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Killer whales

J Z Abramson, M V Hernández-Lloreda, L García, F Colmenares, F Aboitiz, J Call
No abstract text is available yet for this article.
February 28, 2018: Proceedings. Biological Sciences
Iris Cáceres-Saez, Daniela Haro, Olivia Blank, Anelio Aguayo Lobo, Catherine Dougnac, Cristóbal Arredondo, H Luis Cappozzo, Sergio Ribeiro Guevara
The study was carried out to determine Hg and Se concentrations in false killer whales stranded on the Estrecho de Magallanes, Chile, South America. Tissue samples of five mature specimens were analyzed (two females and three males). Mean Hg concentration in liver 1068 (234) μg g-1 dry weight (DW) (standard deviation in parenthesis) was markedly higher than those in kidney 272 (152) μg g-1 DW, lung 423 (325) μg g-1 DW, spleen 725 (696) μg g-1 DW, muscle 118 (94) μg g-1 DW and testicle 18.0 (2.8) μg g-1 DW...
February 10, 2018: Chemosphere
Henry E Heffner, Rickye S Heffner
Branstetter and his colleagues present the audiograms of eight killer whales and provide a comprehensive review of previous killer whale audiograms. In their paper, they say that the present authors have reported a relationship between size and high-frequency hearing but that echolocating cetaceans might be a special case. The purpose of these comments is to clarify that the relationship of a species' high-frequency hearing is not to its size (mass) but to its "functional interaural distance" (a measure of the availability of sound-localization cues)...
January 2018: Journal of the Acoustical Society of America
José Z Abramson, Mª Victoria Hernández-Lloreda, Lino García, Fernando Colmenares, Francisco Aboitiz, Josep Call
Vocal imitation is a hallmark of human spoken language, which, along with other advanced cognitive skills, has fuelled the evolution of human culture. Comparative evidence has revealed that although the ability to copy sounds from conspecifics is mostly uniquely human among primates, a few distantly related taxa of birds and mammals have also independently evolved this capacity. Remarkably, field observations of killer whales have documented the existence of group-differentiated vocal dialects that are often referred to as traditions or cultures and are hypothesized to be acquired non-genetically...
January 31, 2018: Proceedings. Biological Sciences
Adam B Smith, Aude F Pacini, Paul E Nachtigall
Odontocete marine mammals explore the environment by rapidly producing echolocation signals and receiving the corresponding echoes, which likewise return at very rapid rates. Thus, it is important that the auditory system has a high temporal resolution to effectively process and extract relevant information from click echoes. This study used auditory evoked potential methods to investigate auditory temporal resolution of individuals from four different odontocete species, including a spinner dolphin (Stenella longirostris), pygmy killer whale (Feresa attenuata), long-finned pilot whale (Globicephala melas), and Blainville's beaked whale (Mesoplodon densirostris)...
January 19, 2018: Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology
Brandon E Chasco, Isaac C Kaplan, Austen C Thomas, Alejandro Acevedo-Gutiérrez, Dawn P Noren, Michael J Ford, M Bradley Hanson, Jonathan J Scordino, Steven J Jeffries, Kristin N Marshall, Andrew O Shelton, Craig Matkin, Brian J Burke, Eric J Ward
Many marine mammal predators, particularly pinnipeds, have increased in abundance in recent decades, generating new challenges for balancing human uses with recovery goals via ecosystem-based management. We used a spatio-temporal bioenergetics model of the Northeast Pacific Ocean to quantify how predation by three species of pinnipeds and killer whales (Orcinus orca) on Chinook salmon (Oncorhynchus tshawytscha) has changed since the 1970s along the west coast of North America, and compare these estimates to salmon fisheries...
November 20, 2017: Scientific Reports
F Alves, J R Towers, R W Baird, G Bearzi, S Bonizzoni, R Ferreira, Z Halicka, A Alessandrini, A H Kopelman, C Yzoard, M H Rasmussen, C G Bertulli, E Jourdain, A Gullan, D Rocha, K Hupman, M-T Mrusczok, F I P Samarra, S Magalhães, C R Weir, J K B Ford, A Dinis
Laterally bent dorsal fins are rarely observed in free-ranging populations of cetaceans, contrary to captivity, where most killer whale Orcinus orca adult males have laterally collapsed fins. This topic has been poorly explored, and data/information on its occurrence and possible causes are limited. The present study: (i) undertakes a review of the available information on bent dorsal fins in free-ranging cetaceans, and updates it with new records, (ii) reports on the proportion of bent fins in different study populations, and (iii) discusses possible causes...
