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1.
PLoS One ; 15(7): e0236749, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730308

RESUMO

Each resident-type (R-type) killer whale pod has a set of stereotyped calls that are culturally transmitted from mother to offspring. The functions of particular call types are not yet clearly understood, but it is believed that calls with two independently modulated frequency components (biphonic calls) play an important role in pod communication and cohesion at long ranges. In this study we examined the possible functions of biphonic calls in R-type killer whales. First, we tested the hypothesis that the additional component enhances the potential of a call to identify the family affiliation. We found that the similarity patterns of the lower- and higher frequency components across the families were largely unrelated. Calls were classified more accurately to their respective family when both lower- and higher-frequency components were considered. Second, we tested the long-range detectability of the lower- and higher-frequency components. After adjusting the received levels by the killer whale hearing sensitivity to different frequency ranges, the sensation level of the higher-frequency component was higher than the amplitude of the lower-frequency component. Our results suggest that the higher-frequency component of killer whale biphonic calls varies independently of the lower-frequency component, which enhances the efficiency of these calls as family markers. The acoustic variation of the higher-frequency component allows the recognition of family identity of a caller even if the shape of the lower-frequency component accidentally becomes similar in unrelated families. The higher-frequency component can also facilitate family recognition when the lower-frequency component is masked by low-frequency noise.


Assuntos
Acústica , Reconhecimento Psicológico , Comportamento Social , Comportamento Estereotipado/fisiologia , Vocalização Animal/fisiologia , Orca/fisiologia , Animais , Feminino , Mães , Ruído
2.
Proc Natl Acad Sci U S A ; 117(12): 6590-6598, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32152110

RESUMO

The effects of predator intimidation on habitat use and behavior of prey species are rarely quantified for large marine vertebrates over ecologically relevant scales. Using state space movement models followed by a series of step selection functions, we analyzed movement data of concurrently tracked prey, bowhead whales (Balaena mysticetus; n = 7), and predator, killer whales (Orcinus orca; n = 3), in a large (63,000 km2), partially ice-covered gulf in the Canadian Arctic. Our analysis revealed pronounced predator-mediated shifts in prey habitat use and behavior over much larger spatiotemporal scales than previously documented in any marine or terrestrial ecosystem. The striking shift from use of open water (predator-free) to dense sea ice and shorelines (predators present) was exhibited gulf-wide by all tracked bowheads during the entire 3-wk period killer whales were present, constituting a nonconsumptive effect (NCE) with unknown energetic or fitness costs. Sea ice is considered quintessential habitat for bowhead whales, and ice-covered areas have frequently been interpreted as preferred bowhead foraging habitat in analyses that have not assessed predator effects. Given the NCEs of apex predators demonstrated here, however, unbiased assessment of habitat use and distribution of bowhead whales and many marine species may not be possible without explicitly incorporating spatiotemporal distribution of predation risk. The apparent use of sea ice as a predator refuge also has implications for how bowhead whales, and likely other ice-associated Arctic marine mammals, will cope with changes in Arctic sea ice dynamics as historically ice-covered areas become increasingly ice-free during summer.


Assuntos
Baleia Franca/fisiologia , Ecossistema , Camada de Gelo , Orca/fisiologia , Animais , Regiões Árticas , Canadá , Biologia Marinha , Modelos Biológicos , Dinâmica Populacional , Comportamento Predatório
3.
Sci Total Environ ; 722: 137776, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32199362

RESUMO

Organochlorine (OC) profiles have been used as chemical "fingerprints" to infer an animal's foraging area. North Pacific killer whale (Orcinus orca) populations are exposed to different levels and patterns of OCs based on their prey, distribution, and amount of time spent in a particular area. To characterize concentrations and profiles of OCs found in various populations of North Pacific killer whales, polychlorinated biphenyls (PCBs), including dioxin-like congeners, DDTs, and hexachlorobenzene (HCB), were measured in biopsy blubber samples of photo-identified resident (fish-eating) and transient (mammal-eating) killer whales collected from 1994 through 2002 from Russian Far East waters to the waters of the west coast of the United States, representing 10 populations. We compared blubber OC concentrations based on ecotype (resident vs. transient), sex and reproductive maturity, and geographic area. We also examined OC mixtures to determine if we could detect segregated geographical areas (foraging areas) among the six populations with sufficient sample sizes. Transients had significantly higher OC concentrations than residents and adult male whales had consistently higher OC levels compared to adult females, regardless of ecotype. Our OC profile findings indicate segregated foraging areas for the North Pacific killer whales, consistent with observations of their geographic distributions. Several potential health risks have also been associated with exposure to high levels of contaminants in top-level predators including reproductive impairment, immune suppression, skeletal deformities, and carcinoma. The results of this baseline study provide information on the geographic distribution of OCs found in North Pacific killer whales, results which are crucial for assessing the potential health risks associated with OC exposure in this species.


