@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 {53330, title = {Manatee behavioral response to boats}, journal = {Marine Mammal Science}, volume = {34}, year = {2018}, month = {Jan-10-2018}, pages = {924 - 962}, abstract = {

The long-term viability of the Florida manatee is threatened in part by mortality from boat collisions. This study investigated manatee behavior during boat approaches to better understand factors that lead to manatee\–boat collisions. Digital acoustic recording tags (DTAGs) and Argos-linked GPS tags were deployed on 18 manatees in southwest Florida, and boat traffic around them was mapped. Suites of manatee behavioral, environmental, and boat-related factors were recorded during opportunistic boat passes. We built generalized linear mixed models to determine which factors accounted for variation in occurrence, number, and timing of manatee behavioral changes during boat passes. Manatees responded to boats, changing their orientation, depth, and fluking behavior most often when a boat approached closely (\<10 m). Manatees were also more likely to change their depth when not on a seagrass bed and when actively fluking before a boat pass. Boat speed did not affect the occurrence or intensity of manatee response. Compared to fast approaches, however, slower passes allowed the manatee more time to respond, and behavioral change occurred earlier relative to the time of the boat\&$\#$39;s closest point of approach. We conclude that faster boats likely pose a greater risk of collision with manatees than do slower boats.

}, keywords = {behavioral response, boat collision, DTAG, Florida, manatee, Trichechus manatus, West Indian}, doi = {10.1111/mms.v34.410.1111/mms.12491}, url = {http://doi.wiley.com/10.1111/mms.v34.4}, author = {Rycyk, Athena M. and Deutsch, Charles J. and Barlas, Margaret E. and Hardy, Stacie K. and Frisch, Katherine and Leone, Erin H. and Nowacek, Douglas P.} }