May 17, 2015

BANDING YUCATAN WRENS
On Wednesday a visiting scientist from Cuba, Anay, was in the area capturing and banding Yucatan Wrens. Yucatan Wrens attract researchers because they're so narrowly endemic -- in the whole world found only in a narrow band of arid scrub habitat along the Yucatan Peninsula's northern coast. My friend and student Rayo and I volunteered to help. You can see Rayo and Anay removing a wren from the mist net strung between two poles in the parched, mostly leafless, late-dry-season scrub at https://www.backyardnature.net/n/15/150517bb.jpg

Walking down a little trail through the scrub we'd locate wrens by their distinctive, funny-sounding call, "ch-hor k-k wohrk, eh-hor k-k wohrk... " as Steve Howell interprets it. The net would be erected in any small clearing Anay thought the birds probably were accustomed to flying through, a recording of Yucatan Wrens calling was set going next to the net, we'd step away and watch, and within ten or fifteen minutes normally a couple of birds, presumably a pair, would fly into the hard-to-see net and get entangled. Anay would drop each bird into a bag, carry it to her study spot, and analyze it. You can see Anay at work surrounded by her equipment at https://www.backyardnature.net/n/15/150517bc.jpg.

The birds were weighed, and measurements made of several parts, from beak length to toenail length. A feather was removed from each bird's tail and a tiny amount of blood taken for genetic studies to be done later. Since male and female Yucatan Wren's are practically indistinguishable, later each bird's gender would be determined with certainty by looking at chromosomes in the blood samples. Then colored bands were clamped onto the legs.

Once all the measurements and pictures were taken, the birds were released with thanks and good wishes.

*****

MAGNIFICENT FRIGATEBIRD BASKING
On flamingo-watching boat trips up the estuary it's normal to see cormorants, Anhingas and other birds facing the sun while spreading their wings. None of these sun baskers looks weirder than the Magnificent Frigatebirds, who seem somehow to shift their long, slender, bent wings to the back of their bodies, giving them an eerie, un-birdlike appearance, as shown at https://www.backyardnature.net/n/15/150517fg.jpg.

*****

MEXICAN PONYTAIL FLOWERING
These days at the dry season's end are the hottest, driest of the year for us. I'm grateful to be on the coast where nice breezes off the Gulf begin stirring in early morning, and by afternoon can raise white caps on the estuary. The wind feels good, and imparts to the landscape a wild, hard, edgy feeling, a kind of nervous tension that keeps one alert. Especially out in the dry scrub or thornforest south of town the wind howls, tree branches gyrate, and the occasional tall cactuses and Mexican Ponytails suggest ragged giants laughing in the wind. You can see a Mexican Ponytail, BEAUCARNEA PLIABILIS -- but remember that the blades of its grass skirts convulse and the wind whistles around its stiff stems -- at https://www.backyardnature.net/n/15/150517mx.jpg.

I first learned about Mexican Ponytails back in 1972 when I bought a potted one at the Missouri Botanical Garden, where I'd just taken a job. It was about two feet high then but years later it reached the ceiling. Its stem remained unbranched, but you can the big ones around here branch freely. The reason I've waited until now to feature our wild Mexican Ponytails is that now they're flowering. A close-up of a diffuse panicle-type flower cluster, or inflorescence, is shown at https://www.backyardnature.net/n/15/150517my.jpg.

I assume that that inflorescence bears or bore only small male flowers, for other plants nearby bore dense panicles heavy with fruits, as seen at https://www.backyardnature.net/n/15/150517mz.jpg.

Up close the fruits showed themselves to be three-cornered, with each corner bearing a papery "wing" that eventually will help with wind dissemination, as you can see at https://www.backyardnature.net/n/15/150517mv.jpg.

Other names for Mexican Ponytail are Ponytail Palm, Red Ponytail Palm, and Bottle Palm, which miss the point that Mexican Ponytail is not the least a palm -- not a member of the Palm Family. In Spanish its main name is Despeinada, which means "un-combed" or, more loosely translated, "Shaggy-head," and that may be the best common name.

