Texas Tigers

You might say I owe a lot to the tiger salamander. One of my earliest memories is turning over a board and finding several of these impressive amphibians at a park near my childhood home in the suburbs north of Chicago. My parents let me take a few home and we kept them in an aquarium for a few years. They were quite personable, for amphibians, and I remember feeding them bits of hamburger meat from toothpicks. This experience was one of the catalysts that sparked a lifelong passion for the natural world. There was just something about those tiger salamanders. I would later come to appreciate all salamanders, but those of the genus Ambystoma, and A. tigrinum in particular would always hold a special place in my heart.

When I was 13 we moved to the suburbs of Houston. In southeast Texas I found a herpetological Eden. There was an abundance and diversity of amphibians and reptiles that was unlike anything I’d previously encountered. But none of these new species inspired me to the degree that my pet tiger salamanders had, and I hoped I might find some nearby. After all, most every map depicting the range of the eastern tiger salamander showed it occurring in or at least near the Houston area. Many years later, after research, conversations, and personal observations I would come to realize that if I wanted to see one, I would have to travel much farther afield.

On New Years Day, 2021, Caro and I joined our good friend John Williams to see if we could find something that very few have encountered, let alone photographed: an adult eastern tiger salamander (Ambystoma tigrinum) in Texas. Our experience that day would rekindle a passion for this amphibian enigma, and spark a fact finding mission, the early stages of which I will present in this narrative.

We set out early to meet John at a site in the Post Oak Savanna where we had previously found larval and juvenile A. tigrinum. The day was cold, gray, and wet. A cold front had just passed through the region, dropping nearly three inches of rain on New Year’s Eve. The conditions seemed perfect for an Ambystoma migration, but there is little information on A. tigrinum breeding habits in Texas, so we could only hope that our timing was right.

To reach the breeding ponds we would have to hike a mile or so through remnant post oak savanna. At spots we noted sand blowouts nearly void of woody vegetation. Habitat like this is important for a variety of rare, range-restricted plant and animal species, and few high quality examples remain. The ponds themselves occurred in clay-bottomed swales where water from rainfall and percolation from adjacent deep sands collected. These ponds had been artificially enhanced – deepened, presumably to provide water for wildlife on a more permanent basis. They remained fish free, however, and as a result the tiger salamanders and other amphibians have been able to persist here.

It was still in the 40s (Fahrenheit) when we reached the pond. John had the good sense to bring a pair of waders to stay warm and dry in the pond. I wasn’t as prepared, and as we stretched out the sein, I mentally prepared myself to enter the frigid water. And it was cold, at least at first. My numb, tingling legs soon went to the back of my mind, however, as we pulled the sein from the water after our first pass and saw that a huge black and yellow amphibian had come with it.

A male eastern tiger salamander (Ambystoma tigrinum) from East Texas. This was the first of four individuals found.

It was a big adult male eastern tiger salamander! And it was one of the most beautiful salamanders I had ever seen. It immediately struck me as an eastern, but with tigers, there is always a hint of doubt in the back of my mind. There is another salamander, the barred tiger salamander (Ambystoma mavortium) that occurs sporadically in the semi-arid regions of the western half of the state. A. mavortium was long considered one of several subspecies of A. tigrinum. At that point, A. tigrinum was the most widespread amphibian in North America, occurring from the east coast to Arizona north to Washington and southern Canada. Within this range they inhabit a wide range of habitats, from forest pools to desert cienegas to subalpine lakes. In portions of their range, like northern Illinois, where I first became acquainted with them, they can even inhabit fishless ponds in urbanized areas, pastures, and agricultural fields.

Within this range they exhibit a broad range of behavioral ecologies and natural histories. In the west populations often contain both terrestrial and neotenic adults. Neoteny is the retention of various juvenile characteristics into adulthood. In this case, some adult salamander remain aquatic, retaining their gills, tail fins, and other characteristics that help them lead a life in the water. Other adults lose those characteristic and morph into gill-less adults that spend the majority of their lives on land in subterranean burrows. Neoteny has only been observed in one population of Michigan eastern tiger salamanders.

