Opinion ID: 6332151
Heading Depth: 2
Heading Rank: 1

Heading: The Jumping Mouse

Text: The New Mexico Meadow Jumping Mouse is a tiny brown mammal with a long tail that accounts for over half its length. As its name suggests, the mouse is a highly skilled jumper—wildlife biologists have observed adult mice jumping as 1 The Secretary of the Interior has jurisdiction over most land species, including the Jumping Mouse, while the Secretary of Commerce generally has jurisdiction over marine species. See 51 Fed. Reg. 19926, 19926 (1986). The Secretary of the Interior has delegated authority to administer the ESA to the U.S. Fish and Wildlife Service. Id.; Nat’l Ass’n of Home Builders, 551 U.S. at 651. 3 Appellate Case: 21-2019 Document: 010110671606 Date Filed: 04/15/2022 Page: 4 high as three feet, which is over ten times the length of the Jumping Mouse’s body. The majority of New Mexico Meadow Jumping Mice can be found in New Mexico, but nearby Arizona and Colorado also contain several populations. New Mexico Meadow Jumping Mouse The Jumping Mouse’s struggle to persist can be traced to its unique hibernation cycle and “exceptionally specialized habitat requirements.” Intervenors’ Supp. App. (Int.-App.) at 110. Unlike most other mammals, the Jumping Mouse is only active in the summer months—it spends the rest of the year in hibernation. Because of this atypical hibernation cycle, the Jumping Mouse’s survival hinges on its ability to quickly gather enough nutrients and nest materials from its surrounding habitat, which is generally comprised of dense vegetation alongside perennial flowing water. Jumping Mouse populations are highly vulnerable in part due to habitat loss and degradation, which can be caused by a variety of factors, including drought, wildfires, flooding, and animals such 4 Appellate Case: 21-2019 Document: 010110671606 Date Filed: 04/15/2022 Page: 5 as cattle and beavers that modify the surrounding habitat. The Jumping Mouse’s relatively short lifespan and low fecundity also affect its ability to thrive. The mice typically live up to three years and give birth to one small litter of young each year. In 2013, the Service proposed listing the Jumping Mouse as an endangered species. 78 Fed. Reg. 37363 (2013). In its proposed rule, the Service noted that since 2005, researchers have only documented 29 geographically distinct populations of the Jumping Mouse, though the Service suspected that 11 of those populations may already have been extirpated. Id. at 37365. The Service also expressed concern that seven populations in Arizona may have been compromised due to flooding after several recent wildfires. Id. Based on these precarious circumstances, the Service surmised that the Jumping Mouse faced an immediate and substantial risk of extinction. Id. at 37367. On the same day it published its proposed rule for listing the Jumping Mouse as endangered, the Service issued a proposed rule designating the Jumping Mouse’s critical habitat. 78 Fed. Reg. 37328 (2013). Because the Service must consider economic impacts when designating critical habitat, the Service solicited comments concerning “[a]ny foreseeable economic . . . impacts that may result from designating any area.” Id. at 37329. The Service later provided a draft economic analysis to the public and requested additional comments on the analysis. In total, the Service received 63 comment letters addressing the proposed critical habitat designation during the public comment period. 5 Appellate Case: 21-2019 Document: 010110671606 Date Filed: 04/15/2022 Page: 6 In March 2016, the Service published a final rule designating about 14,000 acres in New Mexico, Arizona, and Colorado as critical habitat for the Jumping Mouse. 2 81 Fed. Reg. 14264 (2016). The designated habitat consists of riparian areas with thick vegetation and flowing water that are either currently occupied by the Jumping Mouse or unoccupied but essential to the conservation of the species. 3 The Service divided the critical habitat into eight units, three of which include subunits. Many of the units contain a mix of land owned by the federal government, state government, or private citizens. 2 The Service issued a final rule listing the Jumping Mouse as endangered in 2014. 79 Fed. Reg. 33119 (2014). 3 The Service determined that it was necessary to designate partially occupied and unoccupied areas as critical habitat because the “areas occupied by the mouse since 2005 do not contain enough suitable, connected habitat to support resilient populations of jumping mouse.” 81 Fed. Reg. at 14300. 6 Appellate Case: 21-2019 Document: 010110671606 Date Filed: 04/15/2022 Page: 7 In its final rule, the Service responded to each public comment. Many of the comments encouraged the Service to designate more land as critical habitat, while other comments raised doubts about whether the proposed areas satisfied the definition of critical habitat and questioned why the Service did not account for certain costs of designation. Along with the final rule designating critical habitat, the Service published its final analysis of the economic impacts of the habitat designation. The analysis, which was performed by a private contractor, Industrial Economics, Inc. (IEc), included an assessment of the costs and benefits of designating critical habitat for the Jumping Mouse. Based on guidance from the U.S. Office of Management and Budget (OMB), IEc utilized a methodology known as the “baseline approach” to determine which costs must be included in the economic analysis. Under the baseline approach, the Service only considers costs that are “solely attributable to the designation of critical habitat” and ignores costs that would exist regardless of the habitat designation. App., Vol. 1 at 127. Thus, for example, if a cost is attributable to both the listing of a species as endangered and the designation of its critical habitat, then the Service would not consider the cost in its economic impact analysis. In accordance with this approach, IEc did not consider “any existing regulatory and socio-economic burden imposed on landowners, managers, or other resource users absent the designation of critical habitat” for the Jumping Mouse. Id. 7 Appellate Case: 21-2019 Document: 010110671606 Date Filed: 04/15/2022 Page: 8 The Service estimated the costs associated with critical habitat designation at $23 million. The Service attributed a minor portion of those costs to future federal agency consultations, which the ESA requires for any federal action likely to destroy or adversely modify the critical habitat of an endangered or threatened species. 16 U.S.C. § 1536(a)(2). The Service determined that most costs would arise from efforts to reduce the impact of livestock grazing on the Jumping Mouse’s habitat. During the rulemaking process, the Service recognized that livestock grazing presents a unique threat to the Jumping Mouse and its habitat because “cattle tend to concentrate their activity in riparian habitat.” Int.-App. at 195. According to the Service, poorly managed grazing harms the Jumping Mouse by causing “trampling of streambanks, burrow collapse, loss of riparian cover, soil compaction, modification of riparian plant communities, lower[] water tables . . . a decline in herbaceous plant diversity, and a loss of riparian shrubs.” Id. To combat these harms, the Service anticipated costs for constructing cattle fences to steer livestock away from the Jumping Mouse’s habitat, as well as the potential costs of reducing animal unit months 4 on U.S. Forest Service grazing allotments. IEc also contemplated that ranchers who graze livestock in the critical habitat areas may need to shift their cattle rotation patterns or develop alternative water sources to minimize the degradation of the Jumping Mouse’s riparian habitat. 4 An animal unit month is “the amount of forage necessary for the sustenance of one cow or its equivalent for a period of 1 month.” 43 C.F.R. § 4100.0–5. 8 Appellate Case: 21-2019 Document: 010110671606 Date Filed: 04/15/2022 Page: 9 The Service has discretion under the ESA to exclude areas from the critical habitat designation if it determines that the benefits of exclusion outweigh the benefits of designation. In its final rule designating critical habitat for the Jumping Mouse, the Service explained that due to ongoing conservation partnerships, it would exclude 230 acres of tribal lands belonging to the federally recognized Isleta Pueblo and Ohkay Owingeh tribes. The Service did not exclude any areas from designation based on economic impact or other factors.