Male Killer Whale Research Articles

Cytochrome P4501A1 expression in blubber biopsies of endangered false killer whales (Pseudorca crassidens) and nine other odontocete species from Hawai'i.

Odontocetes (toothed whales) are considered sentinel species in the marine environment because of their high trophic position, long life spans, and blubber that accumulates lipophilic contaminants. Cytochrome P4501A1 (CYP1A1) is a biomarker of exposure and molecular effects of certain persistent organic pollutants. Immunohistochemistry was used to visualize CYP1A1 expression in blubber biopsies collected by non-lethal sampling methods from 10 species of free-ranging Hawaiian odontocetes: short-finned pilot whale, melon-headed whale, pygmy killer whale, common bottlenose dolphin, rough-toothed dolphin, pantropical spotted dolphin, Blainville's beaked whale, Cuvier's beaked whale, sperm whale, and endangered main Hawaiian Islands insular false killer whale. Significantly higher levels of CYP1A1 were observed in false killer whales and rough-toothed dolphins compared to melon-headed whales, and in general, trophic position appears to influence CYP1A1 expression patterns in particular species groups. No significant differences in CYP1A1 were found based on age class or sex across all samples. However, within male false killer whales, juveniles expressed significantly higher levels of CYP1A1 when compared to adults. Total polychlorinated biphenyl (∑PCBs) concentrations in 84% of false killer whales exceeded proposed threshold levels for health effects, and ∑PCBs correlated with CYP1A1 expression. There was no significant relationship between PCB toxic equivalent quotient and CYP1A1 expression, suggesting that this response may be influenced by agonists other than the dioxin-like PCBs measured in this study. No significant differences were found for CYP1A1 expression among social clusters of false killer whales. This work provides a foundation for future health monitoring of the endangered stock of false killer whales and other Hawaiian odontocetes.

Young killer whale males learn dialect

![Figure][1] A young male killer whale vocalizing. Photo credit: J. Crance, HSWRI. If you travel through a country and you have an ear for dialect, you might notice odd words pop up that are particular to the location. Dialects are an occupational hazard of travel, and it turns out that

Evidence for vocal learning in juvenile male killer whales, Orcinus orca, from an adventitious cross-socializing experiment.

Killer whales (Orcinus orca) are thought to learn their vocal dialect. Dispersal in the species is rare, but effects of shifts in social association on the dialect can be studied under controlled conditions. Individual call repertoires and social association were measured in three adult female killer whales and three males (two juveniles and an adult) during two periods, 2001-2003 and 2005-2006. Three distinct dialect repertoires were represented among the subjects. An adventitious experiment in social change resulted from the birth of a calf and the transfer of two non-focal subjects in 2004. Across the two periods, 1691 calls were collected, categorized and attributed to individuals. Repertoire overlap for each subject dyad was compared with an index of association. During 2005-2006, the two juvenile males increased association with the unrelated adult male. By the end of the period, both had begun producing novel calls and call features characteristic of his repertoire. However, there was little or no reciprocal change and the adult females did not acquire his calls. Repertoire overlap and association were significantly correlated in the first period. In the second, median association time and repertoire similarity increased, but the relationship was only marginally significant. The results provided evidence that juvenile male killer whales are capable of learning new call types, possibly stimulated by a change in social association. The pattern of learning was consistent with a selective convergence of male repertoires.

Basal metabolism of an adult male killer whale (Orcinus orca)