Morphologically, however, there is little to no difference between tiger salamanders throughout their range. A mavortium was split from A. tigrinum based primarily on adult coloration, egg mass characteristics, and the occurrence of neoteny. In the resulting split, eastern tiger salamanders remained A. tigrinum with no subspecies, while all other previously recognized subspecies were absorbed into A. mavortium. A. tigrinum is recognized as having more numerous, smaller spots and blotches on the body that range from creamy yellow to copper to olive brown. A. tigrinum also lays eggs in loose gelatinous masses, and only very rarely exhibits neoteny. A. mavortium mavortium (the barred tiger salamander) is recognized as having fewer larger spots, blotches, and bars that range from lemon yellow to olive. Barred tigers generally lay their eggs in lines or strips along vegetation, and neotenic populations are numerous. If you fine explanation for differences in the appearance of adults to be rather vague, you’re not alone. Tiger salamanders are extremely variable, and there are considerable differences in the patterns of individuals between and even within populations. The papers I’ve seen advocating for this split leave a lot to be desired, in my opinion, which begs the question, should they really be considered separate species? I could talk at length about the philosophy of species delineation, which isn’t the intended purpose of this blog, but to keep it short I’ll say that there is considerable disagreement and a wealthy of opinions in the field of taxonomy as to what should constitute a species. The concept of a “species” is far from black and white, and as a result we see a constant flow of changing taxonomies, with species being split, lumped back together, and so on and so forth.

The salamander that we had caught definitely fit the bill for A. tigrinum. Numerous orange-yellow spots scattered about its head, back, sides, and tail. It was easily identifiable as a male by it’s swollen cloaca and flattened, rudder like tail. These are changes that occur in males during the breeding season. The tiger salamander is one of the largest terrestrial salamanders in the world, and seeing one in person is an unforgettable experience.

It was quite clear to me that John and I had seined up an eastern tiger, but the plot thickens. Larval tiger salamanders and neotenic adults have long been used as fishing bait. They are famous for their ability to snag large bass, and can frequently been found in bait shops. These bait salamanders are most often A. mavortium as they are more readily obtained from breeding ponds year round. A. tigrinum and A. mavortium also differ in their breeding ecology, for the most part. A. tigrinum are animals eastern North America, where the winters are typically wet, and seasonal pools fill during the winter and early spring when rainfall is more abundant and water requirements of plants is lower due to winter dormancy. For this reason they breed in the winter and early spring in more northern latitudes and late fall and early winter in the more southerly portions of their range.

Throughout much of their range, A. mavortium occur in habitats that are influenced by summer monsoonal range and experience dry winters. As a result, many of these populations breed in the summer months. Once again, however, there is overlap, and many populations of A. mavortium breed in the winter months similar to A. tigrinum.

But I digress. Salamander larvae used as fish bait have been introduced to many areas where they do not natural occurred, or distributed to new areas within their range, changing the genetics of local populations. This has become a major problem in the western U.S., where non-native barred salamanders have become established in parts of California and Arizona. Here they interbreed with the federally endangered California tiger salamander (Ambystoma californiense) and Sonoran tiger salamander (Ambystoma mavortium stebbinsi), and threaten native populations here by diluting the gene pool.

This same phenomenon has been purported to occur in East Texas as well, however I am skeptical that it has actually occurred, particularly to a sufficient degree to threaten native populations here. The only evidence that I have been able to find that this could occur is the presence of A. mavortium larvae or neotenic adults at bait shops in the region. I have heard from several individuals that they have found, purchased, and used these as bass bait in popular East Texas fishing spots. I have yet to find evidence, however, that these larvae have been introduced and formed naturalized populations. I think it is unlikely that this is occurring for the following reasons:

  • Tiger salamanders in East Texas are apparently quite rare and declining. With few known populations, it is unlikely that numerous introduced populations have become established.
  • The appearance of animals from East Texas and adjacent western Louisiana is quite similar. If introduced populations were prevalent here, I would expect there to be significant variation in the appearance of animals from the region. Granted, many of these animals do seem to show some similarity to the coloration of barred tiger salamanders, however the same is true of eastern tiger salamanders in other parts of their range. In east Texas, this may also be influenced by the proximity to the contact zone with naturally occurring barred tiger salamander populations.
  • Known populations by and large do not occur near fishing hotspots, despite the presence of suitable habitat. I would expect that populations established from introduced fish bait would be more common in those areas where fishing and bait shops are more prevalent.
  • Tiger salamanders in east Texas exhibit a very specific distributional pattern and habitat preference, which I will describe further below.

