Cicindela willistoni estancia. Photo by David Melius.
The latest issue of CICINDELA (December 2009, vol. 41, no. 4) contains an interesting paper by David A. Melius titled, “Post-monsoonal Cicindela of the Laguna del Perro region of New Mexico.” This paper continues a theme that I have touched on a few times in recent posts regarding the partioning of resources by multiple species of tiger beetles utilzing the same habitat. The author reports on the results of two visits to the Laguna del Perro salt lake region of New Mexico (Torrance County) in July 2009, during which time he recorded a total of eight tiger beetle species in the area. As in many other parts of the arid west, tiger beetles in this region are highly dependent upon summer monsoonal rains to trigger adult emergence (Pearson et al. 2006), resulting in multiple species occupying a given habitat during the relatively short post-monsoonal period. However, according to the competitive exclusion principle (Hardin 1960), two species cannot stably coexist in the same habitat and compete for the same resources—one of the two competitors will always overcome the other unless resources are partitioned to avoid competition.
Cicindela willistoni estancia. Photo by David Melius.
Tiger beetles that occupy the the same habitats employ a variety of mechanisms for avoiding direct competition. One of these is partitioning the environment into different “microhabitats.” One of the earliest reports of this was by noted American ecologist Victor Shelford, who reported that adult tiger beetles on the southern shores of Lake Michigan occupied different habitats from water’s edge to oak forest floor (Shelford 1907). Similarly, Choate (2003) found three sympatric species of tiger beetles in a coastal mudflat region in South Carolina, each of which utilized a different portion of the salt marsh. I myself have noted multiple species occupying the same habitat in Oklahoma’s Salt Plains National Wildlife Refuge, on a coastal salt marsh in Florida, and in the White River Hills of southwestern Missouri.
In the present study, the author noted distinct preferences among the eight species for different microhabitats within and adjacent to the salt flats, including 1) thick, wet mud immediately adjacent to the water, 2) damp, soft sand 10-20 m from the water and devoid of vegetation, and 3) dry to damp sand further away from the water with salt-tolerant plants. Nearby roadside habitats were also noted as an additional microhabitat. The species found and their preferred niches were:
- Cicindela fulgida rumppii, exclusively in vegetated dry sand areas around the salt flats.
- Cicindela (Cicindelidia) nigrocoerulea, mostly 10-20m from the water’s edge, a few also in roadside habitat.
- Cicindela (Cicindelidia) punctulata chihuahuae, exclusively in roadside habitats.
- Cicindela (Cicindelidia) willistoni estancia, mostly along the water’s edge.
- Cylindera terricola cinctipennis, exclusively in dry grassy areas away from the water.
- Ellipsoptera nevadica, exclusively along the water’s edge.
- Eunota togata fascinans, unvegetated areas near and 10-20m from the water’s edge.
- Habroscelimorpha circumpicta johnsoni, limited to roadside habitats and vegetated dry sand areas around the salt flats.
These microhabitat partitions can be visualized below. Note that although eight total species were collected, only 2-4 occur within each particular microhabitat and that all eight species were limited to just 1 or 2 microhabitats, resulting in unique species-guilds for each.
Some differences were also noted in species present during the different trips, suggesting that species occurring within the same microhabitat are also utilizing differences in temporal occurrence to further minimize competition. Differences in size among the different species were noted as well – for example, of the four species occurring in the vegetated, dry-damp sand microhabitat, Cylindera terricola is notably smaller and Habroscelimorpha circumpicta notably larger than the others. Since mandible length of adult tiger beetles is highly correlated with preferred prey size (Pearson et al. 2006), this likely results in utilization of different prey, further partioning resources within the different microhabitats.
I thank David A. Melius (Albequerque, New Mexico) for allowing me to include his stunning photographs of Cicindela willistoni estancia in this post.
