Search

The first record of killer whale (Orcinus orca) predation on false killer whales (Pseudorca crassidens) is reported here. On 25 March 2010, a group of 50 to 60 false killer whales, including approximately 15 calves and accompanied by three to five bottlenose dolphins (Tursiops sp.), were sighted in the Bay of Islands, New Zealand. Within 30 min, they were approached by a group of approximately eight killer whales. Five false killer whales were attacked, with at least three rammed from below, forcing them out of the water. After 29 min, the killer whales were milling at the surface and feeding on the carcass of a false killer whale calf, possibly the only individual killed. The killer whales had prolific fresh and healed oval wounds, which were attributed to cookie cutter shark (Isistius sp.) bites. [ABSTRACT FROM AUTHOR]

The article offers information on the observational study regarding the migration of the Pacific gray whales. It mentions that these whales have their travel routine from Baja California to Beaufort Sea and Alaska. In addition, it cites that these whales have traveled for about 19,956 kilometers between December and April in order to breed and feed. Meanwhile, it notes the instructional guides for both teachers and students in order to determine the study's connection in other fields including science, social studies, and language arts. Moreover, the impact of the sea water quality on gray whales' migration is also highlighted.

Instances of aggressive chase over a 5-mo period were investigated in captive killer whales (Orcinus orca). Such episodes were found to be quite rare, occurring only eight times in 1,872 h of observation. A consistent vocal pattern was found to be associated with agonistic episodes that differed markedly from the pattern recorded during non-aggressive, time-matched control periods. In general, vocalizations associated with aggressive chase were characterized by amplitude and frequency modulated pulses of approximately 190 ms in duration. In addition, three specific call types were found to occur only during chase events. As a whole, these particular call types and associated features are offered as an acoustic signature of agonism in the killer whale. It is hoped that these sounds might aid researchers in interpreting heretofore enigmatic killer whale vocalizations recorded from wild populations. [ABSTRACT FROM AUTHOR]

This study assessed the short-term responses of humpback whales to whale-watching vessels during their southward migration along the south coast of New South Wales (NSW), Australia. The behavior of pods was recorded from commercial whale-watching vessels during tours and compared to pods observed in the absence of vessels from the shore in the same area. While some individuals showed obvious signs of horizontal avoidance, others approached vessels, initiating interactions. Calf pods were more sensitive to the presence of vessels than non-calf pods. Dive times and the overall percentage of time whales spent submerged were higher in the presence of vessels, but respiration intervals did not differ. Some surface behaviors occurred less often in the presence of vessels. Whales' responses differed according to whether vessels were operating in accordance with regulations or not. Whales were more likely to avoid a vessel moving within the permitted 100 m approach limit than vessels outside the limit. Whales showed some behavioral changes when vessels operated in accordance with whale-watching regulations, compared with whales in the absence of vessels. Pods that showed no obvious horizontal responses to vessels changed their diving and surface activity when compared with pods in the absence of vessels. Because the long-term impacts of effects of vessels are unknown, management of the humpback whale-watching industry should adopt a conservative approach. Improved knowledge of long-term impacts of multiple exposures to vessels is required to inform management of the effects of whale-watching. [ABSTRACT FROM AUTHOR]

The article presents a study examining the foraging behavior of Bryde's whales. It highlights an observation of the whale's deep dives at early night and the sequentially deep dives at early morning. Moreover, a study on the maximum dive duration, the dive depth, and the synchronization of deep dive are also discussed.

This paper focuses on the robust indexing of sperm whale hydrophone recordings based on a set of features extracted from a realtime passive underwater acoustic tracking algorithm for multiple whales using four hydrophones. Acoustic localization permits the study of whale behavior in deep water without interfering with the environment. Given the position coordinates, we are able to generate different features such as the speed, energy of the clicks, Inter-Click-Interval (ICI), and so on. These features allow to construct differentmarkers which allow us to index and structure the audio files. Thus, the behavior study is facilitated by choosing and accessing the corresponding index in the audio file. The complete indexing algorithm is processed on real data from theNUWC (Naval Undersea Warfare Center of the US Navy) and the AUTEC (Atlantic Undersea Test & Evaluation Center-Bahamas). Our model is validated by similar results from the US Navy (NUWC) and SOEST (School of Ocean and Earth Science and Technology) Hawaii university labs in a single whale case. Finally, as an illustration, we index a single whale sound file using the extracted whale's features provided by the tracking, and we present an example of an XML script structuring it. [ABSTRACT FROM AUTHOR]

The article presents a study which focuses on the value of passive acoustics technology, bottom-mounted buoys, towed arrays and real-time acoustic sensors for scientific and management applications with marine animals in widely spatial scales. It states that the majority of the application of the passive acoustic technologies focused on cetacean research, management and mitigation. It says that the study offers various case studies of the applications for most taxa and multi-species detectors were built for all big whales and fish species. It mentions that the social interaction of right whales change throughout the season and the gunshot sounds has increased. It also notes that passive acoustic monitoring (PAM) can only be useful when taken in the acoustic behavioural ecology of animals.

The article discusses the effect of human-generated noises on the behavior of whales and other marine mammals. It mentions that biologist Roger Payne and ocean engineer Douglas Webb were the first to discover the association of low-frequency calls and the reproduction of baleen whales. It presents a comparable experiment which holds that anthropogenic sound can cause death to whales.

Efforts to identify the specific causal mechanisms responsible for beaked whale strandings coincident with naval exercises have been hampered by lack of data concerning the hearing abilities of beaked whales and their physiological and behavioral responses to sound. In this study, auditory capabilities of a stranded Gervais’ beaked whale (Mