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.

[Usage Notes] Data This folder contains 1.) the metadatabase of 22 data sources with 115,356 standardised demographic records for 14,529 taxonomically standardised species of 10 standardised demographic variables that were used in the article, 2.) the Demographic species knowledge index (DSKI), which indicates the amount of knowledge on mortality and fertility for a total of 32,144 species, which was calculated based on the amount of information present in the “DemographicDatabase.csv” used in the article. Additionally it includes the IUCN Red List Status and if the species is present in a zoo or aquarium in ZIMS, and the species taxonomic id for Catalog of Life and GBIF. MetaData The folder contains detailed documentation of the content of the data files in the folder “Data”: 1.) the documentation of column names, 2.) the references of the 22 demographic source databases, 3.) the original demographic variable names provided in the 22 source databases before demographic standardisation, their definition, and their demographic variable name after standardisation.

Peer reviewed