Sage-Grouse in Nevada - Integrating Science & History

Sage-Grouse in Nevada - Integrating Science & History
Kent McAdoo, Univ. Nevada Coop. Extension George Gruell, US Forest Service (retired)

Objective Achieve an understanding of history and science that allows us to effectively communicate regarding the management of sage-grouse (SG) and its habitat Note: This review is a work in progress

For Context: Historical Habitat Perspective Miller and Eddleman (2001): “The Wyoming big sagebrush and low sagebrush cover types, with less frequent disturbance events but slower recovery rates, and the mountain big sagebrush cover type, with more frequent disturbance but faster recovery rates, created a mosaic of multiple vegetation successional stages across the landscape.”

Miller and Eddleman (continued): “In addition, fire patterns were patchy, leaving unburned islands, particularly in Wyoming big sagebrush cover types, because of limited and discontinuous fuels. Plant composition ranged from dominant stands of sagebrush to grasslands.”

Translation Vegetation in intact sagebrush-perennial grass communities is not static, but dynamic.
Over time, it may range from completely herbaceous (grass & forb dominated) to shrub dominated. Physical disturbance (e..g, fire, aroga moth infestation, etc.) is the driver

Sage Grouse Require sagebrush for food and cover
Thrive best in sagebrush mosaics Optimal habitat has varying sagebrush heights/species and diverse understory Also need meadows

Proto-historic Period Aboriginals and Sage-grouse (SG)
SG important for food & ceremonies Anthropologists indicate unconstrained hunting pressure, with several very effective hunting methods Humans as keystone/apex predators with likely result of SG population suppression at times in some areas Aboriginal fire used for vegetation management (Stewart 2002; McAdoo et al. 2013) Relative abundance of herbaceous-assoc. species (pronghorn, bighorn sheep, white-tailed jackrabbit, sharp-tailed grouse in some areas) ...implies early seral habitat/disturbance in some areas (Gruell & Swanson 2012; McAdoo et al. 2013) Conclusion – SG populations unknown, but assumed variable with habitat disturbance & hunting pressure

Euro-American Impacts - Observer Influences
Time of year Trip purpose Frame of reference Travel route(s) Time since last disturbance Preceding weather conditions

Euro-American Exploration Period [1820 – 1839]
P. Ogden, – only 1 note - a few scattered SG (“pheasants”) near Spruce Mtn. in 1828; no SG noted during 2 months in spring 1829 in no. Elko & Humboldt Counties, traveling through some of today’s best SG habitat J. Smith, 1827 – no SG mention – compelled to eat horses traveling across middle of state J. Work, 1831 – no SG mention in daily journals, 40-day trip from NE corner, then along Humboldt River – ate horses J. Walker, 1833 – no SG mention – traveled from Pilot Peak to Humboldt sink – also ate domestic stock Z. Leonard, 1833 – no SG mention in daily journals – traveled from NE Nevada to Carson City area – confirmed scarcity of game Conclusion – SG populations apparently low

Early Travelers & Settlement [1840 – 1869]
Chiles (Bartleson & Bidwell party, 1841 – saw SG along Humboldt River, Elko County (first mention in this area) J. Fremont, – mentioned SG (NW Nevada); in 1845, no mention of SG traveling through middle part of state from east to west E. Bryant, Aug – saw several SG in at least 4 areas along Humboldt River between Halleck and Battle Mtn. California Gold Rush, Mormon Battalion, Sep. 1848, killed several SG near Thousand Springs returning from California to Salt Lake Valley Little Ice Age ends

Early Travelers & Settlement (cont’d) [1840 – 1869]
A. Delano, Jul.–Aug – SG described as numerous and easily killed near Wells and Carlin areas J. Bruff, Sep – bagged SG in 3 locations along Humboldt River in Lander & Humboldt County areas “Out of 173 total journals, diaries, letters and other miscellaneous notes reviewed for those emigrants that passed through Elko County between 1849 and 1859, only twenty or 11.6 percent made any written mention of grouse… A vast majority of the travelers, however, made no mention of grouse or any other wildlife species, and most often wrote of the extreme hardships associated with the venture, including the general lack of food resources on which to survive” (McQuivey 1999).

