Two global demographic databases

Demography is simply the study of how the population of a species grows or shrinks over time. Obtaining high quality demographic information about a species is fundamental to conservation science. If a population declines too far it ultimately leads to its extinction (consider the Tasmanian tiger). If it expands too much, you may have an invasion (consider the cane toad). Not only will demographic information help us make better-informed decisions on which species need our attention before it’s too late, it also guides us on what is the most appropriate action to take.

Unfortunately, obtaining demographic data can be a real challenge. It can be tedious to collect and often expensive; demographic fieldwork often involves following many individuals of several populations over multiple years to estimate their probabilities of survival, growth, reproduction and establishment. Despite this effort, the value of this information is enormous, and in recent decades population ecologists have been amassing a wealth of demographic info for both animals and plants. Until recently, however, these data were dispersed throughout the scientific literature, making it difficult to access and analyse with speed – and a rapid response is typically necessary for effective conservation.

So, when it comes to answering some of the big research questions in conservation science such as “how does climate change affect population dynamics of birds worldwide?”, or “what life cycle stages should be the focus of conservation actions before the global decline of amphibian populations?” or “are sessile organisms like corals more prone to local extinction than mobile organisms like mammals?”, there has been no central repository of demographic information to draw on.

It is our hope that COMADRE and COMPADRE will meet this need. COMADRE and COMPADRE are two demographic databases that I have been developing in collaboration with an international team (a project catalysed by the Max Planck Society and the ARC). COMPADRE is a Plant Matrix Database (Salguero-Gómez et al. 2015) (the name comes from the letters in ‘Comparative Plant Matrix Database’), while COMADRE is an Animal Matrix Database (from ‘Comparative Animal Matrix Database’). Each database is unprecedented in terms of data quality, taxonomic richness and global coverage.

What’s more, access to these databases is free; COMADRE and COMPADRE are fully open-access, meaning anyone can use them. More information will be released periodically as it is digitised, error-checked and complemented with other information.

More info: Roberto Salguero-Gomez &


Salguero-Gómez et al. (2015) The COMPADRE Plant Matrix Database: an online repository for plant population dynamics. Journal of Ecology 103, 202-218.

Salguero-Gómez et al. (In press) COMADRE: a global database of animal demography. Journal of Animal Ecology. Archived in bioRxiv 10.1101/027821

Leave a Reply