Assuntos
Orca , Animais , Monitoramento Ambiental , Extremo Oriente , Feminino , Masculino , Bifenilos Policlorados , Federação Russa , Poluentes Químicos da Água
4.
Mar Pollut Bull ; 151: 110699, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31780087

RESUMO

Bio-accumulation of persistent organic pollutants including polychlorinated biphenyls (PCBs), brominated flame retardants and organochlorine pesticides continue to be of major concern for marine apex predators such as killer whales. The concentrations of 16 polychlorinated biphenyls, 7 poly-brominated diphenyl ethers (PBDEs), 1 poly-brominated biphenyl (PBB) and a range of 19 organochlorine compounds (OCs) was investigated in blubber samples from a mother-foetus pair, an adult female and an adult male killer whale stranded in Ireland between 2010 and 2017. Concentrations ranged from 1.5 mg/kg to 49.3 mg/kg lipid weight and 0.04-1.2 mg/kg lipid weight for Σ16PCBs and Σ7PBDEs respectively. Concentrations of organochlorine compounds were also investigated in the male killer whale; a Σ19OC concentration of 49.4 mg/kg lipid weight was recorded. This study shows high levels of persistent organic pollutants occur in this species of whales stranded in Ireland.


Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água/metabolismo , Orca/metabolismo , Animais , Feminino , Feto , Éteres Difenil Halogenados/metabolismo , Irlanda , Masculino , Bifenilos Policlorados/metabolismo
5.
Gen Comp Endocrinol ; 285: 113273, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31525377

RESUMO

There exists a surprising diversity in the physiology and endocrinology of pregnancy among mammals in both the source (luteal/placental) and metabolism of progesterone. To evaluate the possible diversity of steroid metabolism within toothed cetaceans, we investigated 5α-reduced progesterone metabolites and androgens in cyclic (luteal phase) and pregnant captive killer whales, belugas and bottlenose dolphins (n = 5/species) bled longitudinally in early, mid- and late pregnancy (0.16, 0.50 and 0.85 fractions of 535, 464 and 380 gestation days, respectively). Mid-luteal samples were also collected. Serum was analyzed by liquid chromatography tandem-mass spectrometry as previously validated for (among others) progesterone, 20αOH-progesterone (20αOHP), 5α-dihydroprogesterone (DHP), several additional 5α-reduced metabolites and androgens (dehydroepiandrosterone, androstenedione and testosterone). The predominant mid-luteal pregnanes were: progesterone, belugas; progesterone and 20αOHP, dolphins; allopregnanolone (3α-DHP) and progesterone, killer whales. Progesterone was 2-4-fold higher in early pregnancy than mid-luteal samples but decreased thereafter. The predominant metabolite, 3ß,20α-dihydroprogesterone (3ß,20α-DHP; 40-80 ng/ml) was higher in mid- and late-than early gestation in all 3 species. Concentrations of 20αOHP and 3ß,20α-DHP were similar at mid-gestation but 20αOHP declined in late-gestation in killer whales, and 20αOHP was lower than 3ß,20α-DHP in belugas and dolphins throughout gestation. Other 5α-reduced metabolites, DHP, 3α-DHP and 20α-DHP, were far lower throughout pregnancy (<10 ng/ml). DHP and 3α-DHP decreased from early to mid-gestation in belugas, but changed little in killer whales and dolphins. These data suggest that progesterone metabolism is relatively conserved among these cetacean species. As in equine pregnancies, 3ß,20α-DHP is the major metabolite, increasing at the expense of progesterone as pregnancy progresses. Androstenedione and testosterone also increased detectably in mid- to late-gestation in these species. The tissue source remains unknown, but progesterone metabolism during gestation in these cetaceans is similar to horses and, together with androgens, may be reliable biomarkers of pregnancy.


