Great Sand Dunes National Park | Saguache and Alamosa Counties, Colorado (click for 1680 x 887 version)

Last year’s Annual Fall Tiger Beetle Trip entered its last day as an unqualified success. Travel partner Jeff Huether and I were doing the “Great Western Sand Dune Tour” on a quest to find and photograph some of North America’s most geographically restricted tiger beetles. The first four days featured successful visits to northwestern Colorado’s Maybell Sand Dunes for Cicindela scutellaris yampae and Cicindela formosa gibsoni, southeastern Idaho’s St. Anthony Sand Dunes for Cicindela arenicola, and southwestern Utah’s Coral Pink Sand Dunes for the prize of the trip—Cicindela albissima. The only endemic that we had failed to find was Cicindela waynei at southwestern Idaho’s Bruneau Sand Dunes (hopefully this was a result of poor fall emergence conditions rather than an indication of further decline of this perilously endangered species).

Small sand dune west of GSDNP in the Nature Conservancy's Medano-Zapata Ranch.

Day 5 featured a visit to southwestern Colorado’s Great Sand Dunes to look for the endemic Cicindela theatina. As on every day previous of the trip, the morning drive saw cool but rising temperatures under bright, sunny skies, so we were optimistic about our chances. Between Great Sand Dunes National Park (type locality of the beetle) and The Nature Conservancy’s Medano-Zapata Ranch west of the park, the entire 290 km² range of C. theatina is on protected land. Not knowing whether the beetle would be out and, if so, how extensively it would occur, our plan was to approach the Park from the west through Zapata Ranch and stop at any sand dunes we sighted along the way until we found the beetle.  It didn’t take long—as soon as we entered the Ranch we began to see small sand dunes in the distance, and within minutes after making the 1-km hike towards one particularly promising looking dune we saw the beetles. Even though this was the fifth western sand dune endemic I had seen in as many days, the first moment I laid eyes upon it was no less exciting—flashing red and green on coppery, white marked elytra, it seemed all hair and teeth!

Great Sand Dunes tiger beetle (Cicindela theatina) | Medano-Zapata Ranch

Despite this being my first sighting of the species, there was no doubt about it’s identity. The only other tiger beetle that occurs with and could possibly be mistaken for C. theatina is the blowout tiger beetle, C. lengi; however, the broad marginal band that runs completely around the elytra and the green/brown dorsal coloration of C. theatina are enough to distinguish it from that species. Temperatures were still a bit on the cool side, but the beetles were already remarkably active and skittish. Like the other sand dune species we had already seen, they were enormously difficult to approach—numerous failed attempts were necessary before I encountered the slightly more cooperative female shown in these photos (although she still required several minutes of stalking to get her sufficiently accustomed to my presence to allow these shots).

Like most sand dune tiger beetles, adults are densely hairy on the lateral and ventral surfaces.

Adults ''hug'' the sand for warmth during the cooler morning hours.

The dense covering of white hairs on the lateral and ventral surfaces of the adults belies their adaptation to the abrading sands of their wind-swept habitat. Scouring sands, however, are not the only hardships that the adults must contend with. Temperatures on the dunes can range from as low as 40° F on a chilly morning to nearly 140° F during the heat of the day. Accordingly, much of the adult beetle’s activities revolve around thermoregulation to maintain optimal body temperatures for activity (Pineda and Kondratieff 2003). These include not only stilting, shade-seeking, and mid-day burrowing to avoid excessive warming (see my post Tiger Beetles Agree—It’s Hot in Florida! for examples of these behaviors), but basking to gain warmth when temperatures are still a bit too cool for effective foraging (photo above).

Fabulous metallic red and green highlights on the head and pronotum contrast with the reddish brown elytra and their white lateral markings.

Despite the fact that the entire range of this species is encompassed by protected land, WildEarth Guardians filed a petition for federal listing as an endangered species in 2007 (Tweit 2010). Whether protection will be granted remains to be seen—Coral Pink’s C. albissima has a global range only 1.3% the size of C. theatina‘s range (only slightly more than half of which is on protected land), yet that species has been awaiting listing for nearly three decades now! (Too bad C. theatina doesn’t have real fur, feathers, or those endearing mammalian eyes that would surely allow it to jump to the front of the line.)

For the first time in BitB Challenge history, we have a 4-way tie for the win. Dorian Patkus, Mr. Phidippus, Mike Baker, and David Winter all share the honors for ID Challenge #15. Mr. Phidippus is the big winner, however, as he strengthens his grip on the overall lead with a lead of 13 or more points over his nearest rivals (Roy, Tim Eisele, Mike Baker, and Dennis Haines). The competition is far from over though—a single misstep is all it would take to see the emergence of a new leader before this session is over.

REFERENCES:

Pineda P. M. and B. C. Kondratieff. 2003. Natural history of the Colorado Great Sand Dunes tiger beetle, Cicindela theatina Rotger. Transactions of the American Entomological Society 129(3/4):333–360.

Tweit, S. J. 2010. Beetle Mania. National Parks 84(4):24–25.

Copyright © Ted C. MacRae 2012