The Biodiversity of the Rio Grande Valley Part 2: The Cacti

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Peyote

Spring in the Tamaulipan Thornscrub is a beautiful, albeit deceiving thing.  When the chaparro, huisachillo, and guayacan bloom above a carpet of wildflowers, its easy to forget just what a harsh, unforgiving land this can be.  I was bleeding through my jeans when I sat a moment to rest in the shade of a mesquite tree.  I don’t think that Carolina, James, or Erin had fared much better.  Despite being early March, it was pushing 90 degrees, and the sun was beating down.  After taking a long draw from my water bottle, I got up and continued my search.  I winced as I pushed through the allthorn, and felt the tasajillo spines pierce my skin.  It’s safe to say at that point my spirits weren’t at their highest.  But then I heard the voice of my wife as she called out, “I found one, with a flower!”  In that moment, pain seemed like an insignificant consideration as I pushed through the tangle of thorns that lay between me and my succulent quarry.  I saw Carolina squatting down looking at the base of a large shrub.  There, under the shade and protection of a condalia I could see the iconic Peyote in bloom.

Despite being very un-cactus like, the Peyote may be the famous of all cacti.  Once fairly common in parts of south and west Texas, decades of over-harvest, poaching, and habitat loss of significantly reduced the populations to the point that today they are a rare sight among the thornscrub.  The reason that it has been so persecuted is the psychoactive compound mescaline contained within its flesh.

In fact, Peyote is one of the most well known psychoactive plants.  It has been utilized for centuries by native peoples for both its medicinal and hallucinogenic effects. Today Peyote is a controlled substance in the United States due to its use as a recreational drug. It is, however, legal for many native tribes to harvest and consume for ritualistic purposes.  And though it may be illegal to harvest or possess, poachers continue to devastate Peyote populations to sell them on the black market.

In the United States Peyote is known only from extreme southern and western Texas. Here it occurs in desert scrub and arid brushland, typically growing beneath dense shrubs. It is one of three spineless cacti in Texas. We were lucky enough to observe some in bloom on an extensive private ranch in the Tamaulipan Thornscrub of South Texas, with the help of our dear friends Toby Hibbits and Connor Adams.

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Peyote

In our pursuit of Peyote we observed several other species growing beneath the shelter of their nurse plants.  We seemed to catch the Heyder’s Pincushion Cactus (Mammillaria heyderi) in full bloom.  This small cactus grows low to the ground, and like many species with this growth habit, is very difficult to spot when not in bloom.  In the early spring a single plant may put on a dozen or more flowers, generally organized in a ring along the top of the cactus.  It occurs from Mexico through south and central Texas west across eastern and southern New Mexico into southern Arizona.

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Heyder’s Pincushion Cactus

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Heyder’s Pincushion Cactus

While the Heyder’s Pincushion Cactus may be difficult to spot when not in bloom, the Hair-covered Cactus (Mammillaria prolifera) is difficult to spot even when in flower.  This species is tiny, with individual stems not much larger than an egg, though they may occasionally form large clumps.  The Hair-covered Cactus is known in the United States only from Texas, where it occurs in only a handful of counties in southern and south-central Texas, most of them along the Rio Grande.

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Hair-covered Cactus

Though it is superficially similar to the Mammillaria prolifera, the Runyon’s Pincushion Cactus (Coryphantha pottsiana) is easily differentiate when in flower.  Like many species of cactus, the taxonomy for Coryphantha pottsiana is a bit cloudy.  It has variably been known as Coryphantha robertii, Mammillaria robertii, Mammillaria bella, Escobaria bella, Escobaria runyonii, and Escobaria emskoetteriana.  Some authorities still use the latter, though Coryphantha pottsiana seems to be more widely accepted.  The Runyon’s Pincushion Cactus is known from northern Mexico and a few Texas Counties along the Rio Grande, where it is generally uncommon.

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Runyon’s Pincushion Cactus

While the previous cacti are generally small, the Horse Crippler (Echinocactus texensis) can reach much larger proportions.  While most seem to be about the size of a basketball, we saw some that were easily 3 or 4 times as large.  They tend to occur in looser soil including sandy alluvium.  They are also frequently found growing in the open, away from nurse plants, though its likely that many plants get their start in the less hostile microclimate of a nurse plant.  Their impressive spines seem to be an effective deterrent against mammalian predators.

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Horse Crippler

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Horse Crippler

Among the most beautiful of all cacti are the hedgehog cacti of the genus Echinocereus, a few of which are endemic to the Tamaulipan Thornscrub of South Texas and northern Mexico.  This year our trip coincided with the peak bloom of Echinocereus fitchii, the Fitch’s Hedgehog Cactus.  Though they are generally hard to find, in the right habitat they can be abundant, and we saw dozens, blazing the thornscrub with their pink blooms.  Like Coryphantha pottsiana and so many other cactus taxa, the taxonomy of Echinocereus fitchii is murky at best.  It is considered by many to be a subspecies of the more broadly distributed Echinocereus reichenbachii.  For anyone interested in the topic I strongly recommend reading “A hard-to-manage taxon: The Black Lace Cactus (Echinocereus fitchii ssp. albertii)“.  Though it discusses the Fitch’s Hedgehog Cactus’s Federally Endangered cousin, it includes a good discussion on the taxonomy of E. fitchii and E. reichenbachii, including characteristics used to distinguish the two.

