Ecological investigations to select mitigation options to reduce vehicle-caused mortality of a threatened butterfly

  • Published source details Zielin S.B., Littlejohn J., de Rivera C.E., Smith W.P. & Jacobson S.L. (2016) Ecological investigations to select mitigation options to reduce vehicle-caused mortality of a threatened butterfly. Journal of Insect Conservation, 20, 845-854.


This study is summarised as evidence for the following.

Action Category

Use infrastructure to reduce vehicle collision risk along roads

Action Link
Butterfly and Moth Conservation
  1. Use infrastructure to reduce vehicle collision risk along roads

    A controlled study in 2012 on a disused road in Oregon, USA (Zielin et al. 2016) reported that “altitude guide” netting, and poles topped with bright colours or flowers, did not alter the behaviour of Oregon silverspot Speyeria zerene hippolyta butterflies. Results were not tested for statistical significance. Of 54 Oregon silverspots which encountered a net erected next to a road, only 10 flew over it, compared to 29 which flew around it, two which walked through it, and 13 which turned around. Of the 39 butterflies which flew over or around the net, 10 subsequently landed on the road. When the net was not present, 35 out of 60 butterflies flew between the net poles, nine turned around, and only four butterflies landed on the road. In a second experiment, of 41 Oregon silverspot that flew within one metre of poles topped with bright colours or flowers (attractive features), none ascended to the top. In 2012, a decommissioned road was divided into ten 8 × 7 m2 sections, spanning the 4-m-wide road and 2 m either side. Six trials, consisting of four 15-minute observation periods, were conducted on different sections. For two periods/trial, a 3-m-tall, 2-cm mesh net was stretched between two pairs of poles (7 m apart) on each side of the road, and for the other two periods the nets were absent. No further details provided. On 25 August and 1 September 2012, seven 1-m-high poles topped with attractive features: a bright colour (red: 3 poles, yellow: 2 poles) or flowers (2 poles), were observed for a total of 90 minutes. No further details provided.

    (Summarised by: Andrew Bladon)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust