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https://www.readbyqxmd.com/read/28223481/sustained-disruption-of-narwhal-habitat-use-and-behavior-in-the-presence-of-arctic-killer-whales
#1
Greg A Breed, Cory J D Matthews, Marianne Marcoux, Jeff W Higdon, Bernard LeBlanc, Stephen D Petersen, Jack Orr, Natalie R Reinhart, Steven H Ferguson
Although predators influence behavior of prey, analyses of electronic tracking data in marine environments rarely consider how predators affect the behavior of tracked animals. We collected an unprecedented dataset by synchronously tracking predator (killer whales, [Formula: see text] = 1; representing a family group) and prey (narwhal, [Formula: see text] = 7) via satellite telemetry in Admiralty Inlet, a large fjord in the Eastern Canadian Arctic. Analyzing the movement data with a switching-state space model and a series of mixed effects models, we show that the presence of killer whales strongly alters the behavior and distribution of narwhal...
February 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28203032/icelandic-herring-eating-killer-whales-feed-at-night
#2
Gaëtan Richard, Olga A Filatova, Filipa I P Samarra, Ivan D Fedutin, Marc Lammers, Patrick J Miller
Herring-eating killer whales debilitate herring with underwater tail slaps and likely herd herring into tighter schools using a feeding-specific low-frequency pulsed call ('herding' call). Feeding on herring may be dependent upon daylight, as the whales use their white underside to help herd herring; however, feeding at night has not been investigated. The production of feeding-specific sounds provides an opportunity to use passive acoustic monitoring to investigate feeding behaviour at different times of day...
2017: Marine Biology
https://www.readbyqxmd.com/read/28126344/characterization-and-longitudinal-monitoring-of-serum-androgens-and-glucocorticoids-during-normal-pregnancy-in-the-killer-whale-orcinus-orca
#3
Todd R Robeck, Karen J Steinman, Justine K O'Brien
The secretory patterns of testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEA), cortisol (C), and corticosterone (Co) were characterized throughout 28 normal pregnancies until two-months post-partum in eleven killer whales. Effects of fetal sex, dam parity or age, and season were evaluated across either day post-conception (DPC), stage of pregnancy (PRE, EARLY, MID, LATE, POST) or indexed month post-conception (IMPC) using a mixed model linear regression with animal ID and pregnancy number as the random variables...
January 23, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28089514/reproductive-conflict-and-the-evolution-of-menopause-in-killer-whales
#4
Darren P Croft, Rufus A Johnstone, Samuel Ellis, Stuart Nattrass, Daniel W Franks, Lauren J N Brent, Sonia Mazzi, Kenneth C Balcomb, John K B Ford, Michael A Cant
Why females of some species cease ovulation prior to the end of their natural lifespan is a long-standing evolutionary puzzle [1-4]. The fitness benefits of post-reproductive helping could in principle select for menopause [1, 2, 5], but the magnitude of these benefits appears insufficient to explain the timing of menopause [6-8]. Recent theory suggests that the cost of inter-generational reproductive conflict between younger and older females of the same social unit is a critical missing term in classical inclusive fitness calculations (the "reproductive conflict hypothesis" [6, 9])...
January 23, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/27923044/killer-whale-orcinus-orca-predation-on-beaked-whales-mesoplodon-spp-in-the-bremer-sub-basin-western-australia
#5
Rebecca Wellard, Keith Lightbody, Leila Fouda, Michelle Blewitt, David Riggs, Christine Erbe
Observations of killer whales (Orcinus orca) feeding on the remains of beaked whales have been previously documented; however, to date, there has been no published account of killer whales actively preying upon beaked whales. This article describes the first field observations of killer whales interacting with, hunting and preying upon beaked whales (Mesoplodon spp.) on four separate occasions during 2014, 2015 and 2016 in the Bremer Sub-Basin, off the south coast of Western Australia.
2016: PloS One
https://www.readbyqxmd.com/read/27908079/using-line-acceleration-to-measure-false-killer-whale-pseudorca-crassidens-click-and-whistle-source-levels-during-pelagic-longline-depredation
#6
Aaron Thode, Lauren Wild, Janice Straley, Dustin Barnes, Ali Bayless, Victoria O'Connell, Erin Oleson, Jit Sarkar, Dan Falvey, Linda Behnken, Sean Martin
False killer whales (Pseudorca crassidens) depredate pelagic longlines in offshore Hawaiian waters. On January 28, 2015 a depredation event was recorded 14 m from an integrated GoPro camera, hydrophone, and accelerometer, revealing that false killer whales depredate bait and generate clicks and whistles under good visibility conditions. The act of plucking bait off a hook generated a distinctive 15 Hz line vibration. Two similar line vibrations detected at earlier times permitted the animal's range and thus signal source levels to be estimated over a 25-min window...