Assuntos
Beluga/sangue , Golfinho Nariz-de-Garrafa/sangue , Cromatografia Líquida/métodos , Esteroides/sangue , Espectrometria de Massas em Tandem/métodos , Orca/sangue , Animais , Feminino , Gravidez , Pregnanos/sangue , Progesterona/sangue , Progesterona/metabolismo
6.
PLoS One ; 14(12): e0226206, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31841529

RESUMO

Since the work of Tower in the 1950s, we have come to expect lower neuron density in the cerebral cortex of larger brains. We studied dolphin brains varying from 783 to 6215g. As expected, average neuron density in four areas of cortex decreased from the smallest to the largest brain. Despite having a lower neuron density than smaller dolphins, the killer whale has more gray matter and more cortical neurons than any mammal, including humans. To begin a study of non-dolphin toothed whales, we measured a 596g brain of a pygmy sperm whale and a 2004g brain of a Cuvier's beaked whale. We compared neuron density of Nissl stained cortex of these two brains with those of the dolphins. Non-dolphin brains had lower neuron densities compared to all of the dolphins, even the 6215g brain. The beaked whale and pygmy sperm whale we studied dive deeper and for much longer periods than the dolphins. For example, the beaked whale may dive for more than an hour, and the pygmy sperm whale more than a half hour. In contrast, the dolphins we studied limit dives to five or 10 minutes. Brain metabolism may be one feature limiting dolphin dives. The brain consumes an oversized share of oxygen available to the body. The most oxygen is used by the cortex and cerebellar gray matter. The dolphins have larger brains, larger cerebellums, and greater numbers of cortex neurons than would be expected given their body size. Smaller brains, smaller cerebellums and fewer cortical neurons potentially allow the beaked whale and pygmy sperm whale to dive longer and deeper than the dolphins. Although more gray matter, more neurons, and a larger cerebellum may limit dolphins to shorter, shallower dives, these features must give them some advantage. For example, they may be able to catch more elusive individual high-calorie prey in the upper ocean.


Assuntos
Cerebelo/anatomia & histologia , Córtex Cerebral/patologia , Mergulho/fisiologia , Golfinhos/fisiologia , Neurônios/patologia , Baleias/fisiologia , Animais , Autopsia/veterinária , Mapeamento Encefálico/veterinária , Contagem de Células , Cerebelo/patologia , Golfinhos/anatomia & histologia , Tamanho do Órgão , Tomografia por Emissão de Pósitrons/veterinária , Fatores de Tempo , Orca/anatomia & histologia , Orca/fisiologia , Baleias/anatomia & histologia
7.
Mar Pollut Bull ; 149: 110593, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31550574

RESUMO

Exposure to persistent organic pollutants (POPs) is a key factor in predicting the collapse of global killer whale (Orcinus orca) populations due to reproductive and immune impacts. Blubber biopsies from killer whales (n = 25) were collected in the Russian Far East in 2002-2004. Biopsies were analyzed for ΣDDT, ΣPCB, and HCB concentrations. A subset of biopsies was further examined for additional contaminants, ΣPBDE, ΣHCH, ΣCHLD, mirex, and dieldrin. Mean concentrations were compared across resident (fish-eating) and transient (mammal-eating) ecotypes and between sexes. ΣPCB analytes (resident males 18,000, resident females 1200, and transient males 420,000 ng g-1 lw) and HCB (resident males 750, resident females 81, and transient males 6200 ng g-1 lw) differed significantly (p < 0.001). No significant difference was observed between sexes. Notable disparities in contaminant levels between ecotypes support the major toxicological theories of contaminant bioaccumulation and dietary impacts on individual contaminant load.


