Occurence data
In this first module we will see where to find occurrence data (if you don’t have your own), how to download them. Furthermore we will focus of cleaning and validation procedures in order to have a suitable dataset to be use in module 2.
Where to find occurrence data?
Ideally, the user should have a file, in txt, csv or other suitable formats for R, providing the coordinates of spatial occurrences of the species under study. If the aim of the study is to build the potential distribution of a species over a large area (continental or global scale), it is a common practice to gather spatial data from online databases that have being collecting and freely providing species records in recent years. The Global Biodiversity Information Facility (GBIF; http://www.gbif.org ) provides a huge amount of occurrences data and it is a good source to gather information on spatial distribution of species. There are also many other database, focusing on specific groups, such as HerpNET2 (http://herpnet2.org ), MaNIS (http://manisnet.org), FishNET2 (http://fishnet2.net) and many others.