Publications

Export 3 results:
Sort by: Author Title Type [ Year  (Desc)]
2018
Lewis, LA, Calambokidis J, Stimpert AK, Fahlbusch J, Friedlaender AS, McKenna MF, Mesnick SL, Oleson EM, Southall BL, Szesciorka AR, Sirovic A.  2018.  Context-dependent variability in blue whale acoustic behaviour. Royal Society Open Science. 5   10.1098/rsos.180241   AbstractWebsite

Acoustic communication is an important aspect of reproductive, foraging and social behaviours for many marine species. Northeast Pacific blue whales (Balaenoptera musculus) produce three different call types-A, B and D calls. All may be produced as singular calls, but A and B calls also occur in phrases to form songs. To evaluate the behavioural context of singular call and phrase production in blue whales, the acoustic and dive profile data from tags deployed on individuals off southern California were assessed using generalized estimating equations. Only 22% of all deployments contained sounds attributed to the tagged animal. A larger proportion of tagged animals were female (47%) than male (13%), with 40% of unknown sex. Fifty per cent of tags deployed on males contained sounds attributed to the tagged whale, while only a few (5%) deployed on females did. Most calls were produced at shallow depths (less than 30 m). Repetitive phrasing (singing) and production of singular calls were most common during shallow, non-lunging dives, with the latter also common during surface behaviour. Higher sound production rates occurred during autumn than summer and they varied with time-of-day: singular call rates were higher at dawn and dusk, while phrase production rates were highest at dusk and night.

2016
Roch, MA, Batchelor H, Baumann-Pickering S, Berchok CL, Cholewiak D, Fujioka E, Garland EC, Herbert S, Hildebrand JA, Oleson EM, Van Parijs S, Risch D, Širović A, Soldevilla MS.  2016.  Management of acoustic metadata for bioacoustics. Ecological Informatics. 31:122-136.   10.1016/j.ecoinf.2015.12.002   AbstractWebsite

Recent expansion in the capabilities of passive acoustic monitoring of sound-producing animals is providing expansive data sets in many locations. These long-term data sets will allow the investigation of questions related to the ecology of sound-producing animals on time scales ranging from diel and seasonal to inter-annual and decadal. Analyses of these data often span multiple analysts from various research groups over several years of effort and, as a consequence, have begun to generate large amounts of scattered acoustic metadata. It has therefore become imperative to standardize the types of metadata being generated. A critical aspect of being able to learn from such large and varied acoustic data sets is providing consistent and transparent access that can enable the integration of various analysis efforts. This is juxtaposed with the need to include new information for specific research questions that evolve over time. Hence, a method is proposed for organizing acoustic metadata that addresses many of the problems associated with the retention of metadata from large passive acoustic data sets. A structure was developed for organizing acoustic metadata in a consistent manner, specifying required and optional terms to describe acoustic information derived from a recording. A client-server database was created to implement this data representation as a networked data service that can be accessed from several programming languages. Support for data import from a wide variety of sources such as spreadsheets and databases is provided. The implementation was extended to access Internet-available data products, permitting access to a variety of environmental information types (e.g. sea surface temperature, sunrise/sunset, etc.) from a wide range of sources as if they were part of the data service. This metadata service is in use at several institutions and has been used to track and analyze millions of acoustic detections from marine mammals, fish, elephants, and anthropogenic sound sources. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

2009
Širović, A, Demer DA.  2009.  Sounds of Captive Rockfishes. Copeia. :502-509.   10.1643/cp-08-121   AbstractWebsite

Sound production by many fish species has been studied extensively, but little is known about sound production by rockfishes (genus Sebostes), and only a few species have been reported to be soniferous. To determine if additional rockfish species produce sounds, passive acoustic recordings were made during 2007/08 at Hubbs-SeaWorld Research Institute and Southwest Fisheries Science Center in tanks containing Bocaccio (S. poucispinis), Cowcod (S. levis), Starry Rockfish (S. constellatus), and Sunset Rockfish (S. crocotulus). Data were collected using pre-amplified hydrophones (HTI-94-SSQ) and digitized at sample rates of 44,100 or 8,000 Hz (using an Edirol R-09 recorder or Edirol UA-5 sound card and Ishmael software, respectively). Three distinct sounds were recorded in tanks containing only S. paucispinis and two of those sounds occurred at different rates during light and dark conditions. Their common characteristics were low frequency (below 800 Hz), short duration (<4 s), and low source levels (103-113 dB re: 1 mu Pa at 1 m). Also, there was evidence one or more other species produced sounds. These findings Indicate that more rockfishes produce sounds, and suggest passive acoustics could be a useful tool for remotely monitoring their populations.