If Mexican Ponytails aren't palms, what are they? Taxonomists still disagree about that, having shifted them between a variety of families in and around the Lily Family branch of the Phylogenetic Tree of Life. Currently the trend is toward the Asparagus Family, the Asparagaceae, but some retain it in the Nolinoideae, which used to be the Ruscaceae, and in the old days they were all part of the Lily Family, so who knows? But they're not palms.

In fact they are just a distinctive and character-imparting member of the thornforest vegetation here, and a species unlike anything else here. When its long leaves swoosh in the hot, fitful afternoon wind beneath such a bright sky, it feels good just to see it being itself.

*****

GUMBO-LIMBO/ CHAKAH FLOWERING
The Gumbo-Limbo, locally called Chakah and technically BURSERA SIMARUBA, is one of the most commonly encountered trees in humid, tropical Mexico. Our Gumbo-Limbo page is at https://www.backyardnature.net/mexnat/gumbo.htm.

Now at the very hot, dry end of the rainy season, Gumbo-Limbos are among the trees issuing flowers despite the continued absence of rain, possibly with the strategy of having ripe fruits ready for dissemination when the rains do return -- which is any time. The Gumbo-Limbo's flowering is eye-catchingly prodigious, as shown at https://www.backyardnature.net/n/15/150517gl.jpg.

Though the tree's amassed flowers can be seen from afar, the individual blossoms are small, but tightly clustered in spike-like, panicle-type inflorescences, as seen at https://www.backyardnature.net/n/15/150517gm.jpg.

In the above photo you see that the season's fresh-looking, compound leaves also are emerging, and you wonder how a tree can be issuing such lushness while rooted in powdery-dry soil and daily having blisteringly hot air gush around it.

In our last Newsletter we found ants abounding among Black Mangrove flowers. Then we quoted researcher V. Rico-Gray's statement that "... during the dry season in coastal Yucatan, ants will rely on the nectar produced on the flowers and other reproductive structures as their main liquid energy source." Supporting this observation, now we find Gumbo-Limbo flowers crawling with ants, shown at https://www.backyardnature.net/n/15/150517gn.jpg.

Not until the above flowers were looked at under magnification was it apparent that the blossoms' male stamens were robust but no female parts were in evidence. Seeing that, I got curious and learned that Gumbo-Limbos are "dioecious" (male and female flowers on separate plants) or "polygamodioecious" (having bisexual and male flowers on some plants, and bisexual and female flowers on others). Bisexual flowers are those with functioning male and female parts in the same blossom. Gumbo-Limbos, then, produce three kinds of flowers: strictly male ones; strictly female ones, and; bisexual ones. Bisexual flowers also are known as "perfect" and "hermaphroditic."

Learning this, I went out looking for Gumbo-Limbos with more developed female parts. It was easy to find a tree bearing the flowers shown at https://www.backyardnature.net/n/15/150517go.jpg.

The green, spherical items are ovaries, the future fruits, which were absent in the previous photo. Since both male and female parts in these flowers are well developed, I'm assuming that they're bisexual blossoms.

After examining about 20 flowering Gumbo-Limbos, I find that about three out of four trees bear nothing but male flowers, with the remaining blossoms being bisexual. No flowers that I judged as strictly female were encountered. This skewed distribution of flower types was intriguing. Why so many males? Is it always like this, or only when we're having an especially dry, hot dry season? Most trees examined were small, on very thin limestone so could it have been that very young trees only produced male flowers? I'd failed to notice that. Would the same flower-type distribution appear if we'd been having plenty of rain?

What a nice research project this would make.

Whatever the case with the Gumbo-Limbo's sexuality, ants sure benefit from its generous supply of nectar, and I benefit from seeing the trees' confidence that soon the rains will return.

*****

SALT HELIOTROPE
Along Río Lagartos's sidewalks, in abandoned lots, at the base of buildings, along streets and the road through the mangroves to town, nowadays a very common herb draws attention to itself because it's one of few herbaceous plants flowering during these super-dry, super-hot, end-of-dry-season days. One is shown leaning over the open gutter of a street at the edge of town at https://www.backyardnature.net/n/15/150517he.jpg.

