U.S. Department of the Interior Bureau of Land Management
Eagle Lake Field Office
2550 Riverside Drive
Susanville, CA 96130
RE: Environmental Assessment DOI-BLM-CA-N050-2019-0011-EA
Bureau of Land Management (BLM) Twin Peaks Herd Management Area Wild Horse and Burro Gather Plan 2019
I hold a Masters in Environmental Planning with a background in Biology and have spent significant time completing my graduate work, and masters thesis researching, surveying and documenting the conflicts related to livestock grazing, wildlife, and wild horses and burros within the Twin Peaks Herd Management Area. The following are my preliminary comments on the Environmental Assessment (EA).
My recent visit to the Twin Peaks HMA on May 10th, 11th and 12th included both an aerial population survey and ground field assessment. My findings are there is no “overpopulation” of wild horses and burros.
The ecosystem and wild horse and burro populations appear to be achieving a “thriving natural ecological balance” consistent with the BLM mandates. The removal of wild horses and burros is the offices status quo in favor of livestock and fails to consider alternative management plans that protect public lands. The EA and BLM fails to prove that removing wild horses and burros improves conditions; while still authorizing intense livestock grazing.
Ecological Contributions of Wild Horses and Burros
The EA does not provide any discussion of the science and ecological contributions of wild horses and burros to the biological diversity on public lands or the negative impacts to wild horses and burros under this plan.
In addition to the following scientific body of knowledge, my research has found that wild horses and burros contribute to the ecosystem and diversity in the Twin Peaks HMA. They are unique in possessing less efficient post-gastric digestive systems that contribute to higher material passage rates (Feldhamer, Thompson, Chapman, 2003). Horses also tend to utilize more abundant, but poorer nutritional quality plant species (Feldhamer, Thompson, Chapman, 2003). Horse droppings pass most seeds intact, which facilitates seed dispersal, and cycles nutrient rich material that builds soil moisture retention resulting in an increase in native plant diversity near horse trails (Downer, 2007) (Ostermann-Kelm, Atwill, Rubin, Hendrickson, Boyce, 2009).
Furthermore, competition between wild horses and burros and other native or domestic species has not been substantiated (Feldhamer, Thompson, Chapman, 2003). Wild horses utilize a broader range of plant species in their diet and are one of the least-selective grazers in the western states (Beever, 2003). Approximately 80% of their diet is composed of shrub and grasslands with less than 1% comprised of riparian vegetation (Berger, 1986). Burros tend to have a broader diet, which includes approximately 50% of browse species such as trees, shrubs and vines with the rest was comprised of grasslands (Feldhamer, Thompson, Chapman, 2003).
Wild horses and burros use the land and resources at different intensities throughout the year, allowing for a natural rest and rotation of foraging pressures (Downer, 2007). Also, wild horses and burros tend to use relatively few trails in traveling to and from grazing, resting and water sources which minimizes trampling and riparian damage near waterways (Beever, 2003) (Ganskopp, Vavra, 1986). These adaptations minimize impacts to their environment and illustrate sustainable integration within the ecosystem.
The science is conclusive that horses originated in North America. However, the BLM does not recognize them as a native species. Opponents argue that since the wild horses were absent from the Americas and then were re-introduced after a period of domestication, they are not a native species. This concept is inconsistent with modern molecular biology and theory. Mitochondrial DNA analysis has proven that Equus caballus is genetically equivalent to the horses found in the North American fossil record (Forsten. 1992). Wild horses meet criteria as a native species by both origin and co-evolution with the habitat in North America, so a period of domestication is “biologically irrelevant” (Kirkpatrick, Fazio, 2008).
Wild horses and burros are classified by the BLM as a national heritage species. This classification places them in a specialized category as neither wild nor domestic, which subjects them to management considerations that are inconsistent with conventional wildlife practices and legal protections, such as the Endangered Species Act (Kirkpatrick, Fazio, 2008).
The EA is inadequate and full assessment of the wild horse and burro populations by not considering an adjustment to the Appropriate Management Level (AML) or livestock use. The EA relies on outdated planning documents from 2001 when this office revised the AML for the Twin Peaks Herd Management Area in the Final Multiple Use Decisions for the Twin Peaks Allotment and then was re-affirmed in the 2008/2009 Resource Management Plan. This EA clearly does not represent new findings about both wild horses and burros and the current conditions and impacts of fire, and heavy livestock use within the Twin Peaks HMA.
