white-sand beach road where it tunnels through scrub next to the mangrove just to our north. While zigzagging around the road's many puddles, suddenly about a dozen dark, inch-long (2.5cm) critters began scurrying below me, spooked by the bike. They reminded me exactly of how cockroaches skitter about when suddenly the lights are turned on in a messy kitchen.

But, these cockroach-like beings had seemed to be gathered at the pools' margins where there was nothing to eat, just white sand meeting chalky-colored water. I went back and photographed the individual shown at http://www.backyardnature.net/n/11/110717my.jpg.

Up closer I could see that, with such a many-segmented body, it wasn't an insect but rather an isopod -- a member of the crustacean order Isopoda, like sowbugs, pillbugs, millipedes and centipedes. But this was like no isopod I'd ever seen.

In the picture you can see that the creature's legs, an antenna and its rear appendages (uropods) were under water; I thought that maybe he'd drowned. I started to nudge him but before my finger got close suddenly he raced off as fast as a guilty cockroach. No, this animal was doing what he wanted to do, which was to hang out half submerged in water.

By day's end, volunteer identifier Bea in Ontario had pointed me toward an isopod family I'd never heard of, the Ligiidae, the Woodlice Family. Building on that insight, now I've about convinced myself that what we have here is the Rock Louse, LIGIA OCCIDENTALIS, known to occur from southern California into Central America.

Rock Lice are regarded as intertidal species -- living among rocks between upper and lower tides -- and are known to be mostly nocturnal. They are scavengers, often feeding on microscopic algae. One source describes them as being nearly terrestrial, despite their having gills. These gills serve them well in the intertidal zone, but restrict their land-roamings to wet areas where they can keep their gills moist.

Therefore, I'm guessing that these Rock Lice, during a night of frequent showers, strayed a little too far from the beach and at dawn were caught where the only water they had to keep their gills moist were puddles in the sand road. With occasional vehicles coming down the road, it was a vulnerable position to be in.

Rock Louse! What a pleasure to meet something so different from anything else you've always known!

*****

MADAGASCAR PERIWINKLE
In this part of the world there's a certain knee-high, evergreen subshrub with pink to white, five-lobed flowers that you're just as likely to see featured in flower gardens as emerging from cracks in sidewalks or growing as weeds along sandy roadsides. Two unplanted "volunteer" plants beside the resort here, one pink- flowered and the one in the back white, are shown at http://www.backyardnature.net/n/11/110717vi.jpg.

Two phlox-like, 2-½ inch wide (4cm) flowers are shown at http://www.backyardnature.net/n/11/110717vj.jpg.

By "phlox-like" I mean that each blossom's corolla tube is topped by five petal-like lobes that expand out horizontally. If you make a longitudinal section of the tube, however, you'll discover a very unphlox-like anatomy. What you'll find are pollen-releasing anthers clustering at and almost blocking the tube's mouth, while below the anthers there's a massive, plug-like stigma head atop a long, slender style leading up from the ovary. In other words, this is anatomy we've often seen, for example in the Yellow Oleander, analyzed at http://www.backyardnature.net/yucatan/y-olean5.jpg.

These leaning-together anthers with short or missing filaments hovering above a pluglike stigma head in a flower with a slender tube atop which petal-like lobes expand outwards is classic anatomy for the big Dogbane Family, the Apocynaceae. Among the most famous species in that family are Oleander, Frangipani, Allamanda and Mandevilla vines, and Periwinkle.

In fact, the ubiquitous, pretty plant in our picture is known as the Madagascar Periwinkle. It's CATHARANTHUS ROSESUS. Older literature calls it Vinca rosea, the genus Vinca being the periwinkles.

Madagascar Periwinkle really is originally from Madagascar, though during my botanist days there when I earnestly looked for it I never saw it in the wild. Now I know that in its native land Madagascar Periwiinkle is an endangered species because of habitat destruction mostly brought about by slash and burn agriculture.

It turns out that Madagascar Periwinkle not only is pretty enough to be planted throughout the world's tropics, and tough enough to live in many relatively inhospitable environments, but also the plant is much used in herbal medicine. In traditional Chinese medicine its extracts have been used for diabetes, malaria, Hodgkin's disease, and more. In the West, Vinblastine and Vincristine extracted from the plant are used in the treatment of leukemia.

In fact, Madagascar Periwinkle has been involved in a certain ongoing international controversy. Western pharmaceutical companies have patented drugs based on compounds in the Madagascar Periwinkle without ever compensating anyone in Madagascar. Thus Malagasies can end up having to pay for medicine that in their own country they can't legally produce using their own plants. This and similar histories have led to accusations of "biopiracy." When I was on expedition in Madagascar, however, the Malagasies monitored very closely what we collected, and made sure they got their part.

*****

MANGROVE VINE
Lately dense, vine-overgrown edges of mangrove swamps have been breaking out with white, yellow-throated, 1.5-inch-wide (4cm) morning-glory-like flowers, shown at http://www.backyardnature.net/n/11/110717rg.jpg.

A close-up showing how white corolla lobes expand from the top of fairly slender corolla tubes is at http://www.backyardnature.net/n/11/110717rh.jpg.

These aren't morning-glories, though. If you make a longitudinal section of a flower you see what's shown at http://www.backyardnature.net/n/11/110717ri.jpg.

