JIM CONRAD'S
NATURALIST NEWSLETTER
Written in the community of 28 de Junio and issued from a ciber in
Venustiano Carranza, Chiapas, MÉXICO
{at about 800 meters in elevation, ± LAT 16° 18'N, LONG -92° 28'W.}

May 19, 2008

FRESHWATER CRABS
I didn't know that freshwater crabs existed until I heard that men here go out at night to harvest them from the area's pesticide-polluted canals. I was told that the crabs emerge only at night. You find them by shining a flashlight into the water, and sometimes you catch whole buckets of them. This week, in the middle of a hot, sunny morning, finally I saw a crab in a canal littered with empty pesticide bottles. It's at http://www.backyardnature.net/n/08/080519lc.jpg.

Eliezer is the main crab collector here and he says they get a bit larger than the one in my hand but not too much. He says that now, just as the wet season is beginning, is when they breed, and that females produce huge numbers of offspring. When he and his friends catch them they check to see if they're carrying eggs and if so they let them go. I asked him what the crabs eat.

"Those little fish in the canals," he said. "You see the crabs with their rear ends up against the bank and facing out into the water, with their arms spread wide and their claws open, and when a fish swims in front of them they grab it. They also eat Chicozapote fruits that fall into the water."

I have no literature on crabs here and can't browse the Internet so I'm very interested in knowing how special our freshwater crabs are. What's their name and are they listed as rare or endangered? If it's particularly rare or endangered possibly the community can get some international help protecting them. I wouldn't mind seeing a freshwater crab reserve set up here.

In case you want to try identifying the crab yourself, a different view from the above is shown at http://www.backyardnature.net/n/08/080519ld.jpg.

*****

FRESHWATER MARINE CATFISH?
As if finding crabs breeding in freshwater wasn't enough, last Tuesday Leuccio brought in a dead catfish he'd just found in a canal. He's holding it at http://www.backyardnature.net/n/08/080519--.jpg.

With fish I'm better prepared bookwise than with crabs, for at least I do carry with me the little Golden Guide called Fishes -- the world's fishes in 160 pocket-size pages. What's interesting about Leuccio's catfish is that the closest thing in the little Golden Guide to our canal catfish is one of the Marine Catfishes, maybe genus Galeichthys.

But Marine Catfish live in saltwater, where I used to think all crabs did their breeding...

I wonder if maybe long ago the Central Valley of Chiapas was occupied by a saltwater inland extension of the Pacific Ocean? As the land rose the connection with the sea diminished and the lake water's salt content slowly dropped. Maybe our crab and catfish species slowly evolved tolerance to freshwater, causing a new species to arise. Maybe here at the very foot of the Chiapas highlands where many springs issue water from the highlands above, we have many endemic and endangered species...

Or maybe freshwater crabs and freshwater catfish looking like Marine Catfish are no big deal at all, just that I haven't heard about them. As soon as I get to where I can browse the Internet I'll find out.

Meanwhile, you are welcome to see what you can come up with!

*****

A TEENY TANTILLITA SNAKE?
The next day Leuccio came to me with a plastic Coke bottle holding the little critter shown in my hand at http://www.backyardnature.net/n/08/080519tt.jpg.

That's a snake. The head is at the top, the yellow-spotted end being the tip of the tail. The yellow spot might cause predators to attack the snake's tail instead of his head.

If you were with me in the Yucatan you may recall the Yucatan Dwarf Centipede Eater we ran across there one day, much smaller than this one. You can see that unbelievably small Yucatan snake and read about it at http://www.backyardnature.net/yucatan/snk_cent.htm.

I suspect that Leuccio's discovery, which he spotted in debris next to a kindergarten he's helping build in a neighboring community, is the same genus as the Yucatan find, Tantillita -- another Centipede Eater -- but a different species.

My impression is that with the arrival of the wet season snakes are becoming easier to see and species other than Speckled Racers are emerging.

*****

A BLUE-SPOT ANOLE DROWNS
Water from the community's spring has such a high carbonate content that the quarter-mile of rubbery tubing conducting water from the spring to the community clogs up every two or three days. Men have to walk the whole length, then, pounding the tubes with sticks, hoping that things will come unclogged. Sometimes days pass before water runs again.

