1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Baird's beaked whale echolocation signals
Rent:
Rent this article for
USD
10.1121/1.4804316
/content/asa/journal/jasa/133/6/10.1121/1.4804316
http://aip.metastore.ingenta.com/content/asa/journal/jasa/133/6/10.1121/1.4804316

Figures

Image of FIG. 1.
FIG. 1.

(Color online) Study area with Baird's beaked whale encounters from Southwest Fisheries Science Center combined visual and acoustic surveys (stars) and acoustic encounters from autonomous HARPs (dots).

Image of FIG. 2.
FIG. 2.

(Color online) Peak frequency distribution of echolocation signals for HARP (A) and towed array data (B). GMM with five mixtures (line) fitted to the HARP peak frequency histogram. Echolocation signals within the first three mixtures were assigned to subsets 1–3, respectively, and those within the last two to subset 4.

Image of FIG. 3.
FIG. 3.

Peak frequency distribution of echolocation signals in ten individual HARP encounters (site, date, time, and number of echolocation signals given). GMM with five mixtures fitted (line) to the peak frequency histogram, probability of fit was omitted, and only dominant fits are shown to simplify graphs.

Image of FIG. 4.
FIG. 4.

(Color online) Description of echolocation signals extracted from towed array recordings split into four subsets (I–IV). (A) Concatenated spectrograms with signals sorted by peak frequency. (B) Spectra with mean signal (solid line) and mean noise before signal (dashed line). (C) Two signal examples with waveform (normalized amplitude, top) and spectrogram [144 points discrete Fourier transform (DFT), 98% overlap, bottom].

Image of FIG. 5.
FIG. 5.

(Color online) Description of echolocation signals extracted from HARP recordings split into four subsets (I–IV). (A) Concatenated spectrograms with signals sorted by peak frequency. (B) Spectra with mean signal (solid line) and mean noise before signal (dashed line). (C) Two signal examples with waveform (normalized amplitude, top) and spectrogram (60 points DFT, 98% overlap, bottom). (D) Histogram of inter-pulse/inter-click interval.

Image of FIG. 6.
FIG. 6.

(Color online) Long-term spectral average (LTSA) of three representative acoustic encounters of Baird's beaked whale on HARP recordings. Different signal types were notable in the LTSA with variable proportions of FM pulses versus clicks in each encounter. Distinct banding pattern was apparent in all three examples.

Image of FIG. 7.
FIG. 7.

(Color online) Example acoustic encounter showing an LTSA (top) and two echolocation sequences (bottom, spectrogram and time series) within the same encounter. Echolocation clicks associated with a certain subset are indicated by subset numbers (1–3).

Image of FIG. 8.
FIG. 8.

(Color online) Two example burst pulse sequences of up to 15 s duration from HARP recordings. All signals were of the FM pulse type. Inter-pulse intervals ranged from slow 30–60 ms to fast 5–10 ms.

Image of FIG. 9.
FIG. 9.

(Color online) Whistles of Baird's beaked whales with fundamental frequencies between 4 and 12 kHz and up to three harmonics from HARP recordings.

Image of FIG. 10.
FIG. 10.

(Color online) Mean spectra of Baird's beaked whale (bold black, Bb) in comparison to Blainville's (Md), Cuvier's (Zc), and Stejneger's (Ms) beaked whales (left). While these species have overlapping geographic distributions, their echolocation signals are species-specific allowing passive acoustic monitoring to be used for population assessment. Mean spectra of the four Baird's beaked whale subsets (s1–s4, right) indicate variability in the relative use of the consistent spectral peaks. The mean spectrum (bold, right) retains the relevant spectral features of all subsets (s1–s4, right), and emphasizes consistent spectral peaks, despite varying peak signal level, independent of subset or signal type.

Tables

Generic image for table
TABLE I.

Baird's beaked whale acoustic encounters for towed-array data.

Generic image for table
TABLE II.

Baird's beaked whale acoustic encounters for autonomous HARP data.

Generic image for table
TABLE III.

Analysis settings for towed array and autonomous HARP data.

Generic image for table
TABLE IV.

Signal characteristics for four subsets of Baird's beaked whale signals with splits based on multi-modal peak frequency distribution in HARP data for both towed array and autonomous HARP data. Number () of echolocation signals in subset, median, and 10%–90% percentiles of distribution in subset are presented.

Loading

Article metrics loading...

/content/asa/journal/jasa/133/6/10.1121/1.4804316
2013-06-05
2014-04-24
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Baird's beaked whale echolocation signals
http://aip.metastore.ingenta.com/content/asa/journal/jasa/133/6/10.1121/1.4804316
10.1121/1.4804316
SEARCH_EXPAND_ITEM