Assuntos
Tecido Adiposo/química , Poluentes Químicos da Água/análise , Orca , Animais , Diclorodifenil Dicloroetileno/análise , Exposição Ambiental , Monitoramento Ambiental , Feminino , Éteres Difenil Halogenados/análise , Hidrocarbonetos Clorados/análise , Masculino , Praguicidas/análise , Bifenilos Policlorados/análise , Federação Russa
8.
Environ Res ; 177: 108602, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31398560

RESUMO

We quantified blubber concentrations of vitamins A (retinol) and E (α-tocopherol) and evaluated associations with persistent organic pollutants (ΣPOPs) in 14 highly-contaminated killer whales (Orcinus orca) sampled in Greenland from 2012 to 2014. We considered the influence of blubber depth, sex/age class and diet (based on biomass % of major fatty acids) in these relationships. Blubber concentrations of vitamin A averaged 34.1 ±â€¯4.7 µg g-1 wet weight (ww) and vitamin E averaged 35.6 ±â€¯4.4 µg g-1 ww. Although overall vitamin A concentrations did not vary between inner (closer to the muscle) and outer (closer to the skin) blubber layer or between sub-adults and adult females, concentrations in the outer layer of sub-adults were lower compared to the outer layer of adult females (p = 0.03). Outer layer may therefore reflect age accumulation of vitamin A, while in the more active inner layer, age effects might be masked by metabolic needs such as lactation. Neither diet nor ΣPOPs affected vitamin A variation, suggesting this vitamin is highly regulated in the body. Given the high exposures in these killer whales, vitamin A might not be a sensitive biomarker for POPs adverse effects. Vitamin E concentrations were significantly higher in inner compared to outer layer (p < 0.001), likely associated with blubber composition, suggesting that biopsies may not fully represent vitamin E concentrations in blubber. Age-accumulation of vitamin E also occurred with higher concentrations in adult females compared to sub-adults, independent of blubber depth (p < 0.01). Diet, ΣPOPs, and an interaction between these two variables significantly affected vitamin E variation in inner blubber, explaining 91% of this variation. The negative relationship between ΣPOPs (especially Σdichlorodiphenyltrichloroethane (DDT) and Σchlordanes in outer layers) and vitamin E was observed only in killer whales with a diet poorer in polyunsaturated fatty acids, suggested that killer whales feeding more consistently on marine mammals in Arctic environments over a fish-based diet, may be at higher risk of POP-induced disruption in vitamin E homeostasis. Considering diet is therefore important to understand the potential effects of elevated contaminant exposures on levels of certain essential nutrients, i.e., vitamin E, in killer whales.


Assuntos
Ácidos Graxos/metabolismo , Vitamina A/metabolismo , Vitamina E/metabolismo , Poluentes Químicos da Água/metabolismo , Orca/metabolismo , Tecido Adiposo/metabolismo , Animais , Monitoramento Ambiental , Feminino , Groenlândia , Vitaminas
9.
J Therm Biol ; 84: 292-310, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466767

RESUMO

There is currently a growing interest in the area of drag reduction. In this work, the thermal effects of body color of some species of aquatics like Orcas and Dusky dolphins are investigated with respect to their swimming routes and geometric and behavioral characteristics. Considering the marine and atmospheric characteristics of these aquatics' routes, a thermal analysis is performed. The surrounding fluxes including the water flux, sun irradiation, and core temperature are considered in an energy balance to determine the skin temperature of the top side of the animal/organism's body. To study the effects of color on the surface temperature of the aquatic species, an experiment is carried out in the water on a flat plate with black and white color. Applying a turbulent analytical solution for heated boundary layers, it will be shown that the black color on the top of the bodies of these marine organisms is very efficient in terms of skin drag reduction. Moreover, to investigate the effects of the temperature on underwater skin friction drag reduction, the turbulent flow is simulated around a flat plate and a 2- dimensional modeled Killer whale at different temperatures. The results show that the top black body color of Orca and Dusky dolphin decreases their skin friction drag by 7%. This study will also provide the reason for this evolution of color scheme of other extremely fast marine animals, such as billfish, whales, and sharks. This method of drag reduction can be considered as one of the effective factors in skin drag reduction of underwater robots.


