#94 - An Endemic Tarantula

For the ten years prior to beginning my road odyssey last year, most of my travel had been to exotic locales in search of tarantulas. Costa Rica, Suriname, Sri Lanka. These were destinations chosen for tarantula field work. Even Malaysian holidays had a primary focus on tarantula hunting. Even going back over thirty years, my road trips to Texas had an arachnological mission.

True, snakes and other reptiles were my primary distraction and deviation, and more than once on that first Costa Rican adventure in 2006, my mate and field trip leader Andrew Smith tried to rein in my desire to chase things that slither with commands of "Tarantulas, Michael, tarantulas!". Now an avid birder and wildlife photographer who often has mammals or other charismatic megafauna in the lens, I'd like to think that I was always a generalist naturalist. I love nature in all its forms. As enthralled as I was by the gorgeous red-legged tarantula (Megaphobema mesomelas) in Costa Rica, the world's largest spider in Suriname (Theraphosa blondi) or my beloved tiger spiders (Poecilotheria sp., ornamental tarantulas) in Sri Lanka, along those journeys Costa Rican hummingbirds enchanted, Surinamese labaria vipers thrilled and a fortunate sighting of a leopard in Sri Lanka amazed. Do I even need to mention orangutans and tree vipers in Borneo, or dusky leaf monkeys and hornbills in Malaysia?

Still, my tarantula-obsessed friends have wondered why my Instagram feed and blog entries have neglected the tarantula. Andrew has emailed me inquiring as to whether I do any tarantula hunting. In truth, last year I paid more attention to scorpions than tarantulas, and much more time was spent in pursuit of rattlesnakes. This year I am all over the place, chasing microfauna like robber and owl flies one moment and bears, bobcats and even the mountain lion the next. For the past two years, with only a few exceptions like the Rio Grande Gold Tarantula (Aphonopelma moderatum) in Texas or the beautiful Aphonopelma marxi tarantula from north of Silver City, New Mexico, both of which were female spiders I observed in burrows, the only tarantulas I have encountered have been wandering mature males found here in southeastern Arizona and southwestern New Mexico while out road-cruising for snakes.

It isn't that I have forgotten tarantulas. It is just that, firstly, this rugged area frustrates tarantula hunters and, secondly, I have many interests. Searching grasslands and desert scrub for burrows for the more abundant species in this region is hard work, so I guess an argument could be made for a third factor: laziness. Admittedly, a fourth reason could be collector bias for sexy spiders. When you've seen stunning tarantulas like Megaphobema mesomelas in Costa Rica and Poecilotheria subfusca in Sri Lanka, the local "brown jobs" like the local Aphonopelma gabeli and A. vorhiesi honestly don't have the same allure.

But let's get back to the first reason. My experience tarantula hunting in this region is limited, but my friend, arachnologist Dr. Brent Hendrixson, knows the tarantulas of the American Southwest better than anyone and has spent years and years searching for them. He has told me repeatedly that they can be very difficult to find. Many make their burrows beneath rocks or in scrapes where flipping rock after rock becomes the search method. Did I mention my laziness? At night I'd rather road cruise for snakes or black light for scorpions (the former enhanced by air conditioning and music; the latter makes finding scorpions rather effortless), and during the blazing heat of the day I can't bring myself to walk alone through the desert turning rocks.

However, there is one tarantula in the region that began to intrigue me. By now every reader should know of my deep love for the Chiricahua Mountains and that this year I am actually living right in the mountain range's Cave Creek Canyon. I have spent little time out in the surrounding flatlands. Most of my time is spent at 5000' or above, from the pine-oak woodlands of the rocky canyons and adjacent riparian zones up to the coniferous forests at 7500' and higher. And there is a newly described species of tarantula that lives in the Chiricahuas from 5000-8000'.

Aphonopelma chiricahua was described in 2016 by Brent and his two co-authors in a complete revision of the American species in the genus (all U.S. tarantulas belong to the genus Aphonopelma, but the genus reaches Central America). Their paper created many synonymies drastically reducing the number of species in the United States (currently 29), but it also established a number of new species endemic to specific localities (primarily Sky Islands) including Aphonopelma chiricahua, which occurs only in pine-oak woodland and mixed conifer forests here in the Chiricahuas.

