Original purpose and application

The RaPTR web GIS tool was created to assist raptor rehabilitators in selecting the best release sites within the Charlotte Metropolitan Area, USA. There are release suitability maps available for six common raptor species. Rehabilitators and releasers can use these maps to view the best areas for the species release, potential release sites, and areas within certain driving times. RaPTR was created in 2023 by Hannah Partridge in collaboration with the Carolina Raptor Center. Any questions or concerns about this tool can be directed to Hannah Partridge at partridgehannahc@gmail.com. An article describing these models and methods in detail is in preparation and will be posted to the website linked below when available.

Getting started

All release suitability maps, and information can be found at www.raptrmaps.com. On the homepage, you can select which species you are interested in selecting a release site for.

Click on the species that you would like to view. You will be redirected to a page like this:

On this page, you see the release suitability map, with the colors indicating release suitability levels. You also see the most suitable release areas outlined in maroon and some potential release sites shown by the orange triangles. This is what you will see each time you open a release suitability map.

A: Add – This button allows you to add other layers. This is not necessary to use the maps but may be of interest to some users.

B: Layers – This is the most important button to know. This allows you to open the list of all layers and view other release suitability layers. Each layer will be discussed in more depth below.

C: More – This button provides access to charts, bookmarks, and importantly – the legend for the map.

D: Properties – This button allows you to view the symbology for the selected layer and adjust the transparency and visibility. The transparency setting allows to make a layer however transparent you like. This can be useful when trying to identify areas by street markers, names, and known places. 

E and F: Styles and Effects – This allows you to change styles and effects for the selected layer.

G: Fields – This allows you to view the different fields that make up the selected layer. This is useful when using the included release sites as you can view the name of the park or nature preserve where the release point is located. 

H: Map tools – This provides access to measurement and location tools. These can be used to find the latitude and longitude of a location or to measure the distance between points.

Note: You can make changes to the maps but the changes will not be saved or viewable by other users.

Viewing other layers

Select the “Layers” button (B in the above photo) and you will see all of the layers that you can view on the map, as shown below.

Description of the available layers

Note: the “Suitability Legend” layer does not show anything and is simply providing a legend for the release suitability map to be viewed in the Legends tab. 

Things to know about the data, including limitations

It is important to remember that these maps show release suitability rather than habitat suitability. Thus, they incorporate not only the habitat and landscape features that are important to the species survival, but also threats that individuals may face such as high road traffic or landcover change vulnerability. Because of these other variables, there may be some different patterns than expected. For example, the red-shouldered hawk release suitability map shows high release suitability primarily in the southeastern region of the study area. This model incorporates a variable for edge habitat between forested and wetland areas, as these habitat are used heavily by the species. These areas are most prevalent in the southeastern region but do occur in other areas. However, in many of the other areas, the release suitability is decreased due to the threat variables (roadways and vulnerability to landcover change).

You may also notice straight lines within some of the release suitability maps, showing what appears to be a line that quickly changes from one suitability level to another. This is most clear on the great horned owl release suitability map. These maps were built using multiple different data sources with different cell sizes. Thus, these apparent squares of different release suitability are due to a data source with a larger cell size than others impacting the suitability level of the entire area. As such, it is important to remember that these maps show the release suitability for general areas but may not necessarily show the release suitability for specific points. When choosing where to release a raptor, these maps are a tool to support the selection of general areas but careful consideration should be given to the specific location selected.

Sources

The data sources that contributed to each map will be available in the article in preparation. Please reach out to Hannah Partridge at partridgehannahc@gmail.com with any questions or concerns about the data or tool.