You can see the inflorescence's curling-under rachis bearing flowers on just one side at https://www.backyardnature.net/n/15/150517hf.jpg.

A peep into a flower's throat showing brownish, triangular, pollen-producing anthers atop short filaments attached to the corolla tube's wall is shown at https://www.backyardnature.net/n/15/150517hg.jpg.

Seeing the curling-under rachis with tiny, bell-shaped flowers arising only on one side, with the oldest flowers at the rachis's base, I could guess that this was a species of heliotrope. That's because the 300 or so species of the genus Heliotropium are configured exactly like this, though their colors can range from white through the violet hues to dark purple.

Heliotropes are members of the Borage or Forget-Me-Not Family, the Boraginaceae, a family embracing about 3000 species worldwide, and producing many garden favorites. Despite there being maybe 300 heliotrope species, our sidewalk plants were easy to identify simply because they were completely hairless (glabrous) and their green parts displayed a slightly glossy, silvery bloom, a condition known as being "glaucous."

In our part of the world, if you're a glabrous, glaucous heliotrope, you're HELIOTROPIUM CURASSAVICUM, known to occur mostly along coastlines and other salty spots in warm regions nearly worldwide. Its predisposition for salty soil earns it common names such as Salt Heliotrope and Seaside Heliotrope. It's native to the tropical and subtropical Americas, though it weedy tendency enables it to pop up in inland places where it's not expected.

In our area it seems to flower year round. Being such a full-time bloomer and capable of enduring hot, dry and salty conditions, it's a natural for planting where people are wisely abandoning their grassy lawns in favor of greenery needing little water. In some places it's called Quail Plant because ground birds feed on its fruits.

*****

WHITE-MOUTH DAYFLOWER
Twining up through a chain link fence along the main road through town a little dayflower was blooming, as shown at https://www.backyardnature.net/n/15/150517cm.jpg.

A close-up the above flower is shown at https://www.backyardnature.net/n/15/150517cn.jpg.

Dayflowers -- genus Commelina of the Spiderwort Family, the Commelinaceae -- are common weeds and wildflowers, and there's a lot of them, about 170 species, some of which are common weeds. They're called dayflowers because theoretically their blossoms last for only a day. You know you have a dayflower because the flower structure is so unusual and constant throughout the genus. The flower normally consists of three petals of which the top two are much larger than the lower one, and often are on little stems, or "claws." The flowers arise from a large, green bract, or modified leaf, usually shaped like a squeezed-together, cone-shaped paper cup. Along with the flower cluster's currently blossoming flower, the cup-like bract normally holds several immature flower buds and already-flowered maturing fruits.

During our travels we've run into several dayflower species and I thought that this was a new one. However, it turned out to be the same species often encountered farther south, just that the top two petals of those usually are whitish. You can the whitish form at https://www.backyardnature.net/yucatan/dayflowr.htm.

This is COMMELINA ERECTA, often known as the White-mouth Dayflower, because the lower petal is white and conspicuous. In many dayflower species the lower petal is bluish, smaller or even missing. Commelina erecta is considered to be the most variable species of dayflower in North America, but that large, white, lower petal is constant. The species is native to much of the world, including the Americas, Africa and western Asia. Often it grows as a weed, albeit it one with an especially delicate and pretty flower, if you take the time to look at it.

*****

DRYMONIA GESNERID
During the last week of April I camped in the mountain-top hydrological reserve above and to the north of San Andrés Tuxtla, Veracruz, Mexico. Our page describing that reserve and showing a satellite view of the entire region is at https://www.backyardnature.net/mexnat/tuxtla.htm.

In the cloud forest atop the mountain, plants were adapted to moist, windless, never-too-cold conditions, and for struggling to get what little light was available. One plant family producing many species able to deal with such conditions is the African Violet or Gesneria Family, the Gesneriaceae. Members of the family often are referred to as "gesneriads." Despite the family being a big one, no gesneriads appear in the vast Flora of North America, and none is listed for the arid northern Yucatan Peninsula, because gesneriads simply can't deal with the cold. Most gesneriads are soft-bodied, hairy and produce fleshy, colorful flowers.