Marine Mammal ScienceVolume 30, Issue 3 p. 1229-1237 Notes Basal metabolism of an adult male killer whale (Orcinus orca) Graham A. J. Worthy, Corresponding Author Graham A. J. Worthy Hubbs-SeaWorld Research Institute, San Diego, California 92109, U.S.ACorresponding author: (e-mail: graham.worthy@ucf.edu).Search for more papers by this authorTamara A. M. Worthy, Tamara A. M. Worthy Hubbs-SeaWorld Research Institute, San Diego, California 92109, U.S.ASearch for more papers by this authorPamela K. Yochem, Pamela K. Yochem Hubbs-SeaWorld Research Institute, San Diego, California 92109, U.S.ASearch for more papers by this authorChristopher Dold, Christopher Dold SeaWorld Parks and Entertainment, Orlando, Florida 32821, U.S.ASearch for more papers by this author Graham A. J. Worthy, Corresponding Author Graham A. J. Worthy Hubbs-SeaWorld Research Institute, San Diego, California 92109, U.S.ACorresponding author: (e-mail: graham.worthy@ucf.edu).Search for more papers by this authorTamara A. M. Worthy, Tamara A. M. Worthy Hubbs-SeaWorld Research Institute, San Diego, California 92109, U.S.ASearch for more papers by this authorPamela K. Yochem, Pamela K. Yochem Hubbs-SeaWorld Research Institute, San Diego, California 92109, U.S.ASearch for more papers by this authorChristopher Dold, Christopher Dold SeaWorld Parks and Entertainment, Orlando, Florida 32821, U.S.ASearch for more papers by this author First published: 05 December 2013 https://doi.org/10.1111/mms.12091Citations: 10Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume30, Issue3July 2014Pages 1229-1237 RelatedInformation

A White Killer Whale in the Central Aleutians

We observed a white adult male killer whale (Orcinus orca) on 7 August 2000 off the north side of Adak Island, Aleutians. An open saddle and a rounded dorsal fin tip suggest that this whale belongs to the fish-eating (“resident”) ecotype. A circular scar matching a cookie-cutter shark (Isistius sp.) bite mark suggested that the animal originated in warmer waters. Photographs and description provided here should enable individual identification should this animal be seen again.

Records of a male killer whale (Orcinus orca) off Southeastern Brazil

Universidade Estadual Paulista Julio de Mesquita Filho (UNESP) Instituto de Biociencias, Departamento de Zoologia Projeto Atlantis, Laboratorio de Biologia da Conservacao de Cetaceos (Campus Rio Claro, Av. 24-A, 1.515, Bela Vista, 13506-900 Rio Claro, SP, Brasil) E-mail: sotalia@gmail.com Killer whales (

Assessing age distributions of killer whale Orcinus orca populations from the composition of endogenous fatty acids in their outer blubber layers

Knowledge of the age distributions of killer whale Orcinus orca populations is critical to assess their status and long-term viability. Except for accessible, well-studied populations for which historical sighting data have been collected, currently there is no reliable benign method to deter- mine the specific age of live animals for remote populations. To fill this gap in our knowledge of age structure, we describe new methods by which age can be deduced from measurements of specific lipids, endogenous fatty acids (FAs) and FA ratios present in their outer blubber layers. Whereas cor- relation of wax and sterol esters with age was reasonable for female 'resident' killer whales, it was less well-defined for males and 'transients.' Individual short-, branched-, and odd-chain FAs corre- lated better with age for transients and residents of both sexes, but these single parameter relation- ships were population specific and seemingly varied with long-term diet. Alternatively, a simple, empirical multi-linear model derived from the combination of 2 specific FA ratios enabled the ages of individual eastern North Pacific killer whales to be predicted with good precision (σ = ±3.8 yr), appeared to be independent of individual diet and was applicable to both genders and ecotypes. The model was applied to several less well-studied killer whale populations to predict their age distribu- tions from their blubber FA compositions, and these distributions were compared with a population of known age structure. Most interestingly, these results provide evidence for the first time that adult male transient killer whales appear to have lower life expectancies than do their resident counter- parts in Alaska.

