JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from the valley of the Dry Frio River on the
southern slope of the Edwards Plateau, northern
Uvalde County, southwestern Texas, USA

April 7, 2013

BROWN CRESTED FLYCATCHERS' "Ha-WHEER"
All winter the hillside where we're building the Nature Education Center has been fairly quiet but this week often the tranquility was punctuated by certain persistent, sharp, somewhat shrill birdcalls. "Ha-WHEER," the birds said again and again, the "wheer" part a little trembly. This is OK with me because the species doing the calling is a summer visitor, and I'm ready for summer.

At first I thought it was the Great Crested Flycatcher so commonly encountered in eastern North America, but the song was a little lower pitched than the Great Crested's. Finally I remembered that now we're in southwestern Texas, plus sometimes this pair of birds broke into "WEEP, WEEP, WEEP" calls exactly like those that for the last several winters in the Yucatan I heard all around my hut. In the Yucatan the call was made by Brown-crested Flycatchers, which are very closely related and looking very much like Great Crested Flycatchers, and we have Brown-cresteds here, too. One early evening this week I snapped the picture of one of the callers, as you can see at http://www.backyardnature.net/n/13/130407fl.jpg.

The light was so dim that the background had to be overexposed in order to reveal the bird's patterns and colors, but at least now we can see important field marks.

First, in southwestern Texas we have three flycatcher species looking very much like this, all listed as uncommon in Michael Overton's Birds of Uvalde County, Texas, downloadable for free in PDF format at http://www.visituvalde.com/media/docs/birds-of-uvalde-county.pdf.

Those three look-alike species are the Brown-crested, Great Crested and Ash-throated Flycatchers. The lower mandible of the Great Crested's beak is light brown but in our picture the entire beak looks blackish, so that's a vote for the Brown-crested. Also, the Great Crested's gray chest changes fairly abruptly to vibrant yellow on the belly, but you can see that on our bird the transition is gradual and the yellow belly is not intensely yellow, so there's another vote for the Brown-crested.

The Ash-throated Flycatcher is smaller than the other two species -- 6½ inches long to the Great-crested's 7¼ inches. In the field it can be hard to judge size, however. Visually maybe the best field mark for the Ash-throated Flycatcher is its bill, which is more slender in shape than the other species' -- more slender than the bird in the picture, to my estimation. Probably the best distinguishing feature of the Ash-throated is the call. The Ash-throated sounds more like a Western Kingbird than the look-alike Great-crested and Brown-crested Flycatchers.

You might like to see better pictures we've taken of Brown-crested Flycatchers in the Yucatan at http://www.backyardnature.net/yucatan/myiarchu.htm.

Brown-crested Flycatchers visit the US only during the northern summer, when they occur here in southern Texas, southern Arizona, and spottily in southern California and New Mexico. They overwinter from Mexico to northwestern Costa Rica, as well as in South America from Colombia to northern Argentina.

These are fairly large birds and they like to eat cicadas, especially silent female cicadas heavy with eggs. The male cicada's loud buzzing when it's captured by a bird seems to disconcert Brown-crested Flycatchers, because often they release their pray when the buzzing begins.

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LINCOLN'S SPARROW
Once more below the kitchen window little brown sparrows with striped backs were hopping about pecking at sow thistle fruits, and once more the birds didn't look like the usual Chipping Sparrows. You can see one displaying the conspicuous dark spot on his chest at http://www.backyardnature.net/n/13/130407ss.jpg.

A rear view of the same bird showing his striped back is at http://www.backyardnature.net/n/13/130407st.jpg.

Not many sparrow species with streaked chests display such a conspicuous dark spot in the chest's center. Fox Sparrows do but they're more rusty-red overall. The spot suggested that this was probably a Song Sparrow, even though it didn't quite look like the ones I know so well from Kentucky, Mississippi and the West Coast. However, I remembered that Song Sparrows occupy many habitats over a large distribution area from coast to coast in North America, and that consequently 24 subspecies have been recognized -- or 31, 39 or some other number, depending on your expert. Song Sparrows are one of the most regionally variable birds in North America. In general, coastal and northern birds are darker and streakier, while southern and desert birds look paler. These birds outside my window stuck me as being less streaked than what I'm used to.

So, at first I was pretty sure that I had a Song Sparrow, but after I showed the picture around and heard from others knowing this area's birds better than I, I had to change my opinion. It's the Lincoln's Sparrow, MELOSPIZA LINCOLNII; I'm fairly sure now, though it's a tough call.