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Fitch’s Hedgehog Cactus

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Fitch’s Hedgehog Cactus

In my opinion, the Lady Finger Cactus (Echinocereus pentalophus) is perhaps the most spectacular cactus native to the United States.  Confined to northern Mexico and extreme southern Texas, they can form huge mats under the shade of mesquite and other trees and large shrubs.  They have even been found growing upon protected ridges adjacent to the Laguna Madre.  Their bright blooms shine neon pink under the midday sun.

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Lady Finger Cactus

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Lady Finger Cactus

The bizarre Pencil Cactus (Echinocereus pentalophus) seems less a cactus and more a tangle of dried branches resting at the base of some thorny shrub.  That is, until it’s giant pink blooms open in the early spring and betray its presence to the world.  Unlike most other members of its genus, the Pencil Cactus produces a massive tuberous roots that aid in water storage.

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Pencil Cactus

The highlight our South Texas cactus hunt, however, was finding the Federally Endangered Star Cactus (Astrophytum asterias) in peak bloom, an experience which I will share in my next blog post.

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Star Cactus

The Biodiversity of the Rio Grande Valley Part 1: The Birds

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Altamira Oriole

At first they appeared as flashes of brilliance – blurs of orange, blue, and green darting through the drab brush country.  It was when we sat still and silent that they revealed themselves to us.  A spectacular cast of avian characters emerged from the dense vegetation.  All around us Green Jays croaked and bobbed.  Plain Chachalacas switched between the earth and low hanging branches.  Only occasionally would an Altamira Oriole appear, descending from the tree tops for a brief moment, it’s bright orange plumage demanding our attention.  The trill of a Golden-fronted Woodpecker broke our concentration, competing with the Great Kiskadee for the loudest call in the thornscrub.

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The Rio Grande Valley of Texas attracts birders from around the world.  A suite of characteristically Latin American species reach the northern limit of their range here.  This subtropical paradise is a naturalist’s playground.  Ecologically speaking, it shares more in common with Mexico than the rest of the Lonestar State.  When Carolina and I began discussing our South Texas vacation with our close friends James and Erin, birds were certainly one of the main targets that we planned the trip around.

Followers of my blog may remember previous posts where I talked about borrowing James’s 600mm lens for bird photography.  Fortunately another of my generous friends (and one of the finest photographers and naturalists that I know), Seth Patterson, offered to lend me his 500mm lens and teleconverters for the trip.  Though he is an excellent bird photographer, recently Seth is more focused on contributing to the “Meet Your Neighbours” project.  Armed with this new gear, James and I would be able to pursue our photographic targets at the same time, and wouldn’t have to worry about missing a shot.

This post contains some of the avian highlights of our trip, which spanned the diverse Lower Rio Grande Valley, from barrier islands and salt marshes, through ancient palm forests into the unforgiving Tamaulipan Thornscrub.

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While there are many South Texas species on the top of birders’ wish lists, perhaps the most famous is the Green Jay (Cyanocorax yncas).  They range from southern Texas through Mexico into northern South America.  Intelligent, inquisitive birds, they are a common sight in the brush country.

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Green Jay

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Green Jay

The Altamira Oriole (Icterus gularis) is the largest “true” oriole.  It takes these striking birds two years to attain their adult plumage, with first year birds being generally duller and lacking the bold black back and wings.  Altamira Orioles build pendant nests, which hang from tree branches.

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Altamira Oriole Adult

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First Year Altamira Oriole

Smaller and less commonly encountered than the Altamira Oriole is the Audubon’s Oriole (Icterus graduacauda).  They too barely enter the United States in southern Texas.  The Audubon’s Oriole is poorly understood, with few data on their natural history.  What little data are available indicate that they may be on the decline, likely due to a combination of habitat loss and nest parasitism by increasing populations of Brown-headed Cowbirds.

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Audubon’s Oriole

Another species that South Texas visitors get excited about is the Great Kiskadee (Pitangus sulphuratus)  This boisterous flycatcher makes its home in resacas and riparian corridors.  I’ve been fortunate enough to observe this bird in South Texas, Costa Rica, and northern Argentina.  It certainly has one of the broadest ranges of any New World songbird.  Interestingly, both the English and Spanish names for this bird are onomatopoeas.  Kisk-a-DEE in English, and Bent-e-VEO in Spanish.  In Argentina it was locally known as “bicho feo” (ugly critter), both because this phrase also sounds like its call, and because its obnoxious vocalizations were enough to drive local communities sharing the Kiskadee’s territory crazy.

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Great Kiskadee

While enjoying an intimate view of the valley’s avifauna from the comfort of a bird blind, we witnessed an incredible moment.  The blind was especially productive, with several Green Jays, White-tipped Doves, Plain Chachalacas, Red-winged Blackbirds, and Northern Cardinals.  The occassional Altamira Oriole, Great Kiskadee, and Lincoln’s Sparrow would appear.  In an instant all of the birds scattered.  We could hear their wings cut through the still air as they vanished in a hurry.  The Plain Chachalacas (Ortalis vetula) retreated to some higher branches and began chattering furiously, sharply focused on the brush below.  It was at that moment that we noticed a series of small black blotches moving through the vegetation: the spotted pelage of a Bobcat as it slinked away, unsuccessful in its hunt.

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Plain Chachalaca vocalizing at a Bobcat

The Plain Chachalaca is a large chicken-like bird that skulks in the understory and forest floor.  They are social birds, generally found in small groups as they forage for fruits, seeds, and similar food sources.  Like the kiskadee, they are named for their raucous call.

