Phenology of nocturnal avian migration has shifted at the continental scale


Climate change induced phenological shifts in primary productivity result in trophic mismatches for many organisms1,2,3,4, with broad implications for ecosystem structure and function. For birds that have a synchronized timing of migration with resource availability, the likelihood that trophic mismatches may generate a phenological response in migration timing increases with climate change5. Despite the importance of a holistic understanding of such systems at large spatial and temporal scales, particularly given a rapidly changing climate, analyses are few, primarily because of limitations in the access to appropriate data. Here we use 24 years of remotely sensed data collected by weather surveillance radar to quantify the response of a nocturnal avian migration system within the contiguous United States to changes in temperature. The average peak migration timing advanced in spring and autumn, and these changes were generally more rapid at higher latitudes. During spring and autumn, warmer seasons were predictive of earlier peak migration dates. Decadal changes in surface temperatures predicted spring changes in migratory timing, with greater warming related to earlier arrivals. This study represents one of the first system-wide examinations during two seasons and comprises measures from hundreds of species that describe migratory timing across a continent. Our findings provide evidence of spatially dynamic phenological shifts that result from climate change.

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Fig. 1: WSR locations and phenological time series.
Fig. 2: Predicted seasonal phenological change.
Fig. 3: Change in spring and fall migration phenology and temperature across 143 WSR stations.
Fig. 4: Anomaly and decadal change comparisons of migration phenology and annual temperature.

Data availability

The datasets generated during and/or analysed during the current study are available at

Code availability

Radar processing code and algorithms can be found at


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NSF Advances in Biological Informatics (ABI-1661259), Division of Information and Intelligent Systems (IIS-1633206) and Integrative and Collaborative Education and Research (1927743) programmes, as well as a Leon Levy Foundation and an Edward W. Rose Postdoctoral Fellowship supported this research.

Author information

All the authors worked to conceive and design this study. K.G.H., F.A.L., D.S. and A.F. drafted the manuscript. T.-Y.L., K.W., G.B., S.M., K.G.H. and D.S. designed the radar algorithms, and processed and summarized the radar data. K.G.H. generated the figures and D.S., W.M.H. and K.G.H. designed the analyses. All the authors provided editorial advice, approved the final version of this manuscript and are in agreement to be accountable for all aspects of the work.

Correspondence to Kyle G. Horton.

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Horton, K.G., La Sorte, F.A., Sheldon, D. et al. Phenology of nocturnal avian migration has shifted at the continental scale. Nat. Clim. Chang. 10, 63–68 (2020).

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