Despite its population of 400,000 Homo sapiens, Tallinn is very species-diverse, according to a paper by the Estonian Institute for Sustainable Development that surveys 30 years' worth of studies on the city's fauna.
The Paljassaare bird sanctuary on an isolated peninsula is perhaps the pride and joy, 81 species of protected birds represented.
The paper is by the institute's project manager Meelis Uustal, who found among other things that there is no consistent monitoring.
"Certainly studies must be conducted as the data gained in the course of the studies help the city government and regional environmental authority make better decisions in planning and giving out permits," Uustal told ETV.
The data he gathered held surprises in store. Kadriorg Park has plentiful bat populations and Tallinn is home to a population of the natterjack toad, which is threatened by habitat loss across Europe.
"One of the most exciting areas studied is eastern Tallinn - Suur-Sõjamäe and Väo - which still looks like brownfield and vacant lots. Actually this signals that the area could be very species-rich," said Uustal.