The Audubon and National Parks Study: Frequently Asked Questions
Everything you need to know about our findings, their implications, and how to interpret the data for the birds and parks you care about.
(Go back to the main website for Audubon's Birds and Climate Change in Our National Parks study.)
Frequently Asked Questions
- What is the Audubon National Parks Climate Study?
- What are the primary findings?
- Where can I find the peer-reviewed scientific paper on the study?
- How does the study project changes in future climate suitability in a park?
- What geographical range does the study cover?
- What types of national parks were included in the study?
- How are birds where I live projected to respond to global warming?
- Are birds with stable or improving climate suitability “safe” from climate change?
- Why can’t I find projections for a specific bird?
- Why are there climate suitability projections for a species that doesn’t really occur in a park?
- How did this study create lists of species currently found in parks?
- Why include projections of potential colonizers that are clearly implausible?
- What are the differences between the information on the Audubon park pages and the scientific publication in PLOS ONE?
- What are the limitations of a study like this that projects changes in climate suitability?
- Why does the National Park Service post similar park-specific briefs on their website?
- Will Audubon continue to conduct research into how climate change affects birds?
- What can I do to help?
What is the Audubon National Parks Climate Study?
Audubon’s National Parks Climate Study, published in peer-reviewed journal PLOS ONE, is the latest research exploring the potential impacts of climate change on 513 bird species across 274 national park management units. Audubon scientists partnered with the National Park Service to summarize how suitable each park’s future climate conditions could be for each species in winter and summer.
This work builds on Audubon’s Birds and Climate Change Report, which used three decades of community-scientist observations from the Audubon Christmas Bird Count and the North American Breeding Bird Survey to define the “climate suitability” for each bird species—the range of temperatures, precipitation, and seasonal changes each species needs to survive. Then, using internationally recognized greenhouse-gas emissions pathways, researchers mapped each bird’s climate suitability in the future as the climate changes. Researchers then quantified the amount of projected change in each park, looked for patterns across geographic regions, and suggested management actions that would help birds respond to climate change.
What are the primary findings?
The public lands protected and managed by the National Park System will be critical refuges for birds as they respond to changing climate conditions. On average across the 274 parks studied, nearly one-quarter of all bird species in a given park may change by 2050 as some species have the potential to colonize individual parks and others have the potential for local extirpation. The amount of change, and thus the risk to birds, is less drastic if global carbon emissions are reduced.
Many National Parks may lose species that currently call them home, particularly in summer. On average, 20 percent of current species may become extirpated from parks in the summer; 29 percent of parks have more potential for extirpation than colonization in the summer season.
In certain parks, some migrant species may remain in parks year-round. For example, the Common Yellowthroat could become a winter resident in 48 parks where it currently breeds as those parks grow warmer. On average, seven present-day migrant species may overwinter per park.
The National Park Service’s Midwest and Northeast regions may see the most change. Birds may move north and colonize these parks as the south grows hotter and drier; examples include the Scissor-tailed Flycatcher from the arid Great Plains, or even southwestern species like the Chihuahuan Raven. At the same time, boreal-breeding songbirds, like the Boreal Chickadee and Bay-breasted Warbler, may leave parks to push north into cooler areas.
Where can I find the peer-reviewed scientific paper on the study?
The paper that communicates these findings about birds and climate change in U.S. national parks is entitled “Projected avifaunal responses to climate change across the U.S. National Park System” and was published in PLOS ONE on March 21, 2018. This national parks work builds on previous continental-scale analysis summarized in Langham et al. 2015.
How does the study project changes in future climate suitability in a park?
Future climate suitability for each species within each park was based on work from Audubon’s Birds and Climate Change Report. Audubon scientists used three decades of community-scientist observations from the Audubon Christmas Bird Count and the North American Breeding Bird Survey to define the “climate suitability” for each bird species—the range of temperatures, precipitation, and seasonal changes each species needs to survive. Then, using internationally recognized greenhouse-gas emissions pathways, they mapped each bird’s climate suitability in the future as the climate changes. For species presently found in a park, they determined whether climate suitability will improve, worsen, or remain stable. When suitable climate ceases to occur, a species could be potentially extirpated from the park. When climate is projected to become suitable in the future for a species not found in the park today, that species could potentially colonize the park. These groupings serve as a guide to how each bird’s climate suitability might change within each national park through mid-century (2050s).