Accumulation and transfer of contaminants in killer whales (Orcinus orca) from Norway: Indications for contaminant metabolism

Blubber tissue of one subadult and eight male adult killer whales was sampled in Northern Norway in order to assess the degree and type of contaminant exposure and transfer in the herring-killer whale link of the marine food web. A comprehensive selection of contaminants was targeted, with special attention to toxaphenes and polybrominated diphenyl ethers (PBDEs). In addition to assessing exposure and food chain transfer, selective accumulation and metabolism issues also were addressed. Average total polychlorinated biphenyl (PCB) and pesticide levels were similar, approximately 25 microg/g lipid, and PBDEs were approximately 0.5 microg/g. This makes killer whales one of the most polluted arctic animals, with levels exceeding those in polar bears. Comparing the contamination of the killer whale's diet with the diet of high-arctic species such as white whales reveals six to more than 20 times higher levels in the killer whale diet. The difference in contaminant pattern between killer whales and their prey and the metabolic index calculated suggested that these cetaceans have a relatively high capacity to metabolize contaminants. Polychlorinated biphenyls, chlordanes, and dichlorodiphenyldichloro-ethylene (DDE) accumulate to some degree in killer whales, although toxaphenes and PBDEs might be partly broken down.

Killer whale evasive tactics vary with boat number

AbstractControlled exposure experiments that measure animal response to vessels can inform relevant wildlife‐viewing guidelines and reveal how they make decisions about changes in their environment. Previous experimental studies documented stereotyped avoidance responses by killer whales to boats. Additional observations collected during these studies showed an apparent shift in avoidance behaviour at high traffic levels. Our study tested experimentally whether whales did respond differently to approach by few (1–3) versus many (>3) vessels. Data were collected in summer 2004 in Johnstone Strait, British Columbia, using a theodolite to track the positions of boats and individually identifiable focal whales during control and treatment (few vs. many boats) phases. The responses of 16 adult male killer whales differed significantly between treatment levels (Wilcoxon's test, P=0.0148). Swimming paths became more tortuous when few boats approached whales, but straighter as many boats approached. Pooling treatments would have masked significant responses with high statistical confidence (Wilcoxon's test, P>0.999), falsely suggesting that boat presence had no effect. The division between few and many boats was supported by 140 opportunistic observations on 26 whales from a population of 216. We used generalized additive models to control for the effects of confounding variables, detected a non‐linear relationship between number of boats and whales' swimming path directness and confirmed an inflection point at approximately three boats within 1000 m. We urge caution when designing controlled exposure assessments that rely on a simple absence–presence framework, which can mask multivariate or non‐linear responses. Experimental design, coupled with analytical techniques incorporating statistical power and appropriateness of treatments and response variables, must be considered when interpreting the biological significance of null findings from impact assessments. Our study provides new information about levels of habitat degradation that this marine apex predator can tolerate.

DOCUMENTATION OF SEA OTTERS AND BIRDS AS PREY FOR KILLER WHALES

Marine Mammal ScienceVolume 22, Issue 1 p. 201-205 DOCUMENTATION OF SEA OTTERS AND BIRDS AS PREY FOR KILLER WHALES Daniel J. Vos, Daniel J. Vos National Marine Fisheries Service, 222 W. 7th Avenue, #43, Anchorage, Alaska 99513, U.S.A. E-mail: daniel.vos@noaa.govSearch for more papers by this authorLori T. Quakenbush, Lori T. Quakenbush Alaska Department of Fish and Game, 1300 College Road, Fairbanks, Alaska 99701, U.S.A.Search for more papers by this authorBarbara A. Mahoney, Barbara A. Mahoney National Marine Fisheries Service, 222 W. 7th Avenue, #43, Anchorage, Alaska 99513, U.S.A.Search for more papers by this author Daniel J. Vos, Daniel J. Vos National Marine Fisheries Service, 222 W. 7th Avenue, #43, Anchorage, Alaska 99513, U.S.A. E-mail: daniel.vos@noaa.govSearch for more papers by this authorLori T. Quakenbush, Lori T. Quakenbush Alaska Department of Fish and Game, 1300 College Road, Fairbanks, Alaska 99701, U.S.A.Search for more papers by this authorBarbara A. Mahoney, Barbara A. Mahoney National Marine Fisheries Service, 222 W. 7th Avenue, #43, Anchorage, Alaska 99513, U.S.A.Search for more papers by this author First published: 10 January 2006 https://doi.org/10.1111/j.1748-7692.2006.00014.xCitations: 12Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume22, Issue1January 2006Pages 201-205 RelatedInformation

Characterization of male killer whale ( Orcinus orca) sexual maturation and reproductive seasonality

