Distribution of Mountain Plovers in the Powder River Basin, Wyoming

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1 Distribution of Mountain Plovers in the Powder River Basin, Wyoming Solicitation No. KAQ Final - February 22, 2002 Prepared For: Bureau of Land Management 5353 Yellowstone Road P.O. Box 1828 Cheyenne, Wyoming Prepared By: Rhett E. Good, David P. Young Jr., and Jamie P. Eddy Western EcoSystems Technology, Inc 2003 Central Avenue Cheyenne, Wyoming 82001

2 INTRODUCTION: The mountain plover (Charadrius montanus) is currently proposed for listing as threatened under the Endangered Species Act by the U.S. Fish and Wildlife Service. In order to better understand the current distribution of mountain plovers in the Powder River Basin, the Bureau of Land Management (BLM) contracted Western EcoSystems Technology, Inc (WEST) to conduct mountain plover presence/absence surveys in the Powder River Basin (Figure 1). The area of the survey has a large potential for coal bed methane production, which could potentially degrade habitat suitability for mountain plovers. Mountain plovers arrive on their breeding grounds, including those in Wyoming, in late March to late April. The nesting season generally occurs from May to July with young birds fledging in July and August (Knopf 1996). After courtship, the male will make several nest scrapes from which one is selected. The female will typically lay three eggs, however, clutch size can vary from one to four. During years of high insect numbers, females can lay one clutch for the male and then a subsequent clutch for herself. Usually one egg is laid a day and incubation does not begin until the clutch is complete to insure synchronous hatching. Eggs are incubated for days. After hatching the adults lead the precocial young away from the nest within a few hours. Post hatching movement varies with age of chicks but generally increases with age. Broods typically remain near the nest location for one day and then begin increasing distances moved. Studies in the Pawnee National Grassland in Colorado, found that broods may move up to 1600 m (.1 mile) from the nest (Knopf 1992, 1996) and generally move m per day (Knopf and Rupert 1996). Fledging occurs around 36 days post hatching (Miller and Knopf 1993). Mountain plovers begin congregating in flocks in late July and typically begin migration away from the breeding ground by August (Knopf and Rupert 1996, Knopf 1996). Mountain plovers are opportunistic feeders whose diet consists almost exclusively of invertebrates (Knopf 1998). In Colorado, mountain plovers eat mostly grasshoppers, crickets, beetles, and ants (Baldwin 1971). The preferred habitat of mountain plover is shortgrass prairie and grassland but they may be observed in other habitats during migration (Bent 1962, Davis and Knight 1989). Typical mountain plover habitat is arid, shortgrass plains with level to gently rolling topography. Vegetation is generally less than 10 cm (4 in) in height and often consists of blue grama (Bouteloua gracilis), buffalograss (Buchloe dactyloides), bluebunch wheatgrass (Agropyron spicatum), low growing sagebrush (Artemesia spp), and other low forbs (Parrish 1988, Knopf 1996). Olson-Edge and Edge (1987) noted a strong association of mountain plovers and prairie dog towns. They also noted that irregular topography and tall vegetation precluded use by this species. Knopf and Miller (1994) suggest bare ground is an important factor for good breeding habitat. Mountain plover use is often associated with prairie dog towns, heavily grazed or burned areas. They will also use areas in and around alkali flats and claypans (Knopf 1996) and plowed agricultural fields (Shackford and Leslie 1995, Young and Good 2000). 1

