spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online June 11, 2007
Journal of Experimental Biology 210, 2104-2112 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.004317
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JEB
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Vasconcelos, R. O.
Right arrow Articles by Ladich, F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Vasconcelos, R. O.
Right arrow Articles by Ladich, F.

Effects of ship noise on the detectability of communication signals in the Lusitanian toadfish

Raquel O. Vasconcelos1,2,*, M. Clara P. Amorim2 and Friedrich Ladich3

1 Departamento de Biologia Animal e Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa. Bloco C2 Campo Grande, 1749-0161 Lisboa, Portugal
2 Unidade de Investigação em Eco-Etologia, I.S.P.A. Rua Jardim do Tabaco 34, 1149-041 Lisboa, Portugal
3 Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria


Figure 1
View larger version (48K):
[in this window]
[in a new window]

  		Fig. 1. Sonogram (above) and oscillogram (below) of the ferry-boat noise recorded in the Tagus River estuary (Portugal). The dashed lines indicate the temporal interval of 4.4 s selected for determining ship noise spectra. Sampling frequency 44.1 kHz, filter bandwidth 10 Hz, Blackmann Harris window, 50% overlap.

 

Figure 2
View larger version (8K):
[in this window]
[in a new window]

  		Fig. 2. Sound power spectra of ambient (blue line) and ship (red line) noises recorded in the Tagus River estuary (Portugal), near an intertidal nesting place of the Lusitanian toadfish. Sampling frequency 44.1 kHz, filter bandwidth 5 Hz, Blackmann Harris window, 75% overlap.

 

Figure 3
View larger version (10K):
[in this window]
[in a new window]

  		Fig. 3. Mean (± s.e.m.) hearing thresholds of the Lusitanian toadfish under laboratory conditions (baseline; black line) and in the presence of ambient noise (blue line) and ship noise (red line). Dashed lines of same colour show the cepstrum-smoothed sound power spectra for the respective noise types used during audiogram determinations. Asterisks indicate statistically significant differences between the ambient noise and baseline (unpaired t-tests) as well as ambient and ship noise (paired t-tests); *P<0.007 and **P<0.001). N=9, baseline; N=6, ambient and ship noise audiograms.

 

Figure 4
View larger version (5K):
[in this window]
[in a new window]

  		Fig. 4. Threshold-to-noise ratios for masked thresholds for ambient (blue stars) and ship (red triangles) noises. Note that only masked thresholds that were statistically significantly different are represented. (T/N ratio=frequencyx21.034+18.008, r=0.760, P<0.001).

 

Figure 5
View larger version (10K):
[in this window]
[in a new window]

  		Fig. 5. Mean (±s.e.m.) hearing thresholds of the Lusitanian toadfish in the presence of ambient (blue line) and ship (red line) noises as well as cepstrum-smoothed power spectra of two conspecific sounds: boatwhistle (green line) and grunt train (brown line). The boatwhistle spectrum is calculated from a distance of 20 cm, the grunt train 10 cm away from the calling animals.

 




© The Company of Biologists Ltd 2007