U.S. FISH AND WILDLIFE SERVICESPECIES ASSESSMENT AND LISTING PRIORITY ASSIGNMENT FORM

SCIENTIFIC NAME: Spermophilus washingtoni

COMMON NAME: Washington ground squirrel

LEAD REGION: 1

INFORMATION CURRENT AS OF: 6/28/04

STATUS/ACTION: Initial 12-month Petition Finding: not warranted

warranted warranted but precluded (also complete (c) and (d) in section on petitioned candidate species- why action is precluded)

Species assessment - determined species did not meet the definition of endangered or threatened under the Act and, therefore, was not elevated to Candidate status

___ New candidate x Continuing candidate

___ Non-petitioned x Petitioned - Date petition received: 3/20/00 (second petition)

90-day positive - FR date: 12-month warranted but precluded - FR date: Is the petition requesting a reclassification of a listed species?

x Listing priority changeFormer LP: 2 New LP: 5

Latest Date species became a Candidate: 10/25/99___ Candidate removal: Former LP: ___

___ A - Taxon is more abundant or widespread than previously believed or not subject tothe degree of threats sufficient to warrant issuance of a proposed listing orcontinuance of candidate status.

___ F - Range is no longer a U.S. territory. I - Insufficient information exists on biological vulnerability and threats to support

listing.___ M - Taxon mistakenly included in past notice of review.___ N - Taxon may not meet the Act ’ s definition of “ species. ”___ X - Taxon believed to be extinct.

ANIMAL/PLANT GROUP AND FAMILY: Mammal (Sciuridae)

HISTORICAL STATES/TERRITORIES/COUNTRIES OF OCCURRENCE: Oregon and Washington

CURRENT STATES/ COUNTIES/TERRITORIES/COUNTRIES OF OCCURRENCE: Oregonand Washington

LEAD REGION CONTACT: Scott McCarthy (1503) 231-6131

LEAD FIELD OFFICE CONTACT: Jodie Delavan, La Grande Field Office, (541) 962-8584;Linda Hallock, Upper Columbia River Basin Field Office, (509) 891-6839.1

BIOLOGICAL INFORMATION:

Species Description

The first Washington ground squirrel (Spermophilus washingtoni) specimen was collected fromthe Washington Palouse grassland of eastern Washington and was described by J.K. Townsendin 1836 (ODFW 1999). Washington ground squirrels are one of the smallest members of thesubgenus Spermophilus. They are distinguished from other Washington and Oregon groundsquirrels by their relatively smaller size, white eye ring, short tail, and white speckled dorsum(Carlson et al. 1980). They range from 185-245 millimeters (7.3-9.6 inches) in total length andtheir weight fluctuates throughout the season as a function of body fat content (Rickart andYensen 1991).

The Washington ground squirrel is diurnal, semi-fossorial, and spends much of its timeunderground. Adults emerge from hibernation between January and early March, depending onelevation and microhabitat conditions (Sherman 2000), with males emerging before females(Bailey 1936; Verts and Carraway 1998; Sherman 2000). Their active time is spent inreproduction and fattening for their 7-8 month dormancy. Adults return to their burrows by lateMay to early June, and juveniles return about a month later (Verts and Carraway 1998).

Washington ground squirrels produce only one litter of young per year due to their limited periodof activity and reproduction. Uterine litter sizes range between 5 and 11 with an average of 8(Scheffer 1941). Carlson et al. (1980) reported an average litter size of 5. Sherman (2000)observed that 1-year old and older females mated, whereas males were not sexually mature untilage 2. Males defend territories of 370-930 square meters (4,000-10,000 square feet) withburrows of up to six females (Sherman 2000). Sherman (2000) also noted that females weresexually receptive on only one afternoon per season, usually 1-2 days post-hibernation, andcopulation occurred underground.

Sherman (1999) indicated that Washington ground squirrels gave birth during the last 2 weeks inFebruary near Othello, Washington. The first litter of pups was seen above ground in mid-March. In Oregon, a litter was seen above ground in early March, 2003 (V. Marr, pers. comm.2003). Sherman (1999) estimated that gestation and lactation required approximately 49-50days.

Carlson et al. (1980) observed Washington ground squirrels feeding on bluebunch wheatgrass(Agropyron spicatum), needle-and-threadgrass (Stipa comata), Sandberg bluegrass (Poasecunda), and cheatgrass (Bromus tectorum) in the spring. They shift to the seeds of grasses andforbs as they become available later in the season (Quade 1994). Specific taxa found in theirstomachs have also included filaree (Erodium sp.), globemallow (Sphaeralcea sp.), slenderwheatgrass (Agropyron pauciflorum), plantain (Plantago patigonica), Indian ricegrass(Oryzopsis hymenoides), and tumbleweed (Salsola collina) (Quade 1994). Crops such ascabbage, peas, corn, oats, wheat, rye, barley, and alfalfa are also consumed when available

(Bailey 1936; Howell 1938). They also eat limited quantities of insects (Carlson et al. 1980), andone juvenile was observed eating phlox (Phlox sp.) (J. Delavan, U.S. Fish and Wildlife Service(Service), pers. comm. 2004). A detailed diet study is not complete, but a fecal analysis todetermine the diet of some Washington populations is currently underway (R. Hill, Service, pers.comm. 2004).

Taxonomy

Washington ground squirrels belong to the family Sciuridae (squirrels, chipmunks, andmarmots), subfamily Sciurinae, tribe Marmotini, subtribe Spermophilina, genus Spermophilus,and subgenus Spermophilus. In the subgenus Spermophilus, only the Columbian ground squirrel(Spermophilus columbianus) and Belding ’ s ground squirrel (Spermophilus beldingi) aresympatric with Washington ground squirrels (Rickart and Yensen 1991). The Washingtonground squirrel was initially confused with the Townsend ground squirrel (Spermophilustownsendii) (Bailey 1936; Betts 1990), but its identification was clarified by Howell (1938) whenhe described the Washington ground squirrel as a separate species with two subspecies (Betts1990). However, phenetic and karyotypic data later indicated that this species is monotypic (Hill1978).

Habitat

Washington ground squirrels are found within the shrub-steppe habitat of the Columbia Basinecosystem. Within this ecosystem, the species is found in a variety of habitats (Quade 1994).Betts (1990) determined that the Washington ground squirrel occupied areas with a greater grassand forb cover than adjacent unoccupied areas. Greene (1999) compared occupied to unoccupiedshrub and grassland habitats to determine the factors most commonly associated with habitatsused by Washington ground squirrels. Washington ground squirrels occurred at sites with highervegetative cover, but soil type may be the most important habitat feature. Greene (1999)determined that the species selects soils with high silt content, such as Warden soils that arefound scattered throughout much of their range. Warden soils not only have a high silt content,but they are also very deep (U.S. Department of Agriculture 1983), allowing for deeper burrowsthat will maintain their structure compared to sandy or shallow soils. Warden soils occur eastand south of the Columbia River. While they appear to prefer Warden soils, they can also befound in other soil types including Sagehill, Royal, Quincy, Koehler, Burbank, and Ellum soils(Greene 1999; Morgan and Nugent 1999; Marr 2001).

Historical Range/Distribution

1The Washington ground squirrel is endemic to the Columbia Plateau, south of the ColumbiaRiver and east of the John Day River (Bailey 1936; Howell 1938; Betts 1990; Csuti et al.1997;Verts and Carraway 1998). Their range was likely contiguous when the region was first settled(NEDC et al. 2000 in David Evans and Associates 2004).

