Changes in Tree Swallow Phenology Due to Climate Change in Alaska

Undergraduate Honors Thesis

Citations

Citeable URL: https://scholar.colorado.edu/concern/undergraduate_honors_theses/k930bx47q

Abstract

Ecological effects of climate change are beginning to be seen across the globe. In avian species, these effects often manifest in earlier breeding dates. Tree swallows in the temperate zones of North America advanced their laying date by nine days between 1959 and 1991. However tree swallows in more arctic regions, where climate change is occurring more rapidly, have not yet been studied. Additionally, two important climate variables, wind and precipitation, have been largely ignored in climate change studies to date. I used tree swallow nest records from Fairbanks, Alaska to examine how climate change is affecting these birds in the northern part of their range. To provide a more comprehensive view on how tree swallows are being affected by climate change, I looked at effects from wind and precipitation in addition to temperature. I found an advance in laying date and a decrease in incubation time, resulting in a greater advance in hatch date, associated with increasing temperatures and decreasing wind speeds. I conclude that tree swallows in Alaska are hatching earlier and that this shift is likely caused by increasing temperatures and decreasing wind speeds in May and June.

Creator