A new map product is now available from TWIC: Species Distribution Maps (SDMs) – Species Presence and Species Abundance.

An SDM – Species Presence map will highlight where in your search area a species has been recorded, while an SDM – Species Abundance map will summarise how many records of that species are present in the search area.

Knowing where species are present (or absent) is critical for nature conservation. This is the reason why Local Environmental Record Centres (LERC) like TWIC exist.

Mapping species records is incredibly useful. For example, recorders might use a species distribution map as a starting point to see if they can fill knowledge gaps; an ecologist could use this information to infer where a species might be present based on the presence of a foodplant/ host species, or to target survey work.

However – as always – maps need interpretation. The absence of a species record does not necessarily mean that the species is absent from the area. The absence may be due to nobody having visited the site to look for the species or due to sighting(s) not having been passed on to the relevant LERC or recording scheme.

Likewise the maps showing species records abundance need careful interpretation. In one of the maps we produced we noted a hotspot of hedgehogs (100+ records) in a single 2km square. When drilling down into the data it turned out that this was due to a diligent recorder who reported every single day the hedgehog visited their garden.

Notwithstanding these caveats, the maps provide a useful visualisation of species records held by TWIC and can complement the other data formats TWIC supplies, such as Excel spreadsheets and GIS shapefiles.

TWIC’s species database holds records at different resolutions (from very coarse 10km scale records right down to records at 1m square resolution). Many of the recording schemes record at 1km or 2km square resolution for Atlas work. For this reason we recommend that users request a Species Distribution Map displaying records at 2km square resolution as this will ensure the most comprehensive coverage of records is provided.

SDMs are available at no cost for non-commercial users, while for commercial users the usual commercial data request rates apply. You can request this new map type by filling the relevant data request form as found on this page.

If you are interested in this new map product, I am happy to answer your questions or discuss your requests, just drop me an email at: admin@wildlifeinformation.co.uk.