Although the species is associated with sagebrush-grasslands of the Columbia Plateau (Betts1990; Verts and Carraway 1998), studies indicate that silt loam soils, especially those classifiedas Warden soils, are of particular importance (Rickart and Yensen 1991; Greene 1999). It is

generally thought that squirrels prefer Warden soils because of the relative ease of digging andmaintaining burrow systems rather than in other soils with high clay content or high sand content(Greene 1999). The burrowing mammal seldom constructs burrows in areas of heavily disturbedsoils, such as areas affected by activities including plowing, discing, and crop production (Betts1990, 1999; Greene 1999).

Current Range/Distribution

Washington ground squirrels occur east of the Columbia River in two populations in the State ofWashington, and one population south of the Columbia River in the State of Oregon (Betts 1990,1999). The three populations are highly disjunct, separated by more than 50 kilometers(30 miles) of unoccupied land (Betts 1990).

The most northwesterly population in Washington, Badger Mountain, is the smallest and mostisolated of the three populations. This population consisted of nine historic locations prior to1989 (Betts 1990). When surveyed in 1987-1989, only four extant colonies were found, all ofwhich were small and classified as highly vulnerable to extinction (Betts 1990). Whenresurveyed in 1998, squirrels were verified at only one of the four previously extant locations.Four additional colonies were reported north of the Badger Mountain population, but detailsabout these sites were not provided (Betts 1999). Recent surveys on the Bureau of LandManagement ’ s (BLM) Wenatchee Resource Area in Washington reported 83 Washingtonground squirrel detections, 33 of which were made in Douglas County (Musser et al. 2002).Four additional sites were incidentally located on private land. It is also not clear whether asingle detection represents a single colony, or whether some colonies were large enough tointersect transect lines more than once and therefore had multiple detections for one colony.

The Columbia Basin population in southeast Washington, as described by Betts (1990), has notbeen exhaustively surveyed, but was reported to have 47 colonies in 1989 (Betts 1990) and 37when resurveyed in 1998 (Betts 1999). Colonies appear to be scattered in this area with a corearea of occurrence at the center of the population range (Betts 1999). Recent, site-specificstudies have located more colonies within the range of the Columbian Basin population in theSeep Lakes Wildlife Management Area and the Columbia National Wildlife Refuge nearOthello, Washington (Sherman 1999, 2000). Sherman (1999, 2000) observed 23 sites withsquirrels in 1999 and again observed squirrels at each site in 2000. Four were located on theColumbia National Wildlife Refuge and 19 were on the Seep Lakes Wildlife Management Area.Only 19 of the 23 sites were active in 2001 showing a 17 percent decrease in the activepopulation from 1999 to 2001 (Sherman 2001). Musser et al. (2002) had 50 detections on BLMland in Grant County during a Washington ground squirrel survey.

In 2004, the Washington Department of Fish and Wildlife (WDFW) revisited 300 of roughly 500known and historic detections in Douglas, Grant, and Adams Counties. They found activity atapproximately 240 (80 percent) of the sites. While there has recently been an overall increase inthe number of detections, it is notable that many of these detections are located in clusters. Theremay be some suitable habitat between these clusters, but some areas have already been developedfor agriculture (R. Finger, WDFW, pers. comm. 2004). Furthermore, a single detection does notnecessarily constitute a single colony. It is possible that a single colony was large enough that ithad multiple detections.

The Oregon population is centered almost entirely on the United States Naval Weapons SystemsTest Facility (Boardman Bombing Range), managed by the U.S. Navy (Navy), and the Boeingtract. The Boeing tract covers approximately 34,555 hectares (ha) (95,000 acres (ac)). R.D.Offutt Company-Northwest (Offutt Company) and Bos Family Oregon Farms (collectivelyreferred to as Threemile Canyon Farms) purchased approximately 36,705 ha (90,700 ac) from theState of Oregon in November 2002. Threemile Canyon Farms leases 1,093 ha (2,700 ac) to TheBoeing Company (Boeing Radar Range), and put 9,146 ha (22,600 ac) of its property into apermanent Oregon Department of Fish and Wildlife (ODFW) Conservation Easement(Boardman Conservation Area). The Boardman Conservation Area is managed by The NatureConservancy (TNC) under a 40-year lease from the Threemile Canyon Farms. Portland GeneralElectric (PGE) owns and/or leases 1,740 ha (4,300 ac) of the Boeing tract and has dedicated 356ha (880 ac) for conservation (PGE Conservation Area) (David Evans and Associates 2004).

Historic and new sites were monitored on the Boardman Bombing Range in 1997, 2000, 2001,2002, and 2003. In 2003, there were 149 sites: 118 small, 25 medium, and 5 large (Marr 2003).Marr (2003) did not provide an exact definition for small, medium, and large colonies on theBoardman Bombing Range. However, they are likely similar to the sizes used when he surveyedthe Boardman Conservation Area in 2004 (small: 0-2,500 square meters (26,610 square feet),medium: 2,500-10,000 square meters (26,610-107,639 square feet), and large: greater than10,000 square meters (107,639 square feet) (Marr 2004). Surveys conducted or funded byODFW, PGE, Threemile Canyon Farms, and TNC from 1999 to 2001 detected 123 Washingtonground squirrel locations on the Boeing tract. Marr (2004) revisited 90 of 92 known colonies(121 of 123 detections) on the Boeing tract. He reported 66 (73 percent) occupied sites in 2004,and incidentally discovered 16 new sites. The PGE Conservation Area site and Boeing RadarRange sites were not revisited in 2004 (Marr 2004). The few known Washington ground squirrelsites apart from the Boeing tract and Boardman Bombing Range in Oregon include one site onTNC property, one site south of Arlington, a few detections on BLM-managed Horn Butte, andlimited sites on private property (Betts 1990, 1999; R. Morgan, ODFW, pers. comm. 2004).

Population Estimates/Status

Carlson et al. (1980), Quade (1994), and Greene (1999) performed mark-recapture studies tolook at sex-ratios, age structure, and Washington ground squirrel abundance. Additional capture-recapture data was collected in 2002 and 2003 as part of a male juvenile dispersal study (Klein2002, 2003). Sherman (1999, 2000, 2001) monitored colonies in the Columbian Basinpopulation as well. Ratios and abundance vary enormously between colony sites and seasons.There is no good calculation of population estimate (trend or size) due to an overall poorunderstanding of their population dynamics (ODFW 1999). However mark-recaptureinformation, combined with recent survey efforts by TNC, PGE, ODFW, WDFW, BLM, andothers, provide useful information on the incidence and distribution of the species.

THREATS: A. Destruction, modification, or curtailment of its habitat or range.

1Betts (1990, 1999) documented the curtailment in the range of the Washington ground squirrel.His surveys on historic and documented occurrences focused on the perimeters of the range with

the intent of evaluating reductions in numbers of colonies and the size of the current range.Although Betts ’ surveys do not provide an exhaustive review of all potential squirrel locationsor numbers of individuals, they do provide a good estimate of the distribution and decline ofWashington ground squirrels in Oregon and Washington. Betts found that the species haddisappeared from 73.8 percent of the sites in Washington and 76.9 percent of the sites in Oregon.

The historic range of the species, distributed over much of the shrub-steppe habitat ofsoutheastern Washington and northeastern Oregon, has been modified and reduced to threedisjunct areas (Betts 1990, 1999; Quade 1994; ODFW 1999; Vickerman et al. 2000). Thesmallest of these areas is the Badger Mountain population. It consisted of nine historic locationsprior to 1989 (Betts 1990). When surveyed in 1987-1989, only four extant colonies were found,all of which were small in size and classified at a high vulnerability to extinction (Betts 1990).When surveyed again in 1998, squirrels were verified at only one of the four previously extantlocations (Betts 1999). At two sites, one colony had been exterminated by the landowner, andthe habitat had been removed for a house at the other (Betts 1999). Four additional colonies havebeen reported north of the Badger Mountain population (Betts 1999), and 33 detections werereported on BLM land in Douglas County (Musser et al. 2002).

