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Acoustic and temporal partitioning of cicada assemblages in city and mountain environments.

Shieh BS, Liang SH, Chiu YW - PLoS ONE (2015)

Bottom Line: Our comparison of activity patterns of seasonal and diel calling revealed that there was no significant temporal partitioning of cicada assemblages in either environment.Furthermore, for the common species found in both environments, the calling activity patterns at both seasonal and diel time scales were significantly consistent across sites and across environments.As a result, cicada assemblages in city environments with low species diversity do not demonstrate a more significant temporal partitioning than those in mountain environments with high species diversity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.

ABSTRACT
Comparing adaptations to noisy city environments with those to natural mountain environments on the community level can provide significant insights that allow an understanding of the impact of anthropogenic noise on invertebrates that employ loud calling songs for mate attraction, especially when each species has its distinct song, as in the case of cicadas. In this study, we investigated the partitioning strategy of cicada assemblages in city and mountain environments by comparing the acoustic features and calling activity patterns of each species, recorded using automated digital recording systems. Our comparison of activity patterns of seasonal and diel calling revealed that there was no significant temporal partitioning of cicada assemblages in either environment. In addition, there was no correlation between the acoustic distance based on spectral features and temporal segregation. Heterospecific spectral overlap was low in both city and mountain environments, although city and mountain cicada assemblages were subject to significantly different levels of anthropogenic or interspecific noise. Furthermore, for the common species found in both environments, the calling activity patterns at both seasonal and diel time scales were significantly consistent across sites and across environments. We suggest that the temporal calling activity is constrained by endogenous factors for each species and is less flexible in response to external factors, such as anthropogenic noise. As a result, cicada assemblages in city environments with low species diversity do not demonstrate a more significant temporal partitioning than those in mountain environments with high species diversity.

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A bi-dimensional plotting of the principal component analysis using the five acoustic variables (PF, Q1, Q2, Q3, pureness) on spectrograms of cicada calling songs at the SP mountain site of Taiwan.
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pone.0116794.g004: A bi-dimensional plotting of the principal component analysis using the five acoustic variables (PF, Q1, Q2, Q3, pureness) on spectrograms of cicada calling songs at the SP mountain site of Taiwan.

Mentions: The SP mountain site had 11 cicada species in 2011. We retained two principal components with eigenvalues greater than one, and they accounted for 98.3% of the total variation (PC1: eigenvalue 3.75, 74.9% variation explained; PC2: eigenvalue 1.17, 23.4% variation explained). Four species pairs out of 55 pairs had acoustic features that overlapped on the plot of PC1 against PC2 (Fig. 4). They were L. sakaii-Me. opalifera; T. taipinensis-T. viridis; Cr. takasagona-T. taipinensis; and Pl. takasagona-Mo. formosana. Among the species pairs with similar acoustic frequency features, only the species pair Cr. takasagona-T. taipinensis showed a significant diel segregation (rs < 0, P < 0.01) (Table G in S1 File). The congeneric and spectrally overlapping T. taipinensis-T. viridis species pair, even demonstrated significantly positive correlations of both seasonal and diel activity patterns (rs > 0, P < 0.01) (Table G in S1 File). Further examination of the spectrograms of calling songs of this congeneric species pair found distinct time-frequency patterns. T. taipinensis had calling songs of mixed patterns, whereas T. viridis had calling songs of pulse trains patterns (Fig. 2). Pl. takasagona and Mo. formosana also had distinctly different time-frequency patterns of calling songs. The calling songs of Pl. takasagona were classified as tonal band patterns (Fig. 1), whereas those of Mo. formosana were classified as mixed patterns (Fig. 3). Although L. sakaii and Me. opalifera had similar spectral features and their calling songs were classified as mixed patterns, their calling songs consisted of different number of note types. The calling songs of L. sakaii consisted of two note types, whereas those of Me. opalifera consisted of more than four note types (Fig. 3).