Often Lincoln Sparrows don't have dark chest spots, but all the ones below my window do. However, from what I can tell, none of the several Song Sparrow subspecies and races display "buffy" chest bands through which the stripes run, as seen on our bird. Song Sparrow chest stripes cross white or only slightly dingy chests, not chests with such warm colors as on ours.

In general, the chest streaking on Lincoln Sparrows also is finer than on Song Sparrow.

Lincoln Sparrows are thought of as one of those species you see only when they pop up from the grass, fly quickly a little distance, then plunge back into the grass where they remain invisible as you fumble with your binoculars. But here they were below my kitchen window feeding on sow thistle seeds.

However, they won't be staying long. Lincoln Sparrows occur in Texas and much of the southwestern and south-central US only during the winter. They nest mostly in Canada and the northwestern US.

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SPHINX MOTHS BENEATH SECURITY LIGHTS
During recent early mornings big, brown moths have been turning up under security lamps that have shined all night. The moths are found still alive but unmoving, maybe having exhausted their energy flying around and around the light all night. You can see one at a neighbor's place at http://www.backyardnature.net/n/13/130407mq.jpg.

This is a sizable moth with a wingspan of about 4½ inches (11.4cm). The head area reminds me of that of a hairy bat's, as shown at http://www.backyardnature.net/n/13/130407mp.jpg.

Once volunteer identifier Bea in Ontario had named it for me, I began thinking that maybe instead of a bat's head it looks more like the front end of the Sphinx, for this is a sphinx moth, the Istar Sphinx, LINTNERIA ISTAR, found from southern Arizona to here in southern Texas, through Mexico into Guatemala. The literature I find says it lives in pike-oak woodlands in the mountains, but here we have juniper-oak woodlands, and instead of mountains we have only fairly modest hills, so maybe here we're adding to the knowledge base about this moth.

At first the moth was so immobile that I thought it might be dead, but after I nudged it with a finger it fluttered briefly and came to rest with its wings spread, revealing bold markings on its hind wings, seen at http://www.backyardnature.net/n/13/130407mo.jpg.

I read that Istar Sphinx larvae feed on various members of the Mint Family, which sounds right because here we have plenty of mint species, such as the Scarlet Sage so common on our wooded slopes, and the field of Basil Beebalm next to the cabin.

Istar females lure night-flying males by issuing pheromones from a scent gland at their rear ends.

*****

MEXICAN BUCKEYES FLOWERING
On ravine slopes and just below limestone ledges adjacent to the Frio River in northern Uvalde County at first glance the small trees opulently abloom with pink blossoms seemed to be eastern North America's Redbud trees, or maybe escaped peach trees, but up close it was clear that they were something else, as shown at http://www.backyardnature.net/n/13/130407gn.jpg.

The tree's leaves were alternate (one leaf per stem node) and pinnately compound, looking a lot like hickory or walnut leaves. However, the asymmetrical flowers with five pink petals and a mess of hard-to-interpret anatomy in their center were completely different from any hickory or walnut flower, as you can see in the blossom close-up at http://www.backyardnature.net/n/13/130407go.jpg.

As I photographed the very unusual, inch-broad (2.5cm) blossoms, Fred pointed out some old fruit pods still hanging on some of the trees' outer branches, such as the ones shown at http://www.backyardnature.net/n/13/130407gp.jpg.

These capsular-type fruits have split to release one large seed from each of three large compartments.

In most of North America there's simply nothing like this. Fruiting capsules with three compartments and asymmetrical or "zygomorphic" flowers immediately bring to mind the Euphorbia Family, but when I checked out all the species in that family found in Texas, there was nothing like it.

Eventually, though, the little trees gave up their identities. They were Mexican Buckeyes, UNGNADIA SPECIOSA, members of the Soapberry Family, the Sapindaceae, a family mostly restricted to the tropics and subtropics. Soapberry Family species North American plant lovers might know include the Goldenrain-Tree, Litchi Tree, and the Heart-Seed Vine, Cardiospermum. Mexican Buckeyes occur very spottily throughout southern Texas, extreme southern New Mexico, and arid northeastern Mexico. Though Mexican Buckeyes belong to a different genus than North America's buckeye species, both are members of the same family. You might note, however, that the North's buckeyes bear opposite, digitately compound leaves, while Mexican Buckeyes have alternate, pinnately (featherlike) compound leaves.