3 Figure 1. A map of the Powder River Basin survey area. 2

4 Mountain plovers historically bred from northern New Mexico north to southern Alberta, Canada, and from northeast Utah east to eastern Montana, western South Dakota, western Nebraska, western Kansas, and northern Texas. Historic winter range included mainly California and Texas, with some birds wintering in Arizona, New Mexico, and Mexico. Today mountain plovers are usually found east of the Continental Divide in Colorado, Wyoming, and Montana (USFWS 1999). Mountain plover distribution within the Powder River Basin is not well known. The Powder River Basin ia an intermontane basin located in northeastern Wyoming and southeastern Montana. The basin is approximately 250 mi x 100 mi (Dolton and Fox 1995). The Powder River Basin contained several mires between river channels and lake margins during the Paleocene era. These mires formed large deposits of coal, some greater than 60 m in thickness (USGS 2001). The methane gas associated with coal beds has been much sought after within recent years. Approximately 3,500 coal bed methane wells have been completed within the Powder River Basin since 1998 (Flores et al. 2001). METHODS: Tape play back surveys were conducted for mountain plovers in the Powder River Basin EIS area from April 26 - May 25, The survey area was split with the Wyoming Natural Diversity Database (WYNDD). Our surveys focused on the western half of the survey area in Johnson, Sheridan and Converse Counties, specifically areas contained within the Sheridan, Buffalo and Kaycee BLM maps (Figure 2). We also surveyed for mountain plovers south of Newcastle. This report only includes data collected by WEST, Inc. Tape Play Back Surveys. Mountain plover courtship songs recorded on the Pawnee National Grassland in Colorado were used during surveys. Tapes were played for 1-2 minutes, and mountain plover auditory responses were listened for. The surrounding area was also scanned with binoculars during surveys. Mountain plover courtship songs were broadcast using walkman tape players amplified through Radio Shack Powerhorns (Model # ). The total cost for one broadcast unit was approximately $50. Two crews (one person per crew) were used to survey for mountain plovers. Tape play back surveys were conducted in areas of low to high potential habitat every 0.5 mile along survey routes. Routes were initially located based upon Gap Analysis Program (GAP) vegetation layers and BLM and Wyoming Game and Fish Department prairie dog coverages. Additional survey routes were selected based upon field observations and requests by district BLM biologists. 3

5 Figure 2. A map of Wyoming showing the location of transects used to survey for mountain plovers by WEST, Inc. in GPS and GIS. The position (UTM NAD 27, Zone 13) of every survey point and observations of BLM sensitive species between survey points were recorded with handheld Trimble Geoexplorer Global Position System (GPS) units. Survey routes were digitized using ArcView. Survey points and observations of BLM sensitive species were loaded in to a shapefile and were delivered to Jeff Carroll, BLM, in October Habitat Potential. Habitat along survey routes were rated as low, medium, high or no potential for mountain plover occurrence. Habitat ratings were developed by WEST personnel based upon published literature and extensive field observations (Appendix A). Areas along survey routes with no potential for mountain plover occurrence (rocky canyons, forests, tall shrubs, rugged topography and residential areas) were not surveyed. Areas with high 4

6 potential were often surveyed at intervals closer than 0.5 mi to confirm the presence or absence of mountain plovers. Nest Searches. Nest searches were conducted within areas where mountain plovers were detected and public lands were present. Nest searches were conducted by driving parallel transects (approximately 50 m apart) and looking for birds flushed from nests. If a mountain plover was detected, the observer moved at least 50 m from the bird and observed the plover to determine if it returned to a nest. Birds were observed for a maximum of 15 minutes to minimize the potential for disturbing nesting birds. RESULTS: Survey Effort. Mountain plovers were surveyed for at 896 points over miles on 37 transects (not including revisits). Areas of high mountain plover potential where plovers were not detected initially were surveyed again at 49 points on transects Irrigary Road, Buffalo-Sussex cutoff and Nine Mile Road (see attached map South of Buffalo, Wyoming). The large prairie dog town on TTT road (see attached map North of Kaycee, Wyoming) was surveyed several times for mountain plovers on our way to other routes (not included in re-visit total). Habitat Potential. The habitat potential for mountain plover occurrence was assessed at 896 survey points (Table 1). A total of 130 (14 %) survey points were considered high potential habitat, 338 (38 %) were medium potential habitat and 428 (48 %) low potential habitat. High potential habitat typically was flat, grazed short-grass prairie with cacti. High potential habitat often included prairie dog towns. Medium potential habitat was characterized by the presence of favorable vegetation (short-grass or low shrubs) or prairie dog towns, but lacking flat topography, or vice versa. Medium potential habitat sometimes included short vegetation or prairie dog towns and flat topography, but lacked large amounts of bare ground. Low potential habitat often included areas with steeply sloping topography or rolling sagebrush. Areas with no potential for mountain plovers along transects were not surveyed, but were described in the transect summaries (Appendix B). Mountain Plover Observations. A total of six mountain plovers were observed during scheduled surveys (Table 2). Three mountain plovers were detected on Middle Fork Road and two mountain plovers were detected on I-25 between Buffalo and Kaycee (see attached map South of Buffalo, Wyoming), and one mountain plover was detected on Cheyenne River Road south of Newcastle (see attached map South of Newcastle, Wyoming). Five of the six mountain plovers responded to the tape with a call. One mountain plover did not call, but walked toward the observer when the tape was played. Mountain plovers were detected from 70 to 200 m from observers (Table 2). 5

