@article {53331, title = {Clicks of dwarf sperm whales ( Kogia sima)}, journal = {Marine Mammal Science}, volume = {34}, year = {2018}, month = {Jan-10-2018}, pages = {963 - 978}, abstract = {

The two species of the genus Kogia are widely distributed throughout the world\&$\#$39;s temperate and tropical oceans, but because they are small and highly cryptic, they are difficult to monitor. The acoustic signals of K. breviceps have been described previously, but the signals of K. sima have remained unknown. Here we present three recordings of K. sima, two from free-ranging animals and one from a captive setting, representing both the Atlantic Ocean and Pacific Ocean. The acoustic signals of K. sima are very similar to the signals of K. breviceps and other species that have narrow-band, high-frequency (NBHF) clicks. Free-ranging K. sima produce \“usual\” clicks that have mean peak and centroid frequencies of 127\–129 kHz, mean \−3 dB bandwidth of 10 kHz, mean \−10 dB bandwidth of 16\–17 kHz, and mean interclick interval of 110\–164 ms. Although K. sima clicks cannot yet be distinguished from those of K. breviceps or other NBHF clicking species, our detailed description of this species\&$\#$39; signals reveals the similarities between the two Kogia species, and thus allows for passive acoustic monitoring of the genus Kogia in regions where other NBHF species are not present.

}, keywords = {Atlantic, Biosonar, click, dwarf sperm whale, echo-location, Florida, Guam, Kogia sima, narrow-band high-frequency, Pacific, The Bahamas}, doi = {10.1111/mms.v34.410.1111/mms.12488}, url = {http://doi.wiley.com/10.1111/mms.v34.4}, author = {Merkens, Karlina and David A. Mann and Janik, Vincent M. and Claridge, Diane and Hill, Marie and Erin M. Oleson} } @article {47323, title = {Estimation of minke whale abundance from an acoustic line transect survey of the Mariana Islands}, journal = {Marine Mammal Science}, year = {2017}, month = {Jan-03-2017}, abstract = {

The minke whale is one of the most abundant species of baleen whales worldwide, yet is rarely sighted in subtropical waters. In the North Pacific, they produce a dis- tinctive sound known as the \“boing,\” which can be used to acoustically localize indi- viduals. A vessel-based survey using both visual and passive acoustic monitoring was conducted during the spring of 2007 in a large (616,000 km 2 ) study area encom- passing the Mariana Islands. We applied line transect methods to data collected from a towed hydrophone array to estimate the abundance of calling minke whales in our study area. No minke whales were sighted, but there were hundreds of acoustic detections of boings. Computer algorithms were developed to localize calling minke whales from acoustic recordings, resulting in over 30 independent localizations, a six-fold increase over those estimated during the survey. The two best estimates of abundance of calling minke whales were determined to be 80 and 91 animals (0.13 and 0.15 animals per 1,000 km2, respectively; CV = 34\%). These are the first den- sity and abundance estimates for calling minke whales using towed hydrophone array surveys, and the first estimates for this species in the Mariana Islands region. These are considered minimum estimates of the true number of minke whales in the study area.

}, keywords = {Balaenoptera acutorostrata, density esti- mation, Mariana Islands, marine mammals., minke whale, Pacific, passive acoustics}, doi = {10.1111/mms.12397}, url = {http://doi.wiley.com/10.1111/mms.12397}, author = {Norris, Thomas F. and Dunleavy, Kerry J. and Yack, Tina M. and Ferguson, Elizabeth L.} }