United Kingdom Butterfly Monitoring Scheme: site indices data 2017

Published by:
Environmental Information Data Centre
Last updated:
16 February 2023
Topic:
Not added
Licence:
Other Licence
View licence information

Summary

Site indices, as a relative measure of the actual population size, for UK butterfly species calculated from data from the UK Butterfly Monitoring Scheme (UKBMS). Site indices are a relative rather than an absolute measure of the size of a population, and have been shown to relate closely to other, more intensive, measures of population size such as mark, release, recapture (MRR) methods. The site index can be thought of as a relative measure of the actual population size, being a more or less constant proportion of the number of butterflies present. The proportion seen is likely to vary according to species; some butterfly species are more conspicuous and thus more easily detected, whereas others are much less easy to see. Site indices are only calculated at sites with sufficient monitoring visits throughout the season, or for targeted reduced effort surveys (timed observations, larval web counts and egg counts) where counts are generally obtained as close to the peak of the flight period as possible and are subsequently adjusted for the time of year and size of the site (area of suitable habitat type for a given species). Wider Countryside Butterfly Survey (WCBS) sites are thus excluded because they are based on very few visits from which accurate indices of abundance cannot currently be calculated. For transect sites a statistical model (a General Additive Model, 'GAM') is used to impute missing values and to calculate a site index. Each year most transect sites (over 90%) produce an index for at least one species and in recent years site indices are calculated for almost 1,500 sites across the UK. Site indices are subsequently collated to contribute to the overall 'Collated Index' for each species, which are relative measures of the abundance of each species across a geographical area, for example, across the whole UK or at country level in England, Scotland, Wales or Northern Ireland. Individual site indices are important in informing conservation management as not all sites show the same patterns for each species and likely reflect a combination of local climate and habitat management at the site. The UK Butterfly Monitoring Scheme is organized and funded by Butterfly Conservation (BC), the Centre for Ecology & Hydrology (CEH), the British Trust for Ornithology (BTO), and the Joint Nature Conservation Committee (JNCC). The UKBMS is indebted to all volunteers who contribute data to the scheme. Full details about this dataset can be found at https://doi.org/10.5285/5c9c946d-34f8-4afb-83e3-f0cbc7123fec

More from this publisher

All datasets from Environmental Information Data Centre

Related datasets

Search

Data links

Link to the data Format File added Data preview
Download the data N/A 16 February 2023 Not available
Supporting information ZIP 16 February 2023 Not available

Additional information

View additional metadata
Added to data.gov.uk
2022-12-16T15:47:22
Access contraints
© UK Centre for Ecology & Hydrology
Harvest GUID
5c9c946d-34f8-4afb-83e3-f0cbc7123fec
Extent
Latitude: 60.861° to 48.776°
Longitude: -8.648° to 1.768°
Spatial reference system
Dataset reference date
2019-07-11 (publication)
Frequency of update
notPlanned
Responsible party
UK Centre for Ecology & Hydrology (pointOfContact); NERC EDS Environmental Information Data Centre (custodian); NERC Environmental Information Data Centre (publisher); Centre for Ecology & Hydrology (author); Butterfly Conservation (author, pointOfContact); British Trust for Ornithology (author)
ISO 19139 resource type
dataset
Metadata language
eng
Source Metadata
XML
HTML

Contact

Enquiries

Environmental Information Data Centre

Freedom of Information (FOI) requests

UK Centre for Ecology & Hydrology enquiry service Freedom of information requests for this dataset

Licence information

[]