Species Richness

Butterfly species richness map
Project Summary


Ever wondered what wildlife is in your street, village or local area? Species Richness mapping identifies the number of different species within a defined area. This provides a better understanding of the ecological characteristics of the landscape and helps influence conservation efforts in Cornwall.

Mapping biological records is in the blood of the ERCCIS team and a core part of what we do,but it can be difficult to understand just by looking at these raw records. Interpretation and analysis is needed analyse and effectively inform conservation effort.

We wanted to make our resources more readily available to the public, and have developed Species Richness maps to do so. See below for how Species Richness Mapping was created and try it out for yourself on our interactive map


The story of ERCCIS Species Richness Mapping




Explore the ERCCIS Species Richness maps for Cornwall

Open this map in full screen view for a better experience 



Request Species Richness maps

Are you interested in requesting species richness maps for your area or species group of interest. These maps can help you understand important wildlife areas to help inform focused recording effort, management decisions and conservation effort. Species richness maps need expert interpretation and should be used alongside other information about your site, such as habitat and the ecology of your species of interest.

Please contact us for more information and to request your species richness maps

Contact us for more information about how a species richness map can help inform conservation, recording and management decisions, and request your own.


The technical information


What information did we use?

ERCCIS has modelled species richness for 9 taxon groups, which were selected based on number of biological records available and to represent a broad spectrum of the ecology of Cornwall. Records were limited to taxon groups considered primarily representative of the terrestrial environment as a representation of the process.

Taxon Group

Number of Records

% of total hosted records

flowering plant






insect - moth



insect - butterfly






terrestrial mammal



Records considered incorrect or invalid were excluded from the datasets for each taxon group. The records were limited to a 20 year timeframe, between 1999 and 2019 to best represent the current state of the ecosystems in Cornwall. Biological records which were recorded at tetrad or better resolution were used to ensure a high number of input records were available for each taxon group as well as giving an acceptable resolution output with each grid cell covering 22km of Cornwall’s landscape.


The Methods explored

Three processes were investigated to produce species richness maps for Cornwall using biological records hosted by ERCCIS;

  1. ERCCIS Method - Count of records per tetrad covering the terrestrial area of Cornwall, processed through SQL script developed by ERCCIS

  2. FSC Method - Using QGIS prebuilt processes from external bodies, in this case the Field Studies Council TomBio QGIS tools (www.fscbiodiversity.uk/qgisplugin/v2)

  3. Frescalo Method - Using R script developed by the Centre for Ecology and Hydrology called Frescalo which corrects for variations in recorder effort through neighbourhood statistics. (https://www.brc.ac.uk/biblio/frescalo-computer-program-analyse-your-biological-records) . More information about the Frescalo analysis principals can be found in Hill 2011 (https://doi.org/10.1111/j.2041-210X.2011.00146.x)


The ERCCIS TomBio and Model

If we do a simple count of species recorded at a small site, we could reasonably record all species within the site but this becomes nearly impossible when we try and consider an entire county. If we were to do a simple count of different species from biological records we start to encounter bias caused by the nature of biological recording. The difficultly with calculating species richness from biological records is variations it the spatial and temporal coverage of biological records and recording effort involved in collecting the records.

This is where statistical modelling comes into play. We’ve used a well-respected and published method developed by Biological Records Centre (BRC) which corrects for variations in recorder effort


Frescalo Model

The CEH Frescalo analysis estimates species richness from biological records where recorder effort is uneven. The model uses neighbourhoods based on proximity and habitat similarity across the study area and calculates the mean weighting for sampling/recorder effort for each neighbourhood based on the records for commonest species, i.e. if a high proportion of the commonest species in a neighbourhood have been recorded, then the neighbourhood is considered well recorded. This weighting is used to re-scale observed species frequency/species richness to give estimate species frequency/species richness and so corrects for o uneven sampling/recorder effort.

For more detail on the model see;

Hill, M.H. (2011) Local frequency as a key to interpreting species occurrence data when recording effort is not known. Methods in Ecology & Evolution, 3 (1), 195-205. http://www.respond2articles.com/MEE

Details of our model - the perimeters and weighting for neighbourhood (200,100) creation and the sampling‐effort multiplier (0.74) were based on the default settings outlined in Hill, 2011 for each taxon group.  The estimated species richness after rescaling was used for producing the output species richness maps.