Do roe deer react to wildlife warning reflectors? A test combining a controlled experiment with field observations

  • Falko BriegerEmail author
  • Robert Hagen
  • Max Kröschel
  • Florian Hartig
  • Imke Petersen
  • Sylvia Ortmann
  • Rudi Suchant
Original Article


Millions of animals are killed by vehicle collisions each year. As mitigation measures, wildlife warning reflectors have become increasingly popular, although clear evidence for their effectiveness is lacking. A reason for inconclusive results in the literature may be that most previous studies on the effectiveness of wildlife warning reflectors compare animal-vehicle collision rates with and without reflectors, a setting characterised by low event rates and weak experimental control. Animal behaviour can be expected to provide a more direct evidence for a possible effect of reflectors. In this study, we analyse roe deer behaviour in the presence of a blue semicircle reflector, one of the most frequently applied wildlife warning reflectors in Germany and other parts of Europe. Behavioural response to these reflectors (classified as no reaction, vigilance, short-distance flight and long-distance flight) was recorded both under controlled experimental conditions with captive roe deer and for free-ranging roe deer at road sections with traffic occurrence. We used generalised linear mixed models (GLMMs) to test if reflector presence induced threat-related behaviour (vigilance, flight) and movement away from the reflectors. We found no significant evidence that the light stimulus emitted by reflectors was perceived as a threat or induced evasive movement. We conclude that our study provides no evidence that blue semicircle reflectors induce behaviour in roe deer that seems suitable to reduce roe deer-vehicle collisions.


Deer-vehicle collision Thermal network camera Road ecology Capreolus capreolus Experimental design Enclosure 



This study was funded by the federal state of Baden-Württemberg (Landesjagdabgabe) and was conducted with animal ethics approval. Falko Brieger was supported with a PhD Scholarship by the foundation ‘Dr. Joachim und Hanna Schmidt Stiftung für Umwelt und Verkehr’. Grateful thanks to Silja Spiecker for field assistants and screening video data in the lab as well as Valerie von Schultzendorff, Virginia Lorek, Jim-Lino Kämmerle and Leonie Cullmann for screening video data. We thank all participating work colleagues and hunters as well the Leibniz Institute for Zoo and Wildlife Research for supporting our experimental study. Grateful thanks to the staff at the Field Research Station in Niederfinow/Germany. We thank two anonymous reviewers for providing helpful comments on an earlier version of this manuscript.

Compliance with ethical standards

Ethical approval

“All applicable international, national and/or institutional guidelines for the care and use of animals were followed.”

Supplementary material

10344_2017_1130_MOESM1_ESM.docx (2.9 mb)
ESM 1 (DOCX 2.90 MB).


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Copyright information

© Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  • Falko Brieger
    • 1
    • 2
    Email author
  • Robert Hagen
    • 1
  • Max Kröschel
    • 1
    • 2
  • Florian Hartig
    • 3
    • 4
  • Imke Petersen
    • 5
  • Sylvia Ortmann
    • 5
  • Rudi Suchant
    • 1
  1. 1.Division of Wildlife EcologyForest Research Institute of Baden-WürttembergFreiburgGermany
  2. 2.Chair of Wildlife Ecology and Wildlife ManagementFreiburg UniversityFreiburgGermany
  3. 3.Department of Biometry and Environmental System AnalysisFreiburg UniversityFreiburgGermany
  4. 4.Theoretical EcologyUniversity of RegensburgRegensburgGermany
  5. 5.Department Evolutionary EcologyLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany

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