November 17, 2017: Journal of Anatomy
Nikolai Hecker, Virag Sharma, Michael Hiller
Kallikrein related peptidase 8 (KLK8; also called neuropsin) is a serine protease that plays distinct roles in the skin and hippocampus. In the skin, KLK8 influences keratinocyte proliferation and desquamation, and activates antimicrobial peptides in sweat. In the hippocampus, KLK8 affects memory acquisition. Here, we examined the evolution of KLK8 in mammals and discovered that, out of 70 placental mammals, KLK8 is exclusively lost in three independent fully-aquatic lineages, comprising dolphin, killer whale, minke whale, and manatee...
November 1, 2017: Genome Biology and Evolution
M Chiarello, S Villéger, C Bouvier, J C Auguet, T Bouvier
Marine animals surfaces host diverse microbial communities, which play major roles for host's health. Most inventories of marine animal surface microbiota have focused on corals and fishes, while cetaceans remain overlooked. The few studies focused on wild cetaceans, making difficult to distinguish intrinsic inter- and/or intraspecific variability in skin microbiota from environmental effects. We used high-throughput sequencing to assess the skin microbiota from 4 body zones of 8 bottlenose dolphins (Tursiops truncatus) and killer whales (Orcinus orca), housed in captivity (Marineland park, France)...
November 10, 2017: Scientific Reports
Ailsa J Hall, Bernie J McConnell, Lori H Schwacke, Gina M Ylitalo, Rob Williams, Teri K Rowles
The potential impact of exposure to polychlorinated biphenyls (PCBs) on the health and survival of cetaceans continues to be an issue for conservation and management, yet few quantitative approaches for estimating population level effects have been developed. An individual based model (IBM) for assessing effects on both calf survival and immunity was developed and tested. Three case study species (bottlenose dolphin, humpback whale and killer whale) in four populations were taken as examples and the impact of varying levels of PCB uptake on achievable population growth was assessed...
October 30, 2017: Environmental Pollution
Paul E Nachtigall, Alexander Ya Supin, Aude F Pacini, Ronald A Kastelein
Hearing sensitivity change was investigated when a warning sound preceded a loud sound in the alse killer whale (Pseudorca crassidens) bottlenose dolphin (Tursiops truncatus) beluga whale (Delphinaperus leucas) and harbor porpoise (Phocoena phocoena). Hearing sensitivity was easured using pip-train test stimuli and auditory evoked potential recording. When the est/warning stimuli preceded a loud sound, hearing thresholds before the loud sound increased elative to the baseline by 13 to17 dB. Experiments with multiple frequencies of exposure and hift provided evidence of different amounts of hearing change depending on frequency, ndicating that the hearing sensation level changes were not likely due to a simple stapedial eflex...
October 27, 2017: Integrative Zoology
Robert C Lacy, Rob Williams, Erin Ashe, Kenneth C Balcomb Iii, Lauren J N Brent, Christopher W Clark, Darren P Croft, Deborah A Giles, Misty MacDuffee, Paul C Paquet
Understanding cumulative effects of multiple threats is key to guiding effective management to conserve endangered species. The critically endangered, Southern Resident killer whale population of the northeastern Pacific Ocean provides a data-rich case to explore anthropogenic threats on population viability. Primary threats include: limitation of preferred prey, Chinook salmon; anthropogenic noise and disturbance, which reduce foraging efficiency; and high levels of stored contaminants, including PCBs. We constructed a population viability analysis to explore possible demographic trajectories and the relative importance of anthropogenic stressors...
October 26, 2017: Scientific Reports
S Ellis, D W Franks, S Nattrass, M A Cant, M N Weiss, D Giles, K C Balcomb, D P Croft
An individual's ecological environment affects their mortality risk, which in turn has fundamental consequences for life-history evolution. In many species, social relationships are likely to be an important component of an individual's environment, and therefore their mortality risk. Here, we examine the relationship between social position and mortality risk in resident killer whales ( Orcinus orca ) using over three decades of social and demographic data. We find that the social position of male, but not female, killer whales in their social unit predicts their mortality risk...
October 25, 2017: Proceedings. Biological Sciences
Christopher T Kello, Simone Dalla Bella, Butovens Médé, Ramesh Balasubramaniam
Humans talk, sing and play music. Some species of birds and whales sing long and complex songs. All these behaviours and sounds exhibit hierarchical structure-syllables and notes are positioned within words and musical phrases, words and motives in sentences and musical phrases, and so on. We developed a new method to measure and compare hierarchical temporal structures in speech, song and music. The method identifies temporal events as peaks in the sound amplitude envelope, and quantifies event clustering across a range of timescales using Allan factor (AF) variance...
