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https://www.readbyqxmd.com/read/28273531/a-rapid-analytical-method-to-quantify-complex-organohalogen-contaminant-mixtures-in-large-samples-of-high-lipid-mammalian-tissues
#1
Jean-Pierre Desforges, Igor Eulaers, Luke Periard, Christian Sonne, Rune Dietz, Robert J Letcher
In vitro investigations of the health impact of individual chemical compounds have traditionally been used in risk assessments. However, humans and wildlife are exposed to a plethora of potentially harmful chemicals, including organohalogen contaminants (OHCs). An alternative exposure approach to individual or simple mixtures of synthetic OHCs is to isolate the complex mixture present in free-ranging wildlife, often non-destructively sampled from lipid rich adipose. High concentration stock volumes required for in vitro investigations do, however, pose a great analytical challenge to extract sufficient amounts of complex OHC cocktails...
February 24, 2017: Chemosphere
https://www.readbyqxmd.com/read/28239473/fine-scale-foraging-movements-by-fish-eating-killer-whales-orcinus-orca-relate-to-the-vertical-distributions-and-escape-responses-of-salmonid-prey-oncorhynchus-spp
#2
Brianna M Wright, John K B Ford, Graeme M Ellis, Volker B Deecke, Ari Daniel Shapiro, Brian C Battaile, Andrew W Trites
BACKGROUND: We sought to quantitatively describe the fine-scale foraging behavior of northern resident killer whales (Orcinus orca), a population of fish-eating killer whales that feeds almost exclusively on Pacific salmon (Oncorhynchus spp.). To reconstruct the underwater movements of these specialist predators, we deployed 34 biologging Dtags on 32 individuals and collected high-resolution, three-dimensional accelerometry and acoustic data. We used the resulting dive paths to compare killer whale foraging behavior to the distributions of different salmonid prey species...
2017: Movement Ecology
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/27923044/killer-whale-orcinus-orca-predation-on-beaked-whales-mesoplodon-spp-in-the-bremer-sub-basin-western-australia
#4
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/27870149/development-of-sociality-and-emergence-of-independence-in-a-killer-whale-orcinus-orca-calf-from-birth-to-36-months
#5
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/27770983/conservation-status-of-killer-whales-orcinus-orca-in-the-strait-of-gibraltar
#6
REVIEW
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
#7
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
#8
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
#9
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
#10
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/27401258/characterization-and-longitudinal-monitoring-of-serum-progestagens-and-estrogens-during-normal-pregnancy-in-the-killer-whale-orcinus-orca
#11
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
#12
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/27269787/longitudinal-evaluation-of-leukocyte-transcripts-in-killer-whales-orcinus-orca
#13
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
https://www.readbyqxmd.com/read/27229472/separating-underwater-ambient-noise-from-flow-noise-recorded-on-stereo-acoustic-tags-attached-to-marine-mammals
#14
Alexander M von Benda-Beckmann, Paul J Wensveen, Filipa I P Samarra, S Peter Beerens, Patrick J O Miller
Sound-recording acoustic tags attached to marine animals are commonly used in behavioural studies. Measuring ambient noise is of interest to efforts to understand responses of marine mammals to anthropogenic underwater sound, or to assess their communication space. Noise of water flowing around the tag reflects the speed of the animal, but hinders ambient noise measurement. Here, we describe a correlation-based method for stereo acoustic tags to separate the relative contributions of flow and ambient noise...
August 1, 2016: Journal of Experimental Biology
https://www.readbyqxmd.com/read/27119362/neuroanatomy-of-the-killer-whale-orcinus-orca-a-magnetic-resonance-imaging-investigation-of-structure-with-insights-on-function-and-evolution
#15
Alexandra Wright, Miriam Scadeng, Dominik Stec, Rebecca Dubowitz, Sam Ridgway, Judy St Leger
The evolutionary process of adaptation to an obligatory aquatic existence dramatically modified cetacean brain structure and function. The brain of the killer whale (Orcinus orca) may be the largest of all taxa supporting a panoply of cognitive, sensory, and sensorimotor abilities. Despite this, examination of the O. orca brain has been limited in scope resulting in significant deficits in knowledge concerning its structure and function. The present study aims to describe the neural organization and potential function of the O...