The area in southeastern Washington (i.e., Columbia Basin population) is the most widelydistributed and least well surveyed population. However, it is likely the most sparsely populatedarea within the species current range due to natural habitat conditions and the modification ofsuitable habitat for agriculture. Historically, approximately 56 sites occurred in this area (Betts1990). Betts ’ (1990) surveys indicated that about 43 sites had been lost in this area, and abouthalf since 1978. Of the approximately 47 historic and new confirmed sites in this area in 1987-1988, Washington ground squirrels were still evident at 37 (78 percent) in 1998 (Betts 1999).Most of these losses have resulted in further range curtailment, occurring primarily at thenorthern and southern boundaries of the range of the Columbia Basin population.

Recent, site-specific studies have located more colonies within the range of the Columbia Basinpopulation in the Seep Lakes Wildlife Management Area and the Columbia National WildlifeRefuge. Sherman (1999, 2000) located 23 new sites in 1999. Only 19 of the 23 sites were activein 2001 showing a 17 percent decrease in the active population from 1999 to 2001 (Sherman2001). Musser et al. (2002) had 50 detections in Grant County on BLM land. Four additionalsites were incidentally located on private land near the surveyed sites. It is not clear how manyof these sites may be multiple detections of the same colony. However, this survey providesuseful documentation of additional sites located on Federal land. These areas may represent thebest stronghold for Washington ground squirrels and their habitat in southeastern Washington.

Range reduction and documented habitat destruction have been greatest in Oregon within theColumbia Plateau population (Betts 1990, 1999). All but one of the 36 new and historic sites,located by Betts in 1987-1989, were located on the 10,595 ha (26,180 ac) Boardman BombingRange or just south of it. Washington ground squirrels had disappeared from 20 of 26 historiclocations, 12 of which were lost between 1979 and 1989 (Betts 1990). By 1999, the 36 observedcolonies had been reduced to nine, a decrease of 75 percent (Betts 1999). Since Betts ’ surveyswere conducted, Greene (1999) completed a more detailed survey of the Boardman BombingRange, documenting 69 colonies. Marr (2003) revisited Greene ’ s locations and foundadditional sites, documenting 149 total sites in 2003 (Marr 2003). While additional colonieshave been reported, a number of colonies have been vacated. For example, only 115 of 188 (61.2

percent) colonies originally located in 1997, 2000, 2001, and 2002 were occupied in 2003 (Marr2003). It is unclear whether new colonies and detections will persist in the long-term. Althoughadditional colonies have been found, the losses in historic populations provide a quantitativemeasure of known declines which was likely paralleled among previously undiscoveredlocations. Anecdotal accounts and references support this unquantified loss in Washingtonground squirrel numbers and colonies (Bailey 1936; Howell 1938; Carlson et al. 1980; Verts andCarraway 1998).

Morgan and Nugent (1999) completed the most comprehensive survey within the species ’range on about 7,824 ha (19,333 ac) of the Boeing tract, on what is currently part of theBoardman Conservation Area. They located a total of 37 colonies from 104 detections. Morerecent surveys located 11 additional sites on the Boardman Conservation Area (TNC 2001), oneon the PGE Conservation Area, and one on the Boeing Radar Range (Marr 2004). No sites havebeen located in areas surveyed on Threemile Canyon Farms outside of the BoardmanConservation Area (CH2M Hill 2000; David Evans and Associates 2004). TNC revisited all ofthe 90 known colonies (or 121 detections) on the Boardman Conservation Area in 2004. Sixty-six (73 percent) of sites were occupied in 2004, whereas 24 (27 percent) were vacant. Of the 62known in 1999, 44 (71 percent) were still occupied while 18 (29 percent) were vacant, making a5-year prorated vacation rate of 5.8 percent per year. Of the 20 sites first identified in 2001, 16(80 percent) were occupied while four (20 percent) were vacant, with a 3-year prorated vacationrate of 6.7 percent per year. While 24 sites have become vacant since 1999, it is notable that 16additional sites were located incidentally in 2004 (Marr 2004). 1

Together, the Boeing tract and Boardman Bombing Range support all but two confirmedcolonies known in Oregon (excluding Horn Butte) and approximately 50 to 60 percent of all theknown colonies within the species ’ range. This is a conservative estimate for two reasons.First, the Boardman Bombing Range has not been systematically surveyed according to theprotocol established by Morgan and Nugent in 1999, whereas the new sites located on BLM landin Wenatchee were surveyed using a similar protocol and the increased effort may result in anincreased number of detections. Secondly, it is likely that there were multiple detections of thesame colony in the BLM survey as there was in the ODFW survey (Morgan and Nugent 1999).While BLM reported the number of detections, there was not an estimate of number of coloniesreferenced in the report. Furthermore, it is important to note that the known sites in Oregon arelocated on the largest contiguous stretch of suitable habitat for Washington ground squirrels (R.Morgan, pers. comm. 2004). While there is an increase in the number of known Washingtonsites, many of these are located in isolated clusters.

Some portions of the Threemile Canyon Farms are restricted and remain unsurveyed. However,outside of the Boardman Conservation Area, the majority of the undeveloped portions of theThreemile Canyon Farms contain relatively small amount of potential suitable habitat. It ispossible that there may be some loss of colonies from future agricultural development, however,the Boardman Conservation Area contains all but two of the known locations on the Boeing tract(David Evans and Associates 2004). The Boeing Radar Range may contain suitable habitat andwill be surveyed for Washington ground squirrels by qualified biologists prior to any grounddisturbing activities (David Evans and Associates 2004). While the proposed development ofThreemile Canyon Farms for agriculture is a threat to the Oregon population, the potentialimpact of this development has been greatly reduced since a large portion of known sites areprotected on the Boardman Conservation Area. Development for agriculture is still a potential

threat for the species throughout its range.

The Boardman Bombing Range, which supports the highest known concentration of Washingtonground squirrels and best available habitat (Carlson et al. 1980; Betts 1990; Quade 1994; Greene1999), is not fully secure. Two portions of the site, totaling 2,046 ha (5,055 ac), are designatedas Research Natural Areas and managed by The Nature Conservancy. The remaining 8,024 ha(19,827 ac) is managed by the Navy for military training and grazing allotments (Quade 1994;Greene 1999). The Navy has not allowed grazing on the site for at least 2 years (V. Marr, pers.comm. 2004), but this does not preclude grazing in the future. The Navy planned todecommission the base within the year, eliminating all military training and military securitypersonnel from the site (S. Pennix, Navy, pers. comm. 2000). However, as of 2004, the Navywas still using the site for military training and had placed additional personnel on the BoardmanBombing Range, which indicates that the Navy will continue to manage the site in theforeseeable future. The Navy will continue to manage the site as it does not have the resourcesto remove potential unexploded ordinances or toxic materials (S. Pennix, pers. comm. 2000), butthe removal of limited unexploded ordinances may occur in the future. There are no formalagreements with private landowners, or State or Federal agencies to protect the Washingtonground squirrel, nor do State or Federal agencies have management plans that specificallyaddress the needs of the species or its habitat.

Betts (1990) subjectively evaluated the vulnerability to extinction of each of the remainingknown colonies based on colony size, isolation, land ownership, and threat from human activity.Approximately 29 percent of all colonies were highly vulnerable to extinction (19 percent inOregon, 35 percent in Washington); 31 percent were moderately vulnerable (39 percent inOregon, 25 percent in Washington); and 40 percent had low vulnerability (42 percent in Oregon,39 percent in Washington). In many cases, Betts ’ predictions proved correct, and manycolonies classified as vulnerable were no longer present by 1999 (Betts 1999).