Early Travelers & Settlement (cont’d) [1840 – 1869]
Simpson, during exploratory trip across central Nevada: “Many signs of sage-hen and antelope in this (Monitor) Valley.” - but never mentions seeing SG. D. DeQuille, Summer, 1860 – in Stillwater Mountains, West Lee Canyon locality, jumped several flocks of SG. R. Ridgeway (ornithologist with King Expedition), – during government assignment to compile observations of Great Basin bird-life; regarding SG, “…we saw it so seldom that little was learned of its habits…abundant in certain localities, but by no means uniformly distributed.” Conclusion – SG populations variable, but at least moderate in some locations

Livestock & Mining Boom [1870 – 1899]
Ranching - 700,000 cattle & 374,00 sheep by 1889 (Hazeltine 1961) Predator bounties, 1873; law repealed in 1877 Intensive harvesting of pinyon & juniper in central Nevada, sagebrush in northern Nevada (fuel for mines) J. Laconte, 1870 – SG very abundant north of Bridgeport D. Hurst, 1870s – SG in Monitor foothills and occasionally sold at Belmont – serious market hunting begins in 1870s first comprehensive state game laws, but only set seasons, with no limits – by 1880s, some limits imposed 1886 – “. . . the ranges of the sagebrush country are deteriorating it will not be many years before the occupation of most of our stockmen will be gone unless they heed the signs of the times.” (Carson City Appeal) Winter of Some ranches lost ~95% of livestock

Livestock & Mining Boom (cont’d) [1870 – 1899]
G. Wheeler (ornithologist), ) with Corps of Engineers, from south of Carson City to the Dalles, OR: “Numerous as is this species in many portions of the Rocky Mountain region, it appears to be even more abundant in the sterile tracts that lie just east of the Sierra Nevada and Cascade Ranges, where it is generally diffused in all suitable localities from a point well up towards our northern boundaries…” He found its most southerly location to be about 50 mi south of Carson City. He emphasized the importance of meadows to these birds, noting areas near springs as “plats of green verdure” forming oases visited 3 times daily by flocks of 50 or more. * Market hunting also common in northeastern Nevada during this time period (McQuivey 2003)

Livestock & Mining Boom (cont’d) [1870 – 1899]
T. Thompson & A. West - said game more abundant in 1880 than in 1850s (from Thompson & West’s History of Nevada, 1881) H. Martin, 1880s – born in 1873, no. Elko County – said SG and sharptails abundant 1880s and 1890s S. Tremewan, 1890s – reported SG so plentiful in Elko county that they “clouded the sky” when they flew; parties came out in wagons from Elko, shot birds and left them in big piles on ground to rot (Gruell & Swanson 2012) G. Nelson, 1890s – Gance Cr. Area of Elko County – said there were so many SG that, when spooked, the flocks would “sound like thunder” when they arose. “I’m not exaggerating, there were thousands” (Gruell 1964) Conclusion – SG populations very high in many locations

Livestock Numbers High & Predator Control Increasing [1900 – 1929]
Nat. Forests established Livestock numbers rebounding (1 million sheep by 1907) Agriculture booming with homesteads W. Wilhelm, traveled with his family on an extended wagon trip from northwestern to northeastern Nevada - “…meadows were full of sagehens evenings and mornings…” In some areas “…so thick we killed them with rocks.” Regarding the Tuscarora area, “…the whole country was alive with sagehens.” W. Kent, – hunting/observing SG on ranches north of Winnemucca, SG “…thrived greatly on alfalfa during the summer.”…seen normally in immense flocks.

Livestock Numbers High & Predator Control Increasing (cont’d) [1900 – 1929]
W. Taylor (scientist), summer 1909 – working for UC Berkeley in Pine Forest Range no. of Winnemucca, said SG were “observed commonly” from late June through the summer; “thousands” on Leonard Creek flats (Taylor 1912). SG season closed, apparently due to a population decline (Mathis 1997) SG populations low, but season w/10-bird limit Rabies epidemic – changed formal predator control 1920s - strychnine use for predators initiated Early 1920s - SG numbers high in some areas (e.g., Ely) 1925 season – “sagehen scarce” in Washoe County SG numbers low in (NFGC 1964) Conclusion – SG populations variable, but high many years in some locations, low in other years/locations

Taylor Grazing Act/Grazing Mgmt & Intensive Predator Control [1930 – 1969]
Great Depression Large range sheep industry & heavy grazing 1932 – predator control greatly reduced due to lack of funding; but continued afterward, including use of poisons 1934 – Taylor Grazing Act 1942–1945 – WW II agricultural boom – 1 million acres seeded to crested wheat 1964 – Elko County fires burn ~300,000 acres – first modern-day large fire ,000 cattle & 311,000 sheep in Nevada (NFGC 1964) 1969 – National Environmental Policy Act