Therefore when we have water I store buckets of it. It was in one of those buckets on my casita floor where this week I found a female Blue-spot Anole, NOROPS SERICEUS, lying at the water's bottom. She' at http://www.backyardnature.net/n/08/080519bs.jpg.

I felt awfully bad about her drowning. That anole had lived on my cement-block walls ever since I got here, always just minding her business and not even making loud croaks during the night the way my House Geckos do.

At first I thought she was a gecko because that's what I'm used to on house walls in this part of the world. But when I took a closer look I saw that her toes didn't bear rounded pads the way most gecko species do, plus the geckos I know aren't as long and slender as she. On the other hand, I remembered how Green Anoles used to populate my trailer's walls back during my Mississippi hermiting days so I figured she might be an anole. Jonathan Campbell's book, Amphibians and Reptiles of Northern Guatemala, the Yucatán and Belize, confirmed this. This one didn't have a fan beneath her chin, so I figured she was a female.

Campbell doesn't mention Blue-spotted Anoles living in houses, but he does say that the species is abundant in a number of habitats. Usually it's found on low bushes and shrubs, on tree trunks, or in leaf litter. He says that females lay single eggs over the course of the rainy season.

The species is distributed from northeastern Mexico to Costa Rica.

*****

FERN-LOOKING
Up north these days many ferns have just emerged, or are in the process of doing so. If you've never paid much attention to wild ferns you might have a lot of fun discovering how interesting and beautiful the fern world is.

We have lots of ferns here. I can't even guess at the identity of most, but that doesn't keep me from looking at them closely. I like to hold their fronds up against the sunlight so I can see clearly the delicate venation reaching toward lacy margins, and the amazing variety of sori.

"Sori" (singular "sorus"), are clusters of almost microscopic, baglike items in which spores are produced. A fern's spores and fruiting bodies are too small to have much fun with unless you have a microscope, but you certainly can admire the many ways the sori manifest themselves.

For example, one common fern along shaded canals here has its sori more or less randomly distributed across its broad, asymmetric frond's lower surface, as shown at http://www.backyardnature.net/n/08/080519f5.jpg.

A completely different approach to sorus arrangement is taken by leather fern, genus Acrostichum, common in mud along our canals. It produces coarse, almost erect fronds reaching about eight feet high. On the undersides of this fern's fertile pinnae sori are crammed so close together that they form a solid, cinnamon-colored sheet. You can see this at http://www.backyardnature.net/n/08/080519f6.jpg.

At http://www.backyardnature.net/n/08/080519f7.jpg yet another completely different approach is shown. Here closely packed sori are crammed beneath the pinnae's curled-under margins.

Up North, most fern species have sori similar to those at http://www.backyardnature.net/n/08/080519f8.jpg. In other words, the sori are clearly distinct from one another, they're arranged in patterns, and often they are partly covered by a papery, thumbnail-like thing usually arising at one side of the sorus, called an indusium. If you get into fern identification you'll spend a lot of time studying sorus and indusium configurations, for between species they're as distinctive as flower color and stamen number among the flower plants.

If you're interested in discovering a whole new, very pretty and interesting world, you might want to go to my web page at http://www.backyardnature.net/ferns.htm and brush up on basic fern facts. Over on the right side of that page you can even order a fern fieldguide available through Amazon.com.

*****

AT DRY SEASON'S END
Behind my casita you can the mixture of dead, dying, hanging-on and thriving plants shown at http://www.backyardnature.net/n/08/080519dy.jpg.

That's a dead Coconut Palm at the lower left. I've tried to keep it alive the last few weeks by dumping laundry water around it but it's died of thirst anyway. Behind the palm is a dead or almost-dead juniper. At the right of the juniper is an Oleander, who you just have to admire for its hardiness. No wonder they're planted in so many towns in places where it seems no plant could survive.

All three of these plants are non-native plantings. They thrived through the rainy season, suffered but survived through most of the dry season, and now at the very end of the dry season one has survived but two haven't. Crowns of native clumpgrasses around the plantings die during the dry season but will begin issuing new shoots in a couple of weeks if the rainy season comes on time, and it seems to be doing so.

Behind the juniper and Oleander there's a native tree with deep roots and waxy leaves that don't lose much water through evaporation. A month ago it was completely leafless, but now it has issued new leaves because it evolved here and "knows" that about now the rains are beginning.