B. Overutilization for commercial, recreational, scientific, or educational purposes.

1Washington ground squirrels, often viewed as pests (Bailey 1936; Howell 1938; Rickart andYensen 1991; Askham 1994), are subject to recreational shooting and poisoning to reduceimpacts to agricultural crops (Betts 1990, 1999; Rickart and Yensen 1991; Sherman 2000).Olterman and Verts (1972 in ODFW 1999) attributed the decline of Washington ground squirrelsfrom 1948 to 1970 to years of control by poisoning and/or shooting, in addition to significanthabitat loss. Sherman (2000) documented deaths of two individuals marked for study. Onecarcass of a pregnant female was found with a bullet wound in the back. The dominant male ofthe colony disappeared and was presumed to have been shot. These individuals represented 22percent of the marked individuals in the colony and were the only observed Washington groundsquirrel mortalities during the 2000 field season.

C. Disease or predation.

1Little disease is known or reported to occur in Washington ground squirrel populations.Ectoparasites (fleas, mites, etc.) are frequently observed on captured individuals but seldomappear to be problematic (Carlson et al. 1980; Sherman 1990, 2000). Townsend ’ s groundsquirrels were seriously reduced by an outbreak of sylvatic plague in Washington in 1936 (Betts1990). Fleas found on Washington ground squirrels were tested for sylvatic plague, but none of

those tested have been positive (Carlson et al. 1980). Sylvatic plague is a continuing threat andcould be devastating to the species.

Predation appears to be a major source of mortality (Carlson et al. 1980; Betts 1990, 1999;Greene 1999; Sherman 1999, 2000). Badgers (Taxidea taxus) appear to be an important predatorof Washington ground squirrels (Bailey 1936; Rickart and Yensen 1991; Betts 1990, 1999;Morgan and Nugent 1999). They are a particular threat to small, isolated colonies and may causelocal extirpations (Betts 1999). Morgan and Nugent (1999) noted that some colonies appeared tohave been eliminated by badgers on the Boeing tract, and badger digging activity is commonwithin Washington ground squirrel colonies (Betts 1990; Sherman 1999, 2000). On twooccasions, Sherman (1999) observed badgers attempting to dig out Washington ground squirrels.Long-tailed weasels (Mustela frenata) are frequently observed near colonies (Martin and Nugent1999), and have been observed hunting and feeding on Washington ground squirrels (Sherman1999).

Other predators include the following: northern harriers (Circus cyaneus), golden eagles (Aquilachrysaetos), red-tailed hawks (Buteo jamaicensis), Swainson ’ s hawks (Buteo swainsoni),ferruginous hawks (Buteo regalis), prairie falcons, (Falco mexicanus), rough-legged hawks(Buteo lagopus), short-eared owls (Asio flammeus), coyotes (Canis latrans), gopher snakes(Pituophis melanoleucus), and western rattlesnakes (Crotalus viridis) (Carson et al. 1980; Greene1999; Verts and Carraway 1998; Sherman 1999, 2000; Klein 2002, 2003).

Raptors appear to be important predators of Washington ground squirrels. In 1995, ODFWstudied the impact of bird predation on the Boardman Bombing Range for the ferruginous andSwainson ’ s hawks. Seven of 19 prey deliveries to the nest were Washington ground squirrels(ODFW 1999). When reporting the fates of collared juvenile males the Boardman BombingRange, Klein (2002, 2003) reported raptors as the most common predator.

D. The inadequacy of existing regulatory mechanisms.

1Several factors related to the inadequacy of existing regulatory mechanisms affect theWashington ground squirrel in Oregon and Washington. In Washington, the species is listed as aState candidate species with no legal protection. A species is considered a candidate if sufficientevidence suggests that its status may meet the listing criteria defined for State Endangered,Threatened, or Sensitive (WDFW 1998). The State of Washington is currently developing astatus review for the Washington ground squirrel (G. Wiles, WDFW, pers. comm. 2004).

In Oregon, the species is listed as an endangered species due to loss of habitat, fragmentation andisolation of colonies and suitable habitat, proposed development of much of the species rangewithin Oregon, and inadequate Federal and State regulations to protect the species (OAR 635-044-0130). The Oregon Endangered Species Act (OESA) provides protection from “ take ” (tokill or obtain possession or control of any wildlife, as defined by ORS 496.004) on State-owned,leased, or managed lands. Once listed, the OESA no longer provides any protection against takeof Washington ground squirrels on private property (ORS 496.192), as was the case when thespecies was classified as sensitive (OAR 635-044-0130).

The State of Oregon previously owned one of the two largest contiguous blocks of land with

Washington ground squirrels in the range of the species. Oregon leased the 38,708 ha (95,650ac) property to Boeing, Inc. in the early 1960s with the stipulation that the land be developed.Boeing ’ s development plans failed to materialize, and to meet the requirements of their lease,they subleased the property to several large agricultural corporations and individuals. The largestblock of land was subleased to Inland Land. Boeing transferred the lease of the site to the OffuttCompany (W. Downey, Offutt Company, pers. comm. 2000). The Offutt Company and BosFamily Oregon Farms (Threemile Canyon Farms) later purchased the property and expressed thedesire to work toward an equitable management of Washington ground squirrel habitat andagricultural development.

Under the State of Oregon ’ s survival guidelines (OAR 635-100-0136), activities detrimental tothe survival of Washington ground squirrels are not to be permitted in areas of occupied habitaton State-owned, managed or leased lands. The OESA requires that survival guidelines beadopted at the time of listing (ORS 496.182; OAR 635-100-0130, 635-100-0136). Survivalguidelines are “ quantifiable and measurable guidelines that [the State Fish and WildlifeCommission] considers necessary to ensure the survival of individual members of the species ”(ORS 496.182(2)). These survival guidelines “ apply only to actions proposed on lands ownedor leased by a State agency, or where a State agency holds an easement ” (OAR 635-100-0136).Survival guidelines were adopted for the Washington ground squirrel on February 4, 2000 (OAR635-100-0136).

The survival guidelines allowed continuation of planned agricultural development by exemptingInland Land from the guidelines between January 21, 2000 and February 18, 2000, providingenough time to complete planned development in 2000. The exemption was established with theprovision that all “ activities detrimental to the survival of Washington ground squirrels ” wereconducted in a manner that avoids take (i.e., killing or possessing) of Washington groundsquirrels (OAR 635-100-0136).

Approximately 35 percent of the Boeing tract ’ s 38,708 ha (95,650 ac) have been modified forirrigated agriculture (ODFW 1999). The majority of known Boeing tract sites are located on a9,146 ha (22,600 ac) permanent ODFW Conservation Easement (Boardman Conservation Area)and are protected under the OESA. For any other State-owned or leased land or easementselsewhere within Oregon where suitable Washington ground squirrel habitat and soil types occur,ODFW mandated State agencies consult with the Department before authorizing activitiesdetrimental to Washington ground squirrels.

Another factor affecting the State ’ s ability to protect the species is conflicting regulationsregarding nongame species and State listed species. The take prohibition under the OESA onlyapplies to State-owned, leased and managed lands, and is narrowly defined as “ k ill or obtain orcontrol ” of the species (ORS 496.004(15)). The Washington ground squirrel is also identifiedby the State as a protected nongame species (OAR 635-044-0130). This designation protects thespecies from hunting, shooting, killing, or possession on all lands within the State. However,ORS 610.105 provides an exception, allowing landowners to kill any rodent by poisoning,trapping, or other means. Because the Washington ground squirrel is a rodent, it may bevulnerable to poisoning, trapping, or other control under this statute.