Taylor Grazing Act/Intensive Predator Control (cont’d) [1930 – 1969]
SG numbers high in many years, but general season also closed in 14 different years ( , , , ) [NFGC 1964], though numbers “legion” in Ely area late 1930s- early 1940s (Mathis 1997) In 1935, chukar were introduced, because of SG in decline in some areas (NFGC 1964) J. Linsdale (ornithologist), wrote in Birds of Nevada that SG were “…formerly more common than now, but still present in considerable numbers” (Linsdale 1938)

Taylor Grazing Act/Intensive Predator Control (cont’d) [1930 – 1969]
Seasons typically 2-3 days long, with bag limits of 3–10 (~consistently 3 in 1950s & 1960s) Record harvests in 1951 (~22,000), 1962 (>19,000), 1969– 1974 (ave. = >20,000) [NDOW data] Longest sustained continuous “modern-day” hunting seasons were during this period (NFGC 1964) and this continued into the 1970s Conclusion – SG populations variable in 1930s – 1940s, but ~maintained at relatively high levels in 1950s-1960s

Conclusion – SG populations in decline (now leveling off ??)
ESA, Grazing Systems, Increasing Fire Frequency, & Litigation [1970 – present] 1973 – Endangered Species Act SG harvest peaks in 1973 (25,000) & 1979 (>28,000) [NDOW data] Since then, bird numbers fell and harvests have fallen commensurately (ave. harvest last 20 yrs = 6,225) [NDOW data] Cattle numbers reduced (25% reduction from 1982 – 1997) Sheep numbers declined from ~300,000 in 1972 to <80,000 Fire frequency increases Large intense wildfires (>2.7 mill. acres burned, ) Litigation & more AUM reductions Conclusion – SG populations in decline (now leveling off ??)

Comparing History & Science
Aboriginals as an Ecological Force Livestock Grazing Predation Hunting Seasons Meadows & Irrigated Crops Upland Vegetation Change and Fire Regime Alteration

Aboriginals as Apex Predators
Science Even at low numbers, aboriginals exerted significant impacts on wildlife (Martin & Szuter 1999; Laliberte & Ripple 2003) Aboriginal “take” of some game species was likely additive mortality (Kay 1998) Aboriginals more efficient predators than other carnivores (Stiner 1990) Shy/skittish wildlife is indication of heavy hunting pressure (Laliberte & Ripple 2003) SG harvest should be <10-11% annually (Sedinger et al. 2000) History Hunted SG with nets on leks and at water holes where birds are most vulnerable (Thomas et al. 1983) Disguised with antelope skins, clubbed SG on leks (Kelly 1932) Hunted SG year-round Antelope & bighorns very skittish, apparently due to constant hunting pressure (from multiple early contact Euro-American accounts) …it is most probable that sage grouse populations were …kept at lower even lower levels because of constant and intense hunting … by the Native Americans” (McQuivey 1999)

Mountain Big Sagebrush In some areas & at some times…
Post-Burn Mosaic In some areas & at some times… Great Basin Native Americans used fire for purposeful vegetation disturbance (Steward 1948; Stewart 2002; Gruell & Swanson 2012) – with consequential effects especially in mtn. big sagebrush communities (McAdoo et al. 2013)

Pre-Settlement Vegetation Sagebrush Vs. Grass – What Was It?
Kern Exploration, 1845 – grass abundance noted in Secret Pass & Emigrant Pass areas – “…among the grass-covered hills…” Bigler Journal, 1848 – grass abundance in Wells area hills (Utah Hist. Soc. 1932) Simpson Expedition, May and July 1859 – grass abundance described for Egan Range, Diamond Mtns., north end Monitor Range, Simpson Park Range, Reese River Valley, & Toiyabe Mtns - abundance of grass mentioned numerous times regarding mountain slopes, along streams, some valleys (Simpson 1876) Compare this to: Botanist Sereno Watson’s report (with Ridgway in ) – walked across Nevada W to E; provided much detail on shrub dominance virtually everywhere he went – says area not adapted to livestock grazing, but does mention scattered grass early in spring/early summer; but looking at Ridgway’s bird list, grass-nesting species were also represented. Numerous journal entries, 1840s, from traveler’s along California Trail and other valleys describing shrub dominance everywhere (McQuivey 1999) – please note that these & other descriptions often referred to tall sagebrush, 5 to 10 feet, which would have been basin big sage along drainanges.

