Dear Colleagues,
My co-authors and I would like to share with you our work recently published in Ecology and Evolution: <https://www.researchgate.net/profile/Karine_Heerah> Heerah, K., Hindell, M., Andrew-Goff, V., Field, I., McMahon, C. R. and Charrassin, J.-B. (2016), Contrasting behavior between two populations of an ice-obligate predator in East Antarctica. Ecology and Evolution, 00: 1–13. doi: 10.1002/ece3.2652<http://dx.doi.org/10.1002/ece3.2652> Abtract: The Austral autumn–winter is a critical period for capital breeders such as Weddell seals that must optimize resource acquisition and storage to provision breeding in the subsequent spring. However, how Weddell seals find food in the winter months remains poorly documented. We equipped adult Weddell seals after their annual molt with satellite-relayed data loggers at two sites in East Antarctica: Dumont D'Urville (n = 12, DDU) and Davis (n = 20). We used binomial generalized mixed-effect models to investigate Weddell seals’ behavioral response (i.e., “hunting” vs. “transit”) to physical aspects of their environment (e.g., ice concentration). Weddell seal foraging was concentrated to within 5 km of a breathing hole, and they appear to move between holes as local food is depleted. There were regional differences in behavior so that seals at Davis traveled greater distances (three times more) and spent less time in hunting mode (half the time) than seals at DDU. Despite these differences, hunting dives at both locations were pelagic, concentrated in areas of high ice concentration, and over areas of complex bathymetry. There was also a seasonal change in diving behavior from transiting early in the season to more hunting during winter. Our observations suggest that Weddell seal foraging behavior is plastic and that they respond behaviorally to changes in their environment to maximize food acquisition and storage. Such plasticity is a hallmark of animals that live in very dynamic environments such as the high Antarctic where resources are unpredictable. All the best, Karine Heerah ------------------------------------------------------------ Postdoctoral Fellow at IFREMER, Brest, France https://www.researchgate.net/profile/Karine_Heerah ________________________________ De : MARMAM <marmam-boun...@lists.uvic.ca> de la part de Fredrik Christiansen <f.christian...@live.se> Envoyé : mardi 27 décembre 2016 12:44 À : marmam@lists.uvic.ca Objet : [MARMAM] New study investigating the underwater noise impacts of UAVs on marine mammals Dear colleagues, My co-authors and I are happy to announce the publication of the following paper in Frontiers in Marine Science: Christiansen F, Rojano-Doñate L, Madsen PT and Bejder L (2016) Noise Levels of Multi-Rotor Unmanned Aerial Vehicles with Implications for Potential Underwater Impacts on Marine Mammals. Front. Mar. Sci. 3:277. doi: 10.3389/fmars.2016.00277 Abstract: Despite the rapid increase in the use of unmanned aerial vehicles (UAVs) in marine mammal research, knowledge of the effects of UAVs on study animals is very limited. We recorded the in-air and in-water noise from two commonly used multi-rotor UAVs, the SwellPro Splashdrone and the DJI Inspire 1 Pro, to assess the potential for negative noise effects of UAV use. The Splashdrone and Inspire UAVs produced broad-band in-air source levels of 80 dB re 20 μPa and 81 dB re 20 μPa (rms), with fundamental frequencies centered at 60 Hz and 150 Hz. The noise of the UAVs coupled poorly into the water, and could only be quantified above background noise of the recording sites at 1 m depth when flying at altitudes of 5 and 10 m, resulting in broad-band received levels around 95 dB re μPa rms for the Splashdrone and around 101 dB re μPa rms for the Inspire. The third octave levels of the underwater UAV noise profiles are (i) close to ambient noise levels in many shallow water habitats, (ii) largely below the hearing thresholds at low frequencies of toothed whales, but (iii) likely above the hearing thresholds of baleen whales and pinnipeds. So while UAV noise may be heard by some marine mammals underwater, it is implied that the underwater noise effect is small, even for animals close to the water surface. Our findings will be valuable for wildlife managers and regulators when issuing permits and setting guidelines for UAV operations. Further, our experimental setup can be used by others to evaluate noise effects of larger sized UAVs on marine mammals. A copy of the paper can be downloaded for free from: <http://journal.frontiersin.org/article/10.3389/fmars.2016.00277/fu>http://journal.frontiersin.org/article/10.3389/fmars.2016.00277/full [http://www.frontiersin.org/files/MyHome%20Article%20Library/223318/223318_Thumb_400.jpg]<http://journal.frontiersin.org/article/10.3389/fmars.2016.00277/full> Noise Levels of Multi-Rotor Unmanned Aerial Vehicles with Implications for Potential Underwater Impacts on Marine Mammals<http://journal.frontiersin.org/article/10.3389/fmars.2016.00277/full> journal.frontiersin.org Despite the rapid increase in the use of unmanned aerial vehicles (UAVs) in marine mammal research, knowledge of the effects of UAVs on study animals is very limited. We recorded the in-air and in-water noise from two commonly used multi-rotor UAVs, the SwellPro Splashdrone and the DJI Inspire 1 Pro, to assess the potential for negative noise effects of UAV use. The Splashdrone and Inspire UAVs produced broad-band in-air source levels of 80 dB re 20µPa and 81 dB re 20µPa (rms), with fundamental frequencies centered at 60 Hz and 150 Hz. The noise of the UAVs coupled poorly into the water, and could only be quantified above background noise of the recording sites at 1m depth when flying at altitudes of 5 and 10m, resulting in broad-band received levels around 95 dB re µPa rms for the Splashdrone and around 101 dB re µPa rms for the Inspire. The third octave levels of the underwater UAV noise profiles are i) close to ambient noise levels in many shallow water habitats, ii) largely below the hearing threshold Best regards, Fredrik Christiansen Postdoctoral Research Fellow Cetacean Research Unit, School of Veterinary and Life Sciences Murdoch University, Murdoch, WA 6150, Australia +61 417 502 098, f.christian...@murdoch.edu.au<mailto:f.christian...@murdoch.edu.au>, twitter: @FChristiansen83 http://scholar.google.com.au/citations?user=vkA5Y3EAAAAJ&hl=en&oi=sra http://www.researchgate.net/profile/Fredrik_Christiansen3/?ev=hdr_xprf
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