Data from: Species’ traits explain differences in Red list status and long-term population trends in longhorn beetles

Some species are more likely to go extinct than others and this is
partially due to species' traits. Therefore, it is important to
establish links between traits and extinction risks. Different aspects of
a species' biology also relates to different sources of threat, such
as fragmented populations or low population growth rate. In a comparative
study of Swedish longhorn beetles (Coleoptera: Cerambycidae), we related
species' traits to two aspects of extinction risk – population
decline and small/fragmented populations – measured by long-term
population trends and IUCN Red list classifications. Trait relationships
were analysed with generalized linear models and multi-model inference. We
found that extinction risk generally increased with longer generation
times, corresponding to slower life histories. Adult activity period was
also related to both metrics of extinction risk, but in different ways. We
also found that extinction risk increased with larval host plant
specialization, but only for Red list classification. Large body size was
related to increased Red list classification in species overwintering as
adults, and overwintering stage also structured the effects of several
other traits. Our results show that both intrinsic demographic traits and
ecological traits affect extinction risks, and also suggest that risks are
shaped by multiple mechanisms. Therefore, researchers should carefully
choose their metric of extinction risk for comparative studies, as the Red
list classification may best capture current risk, whereas population
trends can be used more proactively but may reflect historical
relationships between traits and extinction risk.