Use shielded “full cut-off” lights to remove outwards lighting

Overall effectiveness category Awaiting assessment
Number of studies: 1
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Effectiveness

not assessed
Certainty

not assessed
Harms

not assessed

Calculating overall effectiveness category

Background information and definitions

Artificial lighting disrupts the activity of nocturnal moths. Although some lighting is necessary for human activity and safety, conventional designs allow light to “spill” outwards from the direction in which the light is required, increasing pollution across a larger area. Changing the design of lights to reduce the amount of light which spills outwards (‘full cut-off’ lighting) may minimize the impact of lights on moths (Gaston et al. 2012).

^{Gaston K.J., Davies T.W., Bennie J., Hopkins J. (2012) Reducing the ecological consequences of night-time light pollution: options and developments. Journal of Applied Ecology, 49, 1256–1266.}

Study locations

Key messages

One study evaluated the effects on butterflies and moths of using shielded “full cut-off” lights to remove outwards lighting. This study was in Slovenia.

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (0 STUDIES)

BEHAVIOUR (1 STUDY)

Behaviour change (1 study): One replicated, paired, controlled study in Slovenia found that fewer individual moths and moth species were attracted to lights fitted with blinds to prevent light scattering (along with filters to remove shorter wavelengths) than to conventional lights without blinds or filters.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A replicated, paired, controlled study in 2011–2013 in 15 churches in Slovenia (Verovnik et al. 2015) found that lights with blinds to prevent light scattering, which were also colour-filtered, attracted fewer individuals and species of moths than conventional lighting. On church walls illuminated with yellow or blue light with blinds, both the abundance (12–20 individuals/year) and species richness of moths (10–15 species/year) were lower than on walls illuminated with conventional lighting and no blinds (abundance: 73 individuals/year; richness: 42 species/year). Fifteen churches in dark, rural areas were grouped into adjacent triplets, and illuminated in one of three ways: blue or yellow metal halide lamps, or the existing light (metal halide or sodium vapour, 70–400 W). Experimental lamps were 70 or 150 W, had custom-made filters to remove wavelengths shorter than 400 nm (blue) or 470 nm (yellow), and blinds to prevent the scattering of light away from the building. The illumination used on each church was rotated within each triplet each year. From May–September 2011–2013, moths were counted for 45 minutes six times/year within a 10 × 3 m area of wall on each church. Churches within a triplet were surveyed on the same night.
Study and other actions tested
Referenced paper
Verovnik R., Fiser Z. & Zaksek V. (2015) How to reduce the impact of artificial lighting on moths: A case study on cultural heritage sites in Slovenia. Journal for Nature Conservation, 28, 105-111.

Please cite as:

Bladon A.J., Bladon, E. K., Smith R.K. & Sutherland W.J. (2023) Butterfly and Moth Conservation: Global Evidence for the Effects of Interventions for butterflies and moths. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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This Action forms part of the Action Synopsis:

Butterfly and Moth Conservation

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Use shielded “full cut-off” lights to remove outwards lighting Action Link	Awaiting assessment	1	Synopsis Link
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Use low intensity lighting Action Link	Awaiting assessment	1	Synopsis Link