Relevant Federal laws include the Endangered Species Act (Act), Clean Water Act, Fish andWildlife Coordination Act, National Environmental Policy Act, and Federal Land Management

and Policy Act. Federal regulations and policies provide no protection to candidate species.Although we recommend that Federal agencies confer with us to avoid economic loss andunnecessary delays if a candidate species is eventually listed and is affected by their actions,there is no requirement under Act that Federal agencies confer with the Service for candidatespecies. Species that have been proposed for listing are covered by the conference procedure ofsection 7(a)(4) of the Act. Listing the Washington ground squirrel as an endangered specieswould provide protection for this species under sections 7, 9, and 10 of the Act.

E. Other natural or manmade factors affecting its continued existence.

1Agricultural conversion of shrub-steppe habitat is the primary cause of the decline of theWashington ground squirrel (Carlson et al. 1980; Betts 1990, 1999; Quade 1994). However,certain types of agriculture are more destructive to squirrel habitat than others. Intensive grazinghas been shown to reduce cover and forage, adversely affecting Washington ground squirrels(Greene 1999). Carlson et al. (1980) found that Washington ground squirrels commenceaestivation 2-4 weeks earlier in grazed areas, potentially indicating that green forage was in shortsupply. Early aestivation can be harmful to Washington ground squirrels if they fail to reach anadequate weight to maintain body functions until emergence the following spring (Carlson et al.1980).

Soil disturbance associated with crop production may be the most damaging agricultural activityto Washington ground squirrels (Carlson et al. 1980; Quade et al. 1984; Greene 1999). Tillingand other soil disturbance destroys the necessary structure of the specific silty soil-types (i.e.,Warden soils) on which the species relies (Greene 1999). Surveys of areas developed forirrigated agriculture on the Boeing tract have not yielded any Washington ground squirrelobservations (CH2M Hill 2000).

In addition to changes in soil composition, historic and current agricultural practices mayinadvertently affect adjacent Washington ground squirrel colonies. Greene (1999) found that inaddition to soil type, Washington ground squirrel density and abundance decreased with higherpercentages of bare ground. Certain practices, such as leaving croplands fallow, could adverselyaffect foraging Washington ground squirrels. Bare ground may also leave squirrels morevulnerable to predation (Greene 1999).

In addition to direct impacts to Washington ground squirrel habitat, agricultural and otherdevelopment has led to fragmentation of habitat and isolation of colonies (Betts 1990, 1999). Inanalyses conducted using mark and recapture techniques, Washington ground squirrels movedonly short average maximum distances 85 - 239 meters (m) (279 - 784 feet (ft)) between capturepoints (Carlson et al. 1980; Quade 1994; Greene 1999). Although the sample size was low,Sherman (2000) observed no movements between marked colonies in Washington. Preliminaryresults from a recent juvenile male dispersal study showed that approximately 65 percent ofsquirrels dispersed, moving an average of 999 m (3,277 ft)(Klein 2003). Studies of adultmovements are underway but not complete and there is no information about juvenile femaledispersal. Isolation and fragmentation of colonies and habitat can severely affect Washingtonground squirrels by limiting genetic exchange and reproduction, exposing small colonies todestruction from unpredictable catastrophic events such as fire or drought, and limiting habitatavailable for escape if occupied habitat becomes unsuitable. The isolation of colonies andfragment of habitat therefore increases the risk of extinction by increasing the probability that

these colonies and interactions between other colonies will be destroyed.

Continued agricultural conversion further fragments suitable habitat and isolates otherwisehealthy populations. Betts (1990) predicted the vulnerability to extinction of known squirrelcolonies based on the size, isolation, and land use, and subsequent surveys (Betts 1999) provedmany of his predictions correct. As Betts (1999) states, while small isolated populations “ maypersist for some time, they are highly vulnerable to extinction from a variety of factors such aspredation, parasitism, and weather that may reduce the population below a sustainable level oreliminate it entirely. ”

Other agricultural practices may adversely affect the continued existence of Washington groundsquirrels. The species has been classified as an agricultural pest since it was first identified(Bailey 1936; Howell 1938). As late as 1999, the Oregon Department of Agriculture receivedapplications to apply pesticides to reduce Washington ground squirrel predation on crops. Otherrodent species occur within and adjacent to the range of the Washington ground squirrel that arealso considered agricultural and residential pests and are targeted with pesticides that couldincidentally impact Washington ground squirrels. At least 27 pesticides are registered in Oregonand Washington for application targeted at ground squirrels (Washington State University(WSU) 2000). Their uses vary from home and garden to general rangeland applications (WSU2000). Applications may also be targeted at other species that occur near Washington groundsquirrel colonies (WSU 2000), but Washington ground squirrels could inadvertently be affectedby runoff, overspray, or accidental ingestion. The authorized use of these pesticides iswidespread in Oregon and Washington (WSU 2000) and is particularly likely to impact smalland isolated colonies, but the overall affect of these chemicals on the species is unknown.

Another potential threat relates to the natural fluctuations of weather and potential for drought.Fluctuations in weather and climate have occurred over the species ’ existence throughout itsrange. However, the short term effects of adverse weather are now more likely to be significantwhen considered with other cumulative human-induced threats (ODFW 1999). Winter andspring drought events limit vegetation quality and quantity. Limited forage in spring and earlysummer may affect juvenile survival to independence and adult survival through aestivation(Carlson et al. 1980; Murie 1994; Greene 1999; ODFW 1999). A series of drought years hasreduced the occurance of Washington ground squirrels (Quade 1994) on Boardman BombingRange. In contrast, Greene ’ s (1999) study occurred after 2 years of above average rainfall,which led to a relatively higher abundance of the species. A closely related species, theTownsend ground squirrel, showed a 50 percent population decline in response to droughtconditions in 1977 (Smith and Johnson 1985 in ODFW 1999).

SUMMARY OF REASONS FOR ADDITION, REMOVAL OR LISTING PRIORITYCHANGE:

In past years, both the magnitude and immediacy of threats for Washington ground squirrelswere high. This was due to various potential threats including the following: the conversion ofpotential and known habitat to agricultural use, the proposal to develop a road through a portionof the largest contiguous tracts of known habitat in Oregon, historic and recent populationdeclines, predation, recreational shooting, disease, unknown but potential impacts of pesticides,and the effects of a potential drought event.

There have been rapid declines of some populations of the Washington ground squirrel despitehabitat protections and limited conservation efforts. In Washington, recent declines have beenprecipitous and for unknown reasons (Sherman 2001). Sherman (2001) noted the loss of entirecolonies of ground squirrels on the Columbia National Wildlife Refuge and Seep LakesManagement Area near Othello, Washington, despite the protected status of the species in thearea. In addition, he observed significant declines in body mass, most individuals measured lessthan 50 percent of the average body mass in previous years.

In addition to observed losses in individual colonies, this species receives no habitat protectionwithin Washington and no protection outside State-managed lands in Oregon and the BoardmanConservation Area. The greatest threat to the species is loss of habitat, and the conversion ofsuitable habitat to agricultural uses is an on-going practice with no limitations. Disturbancethrough activities such as tilling and irrigation of the appropriate soil types renders the habitatunsuitable and can result in mortality of occupied colonies. There is currently no mechanism toprotect occupied colonies.

Disease continues to be a potential threat to the species. The sylvagic plague was recordedwithin the range of the species, and has been a factor in the abrupt decline of the pygmy rabbit(Brachylagus idahoensis), a species which is distributed within the range of the Washingtonground squirrel. The fragmentation of remaining habitat and isolation of small colonies thatremain in eastern Washington have made extant colonies of Washington ground squirrels highlysusceptible to disease, predation, and adverse environmental conditions such as drought.

