The Habitat Suitability Index (HSI) for Great Crested Newts is based on the HSI methodology developed by the US Fish and Wildlife Service as a means of evaluating habitat quality and quantity using a numerical index, between 0 and 1.
The HSI for Great Crested Newt incorporates ten suitability indices, all of which are factors known to affect this species.
I have used the Habitat Suitability Index (HSI) framework in the past for an initial field assessment of the capability of the habitat to support Great Crested Newts near to construction sites & even developed a simple Microsoft Excel spreadsheet to drive the underlying calculations.
An enterprising ecologist – Martin Brammah (Principal Ecologist at MLM Group) has taken the development further with a web app, NEWT.N, which allows ecologists and any other interested parties to undertake Habitat Suitability Index (HSI) assessments of ponds on and within 500 m of development sites, both in the field using mobile data and in the office.
The app has a built-in Google maps tool to allow selection of a 1 km-radius circle around the pond on the map and count any ponds within that circle to give you your pond count for suitability index 8. The mapping tool can, also, be used to draw a 500 m or 250 m radius around a point, which can be useful for identifying ponds for consideration around smaller sites.
The app allows users to select the relevant pond parameters from drop down menus, for each of the ten suitability indices. Based on these individual scores, it automatically calculates and presents the HSI score with an indication of the suitability of the pond for Great Crested Newts.
If your device has an installed Microsoft Exchange or Outlook, it is possible to email the results to anyone together with a photo of the pond).
It should be noted that the calculations and figures in the app are based on the guidance given in the Amphibian and Reptile Groups of the United Kingdom (ARG) UK Advice Note 5 on the Great Crested Newt Habitat Suitability Index (May 2010).
If you have a need to undertake Habitat Suitability Index (HSI) for Great Crested Newts, I urge you to look at NEWT.N and try it yourself.