The range of the eastern tiger salamander, whether relating to the subspecies or the full subspecies, generally is shown as reaching its southwestern limit in eastern Texas. Being the salamander fanatic that I am, I long wanted to find them, but soon came to realize that it would be no easy task. Through years of research and personal experience, a pattern of habitat preference began to develop. Virtually all of the records I could locate of A. tigrinum in East Texas are from three bands of Eocene sand deposits: The Queen City, Sparta, and Carrizo sands of the Claibourne Formation. Here they primarily breed in clay-bottomed depressions, and in some cases man-made ponds, in sandy uplands that are or were historically post oak savanna.

After a prolonged bout of exciting shouting, high fives, and hugs, John and I made another pass with the sein, which yielded another strikingly patterned male tiger salamander. It too was characterized by numerous small spots. It was shaping up to be one of my most memorable salamander hunting experiences to date.

A male eastern tiger salamander (Ambystoma tigrinum) from East Texas. This was the second of four individuals found.

Our next pass yielded a huge gravid female. This individual, with the exception of having slightly brighter colors, was nearly identical to the salamanders I found under that board in northern Illinois all those years ago. She was the last salamander we caught in that first pond, but another pass yielded a large gelatinous egg mass – further supporting our claim that these were eastern tiger salamanders, and not A. mavortium or some mix of the two. It should also be stated that neoteny has not been observed in this population or any other population of A. tigrinum in East Texas.

A gravid female eastern tiger salamander (Ambystoma tigrinum) from East Texas. This was the third of four individuals found.

When photographing salamanders, I like to take images from several images. A standard field guide shot of a posed salamander in interesting substrate is always nice, but in recent years I’ve really come to like photographing them from above. Their patterns and colors are most striking on their dorsum, and photographing them this way helps place them in their environment. It also helped to highlight the plumpness of this gravid female.

After photographing our salamander finds, we moved on to another nearby pond. Here we found a single female. Of all of the salamanders we found that day, she bore the closest resemblance to A. mavortium. Her spots and blotches were larger than the others, and some were bleeding into bars. In my opinion, however, she was still well within the realm of A. tigrinum patterning and coloration, and as I’ve noted above there is considerable overlap.

A gravid female eastern tiger salamander (Ambystoma tigrinum) from East Texas. This was the fourth of four individuals found.

Satisfied with a highly productive outing, we packed up after four salamanders, dozens of photographs, and a couple of hours in good company. The very first day of 2021 will be a hard one to top! The experience served to enhance and deepen my appreciation for these animals and opened up a wormhole about their genetics, regional relationships, patterns, habitat preference, and much more. I think that finding answers to these questions is important, as by all accounts and appearances, the eastern tiger salamander in Texas is rare and declining, and most certainly worthy of conservation efforts.

2020 Highlights in Biodiversity

2020 was a hard year for so many. Caro and I were extremely fortunate in that we were able to keep our jobs and work from home. We retained our health and the health of our loved ones. For many this was not the case. We also were fortunate that we were able to find refuge and comfort from the pandemic and turmoil in nature.

I only managed to check two new species off my list of biodiversity goals this year:

Alligator Snapping Turtle (Macrochelys temminckii)

Texas Red-headed Centipede (Scolopendra heros)

I also provided a more thorough treatment of the White-tailed Deer (Odocoileus virginianus), which I technically photographed last year, but only briefly mentioned the encounter.

Though it may not be reflected in the number of species checked off my list, 2020 was full of biodiversity, and was perhaps my most productive year yet in terms of photography. The following are just a handful of highlights. There are many images taken this year that I have not yet shared on this page, and hope to include many in future posts.

A favorite past time of mine is roaming the woods on a warm day in early spring. On those lucky days where conditions are just right, I just might catch a glimpse of some rare spring ephemeral forb opening its blooms. One of the first to flower this year was the lovely white trout lily (Erythronium albidum).

White Trout Lily

Not far from the trout lilies above I stumbled upon a large patch of bloodroot (Sanguinaria canadensis), one of my all time favorite wildflowers.

