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Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat

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Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat. / Simon, R; Holderied, MW; Helversen, Ov.

In: Journal of Experimental Biology, Vol. 209(18), 09.2006, p. 3599 - 3609.

Research output: Contribution to journalArticle

Harvard

Simon, R, Holderied, MW & Helversen, O 2006, 'Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat', Journal of Experimental Biology, vol. 209(18), pp. 3599 - 3609. https://doi.org/10.1242/jeb.02398

APA

Simon, R., Holderied, MW., & Helversen, O. (2006). Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat. Journal of Experimental Biology, 209(18), 3599 - 3609. https://doi.org/10.1242/jeb.02398

Vancouver

Simon R, Holderied MW, Helversen O. Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat. Journal of Experimental Biology. 2006 Sep;209(18):3599 - 3609. https://doi.org/10.1242/jeb.02398

Author

Simon, R ; Holderied, MW ; Helversen, Ov. / Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat. In: Journal of Experimental Biology. 2006 ; Vol. 209(18). pp. 3599 - 3609.

Bibtex

@article{70138ad1b4f54c5f8c16a69cdabadf3d,
title = "Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat",
abstract = "Nectar feeding bats use echolocation to find their flowers in the dense growth of tropical rainforests, and such flowers have evolved acoustic features that make their echo more conspicuous to their pollinators. To shed light on the sensory and cognitive basis of echoacoustic object recognition we conducted a size discrimination experiment with the nectarivorous bat Glossophaga soricina and compared the bats' behavioural performance with the echoic features of the training objects. We chose a simple geometric form, the hollow hemisphere, as the training object because of its resemblance to the bell-shaped concave form of many bat flowers, as well as its special acoustic qualities. The hemispheres showed a characteristic echo pattern, which was constant over a wide range of angles of sound incidence. We found systematic size-dependent changes in the echo's temporal and spectral pattern as well as in amplitude. Bats were simultaneously confronted with seven different sizes of hollow hemispheres presented from their concave sides. Visits to one particular size were rewarded with sugar water, while we recorded the frequency of visits to the unrewarded hemispheres. We found that: (1) bats learned to discriminate between hemispheres of different size with ease; (2) the minimum size difference for discrimination was a constant percentage of the hemisphere's size (Weber fraction: approximately 16{\%} of the radius); (3) the comparison of behavioural data and impulse response measurements of the objects' echoes yielded discrimination thresholds for mean intensity differences (1.3 dB), the temporal pattern (3-22 mu s) and the change of spectral notch frequency (approximately 16{\%}). We discuss the advantages of discrimination in the frequency and/or time domain.",
author = "R Simon and MW Holderied and Ov Helversen",
note = "Publisher: Company of Biologists Ltd 2006",
year = "2006",
month = "9",
doi = "10.1242/jeb.02398",
language = "English",
volume = "209(18)",
pages = "3599 -- 3609",
journal = "Journal of Experimental Biology",
issn = "0022-0949",
publisher = "Company of Biologists Ltd",

}

RIS - suitable for import to EndNote

TY - JOUR

T1 - Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat

AU - Simon, R

AU - Holderied, MW

AU - Helversen, Ov

N1 - Publisher: Company of Biologists Ltd 2006

PY - 2006/9

Y1 - 2006/9

N2 - Nectar feeding bats use echolocation to find their flowers in the dense growth of tropical rainforests, and such flowers have evolved acoustic features that make their echo more conspicuous to their pollinators. To shed light on the sensory and cognitive basis of echoacoustic object recognition we conducted a size discrimination experiment with the nectarivorous bat Glossophaga soricina and compared the bats' behavioural performance with the echoic features of the training objects. We chose a simple geometric form, the hollow hemisphere, as the training object because of its resemblance to the bell-shaped concave form of many bat flowers, as well as its special acoustic qualities. The hemispheres showed a characteristic echo pattern, which was constant over a wide range of angles of sound incidence. We found systematic size-dependent changes in the echo's temporal and spectral pattern as well as in amplitude. Bats were simultaneously confronted with seven different sizes of hollow hemispheres presented from their concave sides. Visits to one particular size were rewarded with sugar water, while we recorded the frequency of visits to the unrewarded hemispheres. We found that: (1) bats learned to discriminate between hemispheres of different size with ease; (2) the minimum size difference for discrimination was a constant percentage of the hemisphere's size (Weber fraction: approximately 16% of the radius); (3) the comparison of behavioural data and impulse response measurements of the objects' echoes yielded discrimination thresholds for mean intensity differences (1.3 dB), the temporal pattern (3-22 mu s) and the change of spectral notch frequency (approximately 16%). We discuss the advantages of discrimination in the frequency and/or time domain.

AB - Nectar feeding bats use echolocation to find their flowers in the dense growth of tropical rainforests, and such flowers have evolved acoustic features that make their echo more conspicuous to their pollinators. To shed light on the sensory and cognitive basis of echoacoustic object recognition we conducted a size discrimination experiment with the nectarivorous bat Glossophaga soricina and compared the bats' behavioural performance with the echoic features of the training objects. We chose a simple geometric form, the hollow hemisphere, as the training object because of its resemblance to the bell-shaped concave form of many bat flowers, as well as its special acoustic qualities. The hemispheres showed a characteristic echo pattern, which was constant over a wide range of angles of sound incidence. We found systematic size-dependent changes in the echo's temporal and spectral pattern as well as in amplitude. Bats were simultaneously confronted with seven different sizes of hollow hemispheres presented from their concave sides. Visits to one particular size were rewarded with sugar water, while we recorded the frequency of visits to the unrewarded hemispheres. We found that: (1) bats learned to discriminate between hemispheres of different size with ease; (2) the minimum size difference for discrimination was a constant percentage of the hemisphere's size (Weber fraction: approximately 16% of the radius); (3) the comparison of behavioural data and impulse response measurements of the objects' echoes yielded discrimination thresholds for mean intensity differences (1.3 dB), the temporal pattern (3-22 mu s) and the change of spectral notch frequency (approximately 16%). We discuss the advantages of discrimination in the frequency and/or time domain.

U2 - 10.1242/jeb.02398

DO - 10.1242/jeb.02398

M3 - Article

VL - 209(18)

SP - 3599

EP - 3609

JO - Journal of Experimental Biology

JF - Journal of Experimental Biology

SN - 0022-0949

ER -