October 2017: Journal of the Royal Society, Interface
Jean-Pierre Desforges, Milton Levin, Lindsay Jasperse, Sylvain De Guise, Igor Eulaers, Robert J Letcher, Mario Acquarone, Erling Nordøy, Lars P Folkow, Trine Hammer Jensen, Carsten Grøndahl, Mads F Bertelsen, Judy St Leger, Javier Almunia, Christian Sonne, Rune Dietz
Most controlled toxicity studies use single chemical exposures that do not represent the real world situation of complex mixtures of known and unknown natural and anthropogenic substances. In the present study, complex contaminant cocktails derived from the blubber of polar bears (PB; Ursus maritimus) and killer whales (KW; Orcinus orca) were used for in vitro concentration-response experiments with PB, cetacean and seal spp. immune cells to evaluate the effect of realistic contaminant mixtures on various immune functions...
September 25, 2017: Environmental Science & Technology
Alexander J Smith, Jeff W Higdon, Pierre Richard, Jack Orr, Warren Bernhardt, Steven H Ferguson
To understand beluga whale (Delphinapterus leucas) estuarine use in the Nelson River estuary, southwest Hudson Bay, we recorded and examined beluga movements and habitat associations for the July through August period in 2002-2005. We compared locations of belugas fitted with satellite transmitters ("tags") (2002-2005) and aerial-surveyed (2003 and 2005) belugas for years of differing freshwater flow from the Nelson River which is influenced by hydroelectric activity. Using the beluga telemetry location data, we estimated an early August behavioral shift in beluga distribution patterns from local estuarine use to a progressively more migratory behavior away from the estuary...
2017: PloS One
Hal Whitehead
Whales and dolphins (Cetacea) have excellent social learning skills as well as a long and strong mother-calf bond. These features produce stable cultures, and, in some species, sympatric groups with different cultures. There is evidence and speculation that this cultural transmission of behavior has affected gene distributions. Culture seems to have driven killer whales into distinct ecotypes, which may be incipient species or subspecies. There are ecotype-specific signals of selection in functional genes that correspond to cultural foraging behavior and habitat use by the different ecotypes...
July 24, 2017: Proceedings of the National Academy of Sciences of the United States of America
Adrianne L Jarvela Rosenberger, Misty MacDuffee, Andrew G J Rosenberger, Peter S Ross
Marine mammals are inherently vulnerable to oil spills. We developed a conceptual framework to evaluate the impacts of potential oil exposure on marine mammals and applied it to 21 species inhabiting coastal British Columbia (BC), Canada. Oil spill vulnerability was determined by examining both the likelihood of species-specific (individual) oil exposure and the consequent likelihood of population-level effects. Oil exposure pathways, ecology, and physiological characteristics were first used to assign species-specific vulnerability rankings...
July 2017: Archives of Environmental Contamination and Toxicology
Eve Jourdain, Dag Vongraven, Anna Bisther, Richard Karoliussen
Killer whales (Orcinus orca) have been documented preying on either fish or marine mammals in several regions, suggesting that this odontocete species has the ability to specialize on different types of prey. Off Norway, killer whales have been shown to rely on the Atlantic herring (Clupea harengus) as a main prey resource. Infrequent observations have revealed seals as an additional component of their diet, yet the extent of predation on marine mammals has remained largely unknown. Here, we present the findings of 29 years of photographic and observational data on seal-feeding killer whale groups identified in Norwegian coastal waters...
2017: PloS One
Samuel K Wasser, Jessica I Lundin, Katherine Ayres, Elizabeth Seely, Deborah Giles, Kenneth Balcomb, Jennifer Hempelmann, Kim Parsons, Rebecca Booth
The Southern Resident killer whale population (Orcinus orca) was listed as endangered in 2005 and shows little sign of recovery. These fish eating whales feed primarily on endangered Chinook salmon. Population growth is constrained by low offspring production for the number of reproductive females in the population. Lack of prey, increased toxins and vessel disturbance have been listed as potential causes of the whale's decline, but partitioning these pressures has been difficult. We validated and applied temporal measures of progesterone and testosterone metabolites to assess occurrence, stage and health of pregnancy from genotyped killer whale feces collected using detection dogs...
2017: PloS One
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