Dagmar von Helversen

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The male song of the duetting grasshopper Chorthippus biguttulus consists of syllables alternating with noisy pauses. The syllable-pause structure is important for song recognition by the female. Using playback experiments we investigated the mechanism by which intensity modulations within the song pattern are used to detect syllable onsets and offsets. We(More)
While the sensing of substrate vibrations is common among arthropods, the reception of sound pressure waves is an adaptation restricted to insects, which has arisen independently several times in different orders. Wherever studied, tympanal organs were shown to derive from chordotonal precursors, which were modified such that mechanosensitive scolopidia(More)
The nectar-feeding bat Glossophaga can be trained to discriminate two hollow forms, a hollow hemisphere and a paraboloid with the same diameter and depth, in total darkness. During training a saturation level of about 85-90% correct choices or more can be reached within 50-100 visits. To investigate generalization abilities, the bats were tested with pairs(More)
In the duetting bushcricket species Poecilimon affinis the male calls at intervals of several seconds and is guided to the female by its short response clicks, which release phonotaxis only when perceived by the male during its sensory time window (40-170 ms after his call). The accuracy of phonotaxis in this acoustically open-loop system was investigated(More)
In the bat-pollinated vine Mucuna holtonii only the first visit to a flower is rewarded with a substantial amount of nectar, which is released when a bat lands on the flower and triggers an explosion mechanism. During later visits the bats receive only small amounts of nectar. Nevertheless, the inflorescences as a whole remain attractive, since further buds(More)
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