As a tool to display the abundance
of a species at any given time during the year, these representations are
called STEM (Spatio-Temporal Exploratory Model) maps that address species'
occurrences in the Lower 48 states.
(Prothonotary Warbler Occurrence Map,
above; if its functionality does not work for you at this site, then go to the above site in line two and click on "Prothonotary Warbler")
For each species depicted, its
migration patterns are accounted for along with its breeding range.
Additional details are necessary to
fully explain the Occurrence Maps and STEM.
For now, suffice to say that Occurrence Maps may be a
tool you wish to add to your repertoire when identifying wood-warblers.