Correction: Differential changes in the onset of spring across US National Wildlife Refuges and North American migratory bird flyways.

[This corrects the article DOI: 10.1371/journal.pone.0202495.].

In Fig 4 the labels for brown and red polygons are swapped in the map legend. Brown polygons should be the Early FLI & FBI and red polygons should be early FLI. Please see the corrected Fig 4 here.

Fig 4

US National Wildlife Refuges with extremely early recent spring onset relative to the historical range of variability.

Shown is the combination of selected data from Fig 3A and 3B; extremely early recent spring onset is defined as earlier than 95% of historical (1901–2012) First Leaf Index (FLI) or First Bloom Index (FBI) values.