Birds and Climate Change National Park Service U.S. Department of the Interior

Assateague Island National Seashore

Background Birds are useful indicators of ecological change because they are highly mobile and generally conspicuous. As climate in a particular place changes, suitability may worsen for some species and improve for others. These changes in climate may create the potential for local extirpation or new colonization. This brief summarizes projected changes in climate suitability by mid- century for birds at Assateague Island National Seashore (hereafter, the Seashore) under two climate change scenarios (see Wu et al. 2018 for full results, and Langham et al. 2015 for more information regarding how climate suitability is characterized). The high-emissions pathway (RCP8.5) represents a future in which little action is taken to reduce We report trends in climate suitability for all species global emissions of greenhouse gases. The low-emissions identified as currently present at the Seashore based on pathway (RCP2.6) is a best-case scenario of aggressive both NPS Inventory & Monitoring Program data and eBird efforts to reduce emissions. These emissions pathways are observation data (2016), plus those species for which globally standardized and established by the climate at the Seashore is projected to become suitable in Intergovernmental Panel on Climate Change for projecting the future (Figure 1 & Table 1). This brief provides park- future climate change. The findings below are model-based specific projections whereas Wu et al. (2018), which did projections of how species distributions may change in not incorporate park-specific species data and thus may response to climate change. A 10-km buffer was applied to differ from this brief, provides system-wide comparison each park to match the spatial resolution of the species and conclusions. distribution models (10 x 10 km), and climate suitability was taken as the average of all cells encompassed by the park and buffer. Results Climate change is expected to alter the bird community at the Seashore, with greater impacts under the high-emissions pathway than under the low-emissions pathway (Figure 1). Among the species likely to be found at the Seashore today, climate suitability in summer under the high-emissions pathway is projected to improve for 28, remain stable for 61, and worsen for 21 species. Suitable climate ceases to occur for 23 species in summer, potentially resulting in extirpation of those species from the Seashore (e.g., Figure 2). Climate is projected to become suitable in summer for 11 species not found at the Seashore today, potentially resulting in local colonization. Climate suitability in winter under the high- emissions pathway is projected to improve for 80, remain stable for 60, and worsen for 24 species. Suitable climate ceases to occur for 13 species in winter, potentially resulting in extirpation from the Seashore. Climate is Figure 1. Projected changes in climate suitability for birds at the Seashore, by emissions pathway and season. projected to become suitable in winter for 26 species not found at the Seashore today, potentially resulting in local colonization.

Birds and Climate Change: Assateague Island National Seashore | Page 1 of 7 Results (continued) Potential Turnover Index 38 of these climate-sensitive species, one, the Mallard Potential bird species turnover for the Seashore (Anas platyrhynchos), might be extirpated from the between the present and 2050 is 0.18 in summer Seashore in summer by 2050. (28th percentile across all national parks) and 0.18 in winter (22nd percentile) under the high- emissions pathway. Potential species turnover declines to 0.13 in summer and 0.14 in winter under the low-emissions pathway. Turnover index was calculated based on the theoretical proportions of potential extirpations and potential colonizations by 2050 relative to today (as reported in Wu et al. 2018), and therefore assumes that all potential extirpations and colonizations are realized. According to this index, no change would be represented as 0, whereas a complete change in the bird community would be represented as 1.

