JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from Rancho Regenesis
in the woods near Ek Balam Ruins north of Valladolid in
Yucatán, MÉXICO

November 6, 2016

*****

MANGROVE TUNICATES
Last week two sets of travelers visiting Genesis in Ek Balam wanted to visit Río Lagartos about 80kms north of here. Since I'd lived there for ten months, I was invited to go along with them.

On the standard Flamingo-viewing boat trip up the estuary, on the first trip we were lucky to have as our boatman Paco, with whom I've made many such trips. About midway up the estuary Paco pulled the boat to the water's edge where a tangle of Red Mangrove "stilt roots" entered the water, and pulled one of the roots from the water to show us something. So you can better visualize all this, especially the stilt roots, you might want to look at our Red Mangrove page, at http://www.backyardnature.net/yucatan/mang-red.htm

During all my times on the estuary I'd never thought to do this, and what Paco showed me was amazing. You can see what was on a root, normally about a foot below the brackish water, at http://www.backyardnature.net/n/16/161106tt.jpg

A close-up of individuals forming the white, root-covering clusters is at http://www.backyardnature.net/n/16/161106tu.jpg

Paco said that fishermen in the area think that the white objects are fish eggs, but the above photo shows that each egg-like thing bears two breast-like protuberances, and each "breast" is tipped with orange, ring-like things -- and no egg is structured like that.

The clusters are colonies of filter-feeding, marine, invertebrate animals known as "tunicates." The name tunicate applies to many genera and species in the subphylum Tunicata. To put that into some perspective, all animals with a "chordate" -- which more or less is the same as a spinal nerve -- are members of the phylum Chordata, and tunicates are subdivision of that enormous grouping. Examples of members of the Chordata range from us humans, to fish, to our lowly tunicate, which also has a primitive chordate.

Tunicates consist of a water-filled, sac-like body bearing two tubular openings known as siphons. In our photo, then, the breast-like items with their orange-rimmed openings are siphons. Water enters one siphon, food is filtered from it, and then is expelled from the other siphon. Most kinds of adult tunicates are permanently attached to rocks or other hard surfaces on the ocean floor, so our picture shows a species occupying a habitat unusual for the tunicates.

Paco wanted to show me something curious. He poked the side of a tunicate body, and a thin, clear stream of water shot a good ten inches (25cm) into the air. In fact, many tunicate species are known as sea squirts. When they feel threatened, they quickly reduce their size, and that requires getting rid of much of the water inside their bodies.

By doing a Google image search on the keywords "tunicate red mangrove roots" it was easy to identify our tunicate as the Mangrove Tunicate, ECTEINASCIDIA TURBINATA, found in warm, shallow waters of the Gulf of Mexico, including Florida, and the Caribbean. Seasonally, Mangrove Tunicates also turn up in the Mediterranean, and along the US coast they've been reported as far north as Chesapeake Bay.

A detailed description of the species' life history can be found on the Smithsonian Marine Station at Fort Pierce Mangrove Tunicate page at http://www.sms.si.edu/irlspec/Ectein_turbin.htm

*****

ANHINGA CLOSE-UP
On that same boat trip through the estuary of Río Lagartos Biosphere, we got to within a few feet of an Anhinga -- a cormorant-like bird that's a permanent resident in the Yucatan -- and were able to see details of the bird seldom noticed, shown at http://www.backyardnature.net/n/16/161106aa.jpg

Note the red eyes, and the yellow bill that narrows to a less-than-yellow, sharp tip. The bills of cormorants are conspicuously hooked. The back's zebra-stripes and the bold, white wingbar are handsome features also lacking on cormorants.

The intensity of the red eye color, the brightness of the yellow bill, and the whiteness of the neck, all vary, depending on the bird's age. After describing in mind-numbing detail the various color variations, Howell says that the species attains adult plumage by the "3d prebasic molt."

*****

MUSCOVY DUCKS
As soon as a visitor to the rancho pulls through the gate and gets out of the car, after dealing with the dogs barking and jumping around, attention often is drawn to a congenial gathering of ducks most likely taking siesta in the shade of an orange tree beside the chicken pen. You can see some of them at http://www.backyardnature.net/n/16/161106mv.jpg

These are Muscovy Ducks, CAIRINA MOSCHATA, and though most of ours are white or mostly so, in most populations they're predominantly black. Wild Muscovies, native from Mexico to South America, are entirely black, except that white wing patches show up when the birds fly. Ours are domesticated, and domesticated birds can display may colors and patterns: There are birds that are blue, bronze, chocolate, lavender, and they come in a variety of pastel colors, plus there are plumages with ripple and pied effects. In the back of our picture you see a couple of pied individuals.

