Filtering is subsetting the Atlas occurrence record data using the facets (attributes of records that are indexed in our database) available via ‘Add to map | Facets‘ and on the legends in the Spatial Portal.
If you want to map all species occurrences that were recorded between 1900 and 1920, you can filter on the total Atlas holdings for the records taken between 1900 and 1920. To do this, you would use ‘Add to Map | Facet’, select the Facet called “Decade” and check boxes for 1900 and 1910. The result will be a new map layer of all occurrences between 1900 and 1920.
You could for example also filter occurrence records that came from certain institutions, by a group of Collectors or various ‘data quality’ flags.
If you have mapped a species (or genus or even list of species), you can use the same mechanism in the legend area of the Spatial Portal to select the facet of interest and then the values of that facet and then create a new mapped point layer representing the occurrence records that have only the selected characteristics.
Filtering can also be applied to a set of occurrence records that have been uploaded using Import | Points.