This office should be reminded that AML is only an administrative tool to establish population levels to minimize range degradation and is subject to re-evaluation by the Field Office as needed (BLM RMP, pg. 136, 2008). In addition, this office acknowledged that a new herd management plan is needed (scoped in July 2016 and not completed) and the current herd management plan is over 30 years old (1989) and a new one should be completed prior to any EA that relies on its findings to remove wild horses and burros.
The EA appears to pre-determine a solution of removing wild horses and burros without full and adequate analysis of the livestock grazing impacts or serious consideration of cancelation or reduction in livestock AUMs or permits.
Population, Surveys and Methodology
Several scientifically accepted aerial methods exist to estimate wildlife populations within a large area. Here we employed the “aerial, straight-line-strip-transect” method for estimating relative population density. In this, the transect strip relative to the total area allows a density ratio to be determined. As modified by other variable factors, this ratio is then used to estimate a low-to-high population range. Our survey was adapted from the Guenzel methodology for estimating the population size of pronghorn and other wildlife species (Guenzel, 1997). Conducting a complete flight survey in a single day or flight provides data that are more accurate. The sampling includes a variety of habitats with adequate transect spacing and minimizes concerns about animal movements that can lead to multiple counts of the same individuals and over estimation of the population. As stated below by this office.
“Based on recent census flights and population growth estimates, the BLM believes there at about 3,500 wild horses and 600 wild burros in the HMA.”
Flight Surveys Details with Census Data
I completed the most recent flight on May 11, 2019. The aerial survey flight left the Susanville Airport at 9:06 AM and returned at 11:21 AM with no stops. The weather presented mostly clear skies with light wind with approximately 30 miles of visibility. A temperature reading of 57° Fahrenheit was taken at flight departure. Aerial transects were randomly selected and flown to cover both previously burned and un-burned portions of the Twin Peaks Herd Management Area. A total of 218 transect miles were surveyed; and totals of 255 wild horses and 16 wild burros were counted during the survey. The survey covered the same path and transects as the flights completed in 2016 and 2017.
Our observed area included all five BLM-assigned wild horse and wild burro “home ranges” within the HMA. Flight height above ground level varied from 800 to 1,000 feet; and there was an adjusted transect strip on both sides of .37 and 0.41 of a mile on each side of the plane. The transects flew through all nine of the major livestock grazing allotments within this wild horse and burro herd management area. The Twin Peaks wild horse and burro herd management area is separated into livestock grazing allotments by fencing and/or natural barriers in order to control domestic livestock movements. However, these fences also restrict wild horse and wild burro movements as well as other wildlife; and this is contrary to the “free roaming” lifestyle mandate for wild horses and burros under the Wild Free Roaming Horses and Burros Act (WFRHBA,1971).
Twin Peaks Independent Population Surveys
This flight is the seventh independent aerial population survey for the Twin Peaks Wild Horse and Burro Herd Management Area since the massive removal of wild horses and burros during the summer of 2010. These surveys have also documented significant fire damage to soils and vegetation and the slow recovery of such within burned areas. We have also documented the continuing livestock trespass on the public lands in the Twin Peaks HMA. The previous aerial survey reports, including photos and videos, have been formally published and are available for reference.
The independent surveys indicate that the Twin Peaks wild horse population has been increasing for the past nine years. Independent research has demonstrated that the annual herd increase, factored from foal survival rates, is approximately 10% for wild horses in the Great Basin region (Gregg, LeBlanc, Johnston 2014). The higher population increase observed is likely the result of a compensatory reproductive responses to the massive wild horse and wild burro removals in 2010.
Compensatory reproduction occurs when an animal’s population is greatly reduced, and this can be either as a direct or indirect consequence of management actions, including bait and water trapping and helicopter-aided removals. Compensatory reproduction involves an increase in fertility and foal and adult survival, and is largely attributed to reduced competition for food, shelter, and other species-specific habitat requirements (NAS, 2013).
The survey and population estimates for wild burros indicates irregular population growth. This is attributed to the relatively small burro population size and also substantiates the documented burro removals that have recently occurred.
Since 2010, the BLM Eagle Lake Office has trapped and removed at least 22 burros from the Twin Peaks Herd Management Area. These removals occurred between October 2012 and November of 2013. Furthermore, in 2014, the BLM officials filed a decision record stating that they would be capturing and removing from 90-110 wild burros from the Twin Peaks Herd Management Area (NEPA Register, 2015). It is currently not known whether this action has been completed, but the smaller burro population detected during the 2014 survey indicates that it has. In addition, in January of 2017 the BLM Eagle Lake field office signed a categorical exclusion document stating that they will be capturing and removing an additional 150 wild burros from the Twin Peaks HMA area within the following 12 months (NEPA File # DOI-BLM-CA-2017-06-CX).