A sunlight-groping, slender shrub-gesneriad that almost was a vine the way it went up a tree and leaned into an open spot is shown at https://www.backyardnature.net/n/15/150517dr.jpg.

This plant's flowers absolutely exploded with pinkness in their little patch of sunlight. Actually the pinkness was produced by the flowers' oversized bracts, or modified leaves, with the fuzzy, tubular flowers being a bright yellow, as shown in a flash-assisted close-up at https://www.backyardnature.net/n/15/150517ds.jpg.

By consulting pictures of every member of the African Violet Family known to occur in the hydrological reserve, the plant revealed itself as DRYMONIA STRIGOSA, which doesn't seem to have an English name. The species occupies moist, shaded habitats from southern Mexico to southern Central America. The genus embraces over a hundred species, many of which are cultivated indoors for their prettiness

Not much information is known about this pretty species in the wild, but gardeners who specialize in growing gesneriads regard Drymonia strigosa as easy to grow, easily producing seed in an orange fruit. Among gesneriad-growing gardeners it's regarded as "a good starter Drymonia" that's relatively easy to find on sale.

You might enjoy scanning a page of many cultivated Drymonia species at a website just for gesneriad growers, at http://www.gesneriads.ca/gendrymo.htm.

*****

COLUMNEA GESNERIAD
Another gesneriad, or member of the African Violet Family, the Gesneriaceae, flowering in the mountain-top cloud forest of the hydrological reserve above and to the north of San Andrés Tuxtla, Veracruz, Mexico was the one shown at https://www.backyardnature.net/n/15/150517co.jpg.

Though growing on a tree epiphytically, this soft-woody plant wasn't a parasite on its host tree, but rather just grew there like the moss, lichens, orchids and bromeliads also populating tree trunks in this moist, shady environment. A close-up of one of the plant's interesting flowers appears at https://www.backyardnature.net/n/15/150517cp.jpg.

This blossom nicely displays characteristic features of gesneriad flowers: The corolla's lobes unite into a tube at its base; the corolla is bilaterally symmetrical, or two-lipped; the four stamens are attached to the corolla (they're "epipetalous"), and; the stamens are of two lengths (they're "didynamous"). The corolla's hairiness and bright color also are typical.

This is COLUMNEA PURPUSII, with no good English name. Not much information is known about it. From what I can see it's endemic to moist tropical forests just to the southern Mexico states of Veracruz, Oaxaca and Chiapas.

Though this species is not well documented, the genus Columnea is well known because it embraces about 200 species of the tropical Americas, many of which are popular ornamentals. The species are epiphytic and tend to trail, as ours is, scrambling over the tree trunk. You might enjoy browsing some of the Columnea species profiled at http://www.gesneriads.ca/gencolum.htm.

*****

PICTOGRAMS ON BIOSPHERE SIGNS
At pretty Petén Tucha deep in the mangroves a few kilometers along the coastal road west of Río Lagartos, the Mexican agency responsible for administering Ría Lagartos Biosphere Reserve, CONANP (Comisión Nacional de Áreas Naturales Protegidas), has erected a sign advising visitors that they shouldn't swim in the pond's clear, inviting water because of crocodiles. For those who can't read Spanish, a sign expresses the prohibition with a pictogram, as shown at https://www.backyardnature.net/n/15/150517si.jpg.

Pictograms at the sign's bottom also tell us that no fishing is allowed in the pond, and that we shouldn't throw trash such as bottles into it. These bottom ones are fairly easy to interpret, but the main one symbolically portraying someone being swallowed by a crocodile borders on abstraction, and one is drawn to analyze it as if it hang on the wall at the Met. Why does the crocodile seem to bear a crest? What does that yellow blob at the lower right represent?

At the sign's bottom, the symbol for CONANP itself -- the round thing with a white middle looking like a snail with tiny shell -- borders on the uninterpretable. I think the white part is Mexico, Baja California on the left and the Yucatan on the Right, with the blue Pacific below but, is that a brown, ambiguous, miniaturized North America at the top? Also at the sign's bottom are a stylized red flamingo and a yellow sun happily issuing sunbeams for us all. Seeing this sign so busy with artwork, one gets the impression that someone at CONANP loves fiddling with symbols, and maybe the symbols are worth paying attention to.

