Shifts in Bird Migration Timing in North American Long-Distance and Short-Distance Migrants Are Associated with Climate Change

Jay Zaifman,Ahmet Ay,Ana Gabriela Jimenez,Daoyang Shan

doi:10.1155/2017/6025646

Abstract

Bird migration is a synchronized event that has evolved over thousands of years. Changing temperatures due to climate change threaten the intricacies of migration timing for birds; however, the extent of these changes has only recently begun to be addressed. Utilizing data from the citizen-science website eBird and historical temperature data, we analyzed bird migration timing in two states warming quickly (Alaska and Maine) and one warming gradually (South Carolina). Using linear regressions, we looked at relationships between different temperature indices and year with bird migration timing from 2010 to 2016. Bird migration through all three states, regardless of warming rate, showed similar rates of alterations. Additionally, in every state over half of the birds that had altered migration timing were long-distance migrants. Furthermore, we performed feature selection to determine important factors for changing migration timing of birds. Changes to summer resident and transient bird migration were most influenced by state. In winter resident migration, departure date and length of stay were most influenced by maximum temperature, while arrival date was most associated with minimum temperature. Relationships between changing temperatures and migration timing suggest that global climate change may have consequential effects on all bird migration patterns throughout the United States.

Highlights

Scientists agree that humans are causing recent global warming [1]
We looked at bird migration through two drastically warming states, Maine and Alaska, and one state not drastically changing in temperature, South Carolina
Of the total 149 species analyzed in South Carolina using eBird sightings from 2010 to 2016, 49 species showed some alteration in their migration timing due to temperature changes (Table 1)

Summary

Introduction

Scientists agree that humans are causing recent global warming [1]. One of the anthropogenic drivers of mean global warming is the increasing concentration of Green House Gas (GHG) emissions, from molecules like CO2, CH4, N2O, and O3 (Rodhe Bera et al (2009) [2]). Despite recent efforts to limit GHG emissions, they continue to rise. Previous studies have determined that additional global warming of more than ∼1∘C will be detrimental due to the probable rising of sea levels and the extinction of species that cannot adjust to rising temperatures (Hansen et al 2006). Several recent models used to predict global climate change indicate that temperatures will continue to rise (Hansen et al (2006) [4], Iselin et al (2017)). Animal populations have three options to deal with increases in temperature: physiologically adjust to new thermal regimes, change distribution patterns, or, at worst, face local extinction [5]

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Results

Conclusion