Assuntos
Golfinhos/fisiologia , Peixes/fisiologia , Pigmentação da Pele , Temperatura Cutânea , Natação , Orca/fisiologia , Animais
10.
Anim Cogn ; 22(5): 863-882, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31230140

RESUMO

Killer whales (KW) may be predators or competitors of other cetaceans. Since their foraging behavior and acoustics differ among populations ('ecotypes'), we hypothesized that other cetaceans can eavesdrop on KW sounds and adjust their behavior according to the KW ecotype. We performed playback experiments on long-finned pilot whales (Globicephala melas) in Norway using familiar fish-eating KW sounds (fKW) simulating a sympatric population that might compete for foraging areas, unfamiliar mammal-eating KW sounds (mKW) simulating a potential predator threat, and two control sounds. We assessed behavioral responses using animal-borne multi-sensor tags and surface visual observations. Pilot whales barely changed behavior to a broadband noise (CTRL-), whereas they were attracted and exhibited spyhops to fKW, mKW, and to a repeated-tonal upsweep signal (CTRL+). Whales never stopped nor started feeding in response to fKW, whereas they reduced or stopped foraging to mKW and CTRL+. Moreover, pilot whales joined other subgroups in response to fKW and CTRL+, whereas they tightened individual spacing within group and reduced time at surface in response to mKW. Typical active intimidation behavior displayed to fKW might be an antipredator strategy to a known low-risk ecotype or alternatively a way of securing the habitat exploited by a heterospecific sympatric population. Cessation of feeding and more cohesive approach to mKW playbacks might reflect an antipredator behavior towards an unknown KW ecotype of potentially higher risk. We conclude that pilot whales are able to acoustically discriminate between familiar and unfamiliar KW ecotypes, enabling them to adjust their behavior according to the perceived disturbance type.


Assuntos
Percepção Auditiva , Aprendizagem por Discriminação , Ecótipo , Baleia Comum , Vocalização Animal , Orca , Baleias Piloto , Acústica , Animais , Baleia Comum/psicologia , Peixes , Som , Espectrografia do Som , Orca/psicologia
11.
Zoo Biol ; 38(4): 323-333, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31215081

RESUMO

The management of socially complex species in captivity is challenging. Research on their social behavior improves our understanding of interactions in captive animals and captive-group management. We conducted a detailed analysis of social relationships shown by the orcas kept at Loro Parque zoo and their tendency to reconcile after aggressive episodes. Affiliative interactions were the most frequent social activities compared to agonistic or sexual interactions. Within affiliative behaviors, we documented the pattern "gentle tongue bite", where an animal touches the other's tongue with his teeth but does not bite it. Affiliative interactions between a specific pair of orcas occurred significantly more often than expected by chance, and together with low levels of agonistic interactions, indicated particular affinity between some individuals. The most frequently observed low-level agonistic relationship was that of the two older males (Tekoa-Keto); however, they also showed frequent sexual and affiliative interactions. Sexual-like behaviors (pursuit, mount, and penis between males) were found in both sexes. Finally, the observed corrected conciliatory tendency (31.57%) was within the range described for other primate and cetacean species. This study provides a systematic way to assess social interactions as well as conflict management strategies in cetaceans housed in zoos and zoo-like facilities and may help to improve animal welfare and management of animals in controlled environments.


Assuntos
Comportamento Animal/fisiologia , Comportamento Social , Orca/fisiologia , Animais , Animais de Zoológico , Feminino , Masculino , Orca/psicologia
12.
Proc Natl Acad Sci U S A ; 116(24): 11812-11817, 2019 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-31110009

RESUMO

In highly social top predators, group living is an ecological strategy that enhances individual fitness, primarily through increased foraging success. Additive mortality events across multiple social groups in populations may affect the social structure, and therefore the fitness, of surviving individuals. This hypothesis was examined in a killer whale (Orcinus orca) population that experienced a 7-y period of severe additive mortality due to lethal interactions with illegal fishing vessels. Using both social and demographic analyses conducted on a unique long-term dataset encompassing periods before, during, and after this event, results indicated a decrease in both the number and the mean strength of associations of surviving individuals during the additive mortality period. A positive significant correlation between association strength and apparent survival suggested that the fitness of surviving individuals was impacted by the additive mortality event. After this event, individuals responded to the loss of relatives in their social groups by associating with a greater number of other social groups, likely to maintain a functional group size that maximized their foraging success. However, these associations were loose; individuals did not reassociate in highly stable social groups, and their survival remained low years after the mortality event. These findings demonstrate how the disruption of social structure in killer whales may lead to prolonged negative effects of demographic stress beyond an additive mortality event. More importantly, this study shows that sociality has a key role in the resilience of populations to human-induced mortality; this has major implications for the conservation of highly social and long-lived species.