Pre/Early-Settlement Vegetation (Other Comments on Grass vs. Shrubs)
Dan Dequille,1860 – “flats and lower parts of hills luxuriantly clothed in bunchgrass” (Stillwater Mtns) Dr. H. Smeathman, 1864 – east of Winnemucca Lake – passed through flats of greasewood and sagebrush, then over “...ranges…richly clothed from base to summit with herbage, particularly the bunchgrass.” Elko Daily Free Press, “In the summer season we have rich bunchgrass covering every hillside with a luxuriant growth…”

Remember! Vegetation in intact sagebrush-perennial grass communities is not static, but dynamic. Over time, it may range from completely herbaceous (grass & forb dominated) to shrub dominated. Physical disturbance (like fire) is the driver * Also, observers were influenced by time of year, trip purpose, frame of reference, travel route(s), and time since last disturbance

Livestock Grazing We learned in the plant growth module how plants grow and how grazing affects them at various stages of their growth. We are now going to discuss how to graze them without negative impacts and in a way that will allow recovery of degraded rangelands. We can’t micro manage allotments for each plant species in each plant community – but we do know from experience that if we take advantage of plant science information and understand how animals graze, we can come up with grazing strategies that produce healthy plant communities and productive livestock operations.

Why Did Ranchers Settle in the Sagebrush Ecosystem?
B. Hazeltine et al. 1961, in A Range History of Nevada - “A significant feature of the virgin sagebrush range was the abundance of palatable grasses and weeds that grew under and between the shrubs.” Elko Daily Free Press, “In the summer season we have rich bunchgrass covering every hillside with a luxuriant growth…” Gruell & Swanson, in Nevada’s Changing Wildlife Habitat – “Early stockmen spoke of the abundance of grass and the sparseness of sagebrush on productive rangelands.”

Effects of Livestock Grazing
History High SG populations in the 1870s,1880s, 1890s, and early 1900s with heavy season-long grazing Relatively high SG populations during much of the 1940s, s, with lower, but still high stocking rates Declining SG populations since 1970s, concurrent with reduced livestock numbers, but other major factors involved, e.g., sagebrush habitat altered by wildfires, large cheatgrass monocultures, & conifer encroachment Science Heavy grazing led to perennial herbaceous decline and increase of shrubs (Young 1981) Indirect impacts from grazing, e.g., conversions to grass forage, weed invasion, forb reduction with herbicides (Beck & Mitchell 2000) Rest-rotation grazing/stocking reduction beginning in 1970s brought healthier range conditions (Box 1990; Laycock 1996) in upper elev., but exacerbated cheatgrass in lower elevations (Young & Clements 2009) Managed grazing can be beneficial to plant communities (Davies et al. 2012; Dalldorf et al. 2013) Grazing as tool for fine fuel reduction (Diamond et al. 2007); weed prevention (Davies et. al. 2009); meadow enhancement (Oakleaf 1971;Klebenow 1985; Evans 1986)

Predation & Predator Control
Science Predation may be limiting in some situations (Connelly et al. 2004; Coates et al. 2008); control can be effective (Baxter et al. 2007) Habitat manipulation more economical than predator control (Schroeder & Baydack 2001) Coyotes very prolific, with pup litter sizes in exploited populations ~ 2X those in unexploited populations (Knowlton 1972) Current threat from ravens (increase by % in recent years caused by anthropogenic subsidy (Coates 2010) - primary nest predator Harvested resident ravens are replaced by transients (Coates 2007) History Very high SG numbers before formal/intensive predator control Variable SG numbers w/ predator control Possibly successful in 1950s – 1960s Many predators historically controlled were likely not the primary impactors, so results varied Some predator control took non-target species Impacts are difficult to measure

USFWS Predator Harvest Information (1915 – 1979) [Preliminary Summary]
373,900 coyotes*, bobcats, & mtn. lions killed, with the following highs: 1915 >10,000 Mid1920s ~7,000 Early 1930s ~6,900 Mid-1940s ~10,500 Mid-1950s ~8,000 Early 1960s ~12,000 Mid-1960s ~11,000 * The vast majority of harvest was coyotes

Predator Control (cont’d)
During this 65-yr period of , ave. # coyotes taken = 4769/yr Comparatively, during the 15-yr period 1996–2010, ADC took 83,646 coyotes, an ave. of 5,576/yr (note: 17% higher than the average for the earlier 65-year period) Note that the period under-estimates take because not all carcasses from poisoning (strychnine and 1080) were recovered Note also that neither period includes take by sportsmen, which was likely higher (annually) during the period because of human population increase