REFERENCES:
Choate, P. M., Jr. 2003. A Field Guide and Identification Manual for Florida and Eastern U.S. Tiger Beetles. University Press of Florida, Gainesville, 224 pp.
Hardin, G. 1960. The competitive exclusion Principle. Science 131:1292-1297.
Melius, D. A. 2009. Post-monsoonal Cicindela of the Laguna del Perro region of New Mexico. CICINDELA 41(4):81-89.
Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.
Shelford, V. E. 1907. Preliminary note on the distribution of tiger beetles (Cicindela) and its relation to plant succession. Biological Bulletin of the Marine Biological Laboratory at Woods Hole 14:9-14.
Copyright © Ted C. MacRae 2009
Beetles In The Bush 
Interesting article and stunning photographs! Thanks for this post Ted.
Yes, David included the first photograph of this species and equally spectacular photographs of Cicindela fulgida rumppii, Cicindela nigrocoerulea, and Eunota togata fascinans in his paper. It was kind of him to send these to me for inclusion.
Cool stuff. I always like the idea of larval stages having evolved in order to partition habitat resources, preventing competition between parents and children.
Yes, larval/adult partitioning seems to be the ultimate in “division of labor” – larvae eat; adults… well… you know.
I had considered discussing habitat partitioning in larval tiger beetles as well, which seem to be even more restrictive than adults in microhabitat associations. As soil inhabitants, they are likely even more sensitive to differences in pH, moisture, and salinity than the adults and, thus, partition the different zones within a habitat with even greater fidelity.
Larval partitioning seems so much more obvious with insects. I’m used to crustaceans, where its all too simple to assume that larvae evolved as a dispersal method. Partitioning is a fairly recent revelation for me.
Of course, insects are nothing more than “flying crusties” 🙂
Interesting — and that is, indeed, a beautiful tiger beetle.
Thanks, Marvin. I hope I get a chance to see this species someday.
Hi Ted, interesting post, but I’m all about the eye candy tonight. WHAT A GORGEOUS CREATURE! So if I want to try to see tiger beetles (any species), can you give me some quick tips? Assuming they can be found in the Dallas/Ft Worth area?
Hi Amber. Sure, you’ve got tigers in Dallas/Ft Worth. The commoner species can be seen fairly routinely if you hike woodland trails during early spring (several species that tend to be green, sometimes marked with red) or look along streamside habitats with open ground during late summer and fall (mostly bronze species with white maculations). Dry, open sand habitats are great during spring and fall for Cicindela scutellaris (blue/purple head and pronotum with red/violet elytra) and C. formosa (dark violet with striking bold white maculations). Saline habitats also are excellent spots to look for tiger beetles – there are a number of species in the southern Great Plains that occur only in these types of habitats, so this might be a good way to see some of the less common species. Look at the habitat photos in my post Salt Plains National Wildlife Refuge to see what these areas should look like.
Finding the many highly specialized species takes real detective work – you have to study the family and learn what species occur in what areas, the time of year they are out, and their habitat preferences and behavior. It takes a dedicated effort, which is exactly why I have become so enamored with hunting tiger beetles in recent years. For me, when I find a rare species, I know I’ve done my homework well. When I find one in a new location because I thought it might be there, well… it doesn’t get any better than that!
This is great! I’ve printed it out to put in my camera bag so that I’ll have it handy when I’m in the field. If I head east of where I live an hour or two, the soil becomes pretty sandy. I think I’ll head that way in March to see what I can find. If I find even 1 tiger beetle, I’ll consider it a major accomplishment. You’ll be the first to know if I do. 🙂
Good luck! I’ll be anxious to hear if you find any.
Don’t forget clay exposures as well – some beautiful red/green species can be found along 2-tracks and sparsely vegetated roadsides in spring and fall.
Hi Ted,
Great post, thanks!
C. willistoni estancia is awesome 😀 what a beauty
Hi Nicholas – many thanks!
