Wagtails (Aves: Motacillidae) as insect indicators on plastic sheets attracting polarotactic aquatic insects

B. Bernáth, Gy Kriska, B. Suhai, G. Horváth

Research output: Contribution to journalArticle

10 Citations (Scopus)


The polarization-based water detection of aquatic insects has evolved in a natural environment with scarce misleading polarization cues. In the last century man produced innumerable highly and horizontally polarizing surfaces acting as supernormal visual stimuli for water-seeking polarotactic insects. Typical examples are the black plastic sheets used in agriculture. To investigate the effects of horizontal plastic sheets on insects and birds, dual-choice field experiments were carried out from 1995 to 1997 with a pair of huge black and white plastic sheets laid on the ground in Hungary. The number of wagtails (Motacilla alba, M. flava) feeding in flocks on the plastic sheets and their feeding rate were counted to estimate the number of insects lured to the plastic sheets. According to our estimation, a raised-bed strawberry plantation of 10 hectares covered by shiny black plastic sheets can kill about 1 ton of aquatic insects day by day. Thus, the possible detrimental effects of such agricultural technologies may be serious and should be investigated thoroughly in the future.

Original languageEnglish
Pages (from-to)145-155
Number of pages11
JournalActa Zoologica Academiae Scientiarum Hungaricae
Issue numberSUPPL.1
Publication statusPublished - 2008



  • Insect indicator
  • Insectivorous birds
  • M. flava
  • Motacilla alba
  • Plastic sheets
  • Polarotaxis
  • Visual deception

ASJC Scopus subject areas

  • Animal Science and Zoology

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