title: Effects of a glyphosate-based herbicide and predation threat on the behaviour of agile frog tadpoles.
abstract: The widespread application of pesticides emphasises the importance of understanding the impacts of these chemicals on natural communities. The most commonly applied broad-spectrum herbicides in the world are glyphosate-based herbicides, which have been suggested to induce significant behavioural changes in non-target organisms even at low environmental concentrations. To scrutinize the behavioural effects of herbicide-exposure we exposed agile frog (Rana dalmatina) tadpoles in an outdoor mesocosm experiment to three concentrations of a glyphosate-based herbicide (0, 2 and 6.5mg acid equivalent (a.e.) / L). To assess whether anti-predator behaviour is affected by the pesticide, we combined all levels of herbicide-exposure with three predator treatments (no predator, caged Aeshna cyanea dragonfly larvae or Lissotriton vulgaris newt adults) in a full factorial design. We observed hiding, activity, proximity to the predator cage and vertical position of tadpoles. We found that at the higher herbicide concentration tadpoles decreased their activity and more tadpoles were hiding, and at least at the lower concentration their vertical position was closer to the water surface than in tadpoles of the control treatment. Tadpoles also decreased their activity in the presence of dragonfly larvae, but did not hide more in response to either predator, nor did tadpoles avoid predators spatially. Further, exposure to the herbicide did not significantly influence behavioural responses to predation threat. Our study documents a definite influence of glyphosate-based herbicides on the behaviour of agile frog tadpoles and indicates that some of these changes are similar to those induced by dangerous predators. This may suggest that the underlying physiological mechanisms or the adaptive value of behavioural changes may similar.
authors.affiliation: Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest 1022, Hungary. Electronic address: miko.zsanett@agrar.mta.hu.
authors.forename: Zsanett
authors.initials: Z
authors.lastname: Mikó
authors.affiliation: Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest 1022, Hungary; Department of Systematic Zoology and Ecology, Eötvös Loránd University, Pázmány Péter sétány 1/ C, Budapest 1117, Hungary.
authors.forename: János
authors.initials: J
authors.lastname: Ujszegi
authors.affiliation: Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest 1022, Hungary; NARIC, Agricultural Biotechnology Institute, Szent-Györgyi Albert u. 4., H-2100 Gödöllő, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Gál
authors.affiliation: Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest 1022, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Hettyey
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods; D004924:Escape Reaction / Q000187:drug effects*; D005998:Glycine / Q000031:analogs & derivatives* / Q000633:toxicity; D006540:Herbicides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects*; D063191:Odonata / Q000502:physiology; D011235:Predatory Behavior / Q000187:drug effects*; D011898:Ranidae; D013037:Spatial Behavior / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D006540:Herbicides; D014874:Water Pollutants, Chemical; D000097797:Glyphosate
keywords: Antipredatory behaviour; Glyphosate; Multiple stressors; Predation; Rana dalmatina tadpole