7 Mountain plovers were observed in relatively flat short-grass prairie (Appendix C). Large amounts of bare ground were present at all mountain plover locations. Habitat along Middle Fork Road consisted of short-grass prairie with large amounts of bare ground and cactus. Two of the mountain plovers on Middle Fork Road were detected in prairie dog towns. The mountain plover detected south of Newcastle was located within an historic prairie dog town (G. Lebsack, BLM, pers. comm.), however few mounds and no active burrows are currently present. Habitat along I-25 and Cheyenne River Road consisted of relatively flat short-grass prairie with large amounts of bare ground. Mountain plovers were not detected in prairie dog towns on I-25 and Cheyenne River Road. One nest search was conducted on public lands surrounding the observation south of Newcastle, Wyoming (Figure 3). One mountain plover was detected on June 15, 2002 during nest searches. The bird was flushed from the location where it was first observed at 0753 H and flew out of sight. The bird was observed in relatively flat short-grass prairie with scattered, low sagebrush. We returned to the initial location 3 hours later and no mountain plovers were observed or flushed. The bird did not appear to be incubating eggs. Mountain plovers with nests always keep observers in sight and rarely fly away after being flushed from nests (F. Knopf, USGS, pers. comm.). Sensitive Species Observations. A total of 61 observations of seven BLM sensitive species, including 10 Brewer s sparrows (Spizella breweri), seven burrowing owls (Speotyto cunicularia), one ferruginous hawk (Buteo regalis), three long-billed curlews (Numenius americanus), 26 loggerhead shrikes (Lanius ludovicianus), 12 greater sage grouse (Centrocercus urophasianus) and two upland sandpipers (Bartramia longicauda) were made during surveys (Appendix D). One active Swainson s hawk (Buteo swainsoni) nest was also recorded. Two potential greater sage grouse leks were detected. A total of 73 separate prairie dog towns ranging in size from approximately 1 ha to 2048 ha were observed. Most prairie dog colonies were less than 100 ha in size. A total of 50 prairie dog colonies were below 20 ha in size. One prairie dog colony on TTT Road was estimated to be 2 miles x 4 miles, or approximately 2048 ha in size. 6

8 Figure 3. A map showing the mountain plover nest search area south of Newcastle, Wyoming. 7

9 Table 1. Habitat ratings of points surveyed along transects. Transect County High Medium Low Total Buffalo - Sussex cutoff (T9) Johnson Buffalo-Kaycee I-25 W side Johnson Cheyenne River Road Weston Cheyenne River Road - other end Weston CO 111 Johnson CO 114 Midwest Natrona CO CO 113 Midwest Natrona CO 238 Johnson CO MT Sheridan CO 70 - Hwy 14/16 Sheridan Coal Mine Road Johnson Double Cross Road Sheridan and Johnson Dry Creek Road Johnson Hutt Road Weston Hwy 16 - CO 40 - CO 38 Campbell and Sheridan Hwy 341 Campbell and Sheridan HWY 87 Buffalo-Kaycee and Middle Johnson Hwy Mesa Road Johnson Irrigary Road Johnson Kaycee-Buffalo I-25 E side Johnson Lindeman Flats N Johnson Lindeman Flats S Johnson and Natrona Lower Powder River Road Sheridan and Johnson Lower Sussex Road (T8 South end) Johnson Middle Fork Road Johnson Morrisey Road (Newcastle) Weston and Niobrara Nine mile road Johnson Old Hwy 85 South of Newcastle Weston and Niobrara Reno Road Johnson Schoonover Road (T 3) Johnson Sleeter Road (T4 South End) Johnson Thompson Cr Road - Clearmont Sheridan and Johnson Tipperary 2 Johnson Tipperary Road Johnson Tipperary-Luddock Road Johnson Trabing Road (T2 North end) Johnson TTT Road Johnson and Natrona Unnamed Johnson Grand Total