In our flower picture it's easy to recognize the five rose-purple petals, as well as the eight or nine well formed stamens with their dark, baglike anthers splitting open and releasing pale pollen grains, atop long, slender, curving, pinkish filaments. One curious thing about the stamens is that their number of eight or nine per blossom is unusual -- "normal" flowers bear 3, 4, or 5 or multiples thereof -- plus their filaments are of varying lengths. Moreover, some of the whitish items clustering about the stamens' bases look like ill-formed, undeveloped stamens, some with dark anthers not producing pollen. In fact that's what the white things are -- sterile, undeveloped stamens, and that's natural for Ungnadia. Maybe they provide a foothold for pollinators.

Mexican Buckeyes are such unusual plants that they are the only species in their genus.

In the past, Mexican Buckeye's sweetish but poisonous seeds were sometimes used by children as marbles. Livestock usually know better than to browse the tree's toxic foliage. Bees produce fragrant honey from the flowers.

In northeastern Mexico in caves occupied by people as far back as 8000 years, remnants of Mexican Buckeye have been found associated with hallucinogenic Peyote and Mescalbean remains, so it's assumed that the species' toxic seeds were used in certain rituals.

The small tree's genus name, Ungnadia, commemorates Baron Ferdinand von Ungnad, Austrian ambassador at Constantinople, who introduced the related Horsechestnut into western Europe in 1576.

*****

SPRING'S FIRST FLOWERING PRICKLYPEARS
In thin, dry soil atop a limestone hill along the Frio River in northern Uvalde County, spring's first flowering pricklypear cactus has appeared, as shown at http://www.backyardnature.net/n/13/130407pp.jpg.

This was a wonderful find, not only because it's always a pleasure to see a robust plant at its flowering peak, but also because ever since I arrived I've been wondering if all the pricklypear cacti occurring in a wide variety of habitats here are the same adaptable species, or different species that can be distinguished only when flowers and/or fruits are available. The moment I saw this plant, despite its close similarity to other non-flowering ones in the valley below, I was pretty sure it was a different species.

For one thing, despite this cactus's abundant flowers, pricklypears on hill lower slopes and in the valley don't even have well developed flower buds yet. Also: the individual green pads of this hilltop cactus seem slightly smaller than pads on cacti down below; the spots from which spines arise (areoles) are darker and closer together; the spines show less of a tendency to point downward than on the valley species, and; the spines themselves are dark but pale tipped, while most other cacti in our area produce yellowish spines. Also, notice than the blossoms in our picture range from pure yellow to pale pink. Flowers on the valley species don't do that.

A close-up of a typical blossom appears at http://www.backyardnature.net/n/13/130407po.jpg.

A side view of flowers showing some pinkness is at http://www.backyardnature.net/n/13/130407pn.jpg.

You can see that only one or two spines arise from most areoles, and that the spines themselves are black-brown at their bases but whitish at their tips at http://www.backyardnature.net/n/13/130407pm.jpg.

Fortunately, the Cactus Family is treated in the online Flora of North America, so by "keying in" the above and other field marks I identified our hilltop cactus as OPUNTIA ATRISPINA, a species of such limited, narrowly endemic distribution that really it has no commonly accepted English name, though in the literature authors have made up names for it, such as the Border Pricklypear, Dark-spined Pricklypear, and Black and Yellow-spined Pricklypear.

So, this is a great find,a species known to occur naturally -- in the whole world -- only here in Uvalde County and two or three counties west of here, and a little bit of extreme northeastern Mexico.

*****

ROSE MALLOW FLOWERING
In a deeply shaded, somewhat weedy spot beneath trees on a low ledge next to the Frio River there was such a large, bright spot of gaudy pinkness that at first I didn't look at it, thinking it must be somebody's trash. But Fred did look closely, and he called me back to see the pretty flower, which you can see at http://www.backyardnature.net/n/13/130407pv.jpg.

A close look at the 1½-inch-wide (4cm) blossom's center instantly told me which family the plant belonged to. See if you can figure it out at http://www.backyardnature.net/n/13/130407pw.jpg.