April 27, 2016: Brain Structure & Function
https://www.readbyqxmd.com/read/27039511/sperm-whales-reduce-foraging-effort-during-exposure-to-1-2-khz-sonar-and-killer-whale-sounds
#16
Saana Isojunno, Charlotte Cure, Petter Helgevold Kvadsheim, Frans-Peter Alexander Lam, Peter Lloyd Tyack, Paul Jacobus Wensveen, Patrick James O'Malley Miller
The time and energetic costs of behavioral responses to incidental and experimental sonar exposures, as well as control stimuli, were quantified using hidden state analysis of time series of acoustic and movement data recorded by tags (DTAG) attached to 12 sperm whales (Physeter macrocephalus) using suction cups. Behavioral state transition modeling showed that tagged whales switched to a non-foraging, non-resting state during both experimental transmissions of low-frequency active sonar from an approaching vessel (LFAS; 1-2 kHz, source level 214 dB re 1 µPa m, four tag records) and playbacks of potential predator (killer whale, Orcinus orca) sounds broadcast at naturally occurring sound levels as a positive control from a drifting boat (five tag records)...
January 2016: Ecological Applications: a Publication of the Ecological Society of America
https://www.readbyqxmd.com/read/27036251/low-frequency-signals-produced-by-northeast-atlantic-killer-whales-orcinus-orca
#17
Filipa I P Samarra, Volker B Deecke, Patrick J O Miller
Killer whale acoustic behavior has been extensively investigated; however, most studies have focused on pulsed calls and whistles. This study reports the production of low-frequency signals by killer whales at frequencies below 300 Hz. Recordings were made in Iceland and Norway when killer whales were observed feeding on herring and no other marine mammal species were nearby. Low-frequency sounds were identified in Iceland and ranged in duration between 0.14 and 2.77 s and in frequency between 50 and 270 Hz, well below the previously reported lower limit for killer whale tonal sounds of 500 Hz...
March 2016: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/26937049/comparisons-of-life-history-parameters-between-free-ranging-and-captive-killer-whale-orcinus-orca-populations-for-application-toward-species-management
#18
Todd R Robeck, Kevin Willis, Michael R Scarpuzzi, Justine K O'Brien
Data collected on life-history parameters of known-age animals from the northern (NR) and southern resident (SR) killer whales (Orcinus orca) of the eastern North Pacific were compared with life-history traits of killer whales located at SeaWorld (SEA) facilities. For captive-born SEA animals, mean age and body length at 1st estrus was 7.5 years and 483.7cm, respectively. Estimated mean age at 1st conception was different (P < 0.001) for the combined data from both northern and southern resident (NSR) free-ranging populations (12...
September 29, 2015: Journal of Mammalogy
https://www.readbyqxmd.com/read/26735849/estimation-of-a-killer-whale-orcinus-orca-population-s-diet-using-sequencing-analysis-of-dna-from-feces
#19
Michael J Ford, Jennifer Hempelmann, M Bradley Hanson, Katherine L Ayres, Robin W Baird, Candice K Emmons, Jessica I Lundin, Gregory S Schorr, Samuel K Wasser, Linda K Park
Estimating diet composition is important for understanding interactions between predators and prey and thus illuminating ecosystem function. The diet of many species, however, is difficult to observe directly. Genetic analysis of fecal material collected in the field is therefore a useful tool for gaining insight into wild animal diets. In this study, we used high-throughput DNA sequencing to quantitatively estimate the diet composition of an endangered population of wild killer whales (Orcinus orca) in their summer range in the Salish Sea...
2016: PloS One
https://www.readbyqxmd.com/read/26629916/the-relationship-between-vessel-traffic-and-noise-levels-received-by-killer-whales-orcinus-orca
#20
Juliana Houghton, Marla M Holt, Deborah A Giles, M Bradley Hanson, Candice K Emmons, Jeffrey T Hogan, Trevor A Branch, Glenn R VanBlaricom
Whale watching has become increasingly popular as an ecotourism activity around the globe and is beneficial for environmental education and local economies. Southern Resident killer whales (Orcinus orca) comprise an endangered population that is frequently observed by a large whale watching fleet in the inland waters of Washington state and British Columbia. One of the factors identified as a risk to recovery for the population is the effect of vessels and associated noise. An examination of the effects of vessels and associated noise on whale behavior utilized novel equipment to address limitations of previous studies...
2015: PloS One
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