The soccer field is as dead looking as anything. However, here and there are low areas and in a few of those low spots for the first time on Wednesday as I jogged around the field at dawn I spotted what's shown at http://www.backyardnature.net/n/08/080519dz.jpg.

Those are seedlings of annuals emerging from among dead leaf stubble, on the first day of their lives. They've lain dormant during the entire dry season but now they've germinated because last Monday we had our first gully-washer, nearly an inch (2 cm), even accompanied by mothball-size hail.

However, most of the soccer field's low spots haven't produced a single germinating plant. That's because water stood in some spots longer than others. Seeds lying dormant through the dry season have to reach a certain threshold of being soaked before they germinate, and in some of Monday's storm-puddles the water pooled long enough to trigger germination, but in most it didn't.

The rainy season commeth! The dry season has been as rough and harsh as it was supposed to be, but last week we had three early-evening rains in all, something I haven't seen since I've been here. All's right with the world, sort of.

*****

INTELLIGENCE
My very smart friend Louise in the Yucatan sent me an article from the New York Times exploring in a tongue- in-cheek manner whether intelligence is all it's cracked up to be. Among other things the article points to a study of fruit flies indicating that smarter fruit flies live shorter lives, possibly confirming the suspicion that "dimmer bulbs burn longer."

The author says that intelligence "takes more upkeep, burns more fuel and is slow off the starting line because it depends on learning — a gradual process — instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to stop."

In my own life I've known plenty of times when I made things more complicated and hurtful than they needed to be because I thought about them too much.

On the other hand, maybe you remember my "Six Miracles of Nature," still archived online at http://www.backyardnature.net/j/o/6miracle.htm.

I think it's miraculous....

Therefore, the abilities to learn and to reflect are miraculous manifestations. Through untold billions of years Nature evolved the Universe, pulling stuff together into forms and shapes that evolved, first physically, then biologically, and now intelligently.

My reading of the matter is that evolution is headed toward something unimaginably splendid, maybe Miracle #7.

But, before #7 can come about, we need to finish with #6. Most of humanity still spends most of its time dealing with its animal nature and blindly fulfilling dictums of genetic and social programming.

The Sixth Miracle, the emergence of intelligence, is still a miracle in the process of coming about.

Whenever one of us does something creative transcending mere biology and programming, the Sixth Miracle ignites like a firefly alone in a big field at night.

The dim bulb may burn longer, but the flow of evolution has always trended toward light, and more light.

At the very least this indicates to me that we need to treasure what little brains we have, do what we can to keep ourselves alert, keep learning enough about the world around us to stay in awe, and to always be imagining new beginnings.

*****

ON THE ROAD AGAIN
Last Thursday my digital camera stopped taking photos. Much of what I do here depends on taking good pictures, so this is a serious development. Cameras cost a lot more here than in the US, plus there's not the selection or the sales backup. Last Thursday, as soon as I knew I had trouble, I found a pretty Anona tree, sat beneath it, and thought things out.

The camera isn't the only thing giving up. The super-anodized metal rods holding up my tent are starting to crack, and Saturday morning I awoke to find the tent sagging because a rod had snapped. My sleeping bag, in use through all my hermiting and Germany years, has lost nearly all its loft. I threw away my hiking shoes up in Querétaro. All my gringo-size clothes are mildewed, stained, torn and patched. My binoculars show images as if seen through oil, and I myself need a new pair of glasses. The selectivity of my little shortwave has diminished to the point that BBC programs hardly can be heard through all the very powerful religious stations broadcasting around-the-clock preaching from the US. To top all that off, I'm running out of cash and need to raid my account.

Therefore, next Wednesday I'm leaving 28 de Junio and will gradually wander northward until reaching the home of my friends Karen and Jackie near Natchez, Mississippi, where my old hermiting trailer is still parked at the edge of their woods and can probably still keep the rain off my head.

I doubt that I'll be in the position next Monday to issue a Newsletter. Just hold on. It'll come when things fall together a bit.

*****

Best wishes to all Newsletter subscribers,

Jim

All previous Newsletters are archived at www.backyardnature.net/n/.

Visit Jim's backyard nature site at www.backyardnature.net