Climate data
We obtained monthly mean temperature (ºC) and monthly precipitation (mm)
from the Climatic Research Unit (CRU TS version 4.03;
~3,025-km2 resolution; released 15 May
2019; https://crudata.uea.ac.uk/cru/data/hrg/) (Harris et al., 2014).
Using data from WorldClim 2.1 (Fick and Hijmans, 2017), we downscaled
the CRU data to 1 km2 and then applied the monthly
correction for all months in each census interval. We used the delta
spatial downscaling method, see Peng et al., (2019) for details. The
average values of MAT and MAP of the years within each census interval
were used in the analyses. For the census intervals that ended in 2019,
to which climate data were not available in CRU TS version 4.03, we used
climate data ranging from the start of the interval to the end of 2018.
To estimate the species climatic niches, we opted to use the bioclimatic
variables from WorldClim 2.1 for being a long-term synthesis of the
sites’ climate.