Impacts of Livestock Grazing
The BLM permits livestock grazing on 94% of the public lands it manages in the western states (Fleischner, 1994). It is estimated that livestock grazing has negatively impacted at least 80% of riperian ecosystems in the western states (U.S. Department of the Interior, 1994a, as cited in Belsky, Matzke, Uselman, 1999). Below is an example of the damage caused by grazing of livestock within the Twin Peaks HMA.
Studies have found that livestock tend to congregate in riparian areas, which negatively impacts the biodiversity and biophysical functioning of these ecosystems (Fleischner, 1994) (Marlow, Pogacnik, 1986).
Livestock grazing has at least the following major impacts:
- Significantly Alters Plant and Animal Communities (Wagner 1978, Jones 1981, Mosconi & Hutto 1982, Szaro et al. 1985, Quinn & Wal-Genbach 1990, as cited in Fleischner, 1994) (Belsky, Matzke, Uselman, 1999) (Donahue, 1999) (Wuerthner, Matteson, 2002)
- Decreases Biodiversity (Fleischner, 1994) (Wilcove, Rothstein, Dubow, Phillips, Losos, 1998) (Belsky, Matzke, Uselman, 1999) (Wuerthner, Matteson, 2002)
- Elimination of Native Predators (Donahue, 1999) (Wuerthner, Matteson, 2002) (GAO, 2005)
- Elimination of Native Predators (Donahue, 1999) (Wuerthner, Matteson, 2002) (GAO, 2005)
- Introduction of Invasive Plants and Diseases (Mackie 1978, Longhurst et al. 1983, Menke, Bradford 1992, as cited in Fleischner, 1994) (Wilcove, Rothstein, Dubow, Phillips, Losos, 1998) (Donahue, 1999)
- Soil Compaction and Accelerated Erosion (Fleischner, 1994) (Belsky, Matzke, Uselman, 1999) (Donahue, 1999) (Wuerthner, Matteson, 2002)
Livestock Allotment Boundaries Limit Free Roaming Behavior and Genetic Mixing
The Twin Peaks wild horse and burro home ranges correlate with livestock allotment boundaries. Livestock allotments are based on fence-lines and natural boundaries restrict wild horse movement to benefit livestock grazing. See maps below showing the livestock allotment and wild horse and burro home range correlations and existing fencing boundaries.
Significant controversy by wild horse and burro preservation groups centers around the genetic viability of wild horse and burro populations. Small isolated or sub-divided populations are subject to reduced genetic diversity (Goodloe, Warren, Cothran, Bratton, Trembicki, 1991). Reduced genetic diversity can “impair vigor, fertility, and disease resistance and could limit ability to respond to environmental variation” (Beard-more 1983, as cited in Goodloe et al. 1991). Other research has shown that significantly reducing populations can result in genetic bottlenecks and within the populations there are hidden population structures that result in behavioral isolation, which further restricts gene flow (Ashley, 2004).
According to the Federal Land Policy Management Act, “wild horses and burros shall be managed as self-sustaining populations of healthy animals in balance with other uses and the productive capacity of their habitat” (FLPMA, 1976). However, according to the leading wild horse genetic expert “the majority of wild equid populations managed by the BLM are kept at population sizes that are small enough for the loss of genetic variation to be a real concern” (Cothran, 2000).
The appropriate population size is dependent on the number of breeding adults and other management considerations specific to the population (Goodloe, Warren, Cothran, Bratton,Trembicki, 1991). The International Union for Conservation of Nature or IUCN Species Survival Commission recommends a minimum of 2,500 individuals are needed to maintain a viable wild population (IUCN, 1992). Other research indicates that an “absolute minimum” of 139-185 wild horses are needed to maintain a population that undergoes several removal disturbances during a generation (Singer, Aeignefuss, 2000). This number represents an “absolute minimum” and is not an ideal population size.
The Twin Peaks Herd Management Area is managed as “5” separate home ranges that divide the wild horses and burros into sub-populations. Only “2” of the “5” home ranges meet the “absolute minimum” population level for wild horses as defined by Singer and Aeignefuss (2000). None of the home ranges meet the minimum population level for wild burros. See table below.
