#106 - Arizona Tarantulas - a December Field Trip with Brent

Aphonopelma catalina, A. chalcodes, A. madera, A. paloma, A. parvum, and A. saguaro, with a guest appearance by A. superstitionense. All in one week; the first week of December. Seven of Arizona’s tarantula species, which sounds like a big number until you realize that sevenTEEN can be found within the borders of “The Grand Canyon State”.

Saguaro, icon of the Sonoran Desert where Brent and I spent the first week of December

Saguaro, icon of the Sonoran Desert where Brent and I spent the first week of December

Full disclosure: the Aphonopelma superstitionense specimens (both male and female) were collected by someone else in advance of our arrival, which allowed Brent Hendrixson and I to only briefly search for this species before concentrating our efforts elsewhere. Three other species were either not targets at all or only of secondary interest. A. chalcodes is Arizona’s most ubiquitous tarantula, widely ranging across the state south of the Colorado river. This species wasn’t of interest. We saw some open burrows but left them alone. Most had been plugged up as this species becomes dormant in late fall and winter and doesn’t resume activity until spring. Brent found one small specimen while flipping rocks in the Santa Catalina Mountains. We did make a trip to an area near the Pinaleño Mountains for A. parvum, in a desert grassland where it is active and breeds in the fall after the syntopic A. gabeli and A. vorhiesi found in the same area become dormant after their late spring and summer breeding seasons, but we were also drawn to the area by a desire to search the nearby mountain range as well. In October Brent had stayed with me in Cave Creek Canyon and we had found A. parvum in the desert grassland near Portal, AZ then and didn’t need to see it again, but just wanted to see if the population between Willcox and Safford was still active the first week of December. Finally, A. madera was another species that wasn’t a goal of this field trip as it has been encountered a number of times previously, but we decided to hike in the Santa Ritas and were just curious if males were still to be found. It was a pretty chilly morning during our ascent of Old Baldy Trail, but the sun was warming Madera Canyon when we were done with our hike so we drove the paved roads and finally I saw one male on the road as we were exiting the canyon. 

So what determined what the target species were? Well, Brent has now disclosed via a social media teaser the project he has been working on so I guess I can reveal it here. He has been seeking and photographing specimens to produce a comprehensive field guide to the scorpions and tarantulas of the United States featuring his own high quality isolated-on-white portraits of each species. Even species he has found and photographed over the years have been sought again over the past couple in order to re-photograph with new gear and technique. Readers of this blog know he already had visited me a few times earlier in the year (see #96, #102) and this early December trip before I headed to Chicago/Malaysia for the winter was to complete his 2018 search for United States tarantulas and scorpions. Our two primary targets were two elusive, difficult to find species: Aphonopelma catalina and A. saguaro. America’s smallest tarantula, A. paloma, became a secondary target as I wanted to see it at the species’ type locality near Maricopa, between Phoenix and Tucson.

After storing my Wheelhouse at Rusty’s north of Rodeo, NM, I drove to Phoenix and spent Friday night in a hotel near the airport. Saturday morning I picked up Brent and we hiked a trail in a canyon where A. superstitionense lives. We didn’t find the species active that day or locate any burrows, but as I wrote above a friend of Brent’s who lives in Mesa had already found him both males and females a few weeks earlier, and they were from the same canyon. So that night we picked up those specimens before enjoying a nice Thai dinner. Sunday we moved from Phoenix southeast to Tucson and detoured to the A. paloma site near Maricopa along the way.

Type locality,  Aphonopelma paloma .  This sandy soil is very difficult to dig in. This desert is primarily vegetated with shrubs like creosote bush and triangle-leaf bursage with some brittlebush or desert-thorn. The short trees in the image are paloverde, and although not seen in this photo the area also has sparse cacti including fishhook barrel cactus and saguaro.

Type locality, Aphonopelma paloma. This sandy soil is very difficult to dig in. This desert is primarily vegetated with shrubs like creosote bush and triangle-leaf bursage with some brittlebush or desert-thorn. The short trees in the image are paloverde, and although not seen in this photo the area also has sparse cacti including fishhook barrel cactus and saguaro.

