Sunday, May 15, 2011

The Sand Dune Lizard Controversy

The following letter was presented to the U.S. Fish and Wildlife Service on April 28th during the public comment portion of the hearing in Roswell, NM. I read this letter during the oral comments and provided a copy to the Fish and Wildlife Service officials. In addition to this letter, I have written an essay which appeared in the Albuquerque Journal on Sunday, May 1, which is available online on Heath Haussamen's New Mexico Politics website,

U.S. Fish and Wildlife Service
Division of Policy and Directives Management
4401 N. Fairfax Drive Suite 222
Arlington, VA 22203.

Re: Sand Dune Lizard (sceloporus arenicolus) Listing as an Endangered Species; FWS-R2-ES-2010-0041

To Whom It May Concern:

In May of 2002 the Center for Biological Diversity and the Chihuahuan Desert Conservation Alliance submitted a petition to have the sand dune lizard listed as a threatened or endangered species under the U.S. Endangered Act.

The petition is based upon studies done by the University of New Mexico (UNM) Department Of Biology in the mid 1990’s. The petition asserts that “the sand dune lizard is at immediate risk of extinction” (petition, summary page). The petition further contends “carefully executed studies found sharp population declines in response to habitat alteration related to vegetation removal and oil and gas development (Snell et al. 1997, Sias and Snell 1998)” (petition, page 6, section V). The petition also claims “given its perilous status and ongoing threats, the sand dune lizard requires immediate protection” (petition, page 14).

The “carefully executed studies” referred to in the petition are summarized in the 1998 report titled The Sand Dune Lizard (sceloporus arenicolus) and Oil and Gas Development in Southeastern New Mexico. Final Report of Field Studies 1995-1997 by Don Sias and Howard L. Snell of the UNM Department of Biology.

The actual studies upon which this petition is based consisted of only 79 days of field work by a mere three observers in 1996, and only 31 days of field work by just four observers in 1997 (Final Report, page 2, line 22). This limited effort fifteen years ago is the sole scientific basis for the petition.

However, even this “final report” contains important data that challenges the assertions of the petition. Among the results not noted in the petition is the fact that the study “found sceloporus arenicolus throughout oil fields at all well densities” (Final Report, page 8, line 11).

The most striking indictment of the flawed petition is found on page 11 of the UNM Report, line 9 through 14, which reads as follows:

More S. arenicolus occurred in well absent areas than in well present areas. In 1996 transects of well absence (n=29) had mean S. arenicolus counts = 10.3 compared to transects of well presence (n=58) with mean S. arenicolus counts = 4.9 (ANOVA on Ln(SaT+2), p = .0002). In 1997 transects of well absence (n = 12) had mean S. arenicolus counts=16.6 compared to transects of well presence (n = 53) with mean S. arenicolus counts =11.6 (Mann Whitney, p - .0350).

The studies plainly show that in a one year time period, the population of the lizard in areas where wells were present increased by a factor of 2.4, a rate that exceeded the increase in the population in areas where wells were absent(a factor of 1.6). This clearly contradicts the claim that oil field operations pose an immediate threat to the continued existence of this species.

The proposition of the Sand Dune Lizard’s imminent demise is contradicted in multiple places in the UNM document, apparently to the consternation of the authors and ignorance of the petitioners. The UNM Biology Department 1998 report states that populations of the lizard continue to exist in the oil field (Final Report, summary page 1, line 36). The report does concede that the lizard continues to occur in areas where there have been oil fields for in excess of 40 years at the time of the report (Final Report, summary page 2, line 29). Again on page 21 of the report, it is recognized that over four decades (now five) of oil field operations had not eliminated the lizard. The report states, “In all of these well dense regions S. arenicolus were still easy to find and abundant in the years we visited these sites (1994-97)[emphasis added]. In some form, these oil fields have existed for several decades. We are therefore left with the impression that, at least in the short term, these populations of lizards are tolerating oil field development, albeit at a reduced level.”

The petition for endangered species listing relies exclusively upon the UNM studies from the mid 1990’s, yet as quoted above, it is clear that the final report on these studies does not in fact support the conclusion that this lizard is at imminent risk of extinction. It has co-existed for over half a century with oil field operations. There is no scientific basis for this listing, and this petition must be rejected.


Dennis J. Kintigh