In fact, once you're into these signs, you start looking for the sign-artist's more spectacular leaps into fantasy. For example, along a road through the mangroves, there's the sign shown at https://www.backyardnature.net/n/15/150517sj.jpg.

That's a crocodile-crossing sign, but while they're at it they also tell us that the area is policed, and that we shouldn't shoot the wildlife or throw trash onto the ground, but that we should enjoy the nearby beach and river. However, that symbol at the top, right needed some cogitation. The red bar indicates that we're not supposed to do something. Eventually I decided that the two, hardly visible, dark-blue stars are fireworks and that the yellow wrench-tip-like-thing is a hand, so the message is "No Fireworks," I think. One's first impression is that this pictograph verges on failure, but then you wonder how else one might convey in symbols simple enough for woodworkers to carve into wood and paint with a palate of limited colors that no fireworks are allowed?

Farther up the road, a sign declaring limited access to the Biosphere's Nuclear Zone #2 offers another pictograph exhibition, as seen at https://www.backyardnature.net/n/15/150517sl.jpg.

"No burning," "No building," "no leaving trash," and "no chopping down trees," the pictographs say. I think the one at the lower, left means "No machete-hacking of the undergrowth," but I puzzle over the one at the left of the word ZONA. Maybe those white things are flowers, so "Don't pick the flowers," maybe, though the white things really look more like cat footprints.

Yet farther up the road another sign appears, shown at https://www.backyardnature.net/n/15/150517sk.jpg.

It warns us of the danger of fires, with the added admonitions that we shouldn't make campfires (I think), shoot wildlife, or cut trees, but that we should cherish our trees and... what?

That sign bears two symbols, both on the sign's right side, top and bottom, that I can only guess about. In some parts of the Yucatan the soil is so thin or absent that folks rob soil and carry it home, so maybe the top, right one means "Don't steal the dirt." However, that one at the bottom, right, appearing to be a bird atop two fish leaping from the water and kissing, just stymies me, unless it simply means "Enjoy the birds and fish."

On certain big signs the symbols are larger, so the artist has more freedom to add detail. On one such big sign the above above "kissing fish" symbol has more detail but only grows more mysterious, as shown at https://www.backyardnature.net/n/15/150517sm.jpg.

The larger CONANP symbol on the left clarifies itself, though. What previously seemed a depauperate North America now resolves into what is surely an angel with wings spread benevolently over Mexico. The oceans are more clearly oceans there, and it certain that Central America just isn't there.

But, that fish-kissing one... Any ideas, anyone?

*****

WAITING FOR THE RAINS
Over the years at this late-dry-season time often I've written about the special feeling of dealing with the long, hot, dry days preceding the rainy season's first rains, so you've heard enough about it from me. One of those essays is at https://www.backyardnature.net/n/p/110529.htm.

I'm not the only one here who feels the season poignantly. This week Katherine, who lives well inland where our sea breezes don't penetrate and the stunning heat and sun glare bear down even more aggressively than here, wrote that now...

"... Begins the period of waiting, longing, pining, scrutinizing the skies .... for the rains, not just from the human perception, but one can feel the whole earth and creation on hold.... waiting.............The big wait, I call it. It's tough, but if one can see it through what a delicious joy when the rains finally come. I love that moment and am prepared to suffer for it!"

She added, "When the occasional heavy dark cloud with rain drifts over these days and the strong smell of it becomes almost something tangible, one can hear the earth calling to it, trying to pull it down like a magnet ... soon, soon promises the cloud, just a little more patience ... when there are more of us we will heed your call."

This amazing heat, glare and dryness makes all of us down here a little edgy, maybe a little crazy, makes sweaty philosophers of us all.

*****

FEATURED ESSAYS FROM THE PAST:

"Colors & The Human Spirit" from the November 8, 2005 Newsletter, at https://www.backyardnature.net/n/p/051108.htm

"Corn, Hibiscus & Nuclear Waste" from the January 26, 2007 Newsletter, at https://www.backyardnature.net/n/p/070126.htm

*****

Best wishes to all Newsletter readers,

Jim

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