This study summarizes projected changes in climate suitability by mid-century for birds at each of the 274 national park management units under two climate change scenarios. The high-emissions pathway (RCP8.5) represents a future in which little action is taken to reduce global emissions of greenhouse gases. The low-emissions pathway (RCP2.6) is a best-case scenario of aggressive efforts to reduce emissions. These emissions pathways are globally standardized and established by the Intergovernmental Panel on Climate Change for projecting future climate change.
What geographical range does the study cover?
The study covers the continental United States, with projections in the contiguous 48 states plus Alaska. Parks in the oceans (e.g. Virgin Islands National Park, national parks in Hawaii) are not covered in this analysis.
What types of national parks were included in the study?
The study included 274 national park management units that fall under the NPS Inventory and Monitoring Program's natural resource park designation. These include congressionally designated National Parks, as well as National Monuments, National Memorials, National Military Parks, National Battlefields, National Battlefield Parks, National Memorial Parkways, National Recreation Areas, National Seashores, National Lakeshores, National Historic Sites, National Historical Parks, National Historical Reserves, and National Scenic Rivers, National Rivers, National Scenic Rivers, National Wild and Scenic Rivers, National Recreational Rivers, National Preserves, National Scenic Trails, and National Historic Trails.
How are birds where I live projected to respond to global warming?
Explore potential future changes to bird populations in a national park near you at Audubon’s National Parks Report website. There you will find an overview of the 53 national park management units designated as “National Parks,” and you can see how each park compares to the broader set and explore the projections within each park in detail. Or, if you are looking for information outside of the national parks, visit the website for Audubon’s Birds and Climate Change Report to check out how birds’ climate ranges might change across North America. Explore by Flyway or state to review local bird species.
Are birds with stable or improving climate suitability “safe” from climate change?
Not necessarily. Our work looks at the most fundamental climate needs each species requires for survival. Projected climate suitability does not take into account specifics of habitat quality, competition from other species, or extreme events (weather or otherwise) that could influence whether a species is able to persist in a park.
Why can’t I find projections for a specific bird?
The study includes projections of climate suitability for 513 bird species (360 species in summer and 396 in winter). This is not inclusive of all birds in North America and there were species left out of the analysis. Included species are well-surveyed by the Audubon Christmas Bird Count or North American Breeding Bird Survey for which climatic variables are reliable predictors of species occurrence. Many rare species are excluded because rare-species distributions, in particular, are often well-explained by other factors, ranging from biogeography (e.g., Island Scrub-Jay) to human impacts. In addition, species whose ranges are almost entirely south of the United States (e.g., Colima Warbler, Brown Booby) are not amenable to analysis.
Furthermore, if a species has not been observed in a park, either by the National Park Service Inventory & Monitoring (I&M) Program or by birders submitting checklists to eBird, nor is it projected to potentially colonize a park, then that species will not appear on the park list. These detection lists are imperfect (e.g. species are likely under-reported in northern Alaska in winter).
Why are there climate suitability projections for a species that doesn’t really occur in a park?
Lists of species currently found in parks were based on National Park Service Inventory & Monitoring (I&M) Program species lists, plus checklists submitted by birders to eBird (see next question for additional methodological details). Any species that these sources indicated as present were treated as such, even less common species.
How did this study create lists of species currently found in parks?
The current park species lists are the combination of NPS Inventory & Monitoring (I&M) Program data for the park and eBird observations occurring within or adjacent to the park. We began with the NPS I&M lists, including all species that were not rare or occasional, and added to the list any species observed in two or more distinct years in eBird. These lists represent the best-available data on which species are present in each park in summer and winter, but even still there may be missing species (because some species are hard to observe or few people are birding in winter) or additions (because an uncommon species could have been observed in two distinct years, or late migrants may pass through). We also report on all species for which the park is projected to become suitable in the future, regardless of dispersal capacity or the availability of suitable habitat.