C. willistoni is really one of the more spectacular species of the family (er… supertribe :)).
This is very informative, Ted. When I ran across C. punctulata at LLELA last autumn, there was another tiger beetle species that was too evasive for me to photograph, but without knowing specifically what it was, I did at least notice the two were occupying different sides of the trail (one in the drier sand closest to the meadow and one in the wetter sand closest to the river). I can’t say if it was habitat partitioning or not, but at least now I know that’s a possible explanation–and something to watch for. Thanks for the education! (And I must admit that’s one mighty fine tiger beetle in the photos.)
Thanks, Jason. Habitat partitioning is a likely explanation for what you saw, as I think it is actually quite common. I’d be willing to bet it was punctulata on the drier sand, as that is really the only preference in its otherwise infidel habitat selections.
Cicindela willistoni has vaulted to near the top of my “must see” list.
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Hi Ted!
Your webpage is fantastic!
Didn’t Norm Rumpp write a paper about the tiger beetle fauna of these New Mexico playas? I remember reading it when I used to live in New Mexico. He did a couple of similar papers on the tiger faunas of specific locations like Death Valley and Wilcox Playa.
TRUMAN
Hi Truman,
Rumpp published papers in 1956 (Bull. S. Calif. Acad. Sci.) and 1977 (Proc. Calif. Acad. Sci.) on the tiger beetles of Death Valley and Sulpher Springs Valley, respectively. I’m not aware of any from him on the Laguna del Perro region. You might be thinking about the papers by Lawton & Willis (1974) and Johnson (1975) (both in the journal Cicindela), each of which recorded six species of tiger beetles from the area.
And thanks for the nice comment.
Regards–ted
Hi Truman/Ted. Here’s the citation for the article by Rumpp! Wish I had found it prior to writing that article. I could have compared the data to what I found:
Rumpp, 1962. Three new tiger beetles of the genus Cicindela in Southwestern United States. Bull. So. Cal. Acad. Sci. 60: 165-187
Thanks for the citation – I wasn’t aware of that one.
Now to find it!
This kind of fine-tuning across a narrow strip of land amazed me quite some time ago at a tiny sandy patch, perhaps 4 ft tops from the water edge, along a deep creek is se. Siberia. The beachlet was shared by up to a dozen Bembidion spp., each confined to a narrow zone with apparently well-defined [not to my eye, though] borders. The beetles were out in numbers, all perfectly compliant, and watching them obey that amazing tacit agreement was an intolerable bliss… I felt like witnessing a complicated board game whose rules were totally unfamiliar to me yet I couldn’t stop following its precise moves.
I’m just imagining how awesome it must have been to observe such a natural history scene in Siberia! A dozen Bembidion spp. is quite a level of diversity.
Yes, the works of that neat community did leave a lifelong impression. The ecology in action — rather like a science museum exhibit designed to teach kids how ecosystems work: the beetles were so diverse, representing a number of subgenera, with all your textbook Bracteon, Netolitzkya and what not. There were no similar patch upstream or downstream to compare. Shilenkov rather casually put the names on all of them, he’s very good with Siberian bembs.
Regarding Hardin (1960), lest I mention the obvious in that habitat and resource partitioning strategies are not restricted to tiger beetles.
Other behavioral and olfactional mechanisms may be involved. For example, females may instinctively distribute oviposition sites to avoid subsequent high larval densities. Within the soil, larvae may avoid each other by means of pheromonal inhibitors or perhaps auditory detection from the movement and feeding of adjacent larvae (vibrations?). Possible high rates of predation and parasitism may also be considered. I have noted two sympatric species of Polyphylla, one of them undescribed, where one of the species is predated upon by an unidentified Pyrgota fly – a dipteran genus of endoparasitoids of Melolonthinae – while avoiding the other species. Consequently, there is a disparity in species’ abundance at this locality – approximately 10:1.
Just my .02 ¢ …
More like 25¢ – good stuff.
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