Rare species viewer

We maintain a list of all documented MESA-listed species observations in Massachusetts. Search this map by common name, scientific name, or town to see where rare species have been observed.

How to use this map

1. Filter by Town: Select a Town from the drop-down menu.  The map will zoom to that town, highlight it and the Species Details table will show information about the rare species observed in that town.
2. Filter by Species Common Name or Species Scientific Name: Select a Species Common Name or Species Scientific Name from the respective drop-down menu. All towns that the species has been observed in will be highlighted on the map. The accompanying Species Details table will also show information about the rare species, as well as the complete list of towns with their most recent observation years.
3. Species Details Table: After making a Town or Species selection, the table will populate with the details. Use the scroll bar on the far-right side of the table to view all rows of data.
4. Clear All Filters: Click on button on the bottom left to clear all searches and begin again. 

Clicking on a column header in the table will sort by that column. Clicking again on the same column heading will reverse sort the order.

This map is updated at regular intervals as new data is accepted and entered into the Natural Heritage and Endangered Species Program's database.

Most recent observation

This field represents the most recent observation of that species in a town. However, because they are rare, many MESA-listed species are difficult to detect even when they are present. Natural Heritage does not have the resources to be able to conduct methodical species surveys in each town on a regular basis. Therefore, the fact that the 'Most Recent Observation' recorded for a species may be several years old should not be interpreted as meaning that the species no longer occurs in a town. However, Natural Heritage regards records older than twenty-five years historic.

For more information about a particular species, view the list of Natural Heritage fact sheets.