So, you have a blossom composed of a narrow tube at the top of which five petal-like lobes expand out, and at the flower's throat five pollen-shedding anthers with very short or missing filaments converge like a tepee over the stigma. All this is exactly like the flower of the Madagascar Periwinkle examined above. A conspicuous difference, however, is that the pluglike stigma head is missing. In the mangrove blossom, the stigma is slender -- lacks the "plug". In the last picture you can see the slender, hairless style with its tiny stigmatic tip making its way up the center of the split-open corolla tube.

This vine, which lives in mangroves and marshes from southern Florida and southern Mexico south through northern South America, goes by the English names of Mangrove Vine, Rubber Vine, and Mangrove Rubber Vine. It's RHABDADENIA BIFLORA, and as you might expect with such structurally similar flowers, it belongs to the same Dogbane Family as the above Madagascar Periwinkle, the Apocynaceae.

*****

HOW OLD IS THIS CORAL?
At the first rocky point south of us there are tons of dead coral chunks and fragments such as what's shown at http://www.backyardnature.net/n/11/110717bc.jpg.

That's what's left of a brain coral that once formed part of the reef offshore. I'm guessing that it's the Symmetrical Brain Coral, DIPLORIA STRIGOSA.

Some coral fragments on that rocky beach are clearly fossils, which lived thousands or even millions of years ago. You know this because they're obviously eroded from bedrock limestone. You might remember our picture of some spongiform fossils in the process of eroding from massive bedrock at http://www.backyardnature.net/yucatan/fossil1.htm.

However, many or most coral fragments at that rocky point surely were broken from the reef just offshore not long ago. After Hurricane Dean in 2007 enormous amounts of new coral fragments and seashells were added to the beach.

So, is the brain coral in my picture of recent or ancient age? I posed the question to a fossil forum on the Internet and the experts weren't too helpful. Of course a lab could determine the chunk's age by analyzing the half-lives of radioactive isotopes in the coral, or even its Carbon-14 content if the chunk is of fairly recent origin.

That doesn't help us. However, one piece of evidence our coral shows is that it's been around long enough for its surface to have become highly eroded. Take a look at a close-up of a fresh brain coral at http://reefguide.org/pixhtml/symmetricalbrain4.html.

Compare that with a similar close-up of our coral at http://www.backyardnature.net/n/11/110717bd.jpg.

The kind of surface-removing erosion indicated in that picture doesn't take place quickly, as during a single hurricane. For such profound erosion to have taken place, some kind of long-term agent is needed, such as wind, water or chemical action.

Sometimes mineral crystallization occurs in fossils. A general rule is that the more crystallization you observe, the older the fossil is. Many of the cells of our brain coral are filled with white matter. which I'm guessing to be crystallized calcite.

So, even though we have living brain coral at the reef right offshore from us, I'm guessing that the coral in my picture is not recent, but rather is at least a few centuries old, maybe a few millennia, or even a few millions of years old.

*****

WILD PURSLANE'S OMEGA-3S & ANTIOXIDANTS
Several pretty colonies of Wild Purslane, PORTULACA OLERACEAE, recently appeared near our compost heap. Purslane, called Verdolaga here, is one of my favorite wild edible herbs, and lately I've been picking and eating my share. You can see a handful of sprouts at http://www.backyardnature.net/n/11/110717pt.jpg.

Wild Purslane flowers look like yellow buttercup blossoms, except that in the flower's center above the cluster of numerous male stamens the single style is topped by five or six long, slender, upward- and outward-arching, pollen-receiving stigmas, as seen at http://www.backyardnature.net/n/11/110717pu.jpg.

Here's something interesting: Wild Purslane contains the highest concentration of omega-3 fatty acids and antioxidants of any green leafy vegetable examined to date.

Cooking Wild Purslane is easy. Put a skillet with a little oil in the bottom over a fire and add about a gallon (4 liters) of leaves and stem tips. While being sautéed the leaves and stems lose maybe 80% of their bulk. Once they've cooked down you can eat them as-is or add something to them. I like to stir in two eggs. The end product tastes like eggs and spinach fried together. Onions, garlic, tomato, etc. can be added but I like the way simple, elemental flavors interact.

*****

EATING WILD PURSLANE
I can't eat Wild Purslane without visualizing it coursing through my gastrointestinal tract releasing fatty-acid molecules and antioxidants like little spaceships -- spaceships deployed with missions to wander throughout my body and land here and there to perform critical maintenance. When I eat Wild Purslane, instantly I feel healthier and more alert. Of course that's psychological, but psychology counts. So much, I've found, boils down to how you feel about things, whether your feelings are rational or not.

When I eat Wild Purslane I develop a mental image of energy erupting from the Sun 93,000,000 miles away, shooting through empty space, and cascading onto Earth. Earth's photosynthesizing plants like Purslane capture the energy, mingle it with nutrients from Earth, water and air, and then make all that magical stuff freely available to other organisms, like me. During this transfer of energy from the Sun to ourselves, and mingling of the Earth's compounds with our own bodies, we various Earthly life forms are drawn into a special kind of community, a community with spiritual dimensions.

In fact, I regard meals such as my Wild Purslane with eggs as constituting nothing less than sacred communions during which I merge with the utterly generous and loving Universal Creative Spirit. Of course, the same feeling can arise from eating a Hostess Twinkie, for in the end a Twinkie's ingredients are natural, too, no matter how they've been processed and packaged by humans.

Still, when I eat wholesome Wild Purslane picked in the fresh air and sunlight and immediately prepared and eaten by myself, somehow the sense of communion is especially convincing and profound.

*****

Best wishes to all Newsletter readers,

Jim

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