Climate Sensitive Species The Seashore is or may become home to 39 species that are highly sensitive to climate change across their range Figure 2. Although currently found at the Seashore, suitable (i.e., they are projected to lose climate suitability in over climate for the American Goldfinch (Spinus tristis) may 50% of their current range in North America in summer cease to occur here in summer by 2050, potentially resulting and/or winter by 2050; Table 1; Langham et al. 2015). in local seasonal extirpation. Photo by John Benson/Flickr (CC BY 2.0). While the Seashore may serve as an important refuge for Management Implications Parks differ in potential colonization and extirpation rates, other stressors. Furthermore, park managers have an and therefore different climate change adaptation opportunity to focus on supporting the 38 species that are strategies may apply. Under the high-emissions highly sensitive to climate change across their range (Table pathway, Assateague Island National Seashore 1; Langham et al. 2015) but for which the park is a falls within the low change group. Parks anticipating potential refuge. Monitoring to identify changes in bird low change can best support landscape-scale bird communities will inform the selection of appropriate conservation by emphasizing habitat restoration, management responses. maintaining natural disturbance regimes, and reducing Caveats The species distribution models included in this study are that affect demography, biotic interactions that inhibit and based solely on climate variables (i.e., a combination of facilitate species' colonization or extirpation, dispersal annual and seasonal measures of temperature and capacity, species' evolutionary adaptive capacity, and precipitation), which means there are limits on their phenotypic plasticity (e.g., behavioral adjustments). interpretation. Significant changes in climate suitability, as Ultimately, models can tell us where to focus our concern measured here, will not always result in a species response, and which species are most likely to be affected, but and all projections should be interpreted as potential monitoring is the only way to validate these projections and trends. Multiple other factors mediate responses to climate should inform any on-the-ground conservation action. change, including habitat availability, ecological processes

Birds and Climate Change: Assateague Island National Seashore | Page 2 of 7 More Information For more information, including details on the methods, Wu et al. (2018) Projected avifaunal responses to climate please see the scientific publication (Wu et al. 2018) and change across the U.S. National Park System. PLOS ONE. the project overview brief, and visit the NPS Climate Change Response Program website. Contacts Gregor Schuurman, Ph.D. References Ecologist, NPS Climate Change Response Program eBird Basic Dataset (2016) Version: ebd_relAug-2016. 970-267-7211, [email protected] Cornell Lab of Ornithology, Ithaca, New York. Joanna Wu Langham et al. (2015) Conservation Status of North Biologist, National Audubon Society American Birds in the Face of Future Climate Change. 415-644-4610, [email protected] PLOS ONE.

Species Projections Table 1. Climate suitability projections by 2050 under the high-emissions pathway for all birds currently present at the Seashore based on both NPS Inventory & Monitoring Program data and eBird observation data, plus those species for which climate at the Seashore is projected to become suitable in the future. "Potential colonization" indicates that climate is projected to become suitable for the species, whereas "potential extirpation" indicates that climate is suitable today but projected to become unsuitable. Omitted species were either not modeled due to data deficiency or were absent from the I&M and eBird datasets. Observations of late-season migrants may result in these species appearing as present in the park when they may only migrate through. Species are ordered according to taxonomic groups, denoted by alternating background shading. * Species in top and bottom 10th percentile of absolute change ^ Species that are highly climate sensitive - Species not found or found only occasionally, and not projected to colonize by 2050 x Species not modeled in this season Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

Potential Green-winged Teal x Improving Fulvous Whistling-Duck - colonization Canvasback - Stable Brant x Worsening* Ring-necked Duck - Improving Cackling/Canada Goose x Worsening Greater Scaup - Improving^ Potential Mute Swan x extirpation Lesser Scaup x Improving

Tundra Swan Stable x Common Eider - Worsening

Wood Duck x Improving Harlequin Duck - Stable

Gadwall Improving^ Improving Surf Scoter x Worsening*

Eurasian Wigeon - Stable White-winged Scoter x Worsening*

American Wigeon Improving^ Improving Black Scoter x Stable

Potential Long-tailed Duck Stable Worsening* American Black Duck x extirpation Bufflehead - Improving Potential Mallard Stable Potential extirpation^ Common Goldeneye - extirpation Blue-winged Teal Stable Improving Hooded Merganser x Stable^ Northern Shoveler Improving^ Improving Potential Common Merganser - Potential extirpation Northern Pintail x extirpation Red-breasted Merganser Stable Stable^

Birds and Climate Change: Assateague Island National Seashore | Page 3 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

Ruddy Duck Stable Improving Potential Mississippi Kite - colonization Northern Bobwhite Worsening Worsening* Northern Harrier Stable^ Improving Potential Wild Turkey x extirpation Sharp-shinned Hawk x Stable

Red-throated Loon Stable Worsening* Cooper's Hawk x Stable

Common Loon Stable Stable^ Potential Northern Goshawk - extirpation Pied-billed Grebe x Improving Bald Eagle x Stable Horned Grebe - Stable Red-shouldered Hawk Improving Improving Red-necked Grebe - Stable^ Red-tailed Hawk Stable Stable Eared Grebe - Improving Potential ^ ^ Rough-legged Hawk - Northern Gannet Stable Worsening* extirpation Potential Neotropic Cormorant - Clapper Rail x Stable colonization Potential King Rail x Double-crested Cormorant x Improving colonization^