The magnitude of threats for the Washington ground squirrel remains high because the majorityof these threats are likely to continue, and appreciably reduce the likelihood of survival of manyWashington ground squirrel colonies across the range of the species. Federal listing of theWashington ground squirrel would provide habitat protection where it currently does not exist,and incentives to landowners and managers to protect known ground squirrel colonies.

However, while the magnitude of threats remains high for the Washington ground squirrel, theimmediacy of threats has declined in the past year. The majority of existing colonies (in Oregonand throughout the species ’ current range) are located on the Boardman Bombing Range andthe Boeing tract. The Boardman Bombing Range and the Boeing tract contain the largestcontiguous suitable Washington ground squirrel habitat. Although Boardman Bombing Rangeactivities are not certain, they are not expected to change significantly in the foreseeable future.

In 2003, the largest threat to colonies in Oregon was the imminent conversion of the Boeing tractfor agriculture. This would have resulted in the permanent loss of habitat for one of the largestcontiguous blocks of Washington ground squirrels. However, under a newly signed agreement,Threemile Canyon Farms placed 9,146 ha (22,600 ac) of the Boeing tract into a permanentODFW Conservation Easement (Boardman Conservation Area) (David Evans and Associates2004). The Boardman Conservation Area will be managed by TNC with the goal to maintainand improve where feasible the integrity of existing native communities and associated coveredspecies (including the Washington ground squirrel). All but two known sites and the majority ofsuitable habitat on the Boeing tract are located on the Boardman Conservation Area and thereforeare protected from irreversible habitat modification.

The establishment of this agreement reduces the imminence of threats for the Washington ground

squirrel in Oregon by protecting the Boardman Conservation Area, which contains a largeportion of the species ’ known current range. Together with the Boardman Bombing Range,this area comprises a large portion (at least 50 to 60 percent) of known Washington groundsquirrel locations. A decrease in the immediacy of threats is also justified by the increasednumber of detections in the Washington populations, suggesting they are more broadlydistributed throughout their range than was previously known. Although they are more broadlydistributed than previously known, additional information on their genetics, distribution, andpotential for dispersal will be helpful to indicate their long-term potential for survival. Also, themajority of new detections in Washington are on Federal or State property. While this does notguarantee the legal protection, the agencies are not likely to significantly change their landmanagement practices in the near future, and have shown an effort to consider Washingtonground squirrels in their management decisions.

While a large portion of sites are protected under the agreement, it will be important to monitorthe long-term survival of the species throughout the range. Furthermore, it will be important tocarefully analyze the results of upcoming genetics analyses, to determine whether any of thethree populations are significantly different from one another.

For removals: NA Is the removal based on a Policy for Evaluation of Conservation Efforts When Making

Listing Decisions (PECE) finding? If “ Yes ” , summarize the specific PECE evaluationcriteria that were met in determining that the conservation effort is sufficiently certain tobe implemented and effective so as to have contributed to the elimination or adequatereduction of one or more threats to the species identified through the section 4(a)(1)analysis.

FOR PETITIONED CANDIDATE SPECIES (also complete c and d for initial 12-month petitionfindings): NA

a. Is listing warranted? Yes__b. To date, has publication of a proposal to list been precluded by other higher priority

listing actions? Yes__c. Is a proposal to list the species as threatened or endangered in preparation? No__d. If the answer to c. above is no, provide an explanation of why the action is precluded.

We find that the immediate issuance of a proposed rule and timely promulgation of afinal rule for this species for the preceding 12 months has been, and continues to be,precluded by higher priority listing actions (including candidate species with lowerLPNs). During the past 12 months, almost our entire national listing budget has beenconsumed by work on various listing actions to comply with court orders and court-approved settlement agreements, emergency listings, and essential litigation-related,administrative, and program management functions. We will continue to monitor thestatus of this species as new information becomes available. This review will determineif a change in status is warranted, including the need to make prompt use of emergencylisting procedures. For information on listing actions taken over the 12 months, see thediscussion of “ Progress on Revising the Lists, ” in the current CNOR which can beviewed on our Internet website (http://endangered.fws.gov/)

LAND OWNERSHIP:

1Betts (1990) classified land ownership for 87 known colonies in Oregon and Washington.Overall, approximately 59 percent were in private ownership, 17 percent were under governmentmanagement (State or Federal not specified), and land ownership was unknown for 24 percent ofthe colonies. In Oregon, 67 percent were in private ownership, 14 percent under governmentmanagement, and 19 percent were of unknown ownership. In Washington, 52 percent were inprivate ownership, 21 percent under government management, and 27 percent under unknownownership.

Betts (1999) revisited sites in 1998, finding nine occupied sites in Oregon and 37 in Washington.He classified the current ownership in Oregon as the following: 78 percent of occupied sitesunder government management, 11 percent under private ownership, and 11 percent wasunspecified. The land ownership for the remaining 37 sites in Washington was not specified, but3 of the vacated sites from Badger Mountain were under private ownership.

Most of the current locations for the Oregon population are located on the Boardman BombingRange which is managed by the Navy, and the adjacent Boardman Conservation Area. There aretwo other known locations on the Boeing tract, one on TNC property, one on private propertysouth of Arlington (Betts 1990, Betts 1999), as well as 2 to 5 other possible sites on privateproperty (Betts 1990, Betts 1999). There may be additional locations on Horn Butte, which isFederal property managed by the BLM (R. Morgan, ODFW, pers. comm. 2004). In summary,roughly 64 percent of known Oregon sites are located on Federal land (Boardman BombingRange and Horn Butte), 35 percent are located on private land that is under an ODFWconservation easement, and the remaining one percent is located on other private lands.

In Washington, most sites are located on the State-owned Seep Lakes Management Area, theBLM ’ s Wenatchee Resource Area, and the Columbia National Wildlife Refuge. The BadgerMountain sites located in Betts ’ 1990 survey were located on private land. Additionalinformation on the distribution of Washington colonies and the land ownership for these sitesshould be available in the future as WDFW continues to monitor the locations.

PRELISTING:

The Threemile Canyon Farms Multi-Species Candidate Conservation Agreement withAssurances (Agreement) between Threemile Canyon Farms, TNC, PGE, ODFW, and the Servicewas signed in 2004. The Agreement includes commitments from the permittees to implement anumber of conservation measures intended to benefit the Washington ground squirrel,ferruginous hawk, sage sparrow (Amphispiza belli), and the loggerhead shrike (Laniusludovicianus gambeli) (Covered Species). If the Covered Species become listed as threatened orendangered under the Act during the 25-year Agreement period, the permits allow each permitteeto take Covered Species within identified portions of the project area (Covered Area) providedthat the take is incidental to implementation of Covered Activities (David Evans and Associates2004). The Covered Area includes approximately 34,555 ha (95,000 ac) of property owned byThreemile Canyon Farms, PGE, and property leased by the Boeing Radar Range from ThreemileCanyon Farms. Approximately 9,146 ha (22,600 ac) of Covered Area was placed under apermanent ODFW conservation easement (Boardman Conservation Area) and will be managedby TNC. Another 356 ha (880 ac) of property was designated by PGE Conservation Area.

1The Service is also cooperating with the State of Oregon to pursue cooperative agreementsprimarily with the Navy to conserve the species on the Boardman Bombing Range. However,the current amount or quality of habitat which may eventually be protected on the BoardmanBombing Range is unknown. It is also uncertain whether the level of protection offered, wouldbe adequate to provide long-term survival of the species.