Why include projections of potential colonizers that are clearly implausible?
Although some of the potentially colonizing species for individual parks may be highly unlikely, these are projections of future conditions, and attempting to “rule out” possibilities or rate probabilities was beyond the scope of this analysis. Multiple factors determine a species’ ability to colonize a new location, including habitat availability, ecological processes that affect survival and reproduction, interactions with other species that inhibit or facilitate species' colonization or extirpation, dispersal capacity, species' evolutionary adaptive capacity, and changes in behavior. Some of these factors may also change due to climate change in ways that we cannot anticipate.
Read more about this in an article by renowned ornithologist Kenn Kaufman.
Are there any differences between the information on the Audubon park pages and the scientific publication in PLOS ONE?
The peer-reviewed study considers 274 national park management units across the U.S., whereas results on the Audubon website focus on the 53 units with the “National Park” designation. On the website, lists of current species in each park were used to calibrate Audubon model projections to the present conditions and available habitats in the park. Therefore, only species observed in the park are displayed on the current park species lists.
The peer-reviewed study is appropriate for providing system-wide (across 274 park management units) comparisons and conclusions. The Audubon park pages and park briefs provide information that is specific to the park and calibrated to current park conditions.
What are the limitations of a study like this that projects changes in climate suitability?
The projections included in this study are based solely on climate variables (i.e., a combination of annual and seasonal measures of temperature and precipitation), which means there are limits on their interpretation. Significant changes in climate suitability, as measured here, will not always result in a species response, and all projections should be interpreted as potential trends. Multiple other factors mediate responses to climate change, including habitat availability, ecological processes that affect demography, biotic interactions that inhibit and facilitate species' colonization or extirpation, dispersal capacity, species' evolutionary adaptive capacity, and phenotypic plasticity (e.g., behavioral adjustments). Ultimately, these projections can tell us where to focus our concern and which species are most likely to be affected, but monitoring is the only way to validate these projections and should inform any on-the-ground conservation action.
Why does the National Park Service post similar park-specific briefs on their website?
Park-specific briefs provide information about the effects of a changing climate on resources in individual parks to help parks understand and use study results. To support wide availability, both the National Park Service and Audubon are providing this information via their platforms. The Audubon-branded and NPS-branded park-specific briefs convey the same information.
Will Audubon continue to conduct research into how climate change affects birds?
Yes. Climate is a key Audubon strategy. We will continue to advance through scientific research our understanding of how climate change may impact birds. This includes working to update our models of future climate suitability. Also, this summer we will be launching a new community-science activity, Climate Watch, in which anyone can count birds and provide scientific information to test whether species’ responses to climate change align with our projections.
What can I do to help?
Birds and parks will undergo less change and less stress if we reduce future carbon emissions. You can help by joining with Audubon to support genuine, bipartisan leadership and action by government and corporations that delivers a future powered by clean energy.
We must protect and enhance our national parks and all public lands in the face of disruption already caused by climate change. These treasures of the past are critical conservation tools of the future.
One way you can help parks and other public lands is by asking your member of Congress to support robust funding and permanent reauthorization of the Land and Water Conservation Fund. The Land and Water Conservation Fund has supported efforts to protect habitat in every state and provided funding to nearly every National Park featured on our website.
Find an Audubon chapter or center near you and participate in Climate Watch, a new community-science program, launching in June, that explores how birds are responding to climate change. Use your bird knowledge to survey target species in your area and help us learn how their distributions are changing in response to a changing climate. This program will help validate the climate-change models used for this research. Sign up here to learn more.
Finally, plan your next trip to a national park and bring someone who hasn’t visited before. These parks have been preserved to be appreciated by us today and by future generations. By sharing these parks with friends and family, you are helping a new group of people appreciate these places that will be so important to birds in the face of climate change. Don’t forget your binoculars!