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Plain Chachalaca

The White-tipped Dove (Leptotila verreauxi) also barely enters the United States in South Texas.  Though they are most frequently observed foraging on the ground in the shade of the dense underbrush, they would occasionally perch on low-hanging limbs.

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White-tipped Dove

Ranging deeper into the United States than the previously mentioned species, the Black-crested Titmouse (Baeolophus atricristatus) none-the-less, is one of the more range-restricted species that we observed during our trip.  It occurs from central Mexico through central and western Texas to extreme southwestern Oklahoma.

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Black-crested Titmouse

The Ladder-backed Woodpecker (Picoides scalaris) is much more widespread, occurring throughout much of Central America and the southwestern United States.  Pictured below is a male, identifiable by its red crown.

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Ladder-backed Woodpecker

Travelling west into western Hidalgo and Starr Counties, the landscape begins to transition from forested brushland to a mix of thornscrub and desert scrub.  Here we were serenaded by Cactus Wrens (Campylorhynchus brunneicapillus) as we looked for the succulent plants that lend this large wren its name.  Erin spotted one particularly cooperative individual that sat atop the developing buds of a prickly pear and sang for several minutes.

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Cactus Wren

The ubiquitous Northern Cardinal (Cardinalis cardinalis) is ever-present in the valley.  I remember on a previous trip, 10 years ago or more with my family, a couple from western Canada excitedly proclaimed that they had just seen one of the “red jays”.  It was one of the birds they were most excited to see during their trip.  It’s easy to take the common birds for granted, but the Northern Cardinal really is a beautiful species.  The generally duller female has a subtle beauty that makes for a fine image.

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Northern Cardinal

Resacas are shallow ponds and wetlands that dot the landscape of the Lower Rio Grande Valley, most of which have formed in old oxbow scars of the Rio Grande.  The term “resaca” apparently originated from a corruption of rio seco, Spanish for “dry river”.  It also means hangover (at least in Argentina).  These Resacas are home to a variety of interesting bird species.  Green and Ringed Kingfishers fish from their banks, and Least Grebes and Masked Ducks breed here.  They are also an important habitat for wintering waterfowl.  We observed several species of duck here, including Cinnamon Teal (Anas cyanoptera), Green-winged Teal (Anas carolinensis), and Northern Shovelers (Anas clypeata).

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Cinnamon Teal

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Green-winged Teal

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Northern Shoveler

James and I spent one morning on our bellies in the tidal flats along the Gulf of Mexico.  We took advantage of the calm, shallow water to photograph foraging shorebirds and wading birds.  There were also large groups of Laughing Gulls, Royal Terns, and Black Skimmers Present.  After a while I had sand all over everything.  All over me, all over my camera.  So many grains of sand became trapped in the buttons of my camera that the shutter button became stuck in a depressed position.  As soon as I turned the camera on it would begin firing in rapid succession.  I was unable to change any settings.  Unfortunately as a result I missed some opportunities for shots of Marbled Godwits and a few other species.  Fortunately I was able to capture a few images prior to this malfunction, like this Short-billed Dowitcher (Limnodromus griseus) on the hunt for invertebrates.

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Short-billed Dowitcher

Perhaps my favorite of the long-legged wading birds, the Reddish Egret (Egretta rufescens) is an uncommon species that appears to be on the decline.  They are closely tied to coastal habitats, and most population estimates put the number of birds at less than 10,000 pairs globally.

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Reddish Egret

These handsome birds put on a truly spectacular show as they forage in the shallows.  They are famous for their graceful, acrobatic hunting technique. They seemingly dance upon the shallow water, running, turning, and waving their wings in a way that seems at the same time chaotic and choreographed. This technique startles small fish in the shallows, and the egrets will then cup their wings over their head to shade out the sun so that they may more easily spot their quarry.

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Reddish Egret oh the hunt

Fortunately, with the help of a needle and some compressed air, I was able to get the sand out of my shutter button, and captured many memorable photographs during our short time in the valley.  While we observed many spectacular landscapes and organisms on our trip, our time spent with the birds was truly special, and I’ll always cherish the memories of chasing after them, camera in hand.

South Texas Part V: A Stop for a Sand Sheet Endemic

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Amelia’s Sand Verbena blooms in the South Texas Sand Sheet

The South Texas Sand Sheet occurs across a handful of South Texas counties.  It consists of layer of loose sand that was blown inland from the Gulf of Mexico in the Holocene.  The sand sheet is home to a suite of endemic plant species.  Perhaps the most spectacular is the Amelia’s Sand Verbena (Abronia ameliae), which can be found nowhere, save the South Texas Sand Sheet.

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Amelia’s Sand Verbena

While returning home from the Rio Grande Valley we passed through the sand sheet.  I began seeing splashes of a deep pinkish purple passing as a blur at 75 miles per hour.  Finally after seeing a large field of pink I shouted “STOP!”  And my dad, despite his better judgement pulled over into the right of way of the busy highway and backed up to the spot that caught my eye.

The Amelia’s Sand Verbena was blooming en masse.  It was great to see such a rare, range-restricted plant thriving.  Recent rains may have helped provide such a spectacular bounty of flowering plants.  Growing among the sand verbena were a number of other South Texas specialties, including Rio Grande Phlox (Phlox glabriflora).

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Amelia’s Sand Verbena

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Amelia’s Sand Verbena and Rio Grande Phlox bloom in the South Texas Sand Sheet

It was a cool, overcast morning, so there were not many pollinators around.  We did however notices a stealthy predator nestled within the amble flowers on the inflorescence of one of the sand verbenas: a Crab Spider.