Last week I encountered my first wandering males of the season while driving Portal Road at night. I was returning to Cave Creek Canyon from road-cruising out in the desert and found two males - the first just west of Portal and the second a little over a mile later closer to the entrance to the canyon. They looked freshly molted and I sent images to Brent for identification help. Mature male A. gabeli and A. vorhiesi look very similar, but it was the time of year that made him think it was probable they were the former species, which matures and breeds earlier than the late summer breeding A. vorhiesi. I had found plenty of both last year, and seeing my first males of the year stirred a desire to find something else. Yes, to tarantula hunt once more! Brent was on the road doing his own tarantula hunting in New Mexico and Texas during our conversations, and while I waited for replies I spent a good deal of time re-reading pertinent sections of the 340 page generic revision he co-authored. It reminded me that the "Arizona blonde" tarantula A. chalcodes is even found in this region (Brent found a male on the road to nearby Paradise that I drive frequently), which made me further bemoan how unlikely it was for me to find a female of any species in its burrow. But what really enticed me was the section on A. chiricahua.

The endemic species in the Chiris was described from only a handful of specimens. The male holotype (a single type specimen upon which the description and name of a new species is based) was actually caught by a retired biologist who is now an area realtor and is well-known to me. That was surprise number one. This male was found at 5083 ft. elevation on the road only a mile up canyon from the corral where my Wheelhouse is camped. Surprise 2. I then learned that the female paratype (additional specimens in the type series, other than holotype, used to describe a species) was from the area surrounding the Southwestern Research Station of the American Museum of Natural History (SWRS). It was collected at 5436 ft. and had been preserved for years at Auburn University in Alabama. The species description of Aphonopelma chiricahua in Hamilton, Hendrixson & Bond, 2016 was accompanied by no photo of a live female. An additional male was designated as paratype and, in total, eight specimens were examined for the species description within the Aphonopelma revision/monograph. The paratype female was the only female. The highest elevation male came from 8432 ft. near Rustler Park. 

Surprise #3 was that this species breeds in autumn. That meant that I wasn't going to come across wandering males this summer. My personal correspondence with Brent made me aware that he knows of females being seen on the roads during summer, presumably flushed out of their burrows during the summer monsoon rains. I began to hope I would be lucky enough to find one.

Jump ahead to this past Thursday, better known as the first day of summer. My previous blog entry recounted my experience that morning observing a behemoth of a black bear on the road just up canyon from the corral. What happened after the bear sighting is what concerns us here. As I have mentioned many times in many blog entries, I often don't know where I am going until I get there. I don't really plan my free days in advance. My truck is guided by whimsy. I could have easily gone hiking up on the Basin Trail in search of snakes or just walked my well-worn path on South Fork looking for Elegant Trogons and other birds. But I passed South Fork Road and then didn't turn off the forest road at the research station as I would have for the Basin Trail, Ash Spring or other popular destinations where I often hike. I decided to, for the countless time, to hunt an area above the research station for Rock Rattlesnakes. I have spent many hours in this prime location without success, but that doesn't prevent me from climbing the steep rocky hillside and shining my flashlight into likely crevices among boulder piles yet again. And this time it was in the back of my head that the location center for Aphonopelma chiricahua was also here. As the description reads, "Most specimens in natural history collections have been collected near the AMNH's Southwest(ern) Research Station".