10 Table 2. A summary of mountain plovers observed during taped play back and nest surveys. Only one bird was observed in each observation. Transect Date (2001) Auditory (A) or Visual (V) 9 Dist. from Observer (m) Direction from Observer Time (H) Prairie Dogs Present? Buffalo-Kaycee I-25 W side 23-May A and V 100 E 0548 N Buffalo-Kaycee I-25 W side 23-May V and A 175 W 0605 N Cheyenne River Road 25-May A and V 100 S 0843 N Cheyenne River Road 15-June V NR NR 0753 N Colony Size (ha) HWY 87 Buffalo-Kaycee 23-May V 70 SE 1008 Y 100 and Middle Fork Road Middle Fork Road 5-May A and V 150 E 0741 Y 10 Middle Fork Road 5-May A 200 E 0846 N DISCUSSION: Mountain plover densities may be low in the Powder River Basin due to limited habitat. This assessment is based upon observations of mountain plover habitat within the western half of the Powder River Basin where surveys were conducted by WEST personnel. Based on our rating of habitat suitability for mountain plovers, less than 15 % of the survey routes covered (896 survey points over miles) were considered highly suitable. Although we attempted to place transects in areas with higher potential for mountain plovers based upon presence of GAP vegetation layers, known prairie dog towns, and topography, the majority of habitat within the the areas we surveyed appears to be of low potential or unsuitable for mountain plovers. Many of the areas surveyed were dominated by rolling sagebrush. Areas with medium potential, such as short-grass prairie, often lacked perhaps the most important habitat component, bare ground (Knopf and Miller 1994). Five of the six mountain plovers located during surveys were clustered within an area located between Buffalo and Kaycee. The mountain plover detected south of Newcastle was located in a similar area. Both areas appears to receive less precipitation than the rest of the Powder River Basin and have greater amounts of flat short-grass prairie. The relative intensity of cattle grazing within the area is not known. Mountain plovers have been described as closely associated with prairie dog colonies (Tyler 1968, Knowles et al. 1982, Knowles and Knowles 1984, Shackford 1991). Black-tailed prairie dogs can occur in high densities and will crop vegetation close to the ground within their colonies. Prairie dog colonies also often have high amounts of bare ground. Mountain plovers were detected at only two of 73 prairie dog colonies. The majority of prairie dog colonies were smaller than 20 ha. Graul (1973) describes three male mountain plover territories in Colorado as 16 ha in size. Prairie dog colonies detected during surveys may not meet a minimum size requirement need by mountain plovers, however, research regarding patch sizes and mountain plover occurrence is lacking. Additionally, some prairie dog colonies appeared to have

11 relatively low densities of active burrows and the amount of bare ground appeared to be relatively low. It is important to note that survey routes were limited to public roads. Because much of the Powder River Basin is privately owned, areas of high quality habitat were inaccessible and not surveyed. Thus the results of this survey may not be representative of the entire Powder River Basin. Coal Bed Methane development has the potential to affect mountain plover populations in direct and indirect ways. Direct effects include disturbance to nesting plovers due to new roads and increases in vehicle traffic. Mountain plover broods may be vulnerable to vehicle collisions prior to gaining the ability to fly. Indirect effects include alterations to habitat. Roads created to access methane wells may serve as pathways for predators as well as invasive plant species such as cheatgrass. Many exotic plant species have the ability to dominate habitats and reduce the amount of bare ground, an essential component of suitable mountain plover habitat. The combination of creating invasive plant pathways, as well as water produced during coal bed methane production, increases the potential for invasive species to become established and reduce the suitability of mountain plover habitat. Alternatively, the disturbed areas and roads associated with coal bed methane development may increase coverages of bare ground, an essential component of mountain plover habitat (Knopf and Rupert 1994). Further research on the effects of coal bed methane on mountain plover abundance and habitat is needed to fully evaluate the potential effects of coal bed methane on mountain plover populations in the Powder River Basin. RECOMMENDATIONS FOR FUTURE RESEARCH: Seven other sensitive species were also detected during surveys, including 12 observations of greater sage grouse. Two potential greater sage grouse leks were observed. Considering the potential for coal bed methane development and disturbance to breeding areas, the leks should be surveyed during Monitoring of mountain plover populations in the Powder River Basin should continue. Very little data concerning mountain plover population trends exist in Wyoming. Monitoring efforts should focus on areas where mountain plovers were detected, as well as areas of highly suitable habitat. By monitoring areas of highly suitable habitat where mountain plovers were not observed in 2001, population increases as well as decreases may be detected. 10

