Change season/timing of prescribed burning

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

  • Two studies evaluated the effects on butterflies and moths of changing the season or timing of prescribed burning. One study was in each of Australia and the USA.



  • Abundance (2 studies): One replicated, controlled, before-and-after study in Australia found that management of a tropical savanna and floodplain with early season burning or no burning for 2–5 years increased the abundance of caterpillars, but management with late season burning did not. One replicated, paired, controlled study in the USA found that Karner blue butterfly abundance was similar on grasslands managed by burning in summer or autumn, and on unmanaged grasslands.


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

  1. A replicated, controlled, before-and-after study in 1988–1995 in a tropical savannah and floodplain reserve in Northern Territory, Australia (Andersen & Müller, 2000) found that management with early season burning or no burning increased the abundance of caterpillars, but late season burning did not. After 2–5 years of burning, the abundance of caterpillars increased at sites with early (before: 1; after: 4 individuals) or no burning (before: 5; after: 8 individuals) but remained similar at sites with late burning (before: 3; after: 3 individuals). From 1990–1994, one of three fire regimes was applied annually to each of nine 15–20 km2 compartments across a 670-km2 area: early fires (lit early in dry season in May/June, equivalent to usual conservation management); late fires (lit late in dry season in September/October, equivalent to unmanaged wildfires); and unburned (no fires). Fire was excluded from all plots for 1–2 years prior to the experiment. Caterpillars were sampled by pitfall trapping and sweep-netting. Pitfall traps were set for 48 hours every November and August from 1988–1994, using 15 traps (10 m apart) per 40 × 20 m plot, with two plots/compartment, one in poorly-drained woodland and one in well-drained forest. Sweep-netting was conducted every February and May from 1989–1995, using five parallel transects of 20 sweeps each, spaced 5 m apart, over the trapping grid.

    Study and other actions tested
  2. A replicated, paired, controlled study in 1993–1997 in 15 oak savannas in Wisconsin, USA (King 2003) found that burning grassland in summer or autumn did not increase Karner blue butterfly Lycaeides melissa samuelis abundance compared to either unmanaged or mown grasslands. The density of Karner blue was similar on both summer burned (31–186 individuals/ha) and paired, unburned (35–101 individuals/ha) grasslands, and on autumn burned (22–478 individuals/ha) and paired, unburned (14–179 individuals/ha) grasslands. Karner blue density was also similar on three summer burned (36–213 individuals/ha), three summer mown (46–111 individuals/ha) and three unmanaged (43–119 individuals/ha) grasslands. Fifteen restored oak savannas were burned on average every 3.5 years for 19–33 years prior to 1993. In 1994, four grasslands (1–11 ha) were summer burned in July and two grasslands (0.5–19.2 ha) were autumn burned in November. In winter 1993–1994, woody vegetation was removed with chainsaws on three additional grasslands, and these sites were then cut with a rotary mower in August 1994. Six control grasslands received no burning or mowing. In July–August 1993–1997, butterflies were surveyed three times/grassland/year (>7 days apart) along transects placed 15 m apart.

    Study and other actions tested
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?

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Butterfly and Moth Conservation

This Action forms part of the Action Synopsis:

Butterfly and Moth Conservation
Butterfly and Moth Conservation

Butterfly and Moth Conservation - Published 2023

Butterfly and Moth Synopsis

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