Acoustic and temporal partitioning of cicada assemblages in city and mountain environments.

Shieh BS, Liang SH, Chiu YW - PLoS ONE (2015)

A bi-dimensional plotting of the principal component analysis using the five acoustic variables (PF, Q1, Q2, Q3, pureness) on spectrograms of cicada calling songs at the SP mountain site of Taiwan.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4295890&req=5

pone.0116794.g004: A bi-dimensional plotting of the principal component analysis using the five acoustic variables (PF, Q1, Q2, Q3, pureness) on spectrograms of cicada calling songs at the SP mountain site of Taiwan.
Mentions: The SP mountain site had 11 cicada species in 2011. We retained two principal components with eigenvalues greater than one, and they accounted for 98.3% of the total variation (PC1: eigenvalue 3.75, 74.9% variation explained; PC2: eigenvalue 1.17, 23.4% variation explained). Four species pairs out of 55 pairs had acoustic features that overlapped on the plot of PC1 against PC2 (Fig. 4). They were L. sakaii-Me. opalifera; T. taipinensis-T. viridis; Cr. takasagona-T. taipinensis; and Pl. takasagona-Mo. formosana. Among the species pairs with similar acoustic frequency features, only the species pair Cr. takasagona-T. taipinensis showed a significant diel segregation (rs < 0, P < 0.01) (Table G in S1 File). The congeneric and spectrally overlapping T. taipinensis-T. viridis species pair, even demonstrated significantly positive correlations of both seasonal and diel activity patterns (rs > 0, P < 0.01) (Table G in S1 File). Further examination of the spectrograms of calling songs of this congeneric species pair found distinct time-frequency patterns. T. taipinensis had calling songs of mixed patterns, whereas T. viridis had calling songs of pulse trains patterns (Fig. 2). Pl. takasagona and Mo. formosana also had distinctly different time-frequency patterns of calling songs. The calling songs of Pl. takasagona were classified as tonal band patterns (Fig. 1), whereas those of Mo. formosana were classified as mixed patterns (Fig. 3). Although L. sakaii and Me. opalifera had similar spectral features and their calling songs were classified as mixed patterns, their calling songs consisted of different number of note types. The calling songs of L. sakaii consisted of two note types, whereas those of Me. opalifera consisted of more than four note types (Fig. 3).

Bottom Line: Our comparison of activity patterns of seasonal and diel calling revealed that there was no significant temporal partitioning of cicada assemblages in either environment.Furthermore, for the common species found in both environments, the calling activity patterns at both seasonal and diel time scales were significantly consistent across sites and across environments.As a result, cicada assemblages in city environments with low species diversity do not demonstrate a more significant temporal partitioning than those in mountain environments with high species diversity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan.

ABSTRACT
Comparing adaptations to noisy city environments with those to natural mountain environments on the community level can provide significant insights that allow an understanding of the impact of anthropogenic noise on invertebrates that employ loud calling songs for mate attraction, especially when each species has its distinct song, as in the case of cicadas. In this study, we investigated the partitioning strategy of cicada assemblages in city and mountain environments by comparing the acoustic features and calling activity patterns of each species, recorded using automated digital recording systems. Our comparison of activity patterns of seasonal and diel calling revealed that there was no significant temporal partitioning of cicada assemblages in either environment. In addition, there was no correlation between the acoustic distance based on spectral features and temporal segregation. Heterospecific spectral overlap was low in both city and mountain environments, although city and mountain cicada assemblages were subject to significantly different levels of anthropogenic or interspecific noise. Furthermore, for the common species found in both environments, the calling activity patterns at both seasonal and diel time scales were significantly consistent across sites and across environments. We suggest that the temporal calling activity is constrained by endogenous factors for each species and is less flexible in response to external factors, such as anthropogenic noise. As a result, cicada assemblages in city environments with low species diversity do not demonstrate a more significant temporal partitioning than those in mountain environments with high species diversity.

Show MeSH