November 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27908070/physical-constraints-of-cultural-evolution-of-dialects-in-killer-whales
#7
Olga A Filatova, Filipa I P Samarra, Lance G Barrett-Lennard, Patrick J O Miller, John K B Ford, Harald Yurk, Craig O Matkin, Erich Hoyt
Odontocete sounds are produced by two pairs of phonic lips situated in soft nares below the blowhole; the right pair is larger and is more likely to produce clicks, while the left pair is more likely to produce whistles. This has important implications for the cultural evolution of delphinid sounds: the greater the physical constraints, the greater the probability of random convergence. In this paper the authors examine the call structure of eight killer whale populations to identify structural constraints and to determine if they are consistent among all populations...
November 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/27870149/development-of-sociality-and-emergence-of-independence-in-a-killer-whale-orcinus-orca-calf-from-birth-to-36-months
#8
Sara Guarino, Heather M Hill, Julie Sigman
Dolphin calves spend most of their time swimming with their mother immediately after birth. As they mature, the calves become increasingly independent, and begin to interact more often with other calves, juveniles, and sub-adults. For bottlenose dolphin calves, sociality is related to maternal behaviors. Unfortunately, much less is known about the development of sociality and emergence of independence for killer whale calves. The purpose of this study was to examine the developmental changes in social behaviors and solitary activities of a killer whale calf across a 36-month period...
January 2017: Zoo Biology
https://www.readbyqxmd.com/read/27804965/killer-whales-differentiating-in-geographic-sympatry-facilitated-by-divergent-behavioural-traditions
#9
A R Hoelzel, A E Moura
No abstract text is available yet for this article.
December 2016: Heredity
https://www.readbyqxmd.com/read/27770983/conservation-status-of-killer-whales-orcinus-orca-in-the-strait-of-gibraltar
#10
R Esteban, P Verborgh, P Gauffier, D Alarcón, J M Salazar-Sierra, J Giménez, A D Foote, R de Stephanis
Killer whales (Orcinus orca) in the Mediterranean Sea are currently restricted to the Strait of Gibraltar and surrounding waters. Thirty-nine individuals were present in 2011, with a well-differentiated social structure, organized into five pods. Killer whale occurrence in the Strait is apparently related to the migration of their main prey, Atlantic bluefin tuna (Thunnus thynnus). In spring, whale distribution was restricted to shallow waters off the western coast of the Strait where all pods were observed actively hunting tuna...
2016: Advances in Marine Biology
https://www.readbyqxmd.com/read/27770981/marine-mammals-in-the-mediterranean-sea-an-overview
#11
G Notarbartolo di Sciara
Despite being a small part of the world's oceans, the Mediterranean Sea hosts a diverse marine mammal fauna, with a total of 28 different species known to occur, or to have occurred, in the region. Species currently recognised as regular in the Mediterranean-the Mediterranean monk seal (Monachus monachus) and 11 cetaceans (fin whale, Balaenoptera physalus; sperm whale, Physeter macrocephalus; Cuvier's beaked whale, Ziphius cavirostris; short-beaked common dolphin, Delphinus delphis; long-finned pilot whale, Globicephala melas; Risso's dolphin, Grampus griseus; killer whale, Orcinus orca; striped dolphin, Stenella coeruleoalba; rough-toothed dolphin, Steno bredanensis; common bottlenose dolphin, Tursiops truncatus; harbour porpoise, Phocoena phocoena relicta) have adapted well to the region's environmental conditions, but their coexistence with humans is problematic...
2016: Advances in Marine Biology
https://www.readbyqxmd.com/read/27636553/androgen-and-glucocorticoid-production-in-the-male-killer-whale-orcinus-orca-influence-of-age-maturity-and-environmental-factors
#12
J K O'Brien, K J Steinman, G A Fetter, T R Robeck
Circulating concentrations of testosterone and its precursor androstenedione, as well as dehydroepiandrosterone (DHEA) and the adrenal hormones cortisol and corticosterone were measured at monthly intervals in 14 male killer whales (Orcinus orca) aged 0.8-38 years. Analyses were performed for examination of the relationships of age, sexual maturation status (STATUS), season, and environmental temperature (monthly air ambient temperature, A-TEMP) with hormone production using a mixed effects linear regression model with animal ID as the random variable...
January 2017: Andrology
https://www.readbyqxmd.com/read/27547372/dietary-habits-of-polar-bears-in-foxe-basin-canada-possible-evidence-of-a-trophic-regime-shift-mediated-by-a-new-top-predator
#13
Melissa P Galicia, Gregory W Thiemann, Markus G Dyck, Steven H Ferguson, Jeff W Higdon
Polar bear (Ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. In the Foxe Basin region of Nunavut, Canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. We used fatty acid analysis to examine polar bear feeding habits in Foxe Basin and thus potentially identify ecological factors contributing to population stability...
August 2016: Ecology and Evolution
https://www.readbyqxmd.com/read/27536700/comparative-in-silico-study-of-sex-determining-region-y-sry-protein-sequences-involved-in-sex-determining
#14
Masoume Vakili Azghandi, Mohammadreza Nasiri, Ali Shamsa, Mohsen Jalali, Mohammad Mahdi Shariati
BACKGROUND: The SRY gene (SRY) provides instructions for making a transcription factor called the sex-determining region Y protein. The sex-determining region Y protein causes a fetus to develop as a male. In this study, SRY of 15 spices included of human, chimpanzee, dog, pig, rat, cattle, buffalo, goat, sheep, horse, zebra, frog, urial, dolphin and killer whale were used for determine of bioinformatic differences. METHODS: Nucleotide sequences of SRY were retrieved from the NCBI databank...
