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

Acadia National Park

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 (hereafter, the Park) 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 Park based on both pathway (RCP2.6) is a best-case scenario of aggressive 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 Park is projected to become suitable in the Intergovernmental Panel on Climate Change for projecting 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 community at the Park, 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 Park today, climate suitability in summer under the high-emissions pathway is projected to improve for 40, remain stable for 29 (e.g., Figure 2), and worsen for 14 species. Suitable climate ceases to occur for 60 species in summer, potentially resulting in extirpation of those species from the Park. Climate is projected to become suitable in summer for 12 species not found at the Park today, potentially resulting in local colonization. Climate suitability in winter under the high-emissions pathway is projected to improve for 51, remain stable for 21, and worsen for 11 species. Suitable climate ceases to occur for 12 species in winter, potentially resulting in extirpation from the Park. Climate is projected to become suitable in winter for 45 species not found at the Park today, potentially resulting in local colonization. Figure 1. Projected changes in climate suitability for birds at the Park, by emissions pathway and season.

Birds and Climate Change: Acadia National Park | Page 1 of 7 Results (continued) Potential Turnover Index climate-sensitive species, 6 might be extirpated from the Potential bird species turnover for the Park Park in at least one season by 2050. between the present and 2050 is 0.44 in summer (80th percentile across all national parks) and 0.46 in winter (78th percentile) under the high- emissions pathway. Potential species turnover declines to 0.36 in summer and 0.40 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 Park is or may become home to 26 species that are Figure 2. Climate at the Park in summer is projected to highly sensitive to climate change across their range (i.e., remain suitable for the American Goldfinch (Spinus tristis) they are projected to lose climate suitability in over 50% of through 2050. Photo by John Benson/Flickr (CC BY 2.0). their current range in in summer and/or winter by 2050; Table 1; Langham et al. 2015). While the Park may serve as an important refuge for 20 of these Management Implications Parks differ in potential colonization and extirpation rates, for birds across boundaries, managing the disturbance and therefore different climate change adaptation regime, and possibly more intensive management actions. strategies may apply. Under the high-emissions Furthermore, park managers have an opportunity to focus pathway, Acadia National Park falls within the on supporting the 20 species that are highly sensitive to high turnover group. Parks anticipating high turnover climate change across their range (Table 1; Langham et al. can focus on actions that increase species' ability to 2015) but for which the park is a potential refuge. respond to environmental change, such as increasing the Monitoring to identify changes in bird communities will amount of potential habitat, working with cooperating inform the selection of appropriate management agencies and landowners to improve habitat connectivity responses. 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: Acadia National Park | 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 , 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 Park based on both NPS Inventory & Monitoring Program data and eBird observation data, plus those species for which climate at the Park 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 Potential Brant - Canvasback - colonization colonization

Cackling/Canada Goose x Improving Potential Ring-necked Duck x colonization Potential Mute Swan - colonization Greater Scaup Stable Improving^

Potential Potential Wood Duck x Lesser Scaup - colonization colonization

Potential Common Eider x Stable Gadwall - colonization Harlequin Duck - Worsening Potential Eurasian Wigeon - colonization Surf Scoter x Stable

Potential White-winged Scoter x Stable American Wigeon Improving* extirpation^ Black Scoter x Improving American Black Duck x Improving Long-tailed Duck Stable Stable Mallard Stable^ Improving Bufflehead - Improving Potential Blue-winged Teal - Common Goldeneye x Stable extirpation Barrow's Goldeneye - Worsening^ Potential Northern Shoveler - colonization Hooded Merganser x Improving^ Potential Green-winged Teal x Common Merganser x Stable colonization Red-breasted Merganser Potential Improving^

Birds and Climate Change: Acadia National Park | Page 3 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

extirpation Red-tailed Hawk Improving* Improving

Potential Rough-legged Hawk - Worsening Ruddy Duck - colonization Potential Clapper Rail - Potential Potential Northern Bobwhite colonization colonization colonization Potential American Coot - Potential colonization Ruffed Grouse x extirpation Potential Black-bellied Plover x Wild Turkey x Stable colonization

