Spring phenology is advancing at a faster rate than arrival times of Common Starling

Abstract

Climate change poses significant impact on most migratory species, altering their breeding and non-breeding distributions, migration distances, and phenology. The ability of a population to track and adjust to the changing environmental conditions is a vital prerequisite for its persistence. In this study, we describe changes in spring arrival phenology of a short-distance migrant, the Common Starling Sturnus vulgaris, in Northeastern Europe and their relation to changes in the onset of meteorological spring during the last century. Phenological data were obtained from an open access database Chronicles of Nature Calendar that held 4291 usable records of the 1st spring observation date of Starlings from 171 phenological network sites between 1922 and 2017. Air temperature data were downloaded from the European Climate Assessment and Dataset database. We found that spring arrival time of Starlings was positively correlated with the onset of spring on a local and broad scale. Spring arrival progression followed a northeast gradient at an average rate of 1.6 days per one degree of latitude (ca. 71 km day−1) and 0.4 days per one degree of longitude (152 km day−1). During the 96-year long period, Starlings on average advanced their spring arrival time by 4.7 days at a rate of 0.05 days per year. However, changes in the onset of spring occurred more rapidly with an average rate of change of 0.18 days per year over the study period. These findings imply broad-scale adjustments in migratory patterns of a short-distance migrant that result from climate change-induced shifts in spring phenology. However, adaptations in bird migration phenology are not occurring fast enough to track and compensate for the rapid increase in air temperature, thus disrupting the earlier matching between bird arrival and spring onset.