Effects of Hunting Seasons
History Aboriginal hunting was apparently unconstrained Market hunting in the late 1870s First seasons were several months long (8/1 – 4/1), with no limits Eventually, season timing was changed, length shortened, limits reduced Seasons were historically closed occasionally, even during decades of general abundance (probably as a result of weather-related production declines) Science SG have “K-selected” life history strategy and thus more vulnerable to hunting impact (Reese & Connelly 2011) Hunting losses can be additive to winter mortality and may result in lower breeding populations (Connelly et al. 2000) Caution should be used in establishing hunting seasons, with conservative limits (Braun 1998; Connelly 2003) Harvesting less than % is apparently compensatory (Sedinger et al. 2010)

Historical Sage-Grouse Hunting in Nevada
1877 Market hunting – “Sagehens…are becoming a drug in the market…Cheaper than beef” (Carson Daily Appeal) 1879 – “The boarders of the Como hotels and restaurants…complain of too much sagehen…” (Territorial Enterprise) Late 1870s – markets throughout the state were being supplied with SG, mostly from mid-July - Sep. (McQuivey 1999) But…“There have been a number of times in the past when either sportsmen or the NV Fish and Game Commission thought the birds (SG) were on their way to extinction” (NFGC 1964)

Meadows & Irrigated Crops
Science Meadows critical in SG life-cycle, esp. in dry years (Klebenow 1969; Connelly et al. 1988); forbs critical component (Apa 1998) SG prefer moderately grazed meadows (Evans 1986); grazing should be used as tool for meadow enhancement for SG (Oakleaf 1971), with 4” herb. vegetation goal (Klebenow 1985, 2001) Severe grazing reduces water table, allows upland veg. invasion (Pritchard 1998) Current success in northern Nevada with riparian recovery through timing and duration management of livestock grazing (Dalldorf et al. 2013) History Increased with homesteading Increased with irrigation Grazed meadows attracted SG because of succulent regrowth and forb availability (observations by ranchers & biologists) Intensive use of alfalfa by SG (observations by ranchers, others)) Abandoned homesteads likely reduced small meadow areas and alfalfa fields once used by SG (Gruell & Swanson 2012)

Forbs and insects in meadows attract sage-grouse

Succulent regrowth in grazed meadows attracts sage-grouse (Oakleaf 1971; Klebenow 1985; Evans 1986)

Upland Vegetation Change and Fire Regime Alteration
History Aboriginal burning ended by late 19th century Promiscuous burning by herders (Hazeltine et al. 1961;Young 1979) in early 20th century stopped by regulation Thousands of acres were stripped of PJ & sagebrush during late 19th century mining Heavy grazing led to perennial herbaceous decline and increase of shrubs Crested wheatgrass seedings replaced sagebrush stands on ~1 million acres Science At lower elevations, increasing fire frequency and size has converted large acreages to cheatgrass monocultures At higher elevations, encroachment of PJ into sagebrush-grass comm., the result of heavy grazing and fire control, has eliminated thousands of acres of habitat that once supported large numbers of SG in central and eastern Nevada Large continuous tracts of sagebrush communities required by SG have been fragmented

Pinyon & Juniper Use by 19th Century Mines
Beginning in 1870s, needs included charcoal for smelter, wood used for home heating/cooking, power (for steam) generation, acreage cleared for mine & home-sites, transportation corridors, fences, etc.; 1 cord of pinyon pine = 28 bushels of charcoal; Eureka mines needed 1.2 million bushels charcoal/yr (43,000 cords pinyon/yr) [Goodwin 2011] Young and Budy (1979) estimated that by 1878, 600,000 acres had been denuded of PJ within 35 miles of Eureka (Eureka was called “Charcoal Flats”) Lanner (1981) very roughly estimated about 750,000 acres were denuded of PJ

Sagebrush Use by 19th Century Mines in Northern Nevada

Sagebrush Use by 19th Century Mines
“Sagebrush is about the only fuel in this timberless country and hundreds of thousands of cords of it are annually consumed…Like the grand forests of the Sierra Nevada, the wild sage of the Great Basin is rapidly disappearing and as it is a plant of exceedingly slow growth, it is not improbable that it may ultimately become extinct…” (December 12, 1877, Tuscarora Times-Review). 1881- Grand Prize Mine using loads of untrimmed sagebrush daily, and the available supply by this point in time had to be transported a distance of ten miles (McQuivey 1999). 1880s – Tuscarora’s mines required sagebrush from within 35-mi. radius, with similar needs for other mines near Cornucopia, White Rock, Paradise, Winnemucca (McQuivey 1999)