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A Crab Spider hidden in the blooms of an Amelia’s Sand Verbena awaits a meal

Seeing these South Texas Sand Sheet endemics was the perfect ending to an incredible trip full of biodiversity.  I was sad that it was coming to an end, but I took comfort in the fact that there were many other natural wonders still waiting to be explored.

 

South Texas Part IV: Star Hunting

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Star Cactus

The Star Cactus (Astrophytum asterias) may be the rarest, most unique cactus in the country.  It is known from only a handful of sites in the Tamaulipan thornscrub of extreme southern Texas and northeastern Mexico.  It is so imperiled that it has been listed as Endangered by the U.S. Fish and Wildlife Service.  It is severely threatened by land use conversion and habitat loss.  Fortunately The Nature Conservancy in Texas acquired the property that may have the largest remaining Star Cactus population in the country.  Here they undertake conservation measures and reintroduction efforts to ensure that this iconic cactus remains for generations to come.

I have donated a number of photographs to The Nature Conservancy in the past.  When we decided on traveling to South Texas I reached out to them to see if I could arrange a visit to see and photograph these imperiled cacti.  They graciously approved my request, and we met with volunteer Paul Bryant, who gave us an excellent tour of the property.  Having previously worked for a non-profit land trust similar to the Nature Conservancy, I know how heavily we relied on our volunteers.  I also learned to recognize the good ones, and I had no doubt that Paul was a valuable asset to the Nature Conservancy.

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Star Cactus

Though many were growing in the open, the star cactus was extremely difficult to spot.  When its not flowering, it is inconspicuous, blending in with the scattered rocks covering the gentle slopes where it grows.  Also known as the Sea Urchin Cactus, Sand Dollar Cactus, and False Peyote, it is a spineless cactus that lies relatively flat against the surface in times of drought.  Following rains, however it swells with water and can appear quite plump.  I had hoped to photograph the bright yellow blooms, but it was not to be.  We saw a number of plants that had recently blooms, and others that were preparing to, but we weren’t fortunate to catch any in the act.  That was ok though, it was a wonderful experience just to get to see them in their element.  The plant itself is beautiful, and made for some interesting photographs even without its bloom.

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Star Cactus

There were several other cacti growing in the vicinity of the Stars.  The most conspicuous was the aptly named Glory of Texas (Thelocactus bicolor).  In Texas this species only occurs in the extreme western and extreme southern portions of the state.  Though the populations are disjunct in Texas, they are more or less connected through Mexico.  We saw many of their bright pink blooms, both in the open and at the base of nurse plants.

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Glory of Texas

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Glory of Texas

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Glory of Texas

We also saw a few of the formidable Horse Cripplers (Echinocactus texensis) in bloom.  Looking at these beasts, its not hard to see how they got their name.

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Horse Crippler

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Horse Crippler

I only saw one Runyon’s Pincushion Cactus (Coryphantha pottsiana) in bloom.  Though not as scarce as the Star Cactus, this species is also rare in Texas, where it is known from only three counties along the Rio Grande.

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Horse Crippler

And then there were more Lady Fingers (Echinocereus pentalophus).  Though these proved to be fairly common during the trip I never tired of seeing them, and could not resist every opportunity to photograph them.

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Lady Finger Alicoche

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Lady Finger Alicoche

I found one particularly robust flowering specimen growing among a clump of Varilla (Varilla texana).  I came to learn that where Varilla grows, there are usually other interesting things to be found.

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Lady Finger Alicoche

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Lady Finger Alicoche

We also observed several Strawberries Pitayas (Echinocereus enneacanthus), Fitch’s Hedgehog Cactus (Echinocereus fitchii), Heyder’s Pincushion Cactus (Mammillaria heyderi), and a few Peyote (Lophophora williamsii) on the property, however these weren’t in bloom.  I had hoped to photograph Peyote this trip, but a suitable opportunity did not present itself.

There were plenty of other flowering plants to admire, however.  Perhaps the most striking was the Berlandier’s Nettlespurge (Jatropha cathartica).  It seemed to prefer the same gravelly slopes as the cacti.

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Berlandier’s Nettlespurge

While on my knees looking for Peyote I spotted a group of tiny yet striking blooms.  The Glandular Milkwort (Polygala glandulosa) occurs in only a handful of South Texas Counties.

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Glandular Milkwort

It was hard not to stop and admire the Guayacan (Guaiacum angustifolium), which was blooming throughout the thornscrub.

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Guayacan

After arriving at the property, we split up to scour the area.  Seth soon came to find me.  He had an excited grin and told me that he had something to show me.  He led me to a large Texas Tortoise (Gopherus berlandieri) that had crawled halfway down its burrow.  I wanted so badly to photograph it, but despite waiting for some time, it refused to show its face, and we had to continue our hunt for the Star Cactus.  I was luck enough to photograph another South Texas Treasure, the orb-weaver Argiope blanda.  A. blanda occurs in the United States only in extreme southern Texas.

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Argiope blanda

Though I did not get to photograph the Star Cactus in bloom, it was a day full of natural wonder spent in good company, and I left with a real sense of contentment, both in the things I had seen and photographed, and in the knowledge that organizations like the Nature Conservancy exist to protect our planet’s great biodiversity.