Longitudinal serum testosterone concentrations ( n = 10 males) and semen production ( n = 2 males) in killer whales were evaluated to: (1) characterize fluctuations in serum testosterone concentrations with respect to reproductive maturity and season; (2) compare morphologic changes to estimated age of sexual maturity, based on changes in serum testosterone concentrations; and (3) evaluate seasonal changes in sperm production. Classification of reproductive status and age class was based on differences ( P < 0.05) in serum testosterone concentrations according to age; juvenile males ranged from 1 to 7 years (mean ± S.D. testosterone, 0.13 ± 0.20 ng/mL), pubertal males from 8 to 12 years (2.88 ± 3.20 ng/mL), and sexually mature animals were 13 years and older (5.57 ± 2.90 ng/mL). For captive-born males, serum testosterone concentrations, total body length and height to width ratio of the dorsal fin were 0.7 ± 0.7 ng/mL, 495.6 ± 17.5 cm and 1.14 ± 0.13 cm, respectively, at puberty; at sexual maturity, these end points were 6.0 ± 3.3 ng/mL, 548 ± 20 cm and 1.36 ± 0.1 cm. Serum testosterone concentrations were higher ( P < 0.05) from March to June than from December to February in pubertal animals (4.2 ± 3.4 ng/mL versus 1.4 ± 2.6 ng/mL) and than from September to December in sexually mature animals (7.2 ± 3.3 ng/mL versus 4.0 ± 2.0 ng/mL). Ejaculates ( n = 90) collected from two males had similar ( P > 0.05) sperm concentrations across all months. These data represent the first comprehensive study on male testosterone concentrations during and after sexual maturation, and on reproductive seasonality in the killer whale.

PBDEs, PBBs, and PCNs in three communities of free-ranging killer whales (Orcinus orca) from the northeastern Pacific Ocean.

Polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and polychlorinated naphthalenes (PCNs) were quantified in blubber biopsy samples collected from free-ranging male and female killer whales (Orcinus orca) belonging to three distinct communities (southern residents, northern residents, and transients) from the northeastern Pacific Ocean. High concentrations of sigmaPBDE were observed in male southern residents (942+/-582 ng/g Iw), male and female transients (1015+/-605 and 885+/-706 ng/g Iw, respectively), and male and female northern residents (203+/-116 and 415+/-676 ng/g Iw, respectively). Because of large variation within sample groups, sigmaPBDE levels generally did not differ statistically with the exception of male northern residents, which had lower sigmaPBDE concentrations than male southern residents, male transients, and female transients, perhaps reflecting the consumption of less contaminated prey items. Male transient killer whales, which consume high trophic level prey including other cetaceans and occasionally spend time near populated areas, had sigmaPBDE concentrations approximately equal to southern residents. No significant age-related relationships were observed for sigmaPBDE concentrations. sigmaPBDE concentrations were approximately 1-3 orders of magnitude greater than those of sigmaPBB (3.0-31 ng/g Iw) and sigmaPCN (20-167 ng/g Iw) measured in a subset of samples, suggesting that PBDEs may represent a contaminant class of concern in these marine mammals.

Diurnal and annual changes in serum cortisol concentrations in Indo-Pacific bottlenose dolphins Tursiops aduncus and killer whales Orcinus orca

