Reduced-effort schemes for monitoring butterfly populations
Roy, D. B. ORCID: https://orcid.org/0000-0002-5147-0331; Rothery, P.; Brereton, T..
2007
Reduced-effort schemes for monitoring butterfly populations.
Journal of Applied Ecology, 44 (5).
993-1000.
https://doi.org/10.1111/j.1365-2664.2007.01340.x
Abstract/Summary
1. Butterflies are one of the few insect groups that can be monitored effectively and have the potential to develop national and Europe-wide trends in abundance. 2. For 20 widespread butterfly species, we assess the relative efficiency of reduced-effort schemes compared to the existing design and estimate the number of sites required to detect changes of given magnitudes over specified periods of time. 3. A scheme restricted to three counts during July and August requires twice as many monitored sites on average to achieve comparable precision to the existing 26-week scheme in the United Kingdom. Such a scheme requires 430 monitoring sites on average to achieve 80% power (5% significance level) for detecting a 25% decline in abundance over 10 years. 4. Such a reduced-effort scheme may also mean that volunteers are more willing to record in areas where they are likely to see only a few individuals of a few common species (such as on intensively farmed areas). This could potentially help to ensure that butterfly monitoring schemes achieve a more even geographical coverage and less of a bias towards areas rich in butterflies. 5. Synthesis and applications. Schemes with few sampling visits per year are cost-effective for expanding butterfly monitoring across Europe, and can be applied to national monitoring programmes and lead to effective assessment of continent-wide trends in populations.
Item Type: | Publication - Article |
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Digital Object Identifier (DOI): | https://doi.org/10.1111/j.1365-2664.2007.01340.x |
Programmes: | CEH Programmes pre-2009 publications > Biodiversity |
UKCEH and CEH Sections/Science Areas: | Pywell |
ISSN: | 0021-8901 |
Additional Keywords: | biodiversity, indicators, Lepidoptera, log-linear model, statistical power, UK butterfly monitoring scheme, wider countryside |
NORA Subject Terms: | Zoology Ecology and Environment |
Date made live: | 30 Jan 2008 16:41 +0 (UTC) |
URI: | https://nora.nerc.ac.uk/id/eprint/2250 |
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