The Twin Peaks Herd Management Area removal plan included a provision to include genetic testing for the horses and burros removed from the Twin Peaks Herd Management Area (BLM NOD, 2010). The genetic testing and results were completed for the wild horses in April 2011, but testing was not done as of October 2011 for burros. The BLM Eagle Lake Field Office did not provide a response to inquiries as to why the burros were not already tested. According to the California BLM State Directors Office the genetic test results are expected between April and July 2012, almost two years after the burros were removed.
Genetic testing was completed on 94 wild horses removed from the Twin Peaks Herd Management Area (Cothran, 2011).
The genetic testing results acknowledged the known population subdivision within the Twin Peaks Herd Management Area, and concluded that the heterzygosity or genetic variation is “approaching concern levels” (Cothran, 2011). This report reflects the population in 2010 prior to the removal of 1,637 wild horses, which significantly reduced the population and compounds concerns regarding genetic variation for the remaining wild horses.
Previous genetic testing for burros was completed in 2003 on “4” burro populations in California showed low heterzygosity or genetic variation in all of the burro populations (Cothran, 2003). No action was confirmed by the BLM to improve the genetic viability for burros. Burros in Twin Peaks remain at significant genetic risk.
I expect that the office will consider the comments provided and provide a full environmental assessment that provide clear evidence that wild horses and burros are compromising the “thriving natural ecological balance” and not livestock grazing, hunting, OHV use, water diversions, predator removal, fire, juniper removal, climate change, and inadequate management policies as I have witnessed and documented over the past nine years of my research.
The office should be prepared to show that any action to remove or disturb the wild horses and burro population (ie. fertility controls) will not cause irreparable harm to the populations and that the plan is not based on outdated planning documents in favor of livestock interests.
I appreciate the consideration of my comments provided in regards to the EA for the Twin Peaks Herd Management Area. I am open to a discussion leading to a sustainable environmental plan that balances and protects all of the natural resources in this region.
Please contact me should you have any questions about my comments or research provided.
Beever, E. (2003). Management implications of the ecology of free-roaming horses in semi-arid ecosystems of the western United States. Wildlife Society Bulletin, 31, 887-895.
Berger, J. (1986). Wild Horses of the Great Basin: Social Competition and Population Size. Chicago, IL: University of Chicago Press.
Conservation Strategy for Sage-Grouse (Centrocercus urophasianus) and Sagebrush Ecosystems within the Buffalo-Skedaddle Population Management Unit (Northern California Sage-Grouse Working Group, 2006). http://www.blm.gov/pgdata/etc/medialib/blm/ca/pdf/eaglelake.Par.29222.File.dat/FINAL %20B- S%20PMU%20S-G%20CONSERVATION%20STRATEGY.pdf
Downer, C. (2007). Wild Horses: Living Symbols of Freedom. Minden, NV.
Feldhamer, G., Thompson, B., Chapman, J. (2003). Wild Mammals of North America: Biology, Management, and Conservation. Baltimore, MD. The John Hopkins University Press.
Forsten, Ann. (1992). Mitochondrial-DNA timetable and the evolution of Equus: Comparison of molecular and paleontological evidence. Ann. Zool. 28, 301-309. Retrieved from http://www.sekj.org/PDF/anzf28/anz28-301-309.pdf
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Journal of Range Management, 39, 207-212. Retrieved from http://www.jstor.org/stable/3899050
Johnston, J. (2011). California’s, Wild Horses and Burros: Twin Peaks HMA. http://csusdspace.calstate.edu/xmlui/bitstream/handle/10211.9/1492/WHB_Thesis_Final%2011. 30.11.pdf?sequence=1
Kirkpatrick, J., Fazio, P. (2008). ECCE EQUUS. Natural History, 117, 30-31. Retrieved from http://ebscohost.com.proxy.lib.csus.edu
Kirkpatrick, J., Fazio, P. (2010). Wild Horses as Native North American Wildlife. Retrieved September 4, 2011 from: http://wildhorsesinwindsofchange.com/wp-content/uploads/2011/02/Wild- Horses-as-Native-North-American-Wildlife-Updated-January-2010-FINAL.pdf
Ostermann-Kelm, S., Atwill, E., Rubin, E., Hendrickson, L., Boyce, W. (2009). Impacts of feral horses on a desert environment. BMC Ecology, 9. Retrieved from http://www.biomedcentral.com1472- 6785/9/22
Wild Horse and Burro Handbook (BLM, 2010). http://www.blm.gov/pgdata/etc/medialib/blm/wo/Information_Resources_Management/policy/ blm_handbook.Par.11148.File.dat/H-4700-1.pdf