Red-throated Loon Stable Improving Killdeer Improving -

Potential Potential Common Loon Stable^ Greater Yellowlegs - extirpation extirpation

Potential Willet Stable^ - Pied-billed Grebe x colonization Potential Lesser Yellowlegs - Horned Grebe - Improving extirpation^

Potential Potential Red-necked Grebe Worsening*^ Upland Sandpiper - extirpation extirpation

Northern Gannet Stable^ Improving^ Ruddy Turnstone x Improving^

Double-crested Cormorant x Improving Potential Dunlin - colonization^ Great Cormorant x Improving Purple Sandpiper x Stable Potential Potential American Bittern extirpation colonization^ Potential Wilson's Snipe - extirpation Great Blue Heron Improving Improving Potential American Woodcock x Great Egret Improving - colonization

Little Blue Heron Stable - Red-necked Phalarope Stable -

Green Heron Improving - Parasitic Jaeger Improving - Potential Black-crowned Night-Heron x Common Murre x Stable colonization Black Guillemot x Worsening* Potential Black Vulture - colonization Potential Bonaparte's Gull Improving extirpation Turkey Vulture x Improving Laughing Gull Stable^ - Potential Northern Harrier Improving extirpation^ Ring-billed Gull Worsening^ Improving

Sharp-shinned Hawk x Improving Herring Gull Worsening Stable^

Cooper's Hawk x Improving Potential Iceland Gull (Thayer's) - colonization Northern Goshawk x Worsening* Great Black-backed Gull x Stable Potential Bald Eagle x extirpation Potential Black Tern - extirpation Potential Red-shouldered Hawk Improving colonization Arctic Tern Stable -

Birds and Climate Change: Acadia National Park | Page 4 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

Rock Pigeon Stable Stable Willow Flycatcher Improving* -

Mourning Dove Improving Worsening Potential Least Flycatcher - extirpation Yellow-billed Cuckoo Improving* - Eastern Phoebe Stable - Black-billed Cuckoo Worsening - Great Crested Flycatcher Stable - Potential Eastern Screech-Owl - colonization Eastern Kingbird Stable -

Great Horned Owl x Improving Potential Northern Shrike - extirpation Snowy Owl - Stable Potential White-eyed Vireo - Barred Owl x Stable colonization

Common Nighthawk Stable - Potential Yellow-throated Vireo - colonization Chimney Swift Improving* - Warbling Vireo Improving - Ruby-throated Hummingbird Worsening - Potential Belted Kingfisher Stable Improving Philadelphia Vireo - extirpation Potential Potential Red-headed Woodpecker Red-eyed Vireo Worsening - colonization colonization Potential Red-bellied Woodpecker Improving* Improving* Gray Jay - extirpation Potential Potential Yellow-bellied Sapsucker Blue Jay Stable Stable extirpation colonization American Crow Worsening Stable Downy Woodpecker Improving Stable Potential Hairy Woodpecker Worsening Worsening Fish Crow Improving colonization Potential Black-backed Woodpecker x Potential Potential extirpation Common Raven extirpation extirpation Northern Flicker Stable Improving Potential Horned Lark - Potential Potential colonization Pileated Woodpecker extirpation extirpation Northern Rough-winged Improving* - Potential Swallow American Kestrel x colonization Purple Martin Improving* -

^ Merlin x Improving Tree Swallow Worsening -

Peregrine Falcon x Improving Barn Swallow Improving - Potential Olive-sided Flycatcher - Cliff Swallow Stable - extirpation Potential Carolina Chickadee - Eastern Wood-Pewee Improving - colonization Potential Yellow-bellied Flycatcher - Black-capped Chickadee Worsening* Stable extirpation Potential Potential Potential Boreal Chickadee Acadian Flycatcher - extirpation^ extirpation colonization Tufted Titmouse Improving* Improving* Potential Alder Flycatcher - extirpation Potential Potential Red-breasted Nuthatch extirpation extirpation

