Code from: The role of intrinsic factors in explaining range shifts of European breeding birds: A meta-analysis

Species are shifting their distribution ranges in response to climate and
land-use change. However, the observed range shift patterns are
idiosyncratic in rate and direction. Species traits, such as ecological,
life-history and movement traits, may play an important role in
determining range shifts by influencing a species’ capacity to shift
successfully. Whilst several studies investigate the role of different
species traits in driving range shifts, they generally consider few traits
and range shift types. Range shift types such as abundance shift and
centroid shift are generally not taken into account. Drivers of range
shifts may however differ per range shift type. We conducted a
meta-analysis to uncover the role of intrinsic factors (9 species
functional traits and 5 spatial abundance characteristics), in explaining
six contemporary range shift types ( range size changes:
expansion/contraction, relative change and rate of change; latitudinal
shifts: abundance shift, centroid shift and range margin shift) in
European breeding birds (n=270). We found that the role of intrinsic
factors in explaining contemporary range shifts in European breeding birds
is indeed range shift type dependent. Natal dispersal distance and clutch
size were for instance positively related with range size changes, while
diet breadth and conservation status showed both negative and positive
relationships depending on the range shift type. Acknowledging limitations
regarding unevenness of data availability across the study region; the
region of study was an important predictor for range size changes,
suggesting a relative importance of local context and extrinsic drivers.
Future trait-based analyses of range shifts would benefit from accounting
for intraspecific variation in functional traits across time and space,
the inclusion of additional traits like phenological traits, exposure to
environmental pressures, and competitive ability, and should be
investigated across multiple scales and for multiple types of range
shifts.