Bloodroot

While looking for these wildflowers one day in mid February I heard Caro shout “SNAKE! SNAKE!” Looking back, I saw this beautiful young canebrake rattlesnake (Crotalus horridus) coiled within 2 feet of where I had just stepped. Their camouflage is absolutely amazing, and their dispositions are so docile. This one obliged our presence for several minutes as we admired and photographed it, without so much as a complaint or even the slightest movement. I figure it was born last year, and it appeared to have a decent meal in its belly.

Neonate Canebrake Rattlesnake

Caro’s sharp eyes also spotted this downy yellow violet (Viola pubescens). Rare in the the state, most populations of this early spring bloomer are known from far northeast Texas. This individual was found close to home in Nacogdoches County in a high quality forested slope.

Downy Yellow Violet

Before the work at home orders were issued, I enjoyed birding around my work campus. During the winter and spring we get a good variety of birds here, and on a whim one day I brought my camera and was able to capture this image of a Yellow-rumped Warbler (Setophaga coronata) during a brief break.

Yellow-rumped Warbler

One of my most exciting finds of the year was a the second population of false rue-anemone (Enemion biternatum) in Deep East Texas. Caro and I found the first a few years ago in a beautiful patch of woods on some friends’ land.

False Rue Anemone

I put in considerable effort this year to finding and photographing Trillium in East Texas. I plan to share a blog this spring discussing these beautiful spring wildflowers and their status and distribution in Texas.

Texas Trillium (Trillium texanum)
Bloody Butcher (Trillium recurvatum)

Whenever I’m feeling low or overwhelmed, I like to mentally transport myself to the forest in spring. There are few things more peaceful and beautiful to me. Scenes like the one pictured below are just as wonderful to me as some endless mountain vista.

Rich Spring Woods

Another exciting wildflower find was a nice population of Nuttall’s death-camas (Toxicoscordion nuttallii) in San Augustine County. This species is quite common and widespread in central Texas, but is rare and highly localized in the Pineywoods. Here is is primarily associated with open forests and glades over the Weches Formation, where it approaches the surface.

Nuttall’s Death Camas

This year I finally took the trip an hour and a half to the west to photograph the federally endangered large-fruited sand verbena (Abronia macrocarpa). This stunning member of the Four O’clock family (Nyctaginaceae) is endemic to a tiny portion of the Post Oak Savanna in Texas, where it is known from nine populations in three counties.

Large-flowered Sand Verbena

2020 was also the first year I captured images of the granite gooseberry (Ribes curvatum) in bloom. We found many of these lovely, fascinating shrubs in the woods of Nacogdoches, Rusk, and Cherokee Counties.

Granite Gooseberry

In early April, Caro and I took a trip to northeast Texas to visit an incredible rich hardwood forest on private land. The landowner loves his woods and we were privileged to experience this special place. Among the rare plants here we found Trillium viridescens. A gorgeous trillium that can reach heights of nearly two feet!

Trillium viridescens

While walking in one of our favorite local parks one fine April afternoon, I spied some brown wriggly thing moving across the trail in front of us. Instinctively I scooped it up, and much to my delight realized that I was holding a smooth earth snake (Virginia valeriae)! Though it is fairly widespread in Texas, populations seem to be widely scattered and localized, and when compared to snakes with similar life histories, records are scant.

Smooth Earth Snake

I put considerable effort into finding, stalking, and photographing breeding songbirds this spring. It was difficult, often very frustrating, but ultimately rewarding. The Swainson’s Warbler (Limnothlypis swainsonii) below was photographed in the woods at my friend James Childress’s farm.

Swainson’s Warbler

I spotted the Bobolink (Dolichonyx oryzivorus) below while out photographing birds with my buddy Skip Pudney. The Bobolink is an infrequent passage migrant in East Texas. Here they may stop to refuel on their journey north to their prairie breeding grounds. They are only irregularly encountered in the state, so I was thrilled to see a breeding-plumaged male at a wildlife management area close to home. During our initial approach, the bird dropped down from its perch into a dense field of grass, vetch, and other herbaceous vegetation. I continued to where the bird was and was immediately set upon by a swarm of fire ants. As I began brushing the stinging insects from my legs I heard Skip shout “There it is!” I looked up and the Bobolink had hopped up to a perch about 30 feet away from me. I immediately ignored the pain and fired off several shots, all the while enduring more and more ant bites. The itching from the bites faded after a few days, but I’ll forever have this image to remember this special encounter.