With so many yellow, pollen-producing anthers atop slender, pale filaments that join at their bases into a cylinder surrounding the extended female parts, what could it be but a member of the enormous Hibiscus Family? It's not a hibiscus itself, however, because the pale column arising from the corolla's center is slightly askew relative to the corolla disc, which is something hibiscus flowers don't do. Also, the flower's ten stigmas issuing above the clustered stamens are asymmetrically grouped, as are the stamens themselves. There's even one stamen arising at the base of the column.

These and other field marks identify this as a Rose Mallow, also commonly known as Rock Rosemallow, Texas Rockrose, Texas Swampmallow, Wright Pavonia, and other similar names. It's PAVONIA LASIOPETALA, endemic to just a few counties along the southern edge of the Edwards Plateau in southern Texas, and across the border into northern Mexico. Its habitat is described as rocky woods and slopes on shallow, dry soil atop limestone.

Rose Mallow, despite being of such limited natural distribution, is so pretty and long flowering -- throughout nearly all the warmer months -- that often it's offered at nurseries and grown in gardens, with one of its virtues being that it's extremely drought tolerant.

*****

HAIRY TUBETONGUE
Just a few feet from the Rose Mallow, in the same shade beneath trees and surrounded by grass and weeds on a low cliff next to the Frio River, a three-inch-tall (8cm) wildflower with a single two-lipped, purple, inch-long (2.5cm) flower was blossoming, as shown at http://www.backyardnature.net/n/13/130407tt.jpg.

A view of the flower from above, showing its long, hairy corolla tube, is at http://www.backyardnature.net/n/13/130407tu.jpg.

With that two-lipped corolla producing only two stamens, and the cluster of leaflike "bracts" at the flower's base, this flower reminded me of members of the Acanthus Family we've seen recently in the Yucatan. That helped me identify the pretty little thing as the Hairy Tubetongue, sometimes called Gregg's Tubetongue and even False Honeysuckle. It's JUSTICIA PILOSELLA, earlier placed in the genus Siphonoglossa, and truly it's a member of the big, mostly tropical Acanthus Family, the Acanthaceae.

Hairy Tubetongue is endemic just to southern Texas, a small part of southern New Mexico, and arid northeastern Mexico. Despite its limited distribution, however, some garden centers sell it as a wildflower that thrives in dry, shaded soil as well as in wetland gardens. It blooms during nearly all the warm months, from now into October.

With that flower shape it's easy to believe reports that Hairy Tubetongue attracts butterflies.

*****

SLENDER FALSE PENNYROYAL
All two-lipped wildflowers with only two stamens are not members of the Acanthus Family, however. If the stem is square, two leaves arise at each stem node, and the two-lipped blossoms with two stamens arise above a deeply four-lobed ovary, the best bet is that it's a member of the Mint Family. That was the case with the delicate, five-inch tall (12cm) herb found flowering among limestone cobbles strewn by floodwaters into a low terrace alongside the little Dry Frio River, as shown at http://www.backyardnature.net/n/13/130407hd.jpg.

A close-up of a hairy, 5/16ths-inch (8mm) long, pink corolla is at http://www.backyardnature.net/n/13/130407he.jpg.

When you recognize a plant as a member of the Mint Family you can't keep yourself from pinching a tiny bit of leaf to see what it smells like. Sometimes you're rewarded with a nice "minty" odor but other times the smell is bad, or there's no odor at all. In this plant's case, the odor was deliciously minty.

Here we have what's sometimes called the Slender False Pennyroyal, HEDEOMA ACINOIDES, a species endemic just to arid northeastern Mexico, a bit of Oklahoma, and Texas. In Texas it's most common in our area, which is the southern border of the Edwards Plateau.

Those of you familiar with eastern North America's American Pennyroyal, Hedeoma pulegioides (thus in the same Mint Family genus, Hedeoma, will find it easy to believe that our cobblestone-growing Slender False Pennyroyal is deliciously fragrant. In fact, I read that sometimes this annual mint is gathered for mint tea. I'm sure that it's a fine tea, but the plant is so pretty and, at least in this area, so uncommonly encountered, that it would be a shame to pick such a plant just for making tea.

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FEATURED ESSAYS FROM THE PAST:

"Barn Swallows & Beethoven," from the July 20, 2003 Newsletter, at http://www.backyardnature.net/n/p/030720.htm.

"Moments of Perfection," from the April 14, 2002 Newsletter, at http://www.backyardnature.net/n/p/020414.htm.

*****

Best wishes to all Newsletter readers,

Jim

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

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