Great Cormorant - Worsening* Virginia Rail x Improving

Potential Potential Potential Anhinga ^ Sora - colonization colonization colonization

American White Pelican - Improving* Common Gallinule x Improving

^ Brown Pelican Stable Stable American Coot x Improving

^ American Bittern Stable Improving American Avocet x Improving^

Great Blue Heron Improving* Improving American Oystercatcher x Stable^

Great Egret Improving* Improving* Black-bellied Plover x Stable

Snowy Egret x Improving American Golden-Plover Stable -

Little Blue Heron Improving* Improving Semipalmated Plover Stable Stable^

^ Tricolored Heron Improving Improving Piping Plover x Improving^ Potential Cattle Egret Improving* Killdeer Improving Improving colonization Potential Spotted Sandpiper x Green Heron Improving* - colonization

Black-crowned Night-Heron x Improving Solitary Sandpiper Stable -

Yellow-crowned Night-Heron Improving Improving Greater Yellowlegs Stable Improving*

White Ibis Improving Improving Willet Stable^ Improving^

Glossy Ibis x Improving Lesser Yellowlegs Stable^ Improving

Black Vulture Improving Stable Whimbrel x Stable

Turkey Vulture x Improving Marbled Godwit Improving^ Stable

Osprey x Improving Ruddy Turnstone x Worsening*^

Red Knot x Stable^

Birds and Climate Change: Assateague Island National Seashore | Page 4 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

Sanderling x Worsening* Potential Groove-billed Ani - colonization Dunlin x Stable^ Barn Owl x Improving Purple Sandpiper - Worsening* Eastern Screech-Owl x Stable Least Sandpiper x Improving* Great Horned Owl x Stable Western Sandpiper Stable Improving Snowy Owl - Improving Short-billed Dowitcher x Stable^ Barred Owl - Improving Long-billed Dowitcher x Improving Common Nighthawk Improving* - Wilson's Snipe - Stable Chuck-will's-widow Improving - American Woodcock x Stable Chimney Swift Worsening - Wilson's Phalarope Stable^ - Ruby-throated Hummingbird Stable - Red-necked Phalarope Stable - Belted Kingfisher Stable Improving Bonaparte's Gull Stable Stable Red-headed Woodpecker Improving Stable Laughing Gull Worsening*^ Stable Red-bellied Woodpecker Improving Stable Ring-billed Gull Stable^ Stable Yellow-bellied Sapsucker - Improving Herring Gull Stable Worsening^ Downy Woodpecker Stable Worsening Glaucous Gull Stable x Potential Hairy Woodpecker Worsening Great Black-backed Gull x Stable extirpation

Potential Potential Gull-billed Tern x Red-cockaded Woodpecker - colonization colonization

Black Tern Improving - Northern Flicker Improving Stable

Arctic Tern Stable - Pileated Woodpecker Stable Stable

Forster's Tern x Improving* American Kestrel x Improving

^ Black Skimmer x Stable Merlin - Improving^ Potential Rock Pigeon Worsening Peregrine Falcon x Stable extirpation Olive-sided Flycatcher Stable - Eurasian Collared-Dove - Improving* Eastern Wood-Pewee Worsening - Potential White-winged Dove - colonization Acadian Flycatcher Stable -

Mourning Dove Worsening Worsening Potential Willow Flycatcher - extirpation Potential Inca Dove - colonization Eastern Phoebe Stable Improving*

Potential Great Crested Flycatcher Stable - Common Ground-Dove - colonization Potential Western Kingbird - Yellow-billed Cuckoo Improving* - colonization

Black-billed Cuckoo Stable - Eastern Kingbird Stable -

Potential Potential Greater Roadrunner - Scissor-tailed Flycatcher - colonization colonization

Birds and Climate Change: Assateague Island National Seashore | Page 5 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