The species only occurs only in Oregon and Washington. The Oregon Fish and Wildlife Office(OFWO), and the La Grande Field Office (LFO) have contacted the Upper Columbia RiverBasin Field Office and will continue to coordinate efforts. LFO has been closely coordinatingwith the State of Oregon to assess the status of the species. In 1997, the Service contracted theODFW to compile information necessary to complete this candidate assessment form. InJanuary 1999, the State of Oregon was petitioned to emergency list the species as an endangeredspecies under the OESA, and the species was listed as a State endangered species in January2000. The Service has attended several meetings with the ODFW and the Oregon Fish andWildlife Commission to obtain and analyze information and data regarding the status andpotential threats to the species.

ODFW and LFO intend to cooperate together to attempt to obtain a conservation agreement onthe Boardman Bombing Range, managed by the Navy. The Navy has been hesitant to consider aconservation agreement.

WDFW is monitoring historic and new sites, and the BLM has completed surveys on portions oftheir Wenatchee Resource Area.

DESCRIPTION OF MONITORING:

A variety of measures are being used in Oregon and Washington to monitor the status of thespecies. ODFW completed a 5 year monitoring effort of the colonies on the Boardman BombingRange in 2003. Marr (2003) revisited historic and new sites and provided some estimates forpercent vacations per year. The entire site has not been surveyed according to the protocolestablished by Morgan and Nugent (1999), but 149 colonies were currently occupied as of 2003.Marr (2003) also estimated the relative size of colonies. In the future, it would be useful tocomplete a survey of the entire site if this becomes an option. In addition to ODFW monitoring,Klein (2002, 2003) investigated the fates and dispersal movements of juvenile males. Thisinformation will help determine the species ’ spatial requirements. OFWO is funding a 2-yearstudy addressing adult movement and foraging behavior of Washington ground squirrels on theBoardman Conservation Area and Boardman Bombing Range.

TNC revisited all known sites on the Boardman Conservation Area in 2004 to determine thepercent vacations since 1999 and 2001. They also estimated the relative size of existing coloniesincluding small (0-2,500 square meters (26,610 square feet)), medium (2,500-10,000 squaremeters (26,610-107,639 square feet)), and large (greater than 10,000 square meters (107,639square feet)). As part of their Agreement responsibilities, TNC will sample availableWashington ground squirrel habitat on the Boardman Conservation Area according to theprotocol established by Morgan and Nugent (1999) every 2-5 years to track the spatialdistribution of colonies and the creation of new colonies over time. Additionally, they willsample known colonies every 1-3 years to document changes in their extent and activity over

time (David Evans and Associates 2004).

There are also a variety of monitoring efforts in effect for the Washington populations. BLMcompleted a survey in 2002 of a large portion of its Wenatchee Resource Area in Douglas andGrant Counties. They made 83 detections using a protocol similar to Morgan and Nugent(1999). WDFW is monitoring historic and new sites (including those visited by Betts) on privateand government property.

There are additional ongoing and upcoming studies on Washington populations. One studyinvolves a fecal analysis to better understand the dietary requirements of the species. Anupcoming study will address the population dynamics of squirrels on the Seep Lakes WildlifeManagement Area as well as a genetic analysis of selected sites in Washington (R. Hill, pers.comm. 2004). This may be a useful opportunity to compare this information with the geneticmakeup of selected squirrels in Oregon. LFO will work with the Upper Columbia River BasinField Office and the Columbia National Wildlife Refuge to coordinate efforts when appropriate.

REFERENCES:

Askham, L.R. 1994. Franklin, Richardson, Columbian, Washington, and Townsend ground squirrels. 6 pp.

1Bailey, V. 1936. The mammals and life zones of Oregon. North American Fauna, No. 55:1-416.

Betts, B.J. 1990. Geographic distribution and habitat preferences of Washington groundsquirrels (Spermophilus washingtoni). Northwestern Naturalist 71:27-37.

Betts, B.J. 1999. Current status of Washington ground squirrels in Oregon and Washington.Northwestern Naturalist 80:35-38.

CH2M Hill. 2000. Washington ground squirrel survey, April 12 and 13, 2000: Beef Northwest,Boeing Boardman Tract, Morrow County, Oregon. Field Report to Beef Northwest. 8pp.

Csuti, B.A., A.J. Kimerling, T.A. O ’ Neil, M.M. Shaughnessy, E.P. Gaines, and M.M.P. Huso.1997. Atlas of Oregon wildlife: distribution, habitat, and natural history. Oregon StateUniversity Press. Corvallis, Oregon. 492 pp.

Carlson L., G. Geupel, J. Kjelmyr, J. Maciver, M. Morton, and N. Shishido. 1980. Geographicalrange, habitat requirements, and a preliminary population study of Spermophiluswashingtoni. Final Technical Report, National Science Foundation Student-originatedStudies Program. 24 pp.

David Evans and Associates. 2004. Multi-Species Candidate Conservation Agreement with Assurances. Portland, Oregon.

Greene, E. 1999. Abundance and habitat associations of Washington ground squirrels in North-Central Oregon. M.S. Thesis, Oregon State University, Corvallis, OR. 59 pp.

Howell, A.H. 1938. Revision of the North American ground squirrels with a classification ofthe North American Sciuridae. North American Fauna 56:69-75.

Inland Land Company, LLC. 2000. Letter from Mr. Bob Hale to the Oregon Fish and WildlifeCommission regarding the petition to list the Washington ground squirrel under theOregon Endangered Species Act. Inland Land Company, LLC, Hermiston, Oregon. 2 pp.

Klein, K.J. 2003. Dispersal patterns of the Washington ground squirrel on Boardman Naval Weapons Training Facility: Project update. Oregon Cooperative Fish and Wildlife Research Unit. 11 pp.

Klein, K.J. 2002. Dispersal patterns of the Washington ground squirrel on Boardman Naval Weapons Training Facility: 2002 field season summary. Oregon Cooperative Fish and Wildlife Research Unit. 17 pp.

Marr, V. 2004. Washington ground squirrel monitoring 2004. 13 pp.

Marr, V. 2003. Unpublished Washington ground squirrel survey data collected on the BoardmanBombing Range.

Marr, V. 2001. Effects of 1998 wildfire on Washington ground squirrels and their habitat atNaval Weapons Systems Training Facility, Boardman, Oregon.

Morgan, R.L. and M. Nugent. 1999. Status and habitat use of the Washington ground squirrel(Spermophilus washingtoni) on State of Oregon lands, South Boeing, Oregon in 1999.Oregon Department of Fish and Wildlife, Portland, OR. 27 pp.

Musser, J. Hedges, N. and E. Ellis. 2002. Washington ground squirrel, pygmy rabbit, and sage grouse survey. Bureau of Land Management, Wenatchee Resource Area. 14 pp.

Northwest Environmental Defense Center (NEDC), Defenders of Wildlife, and the Oregon Natural Desert Association. 2000. Petition for emergency listing of the Washington ground squirrel. in David Evans and Associates. 2004. Multi-Species Candidate

Conservation Agreement with Assurances. Portland, Oregon.

Olterman, J.H., and B.J. Verts. 1972. Endangered plants and animals of Oregon . IV.Mammals. Oregon State Univ. Ag. Exp. Stat. Spec. Report No. 364, Corvallis, OR. 47pp. in Oregon Department of Fish and Wildlife. 1999. Washington ground squirrelbiological status assessment. ODFW, Portland, OR. 62 pp.

Oregon Department of Fish and Wildlife. 1999. Washington ground squirrel biological statusassessment. ODFW, Portland, OR. 62 pp.