April 2016: Reports of Biochemistry & Molecular Biology
https://www.readbyqxmd.com/read/27485668/genome-wide-snp-data-suggest-complex-ancestry-of-sympatric-north-pacific-killer-whale-ecotypes
#15
A D Foote, P A Morin
Three ecotypes of killer whale occur in partial sympatry in the North Pacific. Individuals assortatively mate within the same ecotype, resulting in correlated ecological and genetic differentiation. A key question is whether this pattern of evolutionary divergence is an example of incipient sympatric speciation from a single panmictic ancestral population, or whether sympatry could have resulted from multiple colonisations of the North Pacific and secondary contact between ecotypes. Here, we infer multilocus coalescent trees from >1000 nuclear single-nucleotide polymorphisms (SNPs) and find evidence of incomplete lineage sorting so that the genealogies of SNPs do not all conform to a single topology...
November 2016: Heredity
https://www.readbyqxmd.com/read/27401258/characterization-and-longitudinal-monitoring-of-serum-progestagens-and-estrogens-during-normal-pregnancy-in-the-killer-whale-orcinus-orca
#16
Todd R Robeck, Karen J Steinman, Justine K O'Brien
The secretory patterns of progestagens and estrogens were characterized throughout 28 normal pregnancies until two month post-partum in eleven killer whales. HPLC analysis of serum from different reproductive stages (luteal phase, EARLY, MID, and LATE pregnancy) identified three major immunoreactive progestagen peaks; progesterone (P4), 5α-pregnane-3,20-dione (5α-DHP) and pregnanediol, with 5α-DHP approximately half of that for P4 in the luteal phase, and EARLY, but approximately 2/3 of P4 during MID and LATE pregnancy...
September 15, 2016: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/27385756/the-significance-of-respiration-timing-in-the-energetics-estimates-of-free-ranging-killer-whales-orcinus-orca
#17
Marjoleine M H Roos, Gi-Mick Wu, Patrick J O Miller
Respiration rate has been used as an indicator of metabolic rate and associated cost of transport (COT) of free-ranging cetaceans, discounting potential respiration-by-respiration variation in O2 uptake. To investigate the influence of respiration timing on O2 uptake, we developed a dynamic model of O2 exchange and storage. Individual respiration events were revealed from kinematic data from 10 adult Norwegian herring-feeding killer whales (Orcinus orca) recorded with high-resolution tags (DTAGs). We compared fixed O2 uptake per respiration models with O2 uptake per respiration estimated through a simple 'broken-stick' O2-uptake function, in which O2 uptake was assumed to be the maximum possible O2 uptake when stores are depleted or maximum total body O2 store minus existing O2 store when stores are close to saturated...
July 1, 2016: Journal of Experimental Biology
https://www.readbyqxmd.com/read/27353529/disturbance-specific-social-responses-in-long-finned-pilot-whales-globicephala-melas
#18
Fleur Visser, Charlotte Curé, Petter H Kvadsheim, Frans-Peter A Lam, Peter L Tyack, Patrick J O Miller
Social interactions among animals can influence their response to disturbance. We investigated responses of long-finned pilot whales to killer whale sound playbacks and two anthropogenic sources of disturbance: tagging effort and naval sonar exposure. The acoustic scene and diving behaviour of tagged individuals were recorded along with the social behaviour of their groups. All three disturbance types resulted in larger group sizes, increasing social cohesion during disturbance. However, the nature and magnitude of other responses differed between disturbance types...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27282468/nearby-grandmother-enhances-calf-survival-and-reproduction-in-asian-elephants
#19
Mirkka Lahdenperä, Khyne U Mar, Virpi Lummaa
Usually animals reproduce into old age, but a few species such as humans and killer whales can live decades after their last reproduction. The grandmother hypothesis proposes that such life-history evolved through older females switching to invest in their existing (grand)offspring, thereby increasing their inclusive fitness and selection for post-reproductive lifespan. However, positive grandmother effects are also found in non-menopausal taxa, but evidence of their associated fitness effects is rare and only a few tests of the hypothesis in such species exist...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27269787/longitudinal-evaluation-of-leukocyte-transcripts-in-killer-whales-orcinus-orca
#20
Tatjana Sitt, Lizabeth Bowen, Chia-Shan Lee, Myra T Blanchard, James McBain, Christopher Dold, Jeffrey L Stott
Early identification of illness and/or presence of environmental and/or social stressors in free-ranging and domestic cetaceans is a priority for marine mammal health care professionals. Incorporation of leukocyte gene transcript analysis into the diagnostic tool kit has the potential to augment classical diagnostics based upon ease of sample storage and shipment, inducible nature and well-defined roles of transcription and associated downstream actions. Development of biomarkers that could serve to identify "insults" and potentially differentiate disease etiology would be of great diagnostic value...
July 2016: Veterinary Immunology and Immunopathology
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