The rock rattlesnake site is based on information from a friend who was part of a group that observed three within 30 yards of each other there during last year's SWRS field herpetology course. It is up a hillside adjacent to the SWRS, but accessed from about a mile up the road. That's about as specific as I choose to be. The steep slope has rock slides and boulder piles and is pine-oak woodland with pinyon pine, scrub oak, alligator juniper, Palmer's agave, prickly pear cactus, mountain yucca and numerous grasses, etc. After ascending to the area that looks like prime rock rattlesnake habitat and scouring the rocky terrain, I decided to continue to crest the hill and entered a grassy area at the top. I continued to hike down canyon from the highest elevation, which means towards the SWRS. I was wondering if I would find a vista where I could see the research station below. Most of my snake searching had been concentrated to a very rocky area about half the size of a football field and I have made a handful of visits this year to combine with dozens and dozens last year. This was, however, the first time I had gone all the way to the top, which reaches almost 5800 ft. above sea level and has extensive grassy flat areas. I found a large area cleared by ants and stopped to enjoy the breathtaking views of the canyon and the valley below. My mind turned to spiders and I began criss-crossing the top of the hill looking for any small creature to photograph. My camera had my macro lens and ring flash on it and I flipped some rocks looking for a subject. Always hoping for a snake or lizard, any beetle, bug or spider would do.

I hadn't hiked with my attnetion focused on the ground for more than a few minutes when I stopped in astonishment. There in my path on what seemed like a well-worn animal trail was a perfect tarantula burrow covered in silk. The species description of A. chiricahua is based on limited natural history information. It states, "Very little is known about the natural history of this elusive species. No burrows or shelters have been observed but these spiders probably seek refuge under rocks and rarely place silk around their burrow entrances". Elusive. Little known. I was very excited as I realized that this must be the spider and here I had found a perfect burrow near the type locality. The morning sun was rising fast and with a high temperature of 100F predicted I was hot, sweaty and tired from my climb. But I forgot all as I dropped to my knees and photographed the "textbook" silk-covered burrow. Perhaps the "rarely place silk" was presumptuous.

  Only a tarantula burrow looks like this. There was no question what lived inside.

Only a tarantula burrow looks like this. There was no question what lived inside.

There are several ways to coax a tarantula from its burrow: flushing, tickling and digging. The latter is to be avoided as the tarantula can be injured or trapped, and it is destructive to the habitat. Furthermore, if you just want to photograph and release you are left to rebuild the retreat and it will always yield a very unsatisfactory result for the spider and alters the habitat. Arachnologists simply cannot dig perfectly round tunnels into the earth terminating in a chamber. Flushing is an easy and non-destructive means that works remarkably well in arid habitat. In essence you are simulating a flash flood and the tarantula will instinctively flee its tunnel and chamber rather than risk drowning inside. When tarantula hunting in the desert one normally carries jugs of water for this purpose. Hiking up the hillside I only had one 20 oz. water bottle and I had already drank half of it. We'll come back to "tickling" in a moment. First, we have to use a twig to brush away the silk layer the tarantula created to shade its retreat and deter pests like ants from house-crashing.

  Tarantulas dig their own burrows and many are so perfectly round it is as if they were drilled by a coring machine.

Tarantulas dig their own burrows and many are so perfectly round it is as if they were drilled by a coring machine.

With the silk removed and the hole once again photographed (yes, we tarantula hunters have far too many images of seemingly empty holes in the ground), I didn't give a moment's thought to my hydration despite my thirst and the heat. I began to pour the last ten ounces of berry flavored electrolyte-enhanced water in my possession down the hole. The orangish-brown furry legs that came forward put a big dorky smile on my face.

   Aphonopelma chiricahua  at the entrance to its lair

Aphonopelma chiricahua at the entrance to its lair

Alas, ten ounces hardly simulates monsoon rain flash flooding. The handsome rusty-brown tarantula came to see the light of day and its trespasser, but then just as swiftly retreated to darkness. I was out of flushing water and also now had nothing to quench my thirst. Two more full water bottles and backup gallon jugs were in my truck way down the hillside. So it was time to practice the art of tickling. But first, let's look at the habitat where the spider and I were spending the morning of the first day of summer.

  In the center foreground you will see my walking stick inserted in the burrow when I returned later that evening to take additional photographs and record GPS coordinates lost during the excitement.

In the center foreground you will see my walking stick inserted in the burrow when I returned later that evening to take additional photographs and record GPS coordinates lost during the excitement.