Burrow,  Aphonopelma paloma .  This is a classic  A. paloma  burrow with a crescent-shaped pile of excavated sandy soil to one side of the perfectly round burrow opening. The smallest species in the United States, this one-inch long tarantula lives in burrows the diameter of a pea. The tiny tunnels can be complex and deep and the composition of the earth also makes it very difficult to extract these spiders.

Burrow, Aphonopelma paloma. This is a classic A. paloma burrow with a crescent-shaped pile of excavated sandy soil to one side of the perfectly round burrow opening. The smallest species in the United States, this one-inch long tarantula lives in burrows the diameter of a pea. The tiny tunnels can be complex and deep and the composition of the earth also makes it very difficult to extract these spiders.

Adult female,  Aphonopelma paloma , Pinal County, Arizona.  Legspan the diameter of a quarter.

Adult female, Aphonopelma paloma, Pinal County, Arizona. Legspan the diameter of a quarter.

The Paloma species group of Aphonopelma is unique in its miniaturization. Comprised of a dozen species that live among larger species, but not among other “mini tarantulas”, the seven Arizona representatives are A. paloma plus A. mareki, A. parvum, A. phasmus, A. prenticei, A. saguaro, and A. superstitionense. For the most part they breed in the autumn after the active periods of the larger tarantulas in the area are coming to an end. With the above female A. paloma “in the bag”, Brent and I next turned our sights on A. saguaro.

We left the Maricopa - Casa Grande area and checked into the Tucson hotel where we’d spend the next five nights. Just down the road was a Whole Foods Market where we’d get most of our meals and it had a bar where we enjoyed a few beers Sunday night with more over the course of our stay. Monday morning we met up with Paul & Karla, a husband and wife from the Wickenburg, Arizona area that Brent had known previously. They wanted to hike and search for tarantulas with us and they were waiting for us at Bear Canyon west of the Santa Catalina Mountains when we arrived. This is where we would search for Aphonopelma saguaro. We were fortunate to come across a couple of burrows right along the trail and Brent persevered to dig among roots and rocks for quite some time to extract a tiny adult female. Later after a nice hike Paul tried his hand at digging another on our return trek. While he was at it Brent went down the trail in search of a male and as I started to follow and saw him approaching I witnessed him look down and give me the thumbs up. Right there at his feet along a little stream was the only male we would see.

Aphonopelma saguaro , female (top) and male, Bear Canyon, Pima County, Arizona

Aphonopelma saguaro, female (top) and male, Bear Canyon, Pima County, Arizona

After lunch Paul & Karla also joined Brent and I for a trip into the Santa Catalina Mountains where we drove up to nearly mile-high elevation, parked and climbed a mountain trail in search of the endemic Aphonopelma catalina. We had little expectations going in of finding the cryptic burrows of females in the rugged and rocky mountain terrain, but were hoping to come across males wandering the trail ascending the Sky Island. On the climb up we found a male at almost exactly one mile above sea level (5267 ft at 2:42 pm), saw nothing else as we pushed on for a couple more miles and then found another male in a hole in the trail descending the trail two hours later within a couple hundred feet of the first male. Searching the area near the males did not result in finding any female burrows and we later said goodbye to Paul & Karla and ended up at Whole Foods for dinner.

Tuesday was our Madera Canyon visit and Wednesday the trip out toward the Pinaleños and the nearby A. parvum site. Each night Brent and I had been trying to catch sunset photos without the sky cooperating, but on Wednesday night we made our third attempt at Catalina State Park and were able to catch a colorful Sonoran Desert dusk on the Nature Trail Loop.