Assuntos
Comportamento Animal/fisiologia , Orca/fisiologia , Animais , Ecossistema , Comportamento Social
13.
Dis Aquat Organ ; 134(3): 209-213, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31120038

RESUMO

An immature killer whale Orcinus orca found dead on the southeastern Brazilian coast had multiple bone proliferations: on the skull, vertebrae, hemal arches, and ribs. The bony formations were characterized as multiple osteochondromas, as defined by osteochondromatosis. The diagnosis was based on macroscopic and radiographic observations. These benign osseocartilaginous tumors affect young individuals and grow until skeletal maturity is achieved. Case reports of this condition, besides humans, include other mammals, with most reports for pets and domestic mammals such as cattle, and a report in a fossil canid (Hesperocyon) from the Oligocene. The etiology, diagnosis, developmental characteristics, and occurrence of osteochondromas are distinct among different species. This report describes the first case of multiple osteochondromas in a wild cetacean.


Assuntos
Exostose Múltipla Hereditária , Osteocondromatose , Orca , Animais , Brasil , Bovinos , Exostose Múltipla Hereditária/veterinária , Osteocondromatose/veterinária
14.
J Comp Pathol ; 168: 35-40, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31103057

RESUMO

A mature, adult female, offshore killer whale (Orcinus orca) was stranded deceased in Portage Bay, Alaska, in October 2015. Full necropsy examination with histopathology was performed. Consistent with previous studies of offshore killer whales, and thought to be a result of their unique elasmobranch diet, all the teeth were significantly abraded and almost flush with the gingival margin. Age was estimated at 30-35 years based on annuli and growth arrest lines in a remaining tooth. The dentate portion of the mandibles were excised en bloc and frozen until imaging could be completed. Radiography and computed tomography revealed lesions consistent with severe abrasion, pulp exposure and evidence of endodontic and/or periodontal disease in nine of the 15 mandibular teeth present (60.0%). Only five (33.3%) teeth were suspected to have been vital at the time of death based on imaging. Lesions were more severe rostrally, with the caudal teeth less affected. Autolysis precluded gingival histopathology and no teeth were analyzed histologically. Necropsy examination revealed a likely multifactorial cause of death, with most significant lesions including the severe chronic periodontal/endodontic disease with abrasion, inanition and emaciation with possible cardiovascular disease. This case highlights the importance of imaging in evaluating periodontal and endodontic status, especially post mortem when other tissues are no longer available, and demonstrates that periodontal and endodontic disease occur naturally in this species and can be a significant cause of morbidity in mature free-ranging killer whales of the offshore ecotype.


Assuntos
Mandíbula/patologia , Doenças Periodontais/veterinária , Doenças Dentárias/veterinária , Orca , Animais , Feminino , Tomografia Computadorizada por Raios X
15.
J Exp Biol ; 222(Pt 3)2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718292

RESUMO

Studies of odontocete foraging ecology have been limited by the challenges of observing prey capture events and outcomes underwater. We sought to determine whether subsurface movement behavior recorded from archival tags could accurately identify foraging events by fish-eating killer whales. We used multisensor bio-logging tags attached by suction cups to Southern Resident killer whales (Orcinus orca) to: (1) identify a stereotyped movement signature that co-occurred with visually confirmed prey capture dives; (2) construct a prey capture dive detector and validate it against acoustically confirmed prey capture dives; and (3) demonstrate the utility of the detector by testing hypotheses about foraging ecology. Predation events were significantly predicted by peaks in the rate of change of acceleration ('jerk peak'), roll angle and heading variance. Detection of prey capture dives by movement signatures enabled substantially more dives to be included in subsequent analyses compared with previous surface or acoustic detection methods. Males made significantly more prey capture dives than females and more dives to the depth of their preferred prey, Chinook salmon. Additionally, only half of the tag deployments on females (5 out of 10) included a prey capture dive, whereas all tag deployments on males exhibited at least one prey capture dive (12 out of 12). This dual approach of kinematic detection of prey capture coupled with hypothesis testing can be applied across odontocetes and other marine predators to investigate the impacts of social, environmental and anthropogenic factors on foraging ecology.