A male Bobolink

In May I saw some interesting images posted by my friend Adam Black of a plant he found and photographed in a forested seep in Jasper County. After some discussion with a number of botanists, a consensus was reached that it was Texas featherbells (Stenanthium texanum), a rare plant with few records from the state.

Texas Featherbells

One glorious day in late May I was able to capture images of two of the loveliest Neotropical migrants breeding close to home. The Painted Bunting (Passerina ciris) and Northern Parula (Setophaga americana) below were photographed in close proximity, but in very different habitats.

A male Painted Bunting
A male Northern Parula

A few weeks later I visited the spot where I had photographed the parula and found a beautiful male Kentucky Warbler (Geothlypis formosa) skulking int he understory. I believe he had a nest nearby as he was constantly foraging and returning to the same spot.

A male Kentucky Warbler

Another day chasing birds I got lucky when a Red-eyed Vireo (Vireo olivaceus) came down low from his normal haunt high in the canopy.

Red-eyed Vireo

The woods in summer are hot, but beautiful. There is a myriad of subtly different shades of green and plant growth is at its peak. I found a particularly lovely scene while exploring some back roads in Cherokee County.

A rich hardwood forest on the Weches Formation.

While exploring in early spring, Caro spotted a huge population of Carolina lilies (Lilium michauxii) with their basal leaves just beginning to emerge. We returned in July and were dismayed to see that most of the area had been logged since our visit. Fortunately we managed to find small area that had been spared and had many plants in bloom.

Carolina lilies in a rich slope forest.

In September we headed west toward Rocky Mountain National Park. We timed our trip to coincide with the elk rut, and we hoped the peak of aspen color. A huge winter storm blew through shortly before our visit and I feared that the trees might respond by simply dropping their leaves rather than undergoing the gradual process of losing chlorophyll to reveal other bright pigments within the leaf. Fortunately my fears were for naught, and we found a beautiful display of aspens and other deciduous trees. I’m glad we visited when we did. Not long after our trip the East Troublesome Fire engulfed this area and overnight spread from a relatively small blaze to the second largest conflagration in Colorado’s history.

An aspen grove in Rocky Mountain National Park.

En route to Colorado we stopped for a night in northeastern New Mexico. Here I took some time to photograph North America’s fastest land animal, the pronghorn (Antilocapra americana).

A pronghorn buck on the plains.

Within Rocky Mountain National Park I was able to photograph a few birds including the iconic camp robber, the Canada Jay (Perisoreus canadensis). Also commonly referred to as the Gray Jay, the Canada Jay is a familiar site around campgrounds and picnic areas. The nickname “whiskey jack” is a corruption of Wisakedjak, an important figure in Cree mythology. Wisakedjak is described as a benevolent trickster. Perhaps the jay earned its name through its charming nature and sneaky picnic robbing ways.

Canada Jay

I also captured an image of a Hairy Woodpecker (Dryobates villosus) while in the park. I had watched it foraging in some dense branches when I spotted a lovely old aspen trunk and thought, “wouldn’t it be great if it landed there?”. And in a turn of events that almost NEVER happens, it went and landed exactly where I hoped it might.

A female Hairy Woodpecker

After spending a few days in the park, we headed south to the San Juan Mountains of southwestern Colorado. Here we found more beautiful fall color and were lucky enough to see an North American porcupine (Erethizon dorsatum) out and about with enough light to capture a few images.

North American Porcupine

Over the Thanksgiving break we took a trip to South Texas. We did a little bird watching on South Padre Island and found a very tolerant Green Heron (Butorides virescens).

Green Heron

While exploring a South Texas mesquite savanna, we found ourselves in the middle of a large squadron of collared peccaries (Pecari tajacu), or javelina. I was able to capture several images as they moved through the grass and brush, and just as quickly as they arrived, they were gone.

A small group of collared peccaries.

2021 is already off to a great start for me (stay tuned for more about that). I sincerely hope that it is a brighter year for so many that faced a dark 2020, and wish all of my nature loving readers another happy, healthy year filled with natural wonders.