Birds and Climate Change: Acadia National Park | Page 5 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

White-breasted Nuthatch Improving Improving Potential Black-and-white Warbler - extirpation Potential Brown Creeper Improving extirpation^ Potential Tennessee Warbler - extirpation House Wren Stable - Potential Potential Potential Nashville Warbler - Pacific/Winter Wren extirpation extirpation colonization Potential Potential Mourning Warbler - Carolina Wren Improving* extirpation colonization Potential Kentucky Warbler - Blue-gray Gnatcatcher Improving - colonization Potential Golden-crowned Kinglet Improving Common Yellowthroat Worsening - extirpation Potential Potential Potential American Redstart - Ruby-crowned Kinglet extirpation extirpation colonization Potential Potential Cape May Warbler - Eastern Bluebird Improving extirpation colonization Potential Potential Northern Parula - Veery - extirpation extirpation Potential Potential Magnolia Warbler - Swainson's Thrush - extirpation extirpation Potential Potential Bay-breasted Warbler - Hermit Thrush Improving* extirpation extirpation Potential Blackburnian Warbler - Wood Thrush Improving* - extirpation

American Robin Improving Improving Yellow Warbler Worsening -

Potential Potential Gray Catbird Improving Chestnut-sided Warbler - colonization extirpation

Potential Potential Brown Thrasher Stable Blackpoll Warbler - colonization extirpation

Northern Mockingbird Improving* Improving* Potential Black-throated Blue Warbler - extirpation European Starling Improving Improving Potential Potential Potential Palm Warbler Bohemian Waxwing - extirpation colonization^ extirpation Potential Cedar Waxwing Worsening Improving Warbler Stable^ colonization Snow Bunting - Worsening* Potential Yellow-rumped Warbler Improving* Ovenbird Worsening* - extirpation

Potential Potential Worm-eating Warbler - Yellow-throated Warbler - colonization colonization

Potential Prairie Warbler Improving - Northern Waterthrush - extirpation Potential Black-throated Green Warbler - Blue-winged Warbler Improving - extirpation Potential Golden-winged Warbler Stable - Canada Warbler - extirpation

Birds and Climate Change: Acadia National Park | Page 6 of 7 Summer Winter Summer Winter Common Name Common Name Trend Trend Trend Trend

Potential Indigo Bunting Improving* - Wilson's Warbler - extirpation Potential Bobolink - Potential extirpation Yellow-breasted Chat - colonization Red-winged Blackbird Improving Improving Eastern Towhee Improving* - Potential Eastern Meadowlark Stable American Tree Sparrow - Worsening colonization

Potential Rusty Blackbird - Improving Chipping Sparrow Stable colonization Common Grackle Stable Improving Potential Field Sparrow Improving* colonization Brown-headed Cowbird Improving Improving Potential Vesper Sparrow Improving - Orchard Oriole - colonization Potential Potential Savannah Sparrow extirpation colonization Baltimore Oriole Improving -

Potential Potential Grasshopper Sparrow - Pine Grosbeak - colonization extirpation

Nelson's/Saltmarsh Sparrow Potential House Improving Improving x (Sharp-tailed Sparrow) colonization^ Potential Purple Finch Stable Potential extirpation Seaside Sparrow - colonization^ Potential Red ^ x Fox Sparrow - Improving extirpation Potential Potential Song Sparrow Stable Improving White-winged Crossbill extirpation extirpation Potential Lincoln's Sparrow - extirpation Common Redpoll - Worsening*

Potential Potential Potential Swamp Sparrow Pine Siskin Stable extirpation colonization extirpation

Potential American Goldfinch Stable Improving White-throated Sparrow Improving extirpation Potential Potential Evening Grosbeak Dark-eyed Junco x Improving extirpation extirpation

Scarlet Tanager Stable - House Sparrow x Improving Potential Northern Cardinal Improving* Improving Eurasian Tree Sparrow - colonization Rose-breasted Grosbeak Worsening -

Birds and Climate Change: Acadia National Park | Page 7 of 7