Assuntos
Etologia/métodos , Comportamento Predatório , Orca/fisiologia , Animais , Fenômenos Biomecânicos , Etologia/instrumentação , Feminino , Masculino , Fatores Sexuais , Washington
16.
Climacteric ; 22(2): 111-116, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30712396

RESUMO

The females of most species die soon after ceasing to reproduce, their purpose in life being to ensure survival of their kin. Human females may live more than one-third of their lives after they cease to reproduce, a property shared by few species, one of which is Orca whales. Orcas have been extensively studied because families live together in stable units or pods and individual whales have distinctive markings, enabling them to be identified. The females survive long after the menopause, one possible reason for this being that the older females provide a survival advantage since they are seen to lead the pods more often than younger females or males, thus providing a survival advantage in times of food shortage. The female lifespan is increasing in most countries worldwide, principally due to decreased infection and maternal mortality. Women are now more active through middle and into older age. Whatever sort of life they wish to lead, women need to be as fit as possible to facilitate healthy aging. Chronic diseases that affect millions of women are cardiovascular disease, osteoporosis, cancer, and dementia. The incidence of all these is increased by obesity, the prevention of which is a major challenge in our society. Hormone therapy may have a place for some women but for many others taking control of their health by lifestyle intervention is a major contributor to disease prevention. It is our duty as doctors to encourage this at every opportunity to help all women live a fruitful and healthy old age.


Assuntos
Envelhecimento Saudável/fisiologia , Menopausa/fisiologia , Idoso , Idoso de 80 Anos ou mais , Animais , Comportamento Animal/fisiologia , Doenças Cardiovasculares/epidemiologia , Terapia de Reposição de Estrogênios , Feminino , Avós , Humanos , Longevidade , Síndrome Metabólica/epidemiologia , Obesidade/epidemiologia , Reprodução/fisiologia , Orca/fisiologia
17.
Vet Clin Pathol ; 48(1): 100-113, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30676655

RESUMO

BACKGROUND: The effects of sex, age, and season on blood analyte concentrations have not been investigated for the killer whale (Orcinus orca). Defining these changes provides background data for improving the care of managed populations and defines normal changes that could occur in wild counterparts. OBJECTIVES: We aimed to define hematologic and serum biochemical variation by age, sex, and season for an ex situ killer whale population. METHODS: Blood samples collected from killer whales during normal wellness exams were retrospectively identified. Killer whales were categorized by age; calf (0-2.9 years), juvenile (3-10.9 years), early adult (11-20.9 years), adult (21-30.9 years), and aged (>30.9 years); sex; and season. Standard CBC and biochemistry were collated, and only samples without evidence of disease were used. A mixed effects maximum likelihood regression with animal identification (ID) as the random effects variable was used to compare groups with a significance set at P ≤ 0.01. RESULTS: All analytes differed by age, while only four differed by sex. Red blood cell parameters and associated renal analytes increased with age, while liver-associated analytes and glucose decreased. Season affected 59% of the blood analytes. CONCLUSIONS: Aged killer whales showed strong evidence of altered physiology as compared with younger animals. Anemia did not develop with age as was observed in one bottlenose dolphin population. Observed decreases in renal function could be caused by chronic disease or dehydration. Decreases in immune function parameters suggest immune senescence. These results provide background data for evaluating the health of managed and free-ranging killer whales.


Assuntos
Orca/sangue , Fatores Etários , Animais , Contagem de Células Sanguíneas/normas , Contagem de Células Sanguíneas/veterinária , Glicemia/análise , Proteínas Sanguíneas/análise , Contagem de Eritrócitos/normas , Contagem de Eritrócitos/veterinária , Feminino , Testes Hematológicos/normas , Testes Hematológicos/veterinária , Masculino , Valores de Referência , Estações do Ano , Fatores Sexuais
18.
Aquat Toxicol ; 206: 102-104, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30468976