Potential Potential Ruby-crowned Kinglet - Improving Loggerhead Shrike colonization colonization Eastern Bluebird Stable Stable Northern Shrike - Stable Hermit Thrush - Improving Potential White-eyed Vireo Stable colonization Wood Thrush Worsening - Potential Yellow-throated Vireo Stable - American Robin Improving extirpation Potential Warbling Vireo - Potential extirpation Gray Catbird Stable extirpation Potential Red-eyed Vireo - extirpation Brown Thrasher Worsening Improving

Blue Jay Stable Improving Northern Mockingbird Improving Improving

American Crow Worsening Worsening European Starling Worsening Stable

Fish Crow Stable Improving* American Pipit - Improving*

Potential Potential Horned Lark Stable Sprague's Pipit - extirpation colonization

Northern Rough-winged Potential Stable - Cedar Waxwing Improving Swallow extirpation

Purple Martin Improving - Potential Smith's Longspur - colonization Potential Tree Swallow Stable extirpation Potential Snow Bunting - extirpation Barn Swallow Stable - Potential Ovenbird - Cliff Swallow Improving* - extirpation

Carolina Chickadee Stable Stable Worm-eating Warbler Worsening -

Tufted Titmouse Worsening Worsening Potential Black-and-white Warbler Stable colonization Red-breasted Nuthatch - Stable Prothonotary Warbler Improving* - Potential Potential White-breasted Nuthatch extirpation extirpation Potential Swainson's Warbler - colonization Brown-headed Nuthatch Stable^ Stable Orange-crowned Warbler - Improving* Brown Creeper - Worsening Kentucky Warbler Stable - Potential House Wren Improving* extirpation Common Yellowthroat Worsening Improving*

Pacific/Winter Wren - Improving Hooded Warbler Stable -

Sedge Wren - Improving* American Redstart Stable -

Marsh Wren x Improving* Northern Parula Stable -

Carolina Wren Stable Stable Potential Yellow Warbler - extirpation Potential Blue-gray Gnatcatcher Stable colonization Palm Warbler - Stable^

Golden-crowned Kinglet - Stable Pine Warbler Worsening^ Improving*

Birds and Climate Change: Assateague Island National Seashore | Page 6 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

Yellow-rumped Warbler - Improving Dark-eyed Junco - Worsening

Potential Summer Tanager Stable - Yellow-throated Warbler Stable colonization Potential Scarlet Tanager - Prairie Warbler Stable - extirpation

Yellow-breasted Chat Stable - Northern Cardinal Improving Worsening

Eastern Towhee Worsening* x Potential Rose-breasted Grosbeak - extirpation Potential Potential Bachman's Sparrow colonization colonization Blue Grosbeak Worsening -

Potential Indigo Bunting Stable - American Tree Sparrow - extirpation Potential Painted Bunting - Potential colonization Chipping Sparrow Improving* extirpation Red-winged Blackbird Worsening Improving Field Sparrow Worsening* Stable Eastern Meadowlark Improving* Improving Potential Vesper Sparrow Improving* extirpation Rusty Blackbird - Improving

Potential Potential Lark Sparrow - Brewer's Blackbird - colonization colonization

Savannah Sparrow - Improving Common Grackle Worsening Improving

^ ^ Grasshopper Sparrow Worsening* - Boat-tailed Grackle Stable Worsening*

Potential Potential Potential Henslow's Sparrow - Great-tailed Grackle colonization colonization colonization

LeConte's Sparrow - Improving* Brown-headed Cowbird Worsening Improving

Nelson's/Saltmarsh Sparrow Orchard Oriole Stable - x Stable^ (Sharp-tailed Sparrow) Potential Baltimore Oriole - Seaside Sparrow Stable^ Stable^ extirpation

Fox Sparrow - Improving Potential Potential House Finch extirpation extirpation Potential Song Sparrow Stable extirpation Purple Finch - Stable

Potential Common Redpoll - Stable Lincoln's Sparrow - colonization Pine Siskin - Stable Swamp Sparrow Stable Improving Potential American Goldfinch Worsening White-throated Sparrow - Improving extirpation

Potential Potential Harris's Sparrow - Evening Grosbeak - colonization extirpation

White-crowned Sparrow - Stable House Sparrow x Stable

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