Those who have read this blog for any length of time know that single-mindedness is not one of my shortcomings. I call myself a coleopterist and even go on trips dedicated specifically towards their study, yet find it impossible to ignore the diversity of non-beetle insects that one finds on such trips. It doesn’t stop there—insect diversity is supported by plants, interesting in and of themselves but even more so in the ways they mix and match to form distinct natural communities. And, of course, natural communities are themselves a product of the landscape—soil and terrain, moisture and its timing, elevation and latitude and longitude. Field trips for me are a constant struggle between the inner specialist—wanting to know everything about my chosen niche (beetles)—and outer generalist—wanting to know something about everything else. But wait—that was a decidedly spineless perspective. There are also animals with spines out there. Not nearly as many as those without, mind you, but that just makes them special—more of a treat to be relished when seen, and among the spined it is the reptiles that get me most excited.

Holbrookia maculata (lesser earless lizard), female(?) | Union Co., New Mexico.

This post presents a trio of reptiles that distracted my attentions one day during last year’s Great Plains Collecting Trip. We were looking for promising habitat for Prionus longhorned beetles in northwestern New Mexico (Union Co.), where two species (P. fissicornis and P. emarginatus) had been collected recently in the area’s vast shortgrass prairie. Remembering our experience the previous day finding another species (P. integer) and its burrows, we were on the lookout for anything that looked remotely like a “burrow” but found nothing. The stark grassland landscape offered little woody vegetation that made the chances of finding any other woodboring beetles remote, and eventually I became distracted by lizards darting amongst the vegetation around us. The first was one I’d never seen before—the lesser earless lizard (Holbrookia maculata), rather small lizards that were extremely wary, difficult to approach, and quick to dash behind the nearest grass clump. I managed one fairly adequate iPhone photo, but I wanted better photos and had grown weary of finding no beetles so broke out the big camera.

Holbrookia maculata (lesser earless lizard), male(?) | Union Co., New Mexico.

I presume the first photo (two above) is a female while the second photo (immediately above) is a male based on the paler coloration and less distinct black markings of the former. The preferred habitat of “relatively level terrain with sparse, low-lying vegetative cover and loose, friable soils” (Degenhardt et al. 2005) describes perfectly the habitat in which we found them. They were extremely difficult to photograph due to their proclivity to hide behind vegetation, and the two photos shown here were about as far in the open as I could get them while trying to approach with the camera.

Crotaphytus collaris (common collared lizard) | Union Co., New Mexico.

I have loved collared lizards ever since I first photographed a nice, big, colorful male Crotaphytus collaris (eastern collared lizard) in western Oklahoma back in 2009. When I saw this still striking but much less colorful individual, I didn’t know what species it was, but I didn’t think it was the eastern species that I had already encountered not only in Oklahoma but also several times on igneous glades in my home state of Missouri. To my surprise, however, the eastern species is the only one inhabiting New Mexico (Degenhardt et al. 2005)—other species distributed further to the west or south. I had better luck photographing this individual, for even though it occasionally ducked into the vegetation (allowing one charming shot of it peering above the “grass” line—see third photo below) it was also content to stay out in the open along the gently sloped road bank where I had found it and dart from spot to spot between suspicious glares. This particular individual was smaller than the big males I have seen, so I suspect it is either a female or a juvenile.

Not shy about remaining fully exposed, it clambered atop a rack to watch more carefully.

Degenhardt et al. (2005) mention an interesting factoid about collared lizards regarding the fact that they, unlike many other lizards, do not readily lose their tails (autotomy). Collared lizards are fast runners, often rearing up on their two hing legs, for which an intact tail would be an important organ for maintaining balance. In the case of these lizards, the advantages of rapid locomotion probably outweigh benefits from tail autotomy.

Peering charmingly above the “grass” line.

While two reptile species at one stop might seem doubly lucky, little did I know a hat-trick still awaited me. We still had no solid evidence to suggest that Prionus beetles were active in the area, but we set out two traps anyway because the soil exposures seemed similar to those we saw the day before and then moved just down the road to where the soils turned redder and seemed to have higher sand content to set one more trap. As Jeff set the trap, my distraction with saurian subjects continued when I ran into a marvelously camouflaged western hognose snake (Heterodon nasicus).

Heterodon nasicus (western hognose snake) | Union Co., New Mexico.

Western hognose snakes are typically found in grassland habitats with sandy soils (Degenhardt et al. 2005), so the occurrence of this individual at this spot was no surprise. What was a surprise was how strikingly marked this individual looked compared to the other two individuals I’d seen to this point—the first a more subtly marked individual in a rare sand prairie in southeastern Missouri, and the second a more uniformly mottled individual in northwestern Oklahoma’s Salt Plains National Wildlife Refuge. This could be a result of subspecific differences—Missouri populations are assigned to the subspecies H. nasicus gloydi (dusty hognose snake), but I am unsure of the subspecific assignment of the Oklahoma individual. According to Degenhardt et al. (2005) only the nominate subspecies occurs in northern New Mexico (subspecies H. n. kennerlyi can be found in the southwestern part of the state, while intergrades with subspecies H. n. gloydi are said to occur in the extreme southeastern part of the state).

The strongly upturned rostral (snout) is one character distinguishing the western from the eastern hognose snake.

All species of hognose snakes are famous for their well-choreographed sequence of defensive displays. While they are said to rear up cobra-like and strike out with their mouth open while hissing, I have never seen this behavior by any of the western or eastern hognose snakes that I’ve encountered. The first western individual I saw (in Missouri) insisted on continually trying to burrow into the deep, loose sand and made no other defensive display, while the eastern individual referenced above simply tried to run, although it did eventually barf up a half-digested frog! The individual shown here seemed reticent to do much of anything, remaining coiled up and watching and coiling even tighter as my molestations continued. At last, this one performed some theatrics by writhing in mock agony and then rolling over on its back and playing dead (a behavior called thanatosis). The Oklahoma snake also did this, adding further dramatic value by opening its mouth wide, allowing the tongue to protrude, and ejecting blood from the lacrymal glands while emitting musk from the cloaca. This one didn’t do too much with its mouth, but it did so much more with its cloaca (defecating!). If the idea of eating a snake isn’t revolting enough to begin with, then surely eating a snake covered in crap is!

The ultimate in thanatotic displays—not only dead, but covered in crap!

In addition to the strongly upturned rostral (snout), best seen in the second photo above (the rostral is only moderately upturned in the eastern species), the black-checkered ventral coloration seen in the third photo confirms this as the western hognose species. The eastern hognose snake is distributed further east and does not occur in New Mexico (Degenhardt et al. 2005).

In an amusing twist to the search for Prionus at this site, while photographing the animal I happened to look down to my side and saw a male Prionus beetle crawling through the vegetation! I recognized the species immediately as P. fissicornis—represented in my cabinet by only a single specimen, and although Jeff and I would find no more after a through search of the area, our traps yielded a “bucket loads” of the beetles the next morning.

REFERENCE:

Degenhardt, W. G., C. W. Painter & A. H. Price. 2005. Amphibians and Reptiles of New Mexico. University of New Mexico Press, 507 pp. [Google Books].

© Ted C. MacRae 2015