RESUMO

A recent Science report predicted the global killer whale population to collapse due to PCB pollution. Here we present empirical evidence, which supports and extends the reports' statement. In 2016, a neonate male killer whale stranded on the German island of Sylt. Neonatal attributes indicated an age of at least 3 days. The stomach contained ∼20 mL milk residue and no pathologies explaining the cause of death could be detected. Blubber samples presenting low lipid concentrations were analysed for persistent organic pollutants. Skin samples were collected for genotyping of the mitochondrial control region. The blubber PCB concentrations were very high [SPCBs, 225 mg/kg lipid weight (lw)], largely exceeding the PCB toxicity thresholds reported for the onset of immunosuppression [9 mg/kg lw ∑PCB] and for severe reproductive impairment [41 mg/kg lw ∑PCB] reported for marine mammals. Additionally, this individual showed equally high concentrations in p,p'-DDE [226 mg/kg lw], PBDEs [5 mg/kg lw] and liver mercury levels [1.1 µg/g dry weight dw]. These results suggest a high placental transfer of pollutants from mother to foetus. Consequently, blubber and plasma PCB concentrations and calf mortality rates are both high in primiparous females. With such high pollutant levels, this neonate had poor prerequisites for survival. The neonate belonged to Ecotype I (generalist feeder) and carried the mitochondrial haplotype 35 present in about 16% of the North Atlantic killer whale from or close to the North Sea. The relevance of this data becomes apparent in the UK West Coast Community, the UK's only residentorca population, which is currently composed of only eight individuals (each four males and females) and no calves have been reported over the last 19 years.Despite worldwide regulations, PCBs persist in the environment and remain a severe concern for killer whale populations, placing calves at high risk due to the mother-offspring PCB-transfer resulting in a high toxicological burden of the neonates.


Assuntos
Bifenilos Policlorados/análise , Orca , Tecido Adiposo/química , Animais , Animais Recém-Nascidos , Causas de Morte , Monitoramento Ambiental , Feminino , Masculino , Mar do Norte , Bifenilos Policlorados/toxicidade , Poluentes Químicos da Água/toxicidade
19.
Mar Pollut Bull ; 139: 459-469, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29983160

RESUMO

Shipping is key to global trade, but is also a dominant source of anthropogenic noise in the ocean. Chronic noise from ships can affect acoustic quality of important whale habitats. Noise from ships has been identified as one of three main stressors-in addition to contaminants, and lack of Chinook salmon prey-in the recovery of the endangered southern resident killer whale (SRKW) population. Managers recognize existing noise levels as a threat to the acoustical integrity of SRKW critical habitat. There is an urgent need to identify practical ways to reduce ocean noise given projected increases in shipping in the SRKW's summertime critical habitat in the Salish Sea. We reviewed the literature to provide a qualitative description of mitigation approaches. We use an existing ship source level dataset to quantify how some mitigation approaches could readily reduce noise levels by 3-10 dB.


Assuntos
Ruído/prevenção & controle , Navios , Orca , Animais , Ecossistema , Espécies em Perigo de Extinção , Comportamento Predatório , Salmão
20.
Mol Ecol ; 28(2): 484-502, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30187987

RESUMO

Recent exploration into the interactions and relationship between hosts and their microbiota has revealed a connection between many aspects of the host's biology, health and associated micro-organisms. Whereas amplicon sequencing has traditionally been used to characterize the microbiome, the increasing number of published population genomics data sets offers an underexploited opportunity to study microbial profiles from the host shotgun sequencing data. Here, we use sequence data originally generated from killer whale Orcinus orca skin biopsies for population genomics, to characterize the skin microbiome and investigate how host social and geographical factors influence the microbial community composition. Having identified 845 microbial taxa from 2.4 million reads that did not map to the killer whale reference genome, we found that both ecotypic and geographical factors influence community composition of killer whale skin microbiomes. Furthermore, we uncovered key taxa that drive the microbiome community composition and showed that they are embedded in unique networks, one of which is tentatively linked to diatom presence and poor skin condition. Community composition differed between Antarctic killer whales with and without diatom coverage, suggesting that the previously reported episodic migrations of Antarctic killer whales to warmer waters associated with skin turnover may control the effects of potentially pathogenic bacteria such as Tenacibaculum dicentrarchi. Our work demonstrates the feasibility of microbiome studies from host shotgun sequencing data and highlights the importance of metagenomics in understanding the relationship between host and microbial ecology.


Assuntos
Metagenômica , Microbiota/genética , Pele/microbiologia , Orca/microbiologia , Animais , Regiões Antárticas , Diatomáceas/genética , Geografia , Orca/parasitologia
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