Tickling involves using anything from a blade of grass to a twig to entice the tarantula to the mouth of its burrow. There are various techniques used that range from dexterous finesse to a slightly more aggressive approach. Each of the gents I have pursued tarantulas with in the field has a personal touch. I admittedly lean toward the aggressive. Tickling can simulate a prey item and, in fact, tarantulas will often grab the twig with their jaws/fangs and can almost be tugged out of the hole. Tickling is usually accompanied by using the free hand to shade the hole so sunlight (or flashlight at night) is less likely to spook the spider. The finesse method employs brushing the forelegs and/or gently tapping the tunnel to elicit a feeding response. This brings the tarantula close to the opening, and typically requires many tries. My impatience usually gets the best of me and I tend to let the length of grass or twig go over or beside the tarantula when the opportunity arises so I can smack its little behind and encourage it to come out post haste. Overheated and without water, with the sun and temperature climbing, I relied more on the aggressive approach. I couldn't shade the hole with my free hand because I was trying to film video of the tickling with my iPhone, nine second of which can be seen below. With the glare of the sun and salty sweat running into my eyes preventing me from really seeing what was on the screen, and my heart racing with the excitement of finding this species in its burrow, the result wasn't great. 

I set down my phone for my final "tickle" and the spider came out. It was missing a leg and I couldn't help but wonder if I caused that during my sun-blinded, overly excited, aggressive tickle. Tarantulas readily autonomize their legs, which will regenerate during next molt. Within two molts the replacement leg will look like the original. With the spider out I then had to quickly decide what to do. I flattened my hand over the burrow opening to prevent reentry while I collected my thoughts. Normally I collect nothing. I might "temporarily restrain" for a later photo shoot in better conditions and later release in exact location, but I quickly realized that this specimen would be important to Brent as a research specimen. He will be visiting the Chiricahuas next month so he can take it for his own photo session. I know full well that it is likely he will pickle it for science, but I try not to dwell on that. I collected scorpions for him last year, and I resigned myself that this tarantula would be a gift to him. I would keep it alive until he and his summer field arachnology students arrive in the Chiricahuas. But, like I said, I don't collect and therefore I had no container. I had my camera, my iPhone, one - now very empty - water bottle, and my walking stick. Thankfully, my water bottle has a wide mouth lid and I put the tarantula inside. It was getting hot quickly so I hurriedly used my Gaia GPS app to find the waypoint and scrambled down the hill before the stainless steel bottle became too hot for the spider within. It wasn't until later that I discovered that in all the excitement I hadn't actually saved the waypoint. I had descended the hillside with a spider without exact location and elevation. I also descended rapidly through an unfamiliar area and wasn't sure where exactly I had been. Still, I'd have to hope I could find the burrow at a later date.

Back at my truck I grabbed a small box waiting for the trash and filled it with dirt and leaf litter from the area. I had one vacant custom tarantula home back at the Wheelhouse that was currently storing millet spray for my parrot that I would use to create a terrarium for the spider. Then I drove straight back to the corral to take some photos and build its new home. Back to WiFi, I posted the above video to my Instagram story and texted Brent. I was one happy tarantula hunter. Later that same evening, after the 100F had dropped to 90F, I returned to the hillside and tried to retrace my steps after climbing back up the rocky slope (again seeing no freaking rock rattlesnakes). I wandered a bit aimlessly for about thirty minutes once I reached the summit until I remembered the small dead tree near the burrow. It can be seen just to the left of my walking stick in the above habitat photo. Once I found that landmark, the burrow was easy to find and I was able to record the precise location. The burrow was at 5645 ft. elevation. As the crow flies it was just under three miles up canyon from my camp, almost directly north of the west side of the complex that is the AMNH Southwestern Research Station. And now I am on a quest for more. And a cricket or two to feed my new roommate ...

   Aphonopelma chiricahua , 5645 ft., Chiricahua Mountains, Cochise Co., Arizona

Aphonopelma chiricahua, 5645 ft., Chiricahua Mountains, Cochise Co., Arizona