Sunburst at Catalina State Park

Sunburst at Catalina State Park

Pink Sunset at Catalina State Park

Pink Sunset at Catalina State Park

On Thursday we returned to the Santa Catalina Mountains to search the area where the two male Aphonopelma catalina had been found on Monday afternoon. They had been encountered so close to each other and the area was along a flat stretch of trail with extensive grassy and rocky areas where females must occur. Other than the desert grasses the vegetation was mostly limited to sparse bushes and the occasional small emory oak tree. Rain had been forecast for the latter half of our week and we had been fortunate so far, but Thursday there was an 80% chance of precipitation predicted for the afternoon so we were up the trail early and searched with some sense of urgency. I’ve blogged and published about A. chiricahua, another Sky Island endemic, and people ask why these spiders are so elusive or difficult to find. There are a number of reasons including steep and rugged terrain with heavy cover and cryptic burrows that may be atypical (e.g., beneath cover, not perfectly round, not covered or accompanied by silk). Brent focused on flipping rocks and searching near them while I used my walking stick to move the tall grasses to look for burrows that might be hidden from view. Beneath the numerous rocks, Brent found a four-inch Southwestern Black-headed Snake (Tantilla hobartsmithi), a scorpion (Superstitionia donensis), a young A. chalcodes tarantula, and even a mouse, but neither of us found what we were looking for. I found some holes that were promising enough to pour some water into but saw nothing and started second-guessing myself, wondering if some I dismissed as rodent holes might actually be tarantula burrows. The skies were threatening and after an exhaustive search of the area we decided to move up the trail. We hadn’t gone far before I found the day’s only male on top of a large boulder and Brent looked a few feet below it and saw a hole. It wasn’t instantly recognizable as a classic tarantula burrow but there was a clump of silk outside it that Brent called “crusty”. We actually wondered whether it could have been this male’s retreat before maturity. Brent got his digging gear out and went to work on it even if we were still doubtful. The ground was very rocky and he immediately had difficulty excavating around the tunnel. We thought that a huge rock might make proceeding impossible, but after removing several large rocks beneath a larger one, Brent could scrape away at the exposed earth and perhaps five minutes later said he saw legs. It would have been so easy to give up on this hole. At discovery it looked questionable and during digging it seemed improbable that the terrain was even workable. The first glimpse of the forelegs had us believing it was a young spider so we were extra surprised when it finally came into view and we knew we had an adult female Aphonopelma catalina, a spider we doubted would see.

Aphonopelma catalina , female, Santa Catalina Mountains, Pima County, Arizona

Aphonopelma catalina, female, Santa Catalina Mountains, Pima County, Arizona

Aphonopelma catalina , male #1, Santa Catalina Mountains, Pima County, Arizona

Aphonopelma catalina, male #1, Santa Catalina Mountains, Pima County, Arizona

Our early start to try to find our spider before rain washed out the rest of our week meant that we had achieved success by 10 a.m. As it turned out, the rain didn’t fall until after dark, but we didn’t know that yet. We just knew that we had exceeded our expectations for the week and had found all of our targets. We went to Whole Foods for lunch and then realizing that the afternoon might be dry decided to hike into nearby Pima Canyon. Each day of the week we had hiked 6-10 miles and it was great to get one more beautiful Sonoran Desert experience before I would head to Chicago and Brent would return to Mississippi.

Friday we checked out of our Tucson hotel and moved back to Phoenix in preparation for Brent’s early Saturday morning flight. We decided to return to the A. paloma type locality site as during our first visit we didn’t find any males. We were more interested in knowing whether they were still active than collecting or photographing. What we discovered is that the female burrows we had found six days earlier were now plugged and again we saw no males. We had caught them right at the end of their season. And so it was also the end of the season for us. We returned to Phoenix and again found a Thai restaurant for dinner and before dawn Saturday morning I dropped Brent off at Phoenix Sky Harbor International Airport. I then drove four hours back to Portal to pick up my parrot Jesse. She had been kindly cared for by my friend Carol while I was off chasing hairy spiders. Then I drove a few hours east to overnight in Las Cruces, New Mexico. This morning I drove 570 miles from Las Cruces to Elk City, Oklahoma. I have 1000 more miles to Chicago …