Quade, C. 1994. Status of Washington ground squirrels on the Boardman Naval WeaponsSystems Training Facility: evaluation of monitoring methods, distribution, abundance,and seasonal activity patterns. Unpublished report submitted to the U.S. Department ofthe Navy, Whidbey Island, WA. 86 pp.

Rickart, E.A, and Yensen, E. 1991. Spermophilus washingtoni. Mammalian Species 371:1-5.

Sherman, P.W. 1999. Behavioral ecology of Washington ground squirrels (Spermophiluswashingtoni). Unpublished report, Cornell University, Ithaca, NY. 9 pp.

Sherman, P.W. 2000. Distribution and behavior of Washington ground squirrels (Spermophiluswashingtoni) in Central Washington. Unpublished report, Cornell University, Ithaca,NY. 13 pp.

Sherman, P.W. 2001. Distribution and status of Washington Ground Squirrels (Spermophiluswashingtoni) in Central Washington. Unpublished report, Cornell University, Ithaca,NY. 10 pp.

Smith, G.W. and D.R. Johnson. 1985. Demography of a Townsend ’ s ground squirrel colonyin southwest Idaho. Ecol. 66(1): 171-178. in Oregon Department of Fish and Wildlife.1999. Washington ground squirrel biological status assessment. ODFW, Portland, OR.62 pp.

U.S. Department of Agriculture. 1983. Soil Survey of Morrow County Area, Oregon. SoilConservation Service, Oregon Agricultural Experiment Station, Corvallis, OR. 223 pp. +maps.

Verts, B.J. and L.N. Carraway. 1998. Land mammals of Oregon. University of California Press,Berkeley, California. 668 pp.

Vickerman, S., J. Belsky, and K.G. Anuta. 2000. Petition for emergency listing of theWashington ground squirrel under the Endangered Species Act. Defenders of Wildlife,Oregon Natural Desert Association, and Northwest Environmental Defense Center.Portland, Oregon. 19 pp. + exhibits.

Washington Department of Fish and Wildlife. 1998. WDFW Policy M-6001. WDFW, Olympia,WA

Washington State University. 2000. Pesticide Information Center On-Line Databases. AccessedApril 9, 2000 at http://picol.cahe.wsu.edu/.

LISTING PRIORITY

THREAT

Magnitude Immediacy Taxonomy Priority

High Imminent

Non-imminent

Monotypic genusSpeciesSubspecies/populationMonotypic genusSpeciesSubspecies/population

1 2 3 4 5* 6

Moderate to Low

Imminent

Non-imminent

Monotypic genusSpeciesSubspecies/populationMonotypic genusSpeciesSubspecies/population

7 8 9 10 11 12

Yes Have you promptly reviewed all of the information received regarding the species for thepurpose of determining whether emergency listing is needed?

Rationale for listing priority number:

Magnitude:

The magnitude of threats for the Washington ground squirrel is high. There are a variety ofpotential threats to the species including the conversion of potential and known habitat toagricultural use, historic and recent population declines, predation, recreational shooting, disease,unknown but potential impacts of pesticides, and the effects of a potential drought event.

Rapid declines of some populations of the Washington ground squirrel have occurred despitehabitat protections and limited conservation efforts. In Washington, recent declines have beenprecipitous and for unknown reasons (Sherman 2001). Sherman (2001) noted the loss of entirecolonies on State and Federal property, despite the protected status of the species in the area. Inaddition, he observed significant declines in body mass, where most individuals measured lessthan 50 percent of the average body mass in previous years. Many adults failed to reproduce in2001, likely as a result of starvation (Sherman 2001).

This species receives no habitat protection within Washington and no protection outside State-managed lands in Oregon and the Boardman Conservation. The greatest threat to the species isloss of habitat, and the conversion of suitable habitat for agricultural use is an on-going practicewith no limitations. Disturbance through activities such as tilling and irrigation of theappropriate soil types renders the habitat unsuitable (Greene 1999) and can result in mortality ofoccupied colonies. There are currently no records of these losses and no mechanism to protect

occupied colonies.

All of these threats are likely to continue, and appreciably reduce the likelihood of survival ofmany Washington ground squirrel colonies across the range of the species. Federal listing of theWashington ground squirrel would provide habitat protection where it currently does not existand incentives to landowners and managers to protect known ground squirrel colonies.

Imminence:

While the magnitude of threats remains high for the Washington ground squirrel, the immediacyof threats has declined in the past year. The majority of existing colonies, and the largestcontiguous suitable habitat, (in Oregon and throughout the species ’ current range) are locatedon the Boardman Bombing Range and the Boeing tract. Although Boardman Bombing Rangeactivities are not certain, they are not expected to change significantly in the foreseeable future.

In 2003, the largest threat to colonies in Oregon was the imminent conversion of the Boeing tractfor agriculture. This would have resulted in the permanent loss of habitat for one of the largestcontiguous blocks of Washington ground squirrels. However, under a newly signed Agreement,Threemile Canyon Farms placed 9,146 ha (22,600 ac) of the Boeing tract into a permanentODFW Conservation Easement (Boardman Conservation Area). The Boardman ConservationArea will be managed by TNC with the goal to maintain and improve where feasible the integrityof existing native communities and associated Covered Species (including the Washingtonground squirrel). All but 2 known sites and the majority of suitable habitat on the Boeing tractare located on the Boardman Conservation Area and therefore are protected from irreversiblehabitat modification.

The establishment of the Agreement reduces the imminence of threats for the Washingtonground squirrel in Oregon by permanently protecting 9,146 ha (22,600 ac) of habitat on theBoeing tract. Together with the Boardman Bombing Range, this area comprises a large portion(at least 50 to 60 percent) of known Washington ground squirrel locations. A decrease in theimmediacy of threats is also justified by the increased number of detections in the Washingtonpopulations, suggesting they are more broadly distributed throughout their range than waspreviously known. Furthermore, the majority of new detections in Washington are on Federal orState property. While this does not guarantee the legal protection, the agencies are not likely tosignificantly change their land management practices in the near future, and have shown an effortto consider Washington ground squirrels in their management decisions.

While the number of detections have increased, it will be important to monitor the long-termsurvival of these colonies. Furthermore, it will be important to determine and closely monitorwhether the increased detections are due an increase in survey effort, an increase in precipitation(which would indicate that sites will decrease in drier years), or other factors.

Is Emergency Listing Warranted? No. While the magnitude of threats facing the speciesremains high, the immediacy of the threats is now moderate to low. The magnitude of threatsremain high because the species faces a variety of continuing, potential threats throughout itsrange including the following: the conversion of potential and known habitat to agricultural use,historic and recent population declines, predation, recreational shooting, disease, unknown but

potential impacts of pesticides, and the effects of a potential drought event. The immediacy ofthreats has decreased from imminent to non-imminent primarily due to the newly signedAgreement that protects a large portion of known colonies on the Boardman Conservation Area.The immediacy is also decreased in part due to an increase in the number of sites detected inparts of its range since 2001.

APPROVAL/CONCURRENCE: Lead Regions must obtain written concurrence from all otherRegions within the range of the species before recommending changes to the candidate list,including listing priority changes; the Regional Director must approve all suchrecommendations. The Director must concur on all 12-month petition findings, additions ofspecies to the candidate list, removal of candidate species, and listing priority changes.

Approve: David B. Allen July 19, 2004 Regional Director, Fish and Wildlife Service Date

Concur: Matt Hogan, Acting 5/2/05 Director, Fish and Wildlife Service Date

Do not concur: Director, Fish and Wildlife Service Date

Director's Remarks:

Date of annual review: June 2004___ Conducted by: Jodie Delavan__

Comments:

(rev. 6/16/04)