Sagebrush harvesting by early mines
Upland Vegetation Changes and Fire Regime Alteration Crested wheatgrass seedings Sagebrush harvesting by early mines 19th century PJ harvesting Current PJ encroachment Large post-fire cheatgrass monocultures

Weather is Huge! (short-term expressions)
Cold/wet weather during nesting and early brood periods often results in poor reproductive success and chick survival Populations can increase substantially after several successive favorable springs Drought conditions during summer months are also detrimental to brood survival Winter conditions are not typically as limiting for SG, as long as they can find taller sagebrush and/or windswept slopes (Note: However, the Mt. Magruder population, Esmeralda county, was reportedly devastated after unusually deep snow in the late 1880s) [Fisher 1891]

In general, science and history may be telling us similar things, but from different perspectives and varying spatial and temporal scales. A knowledge of both history and science is paramount in managing sage-grouse and its habitat.

General Conclusions (My Opinion) Historically, sage-grouse benefitted from meadow enhancement & crops, water developments in previously dry areas, introduction of plants like dandelions & alfalfa, and livestock grazing initially as it impacted meadows and some upland areas that were initially herbaceous-dominated. The early livestock numbers were not sustainable. In some areas and at some times SG may have also benefitted from reduction of PJ & sagebrush, as well as predator control.

Conclusions & Cautions
History: Sage-grouse are adapted to & even thrive under some level of disturbance Science: Disturbance is necessary (West 1983), but - Under contemporary conditions, severe disturbances should be minimized (Sheley et al. 1999); intentionally-applied low severity disturbances can serve to increase capacity for intact sagebrush-perennial grass communities to be more resistant to exotic weed invasion in the long term and resilient after severe (e.g., wildfire) disturbances (Davies et al. 2008, 2009); active management is necessary (McAdoo et al. 2013) Mgmt. should also promote heterogeneity (Boyd et al. 2011), but resilience is paramount (Bestelmeyer & Briske 2012) Because of risks associated with disturbances in Wyoming big sage communities (Beck et al. 2012), active mgmt. focus should be on mtn. big sage communities, where recovery rates are more rapid (Miller et al. 2015)

Management Implications (my view)
Meadow enhancement is low-hanging fruit * Reduce sagebrush, rabbitbrush, & PJ encroachment * Interseed forbs where needed * Moderate grazing appropriately to enhance SG use Predator control – need season on ravens and/or increased control by agencies Manage sagebrush-grass communities for resistance (to cheatgrass) and resilience after disturbance Actively manage upper elevation (mtn. big sage communities) for mosaics Reduce wildfire in Wy big sage communities, including use of strategic and targeted livestock grazing as appropriate - Integrated Management -

According to the old adage: “Those who ignore history are condemned to repeat it.” Regarding sage-grouse, we can’t repeat history & certainly shouldn’t repeat some episodes, but we should definitely try to learn from it. Both science and history should inform management.

University of Nevada Cooperative Extension

Ecosystems change. Like other species, humans represent an ecological force within an ecosystem—influencing its trajectory in ways that are often highly culture-specific (Anderson in Stewart 2002). Euro-American arrival in N. America Indigenous Altered Ecosystem Euro-American Altered Ecosystem Disturbance Indian arrival in N. America Original Material Original ecosystem (in the absence of indigenous disturbance) Time Trajectory of ecosystem change without event Trajectory of ecosystem change with human arrivals

Early conflicting views regarding sheep-grazing impacts on vegetation:
1903 – traveling from Winnemucca, NV to Ontario, OR – high elevation ranges were denuded by tremendous concentrations of sheep (D. Griffiths, USDA) 1920s – Northeast California - “ I’ve come upon areas where a band of sheep had camped and the ground was all torn up and the whole area would be alive with sagehens…so thick it looked like the ground was moving” (A. Flourney, rancher – acc. Nelson 2011)

Once the focus of repeated 140-mi (round-trip) migratory hunts by aboriginals in Grass Valley, central Nevada (Steward 1938), white-tailed jackrabbits are gone from much of their range in this area (McAdoo 1980; Gruell and Swanson 2012), likely due to declining perennial grass component.

Sage-Grouse in Nevada - Integrating Science & History

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