Data From: Winter mortality of a passerine bird increases following hotter summers and during winters with higher maximum temperatures

Climate change influences animal population dynamics via effects on
survival or reproduction. However, attributing changes in mortality to
specific climate variables is challenging as it is often not known exactly
when individuals died within a year. Here, we investigated climate effects
on adult mortality in Australian superb fairy-wrens (Malurus cyaneus).
Over a 27-year period, mortality outside the breeding season nearly
doubled. This non-breeding season mortality increased with both lower
minimum and higher maximum temperatures in winter, and with higher
heatwave intensity in the previous summer. Fine-scale analysis showed that
higher mortality in a given week was associated with higher maxima two
weeks prior, as well as with lower minima in the current fortnight.
Increases in summer heatwaves and in winter maximum temperatures
collectively explained 62.6% of the increase in mortality over time.
Warming climate in both summer and winter can thus adversely affect
survival, with potentially substantial population consequences.