Muscovies are members of an entirely different taxonomic "tribe" from Mallards, and so display several features not encountered among most other domesticated ducks. The feathers atop their heads can be raised into a kind of crest. Except that sometimes females deliver half-hearted quacks, normally the only sound they make is a hiss. Back on the farm in Kentucky we used to call them Whispering Ducks. Maybe their most noticeable physical feature is the red, fleshy region around their eyes and at the beak's base, shown handsomely at http://www.backyardnature.net/n/16/161106mw.jpg

Why do we have Muscovies here at the rancho? Besides the fact that they make a friendly presence and don't cause much trouble -- though sometimes they poop where you wish they wouldn't -- when they're not resting they're wandering around looking for food, which often consists of critters we'd rather not have -- flies, maggots, mosquitoes, and bugs and spiders of all sorts. Because of the livestock here we have big tick problems, and I'm sure I've seen them pecking ticks from the tips of grassblades along pathways. You can see one at work peeping beneath a leaf at http://www.backyardnature.net/n/16/161106mu.jpg

I've also seen them eating low-hanging Chaya leaves, and soft, new squash leaves, so I try to keep them out of the garden. I bet they'd enjoy the lettuce beds. The other day one of the rancho's cats killed a Social Flycatcher, leaving only a wing with its long primary feathers. A Muscovy came along, gobbled down the whole wing, spending a minute or so with the primaries poking from his beak, as the wing inched it way down the esophagus.

*****

PLANT BED FOR AN ARID CLIMATE
I arrived here just as the young engineer Carlos was leaving. One project he left undone consisted of a rectangular pit about 15 inches deep (40cm) with decaying, woody stems lined up next to one another on the pit's bottom, forming a kind of floor. I had to ask what it was for.

"The rotting wood is soft and spongy," I was told. "Once it's covered with dirt and things are planted atop the bed, the wood will hold water for the plants even as the soil all around dries out during the dry season."

That sounded like a good, workable idea to me, so I set about filling the pit with spongy, decaying, woody stems and tree trunks. I'm sure that someplace an expert has worked out how thick the layer of woody stems needs to be, how deep the soil should be piled atop it, and the proper procedure for doing it all, but I didn't have access to that, and just my own intuition on the matter.

The Maya fellows who did the labor for Carlos had made a very neat floor with straight stems of similar size, but many of the poles were bamboo. I didn't use bamboo because those stems are mostly hollow inside, so when the walls eventually decay and collapse, dirt above the bamboo would settle, and I didn't want that. I used regular bush and tree stems, including some leg-thick ones, just so they were so rotten that they were soft and spongy inside. Usually I could force my thumb into a stem, it was so soft.

After fmaking the pit's bottom layer about half a foot deep, I hosed water over the rotten wood, spread a thin layer of dirt atop that, and hosed it down, remembering that the whole idea is to establish a sponge-like reservoir for moisture. You can see the pit at the point when the bottom layer was half covered with dirt, and a wheelbarrow with more wood to add atop that stood at the pit's side, at http://www.backyardnature.net/n/16/161106er.jpg

A close-up of the decomposing wood in the wheelbarrow shows how the stems' bark is flaking off and in places the wood itself is crumbling away, at http://www.backyardnature.net/n/16/161106es.jpg

Then I spread another half-foot layer of pithy, crumbly wood atop that, hosed it down, and spread the remaining dirt that earlier had been shoveled from the pit atop it. You can see what the pit looked like after I'd covered about half the wood, at http://www.backyardnature.net/n/16/161106eq.jpg

We have other beds not containing decaying wood, and as our winter garden develops during the dry season, which is beginning about now, it'll be interesting to see if any differences become apparent.

*****

READING TOLSTOY
Each afternoon I bring out the Kindle and read from the 200 or so books I've downloaded for free from the Internet, mostly from the Project Gutenberg web site. This week I finished Tolstoy's novel Anna Karenina."

I'd read that novel before, back in my university days, but this second reading was different. Earlier, mostly I'd enjoyed the story line, and learning how people thought and lived in Russia during the story's time period. With this second reading, besides admiring the pure artistry Tolstoy displayed in bringing all his characters' stories together so nicely, mostly I was struck by how generous the author was to the people in his story.

His characters often had serious faults and sometimes behaved in ways we might not like, but each was treated with dignity, and one could see how a person might turn out behaving like that. Even the conflicting urges of a hunting dog were examined, a dog caught between his need to do what his nose told him to do, and the command of the master, who obviously couldn't smell the quarry just inches away.

This generosity of a great author's spirit is something I like to think about. For, in my experience, it seems that any true genius clearly sees the world's irrationality, and people's hypocrisies, self deceptions and hurtful behaviors, but also he or she understands that such weaknesses and flaws usually are the consequences of past misfortunes, of present difficulties, of an unfortunate genetic predisposition, or maybe they are as they are because that's just how personalities form, with some features maturing faster than others, or maybe never maturing at all.

A pretty feature of this line of thinking is that it seems to apply to much more than just the human condition. For example, it seems to apply to the whole Universe.

In terms of the Universe, the genius with the generous spirit is the Universal Creative Impulse responsible for the Universe in the first place. This Universal Creative Impulse, like Tolstoy, artfully creates a reality that on the one hand is a tempestuously gorgeous blossoming of a hugely diverse community of diverse actors, while on the other hand the Universe's story line is complicated by such features as galaxies disappearing into black holes, wandering asteroids that bump into things and, closer to home, diseases, extinctions, and the outrageous fact that thinking, sentient beings often fail to live up to their potentials.

In that context, the Universal Creative Impulse's generosity of spirit is affirmed whenever a mind that is part of the blossoming Universe takes stock of its situation, judges the whole setup as beautiful, and decides to live on a little longer.

*****

Best wishes to all Newsletter readers,

Jim

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