 

South Texas Part III: The Lady and the Pencil

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Lady Finger Alicoche

Though the Trans Pecos is the center of cacti diversity for Texas, the cactus community of the Tamaulipan thornscrub is no less spectacular.  It includes a number of Mexican species that just barely enter the states in extreme South Texas.  Two species in particular, have been on my bucket list for years now: the Lady Finger Alicoche (Echinocereus pentalophus) and the Pencil Cactus (Echinocereus poselgeri).  I would have included them on my 2017 biodiversity list, however I didn’t anticipate taking a trip to South Texas this year.  So when a march trip to Big Bend fell through, I delighted in the opportunity to finally observe these species in their natural setting.

This is the part of the story where the patience of Carolina, my parents, and my brother really come into play.  They waited patiently while I sought out and photographed these species, and even helped me in my endeavor.  Carolina has a real interest in cacti as well, and she enjoyed seeing so many species in bloom.

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Lady-Finger Alicoche

The Alicoche is a cactus of the Tamaulipan thornscrub of northeastern Mexico and South Texas.  It can form large mats under the shade of nurse plants, however its stems are relatively nondescript, and the plant itself is difficult to see when not in bloom.  When it blooms, however, its gives its presence away in spectacular fashion.  The huge pink blooms seem to explore from the thornscrub.  It is easily one of the most spectacular plants I have ever had the good fortune to observe.

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County-level distribution of Echinocereus pentalophus from http://www.bonap.org.  Yellow counties indicate that the species is present and rare.

I found the Lady Finger to be an extremely photogenic plant, lending itself both to portraits of the blooms and landscape shots featuring the plant as a foreground element.  We were fortunate to observe many individuals in many different settings throughout the trip.  Spending time with this species was a truly memorable experience that I look forward to repeating some day in the future.

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Lady Finger Alicoche

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Remnant Tamaulipan thornscrub forest with Lady Finger Alicoche in bloom.

Fortunately the Alicoche was fairly easy to find.  That was not the case with the Pencil Cactus.  If the Lady Finger is hard to see when not flowering, the Pencil Cactus is virtually impossible.  Also known as the Sacasil or Dahlia Hedgehog Cactus, the Pencil Cactus has an extremely narrow stem that does not look much different than a stick.  Couple that with their tendency to grow among dense tangles beneath thornscrub shrubs, and you could imagine how hard it would be to pick them out.  When they bloom, however, the light up the thornscrub.

I spent a large part of the trip looking for this species in vain.  I went to sites where others had seen them, and scoured seemingly suitable habitat.  I did not see one until late afternoon on our last day in the valley.  After trudging through the dense thornscrub, cut, tired, and full of spines from allthorn, mesquite, and prickly pears I was ready to give up.  Then, as we were preparing to leave, driving through an undeveloped area adjacent to a small subdivision Carolina shouted “STOP!  The Pencil Cactus!”.  I looked up and saw it.  It’s flower had been nipped off.  Disappointed, I looked around hoping that there might be another in the area, and then I saw it up a steep slope.  I grabbed my camera and scrambled up the slope.  As my shutter clicked I felt a real sense of contentment, both in having found the Pencil Cactus, and that I have such a wonderful family that indulges my passion and obsession for the natural world.

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Pencil Cactus

The range of the Pencil Cactus is virtually the same as that of the Lady Finger.  It seems to be found in slightly denser clumps of brush where its slender, fragile stem can lean on the limbs of nurse plants for support.

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County-level distribution for Echinocereus poselgeri from http://www.bonap.org.  Yellow counties indicate that the species is present and rare.

We were lucky enough to observe two other species of Echinocereus in bloom in our pursuit of the Lady and the Pencil.  The Strawberry Pitaya (Echinocereus enneacanthus) was abundant throughout much of the thornscrub.  We were a bit early in the season to see many flowers, but I was lucky enough to spot a few in bloom.  E. enneacanthus is a fairly widespread species throughout much of Mexico and southern and western Texas and New Mexico.  The variety in South Texas is Echinocereus enneacanthus var. brevispinus, identifiable by its short spines.

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Strawberry Pitaya

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Strawberry Pitaya

Much less common was the Fitch’s Hedgehog Cactus (Echinocereus fitchii).  E. fitchii was initially, and still is considered by some to be a variety of Echinocereus reichenbachii, the Lace Cactus.  There are significant differences between the two, however, including root structure and spine and flower characteristics.  Most cactus flowers are at their best midday on sunny days.  This makes photographing them a challenge, as shading them often takes away some of the brilliance of their blooms.

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Fitch’s Hedgehog Cactus

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Fitch’s Hedgehog Cactus

Most of the cacti we observed during our trip were on Nature Conservancy property.  I can’t say enough good things about the Nature Conservancy in Texas.  I will discuss the Nature Conservancy and their contributions to conservation in my next blog post, but wanted to mention them here, as one afternoon Seth and I took a hike at one of their South Texas preserves.  We saw more cacti on this hike than the rest of the trip combined.  Echinocereus pentalophus and E. enneacanthus were abundant, as were Texas Prickly Pear (Opuntia lindheimeri) and Dog Cholla (Grusonia schotii).  We also observed Christmas Cholla (Cylindropuntia leptocaulis) and Lower Rio Grande Valley Barrel Cactus (Ferocactus hamatacanthus var. sinuatus), though none were in bloom.  We were, however, fortunate enough to see three other species in bloom: Heyder’s Pincushion Cactus (Mammillaria heyderi), Hair-Covered Cactus (Mammillaria prolifera),  and Twisted-Rib Cactus (Hamatocactus bicolor).