12 LITERATURE CITED: Baldwin, P.H Diet of mountain plover at the Pawnee National Grassland, U.S. International Biological Program, Grassland Biome Program Report 134, Fort Collins, Colorado. Bent, A.C Life histories on North American shore birds. Dover Publications, Inc. New York. Davis, M.W., and G. Knight First Mississippi record of mountain plover. Miss. Kite 19:2-3. Dolton, G.L., and Fox, J.E., Powder River Basin Province (033): in Gautier, D.L., Dolton, G.L., Takahashi, K.I., and Varnes, K.L. eds. in 1995 National assessment of United States oil and gas resources--results, methodology, and supporting data. U.S. Geological Survey Digital Data Series 30. Flores R.M., G.D. Stricker, J.F. Meyer, T.E. Doll, P.H. Norton, R.J. Livingston, and M.C. Jennings A field conference on impacts of coalbed methane development in the Powder River Basin, Wyoming. Open-File Report Graul, W.D Adaptive aspects of the Mountain Plover social system. Living Bird 12: Knopf, F.L Status and Conservation of Mountain Plovers, Report of Research Activities, 25 September USFWS National Ecology Research Center, Fort Collins, Colorado. Knopf, F.L Mountain Plover (Charadrius montanus). In The Birds of North America, No. 211 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists Union, Washington, D.C. Knopf, F.L Foods of mountain plovers wintering in California. Condor 100: Knopf, F.L., and B.J. Miller Charadrius montanus- montane, grassland, or bare-ground plover? Auk 111: Knowles, C.J., and P.R. Knowles Additional records of Mountain Plovers using prairie dog towns in Montana. Prairie Naturalist 16: Knowles, C.J., C.J. Stoner, and S.P. Gieb Selective use of black-tailed prairie dog towns by Mountain Plovers. Condor 84:

13 Miller, B.J. and F.L. Knopf Growth and Survival of mountain plovers. Journal of Field Ornithology 64(4): Olson-Edge, S.L. and W.D. Edge Density and distribution of mountain plover on the Charles M. Russell National Wildlife Refuge. Prairie Nat. 19(4): Parrish, T. L Mountain Plover Habitat Selection in the Powder River Basin, Wyoming. M.S. Thesis. University of Wyoming. Shackford, J.S Breeding ecology of the Mountain Plover in Oklahoma. Bull. Okla. Ornithol. Soc. 24: Shackford, J.S., D.M. Leslie, Jr., and W.D. Harden Range-wide use of cultivated fields by mountain plovers during the breeding season. J. Field Ornithol. 70: Tyler, J.D Distribution and vertebrate associates of the black-tailed prairie dog in Oklahoma. Ph.D. diss., University of Oklahoma, Norman. Young, Jr., D.P. and R. Good Mountain Plover Surveys Laramie, Carbon, Sweetwater Counties, Wyoming. Technical Report for U.S. Fish and Wildlife Service, Cheyenne, Wyoming. 14 pp. U.S. Fish and Wildlife Service. 1999a. Endangered and Threatened Wildlife and Plants: Proposed Threatened Status for the Mountain Plover. Fed. Reg. 64(30): U.S. Geological Service Depositional History of Paleocene Coals. Accessed October 16,