At that time, according to estimates from temperature-sensitive beetle species found at the site, mean winter temperatures in this forested region hovered between 0 and –3˚C (at least 3˚C lower than today).
A rise of 1°C in mean summer temperatures killed 1% more people, whereas that same rise in mean winter temperatures saved a mere 0.6%, according to an analysis of death records for nearly 3 million people 65 years and older living in New England from 2000 to 2008.
Its distribution is generally limited to areas with mean winter temperatures over 12 °C (54 °F), mean annual temperatures over 18 °C (64 °F), annual rainfall over 1,100 mm (43 in), and a long rainy season averaging over 200 days.
Monthly mean winter temperatures range between −0 and 3.5°C [32].
Thus, we restricted them to mountainous regions by excluding areas with an altitude lower than 400 m, given that G. pyrenaicus populations very rarely occur below this altitude [33] and to regions with mean winter temperatures not lower than those found within the species' current distribution.
An increase in mean winter temperatures in Europe is known to drive moth expansion northward and to higher altitudes, in regions where hosts are available, by providing suitable conditions in places were larvae could not previously have survived [ 18].
