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Climate change represents one of the foremost drivers of ecological change, yet its documented impacts on biodiversity remain uncertain and complex. Although there have been many published studies on species shifting their geographic ranges in response to climate change, it is still challenging to identify the specific mechanisms and conditions that facilitate range shifts in some species.


Contemporary climate change represents one of the foremost drivers of ecological change. Species can respond to shifting climate conditions in a variety of ways, including changes in morphology (e.g., decreasing in size), behavior (e.g., foraging on different food sources), phenology (e.g., shifting migration timings), and geographic range (e.g., moving to cooler habitats). 

Among the most significant and widely discussed of these responses are shifts in species’ spatial distributions (i.e., range shifts). Range shifts have the potential to reshape ecological communities, alter ecosystem functions and services, impact human health and well-being, and even have feedback effects on the climate system. Understanding how species are shifting as a function of climate change is important for effectively managing species and habitats. In fact, in a 2020 survey of state and territorial fish and wildlife employees conducted by the Association of Fish and Wildlife Agencies (AFWA), respondents identified “understanding shifting species distributions” as among their highest-priority climate information needs.    

The Contractions and Range Expansions (CoRE) Database contains information on range-shift studies that can be used to explore how different species are moving in response to climate change.  

About the Database 

The CoRE Database includes 315 primary research articles published between 1954-2020 that document species-level distribution shifts in animals or plants in response to recent anthropogenic climate change. It favors empirical data sets, and thus excludes papers that modeled projections of future shifts. It also does not include articles related to paleoclimate conditions or temporary or seasonal climate variations such as El Nino. 

For each study, the database includes information on the: 

  1. Study: duration, location, metadata on the study design.  
  1. Species: scientific names and taxonomic groups.  
  1. Observed shift: range dimension (latitude, elevation, depth), shift type (occupancy shift or abundance shift), range edge (leading edge, trailing edge, center of range) 
  1. Description of shift: range shift direction, magnitude of the shift (km/decade), and whether it supported prevailing range shift hypotheses. 
  1. Climate drivers mentioned in the study. 
  1. Details on species vulnerability and adaptive capacity 

This dataset goes beyond previously published databases by including shifts in abundance along range edges in addition to more traditional occupancy shifts. Additionally, the database includes studies that only reported range shift directions, and not just those that reported quantitative estimates of range shift magnitudes. 

An infographic describing the distribution of the CoRE Database.
Distribution of studies included in the CoRE database, broken down by taxonomic group, hemisphere, and ecosystem type. Observations are concentrated in the Northern Hemisphere (90%) and are mostly from terrestrial organisms (89.5%). Plants make up approximately a third of all data, followed by insects (27.0%), birds (22.8%), and fish (6.5%). Mammals, reptiles, and amphibians are not well represented. 


Accessing the Data 

The CoRE Database can be accessed here.  

Learn more about the project here.  

Any future updates to this database will be added to the project page. 

Data Applications 

Testing Range Shift Hypotheses 

Prevailing range shift hypotheses predict that as temperatures rise, species will follow cooler climate conditions to try to remain within their historical temperature range. Because temperatures generally decrease with increasing terrestrial latitude and elevation, and with increasing depth in freshwater and marine environments, species are generally expected to shift in these directions as the climate warms. The CoRE Database includes information about range shift directions and rates, and thus whether studies support these hypotheses or not, making it a powerful tool to explore range shift hypotheses across different species, regions, and taxonomic groups. 

An infographic describing range shifts for different animals.
Prevailing range shift hypotheses predict that species will move to higher latitudes (poleward), to higher elevations (upslope), or to greater depths (deeper under water). 


Investigating Patterns in Range Shifts 

These data can also be used to analyze range shift patterns within and between groups of species. The database showed statistically significant latitudinal shifts for birds, insects, and fish, whereas mammals did not demonstrate significant latitudinal shifts. Future research could look for patterns in the behavior or morphology in species who demonstrate range shifts versus those who do not. 

For example, a postdoc who formerly participated in a National Science Foundation Graduate Internship Program with the USGS is exploring range shifts in insects by investigated which insect traits may influence variation in shifts between species. 

More Information 

To learn more about this database, see:  

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