Abstract
Climate change is reshaping the distribution of animal species at unprecedented rates, with documented range shifts,
phenological mismatches, and altitudinal and latitudinal redistributions across taxa globally. This study quantifies
observed and projected climate-driven distributional changes for thirty vertebrate species across five taxonomic groups
(freshwater fish, amphibians, reptiles, breeding birds, and terrestrial mammals) in the Netherlands, Germany, and Spain
using long-term atlas data (1990-2023), species distribution models (MaxEnt), and CHELSA-CMIP6 climate projections
under SSP2-4.5 and SSP5-8.5 scenarios to 2050 and 2100. Observed range shifts over 1990-2023 were significant for
22 of 30 species (73.3%), with a mean northward shift of 48.4 +- 12.1 km per decade across all groups (linear mixed
model p < 0.001) and a mean upslope shift of 12.8 +- 4.1 m per decade for montane species. Thermophilous reptiles
showed the most pronounced range expansions (mean +124.4 km northward since 1990), while cold-adapted freshwater
fish showed the most severe range contractions (mean -38.4% suitable habitat area since 1990). MaxEnt SDM
projections under SSP5-8.5 predict that 64.0% of study species will lose > 20% of current suitable habitat by 2050, while
28.0% are projected to gain suitable habitat through northward or upslope range expansion. Phenological data for eight
bird species confirm advancing spring arrival dates (mean -5.8 +- 1.4 days per decade), creating measurable
mismatches with invertebrate prey phenology at three study sites. These findings quantify the urgency of
climate-adaptive conservation planning under the Kunming-Montreal GBF and EU Climate Adaptation Strategy.