Data from: Data gaps and opportunities for comparative and conservation biology

Biodiversity loss is a major challenge. Over the past century, the average
rate of vertebrate extinction has been about 100-fold higher than the
estimated background rate and population declines continue to increase
globally. Birth and death rates determine the pace of population increase
or decline, thus driving the expansion or extinction of a species. Design
of species conservation policies hence depends on demographic data (e.g.,
for extinction risk assessments or estimation of harvesting quotas).
However, an overview of the accessible data, even for better known taxa,
is lacking. Here, we present the Demographic Species Knowledge Index,
which classifies the available information for 32,144 (97%) of extant
described mammals, birds, reptiles, and amphibians. We show that only 1.3%
of the tetrapod species have comprehensive information on birth and death
rates. We found no demographic measures, not even crude ones such as
maximum life span or typical litter/clutch size, for 65% of threatened
tetrapods. More field studies are needed; however, some progress can be
made by digitalizing existing knowledge, by imputing data from related
species with similar life histories, and by using information from captive
populations. We show that data from zoos and aquariums in the Species360
network can significantly improve knowledge for an almost eightfold gain.
Assessing the landscape of limited demographic knowledge is essential to
prioritize ways to fill data gaps. Such information is urgently needed to
implement management strategies to conserve at-risk taxa and to discover
new unifying concepts and evolutionary relationships across thousands of
tetrapod species.