Quadrate Calculation from Coordinates
Here is the discussion about endangerment of particular arachnids in Czechia. We collect relevant information about distribution, habitat demands, size of population, natural history and experience from other countries.
Beside this the members of the Czech Arachnological Society express their opinions in the form of voting. In order to be able to classify a wide range of species we use unsophisticated definitions of particular red list cathegories:
Regionally extinct - the species which have not been found in the last fifty years
Critically endangered - the species can extinct in near future
Endangered and vulnerable - two cathegories representing gradient between critically endangered species and near threatened species
Near threatened - still common species, which are, however, restricted to natural habitats (all natural habitats are slowly but surely disappearing from European landscape)
For comparison we present redlists of spiders of other European countries.