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Heyder’s Pincushion Cactus

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Heyder’s Pincushion Cactus

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Hair-Covered Cactus

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Twisted-Rub Cactus

We also observed several other interesting plants in the thornscrub.  Some of these have been covered in previous blog posts.  Others I didn’t photograph for various reasons.  One of the most interesting was the terrestrial bromeliad Gaupilla (Hechtia glomerata).  We also observed a number of birds typical of the desert southwest, including Pyrrhuloxia (Cardinalis sinuatis), Black-throated Sparrows (Amphispiza bilineata) and Cactus Wrens (Campylorhynchus brunneicapillus).  At one point I flipped over a dried cow patty and found a little Western Narrowmouth Toad (Gastrophryne olivacea) sheltering in some remnant moisture beneath it.

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Western Narrowmouth Toad

Stay tuned for more cactus-seeking adventures in my next blog entry.

 

South Texas Part II: Into the Thornscrub

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Common Pauraque

Beyond the South Texas coastal dunes, marshes, and prairies lies a unique, biodiverse community dominated by a variety of shrubs and small trees.  Variably referred to as South Texas brush country, mezquital, and Tamaulipan thornscrub, this semi-arid, subtropical community occurs in South Texas and the Mexican states of Tamaulipas, Nuevo Leon, and Coahuila.  It is home to plants and animals found nowhere else on earth, and in South Texas, marks the northern extent of several Latin American species that just barely enter the United States.

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Tamaulipan Thornscrub with blooming Lady Finger Alicoche alongside Strawberry Pitaya.

The Tamaulipan thornscrub in the Rio Grande Valley of South Texas is one of the United State’s premier birding locations.  My parents and I have made a number of birding trips here in the past, drawn in by the promise of catching a glimpse of one of these South Texas specialties.  During this trip the birding was fairly slow, but we did see many of the typical Rio Grande Valley species including Plain Chachalacas (Ortalis vetula), White-tipped Doves (Leptotila verreauxi), Green Jays (Cyanocorax yncas), Long-billed Thrashers (Toxostoma longirostre), Altamira Orioles (Icterus gularis), and Olive Sparrows (Arremonops rufivirgatus).  Unfortunately these species did not present me with any good photo ops.  I did luck out, however, when we found another Valley specialist, the Common Pauraque (Nyctidromus albicollis) roosting alongside a trail.  These members of the nightjar family are nocturnal and rely on their camouflage to roost on the ground during the day.  It was nearly invisible among the dried leaves and sticks littering the earth.  I utilized the dense natural debris to create the window effect seen on the photo at the start of this blog entry.

Many mammal species also reach the northern extent of their range in deep South Texas.  Unfortunately many of them are now gone.  The last Jaguar (Panthera onca) in Texas was killed in the Tamaulipan thornscrub in the 1940’s.  There are some that still hold onto hope that there may be a few Jaguarundi left in the Rio Grande Valley.  Though there have been no verified sightings in many years, there have been unverified reports.  Ocelots (Leopardus pardalis) are still hanging on in the brush country, though they are now rare, and protected under the Endangered Species Act.  In our explorations of the thornscrub we observed a number of mammals including White-tailed Deer (Odocoileus virginianus) and Collared Peccaries a.k.a. Javelinas (Tayassu tajacu).  The only mammal I was able to photograph was the little Eastern Cottontail (Sylvilagus floridanus) pictured below.

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Eastern Cottontail

There are many reptile and amphibians whose United States distribution is also limited to the Rio Grande Valley.  Being an amphibian enthusiast, I was disappointed that we missed the heavy rains that brought out such rarities as the Mexican Burrowing Toad (Rhinophrynus dorsalis) and White-lipped Frog (Leptodactylus fragilis) by just a couple of days.  These species are explosive breeders that emerge to breed after heavy rains.  I did spend some time looking for the beautiful Speckled Racer (Drymobius margaritiferus), a primarily Latin American species that is known from only a couple of sites in South Texas.  I struck out on the snakes, but was able to photograph a couple of the areas conspicuous lizards: the Texas Spiny Lizard (Sceloporus olivaceus) and the Rose-bellied Lizard (Sceloporus variabilis).

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Texas Spiny Lizard

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Rose-bellied Lizard

The Rio Grande Valley is also world famous for its butterflies.  While we observed many species, the only one I obtained a decent photo of was the Common Mestra (Mestra amymone).

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Common Mestra

The Tamaulipan thornscrub is named for the typically thorny shrubs and small trees that dominate the community.  Typical species of this community include Mesquite (Prosopis gladulosa), Chaparro (Ziziphus obtusifolia),  Whitebrush (Aloysia gratissima), Texas Paloverde (Parkinsonia texana), Texas goatbush (Castela erecta), Saffron Plum (Sideroxylon celastrinum), Blackbrush Acacia (Vachellia rigidula), Corona de Cristo (Koeberlina spinosa), Guayacan (Guaiacum angustifolium), and Ebano (Ebenopsis ebano).  These shrubs form often impenetrable thickets.  On some sites, particularly as one moves further west in the Rio Grand Valley the shrubs may become more scattered, forming dense clumps with areas of exposed gravel and caliche.  It was in areas such as this where we observed the rare Baretta (Helietta parvifolia).

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Texas Paloverde

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Texas Paloverde

Occasionally growing in the crooks of mature Ebano, a real botanical treasure can be found.  The epiphytic bromeliad Tillandsia baileyi, commonly known as Bailey’s Ball Moss barely enters the United States in South Texas, where it is rare.  It is much more striking than other members of its genus, which includes the familiar Spanish Moss (Tillandsia usneoides).

