Western Sandpiper (Calidris mauri) Vulnerability: Presumed Stable Confidence: Low

The Western Sandpiper is one of the most abundant sandpipers in the western hemisphere. In Alaska, the core of its breeding population is in the Yukon-Kuskokwim River Delta. It also breeds less commonly in the western portion of the North Slope (Johnson et al. 2007). This species nests in well-drained moist to upland tundra habitats dominated by dwarf shrubs and tussock grasses (Wilson 1994). During the breeding season Western Sandpipers typically forage on aquatic insects in wet tundra habitats and along pond edges near nesting areas, but occasionally forage on terrestrial arthropods as well (Wilson 1994). This species winters along the west coast of North America from California to Peru (Wilson 1994). Current population estimate for North America is 3.5 million with a declining trend (Morrison et al. 2006).

Physiological Thermal Niche: The heart of the Western Sandpiper breeding range is in the sub- arctic and so presumably, as arctic temperatures rise, themal conditions could become more amenable for expansion of their breeding range into more of the coastal plain potentially increasing competition with the closely related Semipalmated Sandpipers. S. Maslowski Range: We modified the NatureServe range map to more closely match the Birds of North America map and evidence from recent studies that suggest greater usage of inland sites in the western portion of the coastal plain (Bart et al. 2012, Johnson et al. 2007). Physiological Hydro Niche: Because Western Sandpipers use wet tundra habitats to some degree, primarily for foraging during both the breeding season and during post-breeding staging they were scored as “neutral-to- increased” vulnerability in the “physiological Disturbance Regime: Climate-mediated hydrologic niche” category (see table). Drying disturbance processes, namely thermokarst, of wet tundra habitats could reduce invertebrate could both create and destroy lake habitats availability. Current projections of annual through both ice wedge degradation and potential evapotranspiration suggest negligible draining of thaw lakes (Martin et al. 2009). atmospheric-driven drying for the foreseeable Increased fire frequency (Racine and Jandt future (TWS and SNAP). Thus atmospheric 2008) could reduce habitat suitability required moisture, as an exposure factor (most influential by the species for nesting, although for the for “hydrological niche” sensitivity category), timeline of this assessment fires will likely be was not heavily weighted in the assessment. localized phenomenon. Increased coastal erosion Human Response to CC: Shoreline armoring and resulting salinization (Jones et al. 2009) related to climate change mitigation could could impacts post-breeding staging birds. reduce the availability of staging habitats this Interactions with Other Species: In terms of species uses prior to fall migration. However, interspecies interactions, this species will shoreline armoring would be limited to existing communally feed and flock with other communities or infrastructure, which is limited shorebirds during post-breeding staging (Taylor in extent at present and thus impacts would be et al. 2010), but it is unknown if these behaviors slight. increase species persistence. Climate change

Western Sandpiper (Calidris mauri) Vulnerability: Presumed Stable Confidence: Low

D=Decrease vulnerability, SD=Somewhat decrease vulnerability, N=Neutral effect, SI=Slightly increase vulnerability, I=Increase vulnerability, GI=Greatly increase vulnerability.

may reduce the amplitude of lemming cycles breeding shorebirds on the Arctic Coastal Plain of Alaska. Arctic 60(3): 277-293. (Ims and Fuglei 2005) and thus could expose this species to greater nest predation pressure if Jones, B.M., C.D. Arp, M.T. Jorgenson, K.M. Hinkel, J.A. lemmings become less available as alternative Schmutz, and P.L. Flint. 2009. Increase in the rate and uniformity of coastline erosion in Arctic Alaska. prey. Geophysical Research Letters 36, L03503

Phenological Response: There is evidence Martin, P., J. Jenkins, F.J. Adams, M.T. Jorgenson, A.C. suggesting some shorebirds are able to track Matz, D.C. Payer, P.E. Reynolds, A.C. Tidwell, and J.R. phenological changes associated with a warming Zelenak. 2009. Wildlife response to environmental Arctic climate at least in terms of nest initiation (J. change: Predicting future habitats of Arctic Alaska. Report Liebezeit and S. Zack unpublished data; D. of the Wildlife Response to Environmental Arctic Change (WildREACH), Predicting Future Habitats of Arctic Alaska Ward, pers. comm.). However, it is unknown if Workshop, 17-18 November 2008. Fairbanks, Alaska, they can synchronize timing to other organisms USFWS, 148 pages.

changing schedules that they depend on (e.g. Morrison, R.I.G., B.J. McCaffery, R.E. Gill, S.K. Skagen, invert. prey). S.L. Jones, G.W. Page, C.L. Gratto-Trevor, and B.A. In summary, while a few potential sources Andres. 2006. Population estimates of North American shorebirds, 2006. Wader Study Group Bulletin 111:67-85. of climate-related vulnerability were identified for this species, the assessment presumes that Racine, C. and R. Jandt. 2008. The 2007”Anaktuvuk Western Sandpiper will be stable in this region River” tundra fire on the Arctic Slope of Alaska: a new at least for the next few decades. phenomenon? In D.L. Kane and K.M. Hinkel (Eds.), Ninth International Conference on Permafrost, Extended Literature Cited Abstracts (p. 247-248). Institute of Northern Engineering, University of Alaska Fairbanks. Bart, J., S. Brown, B. Andres, R. Platte, and A. Manning. 2012. North slope of Alaska. Ch. 4 in Bart, J. and V. The Wilderness Society (TWS) and Scenarios Network for Johnston, eds. Shorebirds in the North American Arctic: Alaska Planning (SNAP), Projected (2001-2099: A1B results of ten years of an arctic shorebird monitoring scenario) monthly total potential evapotranspiration from 5 program. Studies in Avian Biology. AR4 GCMs that perform best across Alaska and the Arctic, utilizing 2km downscaled temperature as model inputs. Ims, R.A. and E. Fuglei. 2005. Trophic interaction cycles in http://www.snap.uaf.edu/data.php. tundra ecosystems and the impact of climate change. BioScience 55: 311-322. Wilson, W.H. 1994. Western Sandpiper (Calidris mauri), The Birds of North America Online (A. Poole, Ed.). Ithaca: Johnson, J.A., R.B. Lanctot, B.A. Andres, J.R. Bart, S.C. Cornell Lab of Ornithology; Retrieved from the Birds of Brown, S.J. Kendall, and D.C. Payer. 2007. Distribution of North America Online: http://bna.birds.cornell.edu/bna/

species/090. doi:10.2173/bna.90

From: Liebezeit et al. 2012. Assessing Climate Change Vulnerability of Breeding Birds in Arctic Alaska. A report prepared for the Arctic Landscape Conservation Cooperative. Wildlife Conservation Society, North America Program, Bozeman, MT., 167pp.