Until present, fundamental studies on cortisol secretory patterns have not been conducted in cetaceans. The objectives of this study were: (1) to examine diurnal changes in serum cortisol concentrations in Indo-Pacific bottlenose dolphins Tursiops aduncus and killer whales Orcinus orca, (2) to investigate annual cortisol changes in killer whales, and (3) to investigate the relationship between cortisol and sex steroids (testosterone and progesterone) concentrations in killer whales. Diurnal changes in serum cortisol concentrations were investigated at various intervals in the two species. In Indo-Pacific bottlenose dolphins, serum cortisol levels exhibited the same episodic fluctuations for 24 h as did diurnal terrestrial mammals: cortisol levels were lower at 18:00 h and higher in the early morning. In killer whales, cortisol concentrations continued to decrease until 18:00 h, after which they fluctuated, and then increased in the next morning. Annual changes in cortisol levels were investigated by collecting blood samples every two weeks from two male killer whales and a pregnant female one twice per day (during 09:00–10:00 and 16:00–17:00 h) throughout a one-year period. Regarding sera collected during 09:00–10:00 h from the female, cortisol concentrations showed cyclic changes having about 4-month intervals. In males, cortisol showed higher concentrations in winter and lower concentrations during the summer season. There was a negative correlation between cortisol and progesterone levels in the female and a negative correlation was also observed between cortisol and testosterone in male no. 2. In the female and male no. 1, cortisol levels during 09:00–10:00 h were significantly higher than those during 16:00–17:00 h, and their data are considered to support observations regarding diurnal changes in cortisol levels in the two cetacean species.

Behavioural responses of killer whales (Orcinus orca) to whale‐watching boats: opportunistic observations and experimental approaches

AbstractJohnstone Strait provides important summer habitat for the northern resident killer whales Orcinus orca of British Columbia. The site is also an active whale‐watching area. A voluntary code of conduct requests that boats do not approach whales closer than 100 m to address perceived, rather than demonstrated, effects of boat traffic on killer whales. The purpose of the study was to test the relevance of this distance guideline. Relationships between boat traffic and whale behaviour were studied in 1995 and 1996 by shore‐based theodolite tracking of 25 identifiable focal animals from the population of 209 whales. Individual killer whales were repeatedly tracked in the absence of boats and during approaches by a 5.2 m motorboat that paralleled each whale at 100 m. In addition, whales were tracked opportunistically, when no effort was made to manipulate boat traffic. Dive times, swim speeds, and surface‐active behaviours such as breaching and spy‐hopping were recorded. On average, male killer whales swam significantly faster than females. Whales responded to experimental approaches by adopting a less predictable path than observed during the preceding, no‐boat period, although males and females used subtly different avoidance tactics. Females responded by swimming faster and increasing the angle between successive dives, whereas males maintained their speed and chose a smooth, but less direct, path. Canonical correlations between whale behaviour and vessel proximity are consistent with these conclusions, which suggest that weakening whale‐watching guidelines, or not enforcing them, would result in higher levels of disturbance. High variability in whale behaviour underscores the importance of large sample size and extensive experimentation when assessing the impacts of human activity on killer whales.

KILLER WHALE PREDATION ON SPERM WHALES: OBSERVATIONS AND IMPLICATIONS

AbstractIn October 1997 we observed a herd of approximately 35 killer whales (Orcinus orca) attack a pod of nine sperm whales (Physeter macrocephalus) 130 km off the coast of central California. During the four hours we watched, adult female killer whales, including some with calves, attacked in waves of four to five animals in what was apparently a “wound and withdraw” strategy. Adult male killer whales stood by until the very end when one charged in and quickly killed a seriously wounded sperm whale that had been separated from the group. The sperm whales appeared largely helpless: their main defensive behavior was the formation of a rosette (“marguerite”‐heads together, tails out). When the killer whales were successful in pulling an individual out of the rosette, one or two sperm whales exposed themselves to increased attack by leaving the rosette, flanking the isolated individual, and leading it back into the formation. Despite these efforts, one sperm whale was killed and eaten and the rest were seriously, perhaps mortally, wounded. We also present details of two other encounters between sperm whales and killer whales that we observed. Although sperm whales, because of various behavioral and morphological adaptations, were previously thought to be immune to predation, our observations clearly establish their vulnerability to killer whales. We suggest that killer whale predation has potentially been an important, and underrated, selective factor in the evolution of sperm whale ecology, influencing perhaps the development of their complex social behavior and at‐sea distribution patterns.

Isolation of St. Louis encephalitis virus from a killer whale

We report the isolation of St. Louis Encephalitis (SLE) virus from a mature male killer whale ( Orcinus orca). This represents the first isolation of SLE virus from a marine mammal. The animal presented with reduced appetite, rapidly became lethargic and subsequently died. Virus-induced CPE was observed in a dolphin cell line, SP-1K (ATCC CCL 78), inoculated with brain, kidney, and lung tissues obtained at necropsy. Electron microscopy of infected SP-1K cells revealed the presence of virions having morphology and size resembling members of the Flaviviridae. Final identification as SLE virus was made by neutralization and immunofluorescence staining tests.