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Bailey’s Ball Moss

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Bailey’s Ball Moss

A conspicuous component of the South Texas brush country is the Anacahuita or Mexican Olive (Cordia boissieri).  Its bright blooms illuminate the native brushlands, and it is a popular native ornamental in South Texas.  The tree was reportedly utilized by native cultures and Spanish settlers to make jellies and dyes.  The leaves can be brewed in a tea that may help with rheumatism and various ailments of the lungs.

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Anacahuita

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Anacahuita

Many invertebrates can be found utilizing Anacahuita leaves and flowers.  The Wild Olive Tortoise Beetle (Physonota alutacea) is found exclusively on these small trees.

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Wild Olive Tortoise Beetle

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Wild Olive Tortoise Beetle

Many pollinators also frequent the blooms.  They due so at their own risk, however, because predators lurk beneath these flowers.  We observed this crab spider (Mecaphesa sp.) awaiting an unsuspecting victim.

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Crab Spider

South Texas is also home to a variety of native lantana species.  Brushland lantana (Lantana achyranthifolia) could occasionally be found scattered about the thornscrub.

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Brushland Lantana

We also observed a couple of species of heliotrope, including the widespread Seaside Heliotrope (Heliotropium curassivicum), and the more range restricted Scorpion Tail (Heliotropium angiospermum) which occurs in South Texas and southern Florida.

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Seaside Heliotrope

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Scorpion Tail

Fiddleleaf Tobacco (Nicotiana repanda), a species of central and southern Texas, was also fairly common.

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Fiddleleaf Tobacco

Shrubby Blue Sage (Salvia ballotiflora) occurs in the U.S. only in southern and western Texas.

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Shrubby Blue Sage

Over the millennia, the meanders of the Rio Grande has slowly changed course, leaving in their wake old depressional oxbow scars.  The scars eventually filled with rainwater and runoff and developed a unique flora.  Known as Resacas these unique wetlands provide habitat for a host of rare plant and animal species.  We observed many Least Grebes (Tachybaptus domincus), another bird species whose U.S. distribution is restricted to South Texas in them.  We also observed the rare Runyon’s Water-Willow (Justicia pacifica) here.

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Runyon’s Water Willow

As one moves further west along the valley, one begins to notice more and more of a desert influence.  I observed many familiar species that I have photographed in West Texas including Snapdragon Vine (Maurandella antirrhiniflora) and Cenizo (Leucophyllum frutescens).  The latter blooms in response to rainfall and humidity.

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Snapdragon Vine

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Cenizo

I observed Purple Groundcherry (Quincula lobata) here.  These showy groundcover primarily occur in the southwestern United States.

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Purple Groundcherry

I also observed Bearded Prairie-Clover (Dalea pogonathera) here.  This member of the pea family is primarily a species of the Chihuahuan Desert.

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Bearded Dalea

South Texas is also home to a few woodsorrel species that do not have the typical “lucky clover” leaf.  Pictured here is Peonyleaf Woodsorrel (Oxalis dichondrifolia).

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Peonyleaf Woodsorrel

The open caliche hills were home to the beautiful Berlandier’s Nettlespurge (Jatropha cathartica), which is restricted to South Texas and adjacent Mexico.

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Berlandier’s Nettlespurge

The most spectacular element of the Tamaulipan thornscrub, however, were the cacti.  These famed succulents were my main target in South Texas, and I was fortunate to observe many species.  Though my next two blog posts will be dedicated to the incredible diversity of South Texas cacti, I have decided to provide a preview of things to come below.

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Lady Finger Alicoche (Echinocereus pentalophus)

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Glory of Texas (Thelocactus bicolor)

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Heyder’s Pincushion Cactus (Mammillaria heyderi)

South Texas Part I: Along the Coast

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Coastal Dunes with Beach Morning Glory

When I was developing my 2017 list I added several species that were contingent on a spring break trip to Big Bend.  Unfortunately I did not plan ahead enough, and by the time I tried to make arrangements out west everything was already booked up.  Fortunately there are so many biodiversity hot spots in Texas that it was not hard to find a substitute.  We decided on the varied subtropical habitats of Deep South Texas.  Here one can encounter a suite of endemics and Mexican specialties that are found nowhere else in the country.  It may come as no surprise that immediately after posting my 2017 list I began thinking about my 2018 list, in which I planned to include many of the South Texas specialties.

So Carolina and I began an adventure with my entire family: my brother, Seth, my mom, Jolynn, and my dad, Jack.  We traveled south in two vehicles intent on seeking out plants, birds, herps, and good food.  Our first couple days were allocated for time along the coast, from Port Aransas to South Padre.

The South Texas coast contains several extensive dune fields, primarily along the barrier islands.  Some are ever shifting, and some have been stabilized with vegetation and debris.  One might be surprised to find plants clinging to life in these sandy wastelands, however several species thrive in these shifting sands.  The most conspicuous species during our trip was the Beach Morning Glory (Ipomoea imperati), which is a coastal specialist ranging from the Atlantic Coast from North Carolina to Florida to the Gulf Coast of Florida to Texas.  We enjoyed the view from the base of the dunes as Sanderlings (Calidris alba), Ruddy Turnstones (Arenaria interpres), Willets (Tringa semipalmata), and Black-bellied Plovers (Pluvialis squatarola) chased the receding waterline only to swiftly retreat with each incoming wave.

