Opinion ID: 775062
Heading Depth: 3
Heading Rank: 1

Heading: Habitat Suitability Index

Text: 27 The Grazing District argues that the Forest Service's habitat suitability index was such an unreliable measure of sharp-tailed grouse nesting habitat that it rendered decisions stemming therefrom arbitrary and capricious. The index compares levels of residual cover that remained after grazing with levels of cover in ungrazed areas in order to assess whether habitat for management indicator species, such as the sharp-tailed grouse, achieved at least 40% of potential. The Grazing District contends that the index did not establish a verifiable correlation between two measurable and quantifiable criteria, because [w]hile visual obscurity can be quantified through direct measurement, habitat suitability can not [sic], and that the Forest Service did not use similar data to set the end points of its graph of the assumed relationship between visual obscurity and habitat suitability for sharp-tailed grouse on the [Grasslands]. 28 These concerns stem from the Grazing District's underlying assumption that the Forest Service should have included the effect of visual obscurity on sharp-tailed grouse populations in its index. However, the Grazing District misapprehends the index, which was designed to assess the effect of grazing on the level of residual cover, not on the grouse population. The Forest Service obtained from other sources data regarding what constitutes habitat suitability and need not have included in chart-form what it knew from its other sources to be the case. For instance, 29 Plains sharptail nesting cover tends to be more grassy and less shrubby than that of the prairie sharptail of the Great Lakes States. The lack of good quality nesting and brood-rearing cover generally is limiting for sharp-tailed grouse throughout their range. Plains sharp-tailed grouse are generally limited by intensive grazing and conversion of rangeland to cropland. Grazing reduces the quantity of residual vegetation. Residual herbaceous vegetation is important nesting cover because little current growth is available in early spring when most nests are constructed. 30 Bart L. Prose, Habitat Suitability Index Models: Plains Sharp-Tailed Grouse, U.S. Fish Wildl. Serv. Biol. Rep. 82(10.142), 9, (1987) (citing various authorities). 10 31 Similarly problematic is the Grazing District's argument that the data used to set the end points of the Forest Service's graph renders its decision arbitrary and capricious. Again, the graph was looking at the relationship between grazing and nesting cover. Basic statistics allows one to ascertain the relationship, or lack thereof, between any two variables. Although such relationships may be spurious, here the Grazing District fails to show that to be the case. Its suggestion that precipitation levels account more for optimal nesting cuts both ways, as precipitation would also affect the height and density of cover. The very report to which the Grazing District directs us undermines the Grazing District's point. Leslie A. Rice & Arthur V. Carter, Evaluation of South Dakota Grassland Management Practices As They Affect Prairie Chicken Populations, 1974-78, Dep't of Game, Fish and Parks Completion Rep. No. 84-11, 11 (1982) (Amounts of moisture received before and during growing season also influenced amounts of forage left ungrazed which was measured the following spring. The Grazing District also ignores predation concerns. Although the Grazing District emphasizes the number of nest-broods found in pastures subjected to various grazing methods, the study was inconclusive regarding nest fate. See id. at 13, 15 (indicating that the sample size may have caused a finding of no significant difference in nest fate when different grazing systems were compared). 32 Furthermore, the Grazing District ignores the Forest Service's charge to protect the Grasslands habitat for fauna other than the sharp-tailed grouse, along with flora and other resources. As the Environmental Assessment points out: 33 Through visual observations, erosion and gullies were noticed due to a lack of vegetative cover and a lower range condition. If livestock continue to graze at this [initial] level, resource conditions will degrade. If intensive grazing continues during a prolonged drought, the vegetative composition will decrease to a lower level of condition and the overall rangeland health declines. 34 The Forest Service's habitat suitability index was not defective for the purpose it was used and does not undermine other data the Forest Service relied upon. Nor was the index the primary tool used in the Forest Service's decision-making, but was merely one of many considerations... along with many other pieces of information, both biological and social. The Forest Service accounted for discrepancies to which the Grazing District directs us and was entitled to rely upon its experts and data even though there may have been some conflicting data. See Perkins v. Bergland, 608 F.2d 803, 807 (9th Cir. 1979) (cautioning trial courts to refrain from entering [the] fray if it turns out that the [plaintiffs'] position would require a choice between experts). That the sharp-tailed grouse can nest in more heavily grazed areas misses the point since the Forest Service seeks to improve the habitat overall. The index was a reasonable tool among others employed and does not render the chosen stocking level arbitrary and capricious.