Killer whales (Orcinus orca) attack and kill a Bryde's whale (Balaenoptera edeni)

On 3 May 1988, we observed a group of killer whales that pursued, killed, and partially consumed a Bryde's whale in the northern Gulf of California, Mexico (31°01′N, 114°15′W). The attack was observed from 06:54 to 08:53 while circling in a single-engine aircraft at an altitude of 160 m. The group comprised about 15 killer whales, including two adult males and at least two calves. Females and (or) subadult males pressed the attack most intently. The killer whales tore skin and blubber from the right flank of the Bryde's whale, and on 11 occasions the killer whales swam onto the head or back of the Bryde's whale, which hindered its breathing. The respiration intervals of the Bryde's whale were short and irregular, and blow rates differed significantly from those of undisturbed Bryde's whales. Fatiguing the whale may have facilitated an easier kill by asphyxiation. After the death of the Bryde's whale, the two adult male killer whales surfaced slowly about 200–300 m away from the remainder of the group, which presumably fed on the submerged Bryde's whale carcass. Two days later, the drifting Bryde's whale carcass was located. A large wound was visible on the abdomen, and sections of the lower jaw had been removed. Like those of canids and some felids that hunt cooperatively when preying on ungulates, attacks by Orcinus orca exhibit coordination of activities and efficiency in dispatching prey.

SURVIVORSHIP PATTERNS IN THREE SPECIES OF CAPTIVE CETACEANS

AbstractSurvival rates for three species of captive cetaceans are reported, based on records of dates of capture, birth, and death of individual animals. The annual survival rate was 0.93 for bottlenose dolphins and killer whales and 0.94 for white whales. Confidence limits of these estimates are discussed. Differences in survival rates between institutions were significant for bottlenose dolphins only. Calf survival for bottlenose dolphins was lower than non‐calf survival. Survivorship of male killer whales was significantly less than survivorship of female killer whales; sex‐specific survival rates were similar for the other two species. Estimates of average or maximum longevity alone were not useful in comparing rates of survival. Because survival in the first year of captivity may be lower than subsequent years, estimates of the expected lifespan, based on data from the first few years of captivity, may be biased.

Comments on "spectral analysis of the calls of the male Killer Whale"

Comments on "spectral analysis of the calls of the male Killer Whale"

Spectral analysis of the call of the male killer whale

Poulter previously presented sonagram analyses of underwater sound recordings of various sea mammals, calling attention to the apparent harmonic progression of components of these signals. Other workers have questioned the presence of these harmonics in the original data and have suggested that they may instead be introduced during the analysis. In this paper we use underwater sound recordings of the male killer whale Namu, taken with equipment flat within ±2 dB to beyond 18 342 Hz, the upper limit of the analysis, to show by means of digital spectral analysis methods that a harmonic progression exists. In the signals analyzed, peaks in the estimated spectrum were observed at each integer multiple of the fundamental frequency. In view of the broad frequency response of the recording equipment and the precision of the subsequent digital analysis, we can say with confidence that these harmonics were actually present in the whaler's call. For the analysis, portions of an audio recording were converted to digital form. In the conversion, a bandpass filter was used to attenuate power below 40 Hz and above 10 kHz. Digital analysis techniques similar to those proposed by Bingham, Godfrey, and Tukey were then used. For each time span of data to be analyzed, a windowed Fourier transform was first computed, using a fast Fourier transform program. The power spectrum was next computed, as the squared modulus of the windowed transform, and a correction was made for the attenuation of high frequencies during A-to-D conversion. The autocorrelation function was estimated by computing the inverse transform of the power spectrum. A moderate amount of digital smoothing was then applied to the spectrum to reduce irregularities due to noise. The resulting smoothed spectrum is used as an estimate of the power spectral density function.