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Beach Morning Glory

Beyond the dunes lie a variety of habitats including wet and dry prairies and marshes.  Marshes vary from saline to brackish to freshwater, depending on the influence of tidal waters.  We spent time exploring some high quality saltmarshes, one of my favorite communities, where we observed several bird species including Long-billed Curlews (Numenius americanus), Marbled Godwits (Limosa fedoa), Spotted Sandpipers (Actitus maculatus), Greater Yellowlegs (Tringa melenaleuca), American Oystercatchers (Haematopus palliatus), Clapper Rails (Rallus crepitans (formerly R. longirostris)), American Coots (Fulica americana), Common Moorhens(Gallinula chloropus), Osprey (Pandion haliaetus), Redheads (Aythya americana), Northern Pintails (Anas acuta), Blue-winged Teal (Anas discors), Black-bellied Whistling Ducks (Dendrocygna autumnalis), and Mottled Ducks (Anas fulvigula). Mottled Ducks are coastal specialists that range from Florida to central Mexico.  These close relatives of the Mallard have experienced population declines throughout much of their range as coastal habitat has been lost to development and sea level rise.

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Mottled Duck

The marshes were also home to a variety of wading birds including American Bitterns (Botaurus lentiginosus), Roseate Spoonbills (Platalea ajaja), White Ibis (Eudocimus albus), Green Herons (Butorides virescens), Great Blue Herons (Ardea herodias), Great Egrets (Ardea alba), Snowy Egrets (Egretta thula), Reddish Egrets (Egretta rufescens), Yellow-crowned Night-Herons (Nyctanassa violacea), Black-Crowned Night-Herons (Nycticorax nycticorax), and some cooperative Tricolored Herons (Egretta tricolor) and Little Blue Herons (Egretta caerulea).

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Tricolored Heron

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Little Blue Heron

A number of songbirds were also present.  We observed several Common Yellowthroats (Geothlypis trichas) and scores of Red-winged Blackbirds (Agaleius phoeniceus) and Great-tailed Grackles (Quiscalus mexicanus).  The Grackles were particular tame, and would perch on the boardwalk support posts mere feet away from us.

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Great-tailed Grackle

Slight variations of topography along the coast result in vastly different vegetative communities.  On small sandy crests and ridges dry prairies and scrublands persist.  These prairies are dominated by a variety of grasses and forbs.  The most visible member of this community is the Spanish Dagger (Yucca treculeana).  These stately yuccas are common in these dry prairies, and in the United States are restricted to southern Texas, New Mexico, and Arizona.

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Spanish Dagger

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Spanish Dagger Flowers

Along the wetter transition zone between marsh and prairie Carolina spotted a pair of Texas Feathershanks (Schoenocaulon texanum).  These bizarre members of the lily family can be found in south, central, and west Texas and southwest New Mexico.

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Texas Feathershank

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Texas Feathershank

The contact zone between the dunes and coastal prairie also harbor an interesting flora.  Arkansas Lazy Daisy (Aphanostephus skirrhobasis) is a widespread species of the south central states that can be common in this community.

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Arkansas Lazy Daisy

The lazy daisy is popular with pollinators, and coincidentally with their predators like this crab spider (Misumenoides formosipes) that awaits a hungry pollinator to fall into its trap.

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A crab spider awaits an unsuspecting pollinator

American Bluehearts (Buchnera americana) was also fairly common in this community.

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American Bluehearts

I have always been a fan of milkworts.  I was delighted to see several White Milkworts (Polygala alba), which we don’t have in East Texas.

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White Milkwort

Texas Palafox (Palafoxia texana) is primarily restricted to southern Texas.  Its brilliant pink blooms added a splash of color to the primarily brown grasses of the coastal prairie.

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Texas Palafox

I observed this wasp, Campsomeris tolteca (thanks to Seth Patterson for the ID), feeding on the nectar-rich flowers of the Texas Palafox..

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Campsomeris tolteca

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Campsomeris tolteca

Scattered along the coast are a series of woodlots primarily dominated by Live Oak (Quercus virginiana and Quercus fusiformis) and Hackberry (Celtis laevigata).  Here we observed a variety of Neotropical Migrant birds including Yellow-throated Vireos (Vireo flavifrons), Northern Parulas (Setophaga americana), Black-and-white Warblers (Mniotilta varia), and Yellow-throated Warblers (Setophaga dominica).

These woodlots are also home to Drummond’s Hedgenettle (Stachys drummondii).  This member of the mint family is restricted to the Texas Coast and the Rio Grande Valley.

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Drummond’s Hedgenettle

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Drummond’s Hedgenettle

Stachys drummondii

County Level Distribution for Drummond’s Hedgenettle from http://www.bonap.org

The wealth of biodiversity along the coast was not limited to land.  We observed a variety of shells, jellyfish, and dead fish along the shore, as well as a number of dolphin pods on the move offshore.  The most exciting encounter of the trip, however, came in the form of this juvenile sea turtle, which I believe is a Mexican Green Sea Turtle (Chelonia mydas).  Thanks to a tip from my good friend John Williams, we were able to observe several foraging just offshore.  Despite the cool morning, 40 mile per hour winds, and spitting rain, everyone enjoyed watching this rare marine reptiles as they surfaced for a breath before returning to the depths.

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Green Sea Turtle

The South Texas Coast was good to us, however the trip had only begin.  Next we would be venturing into the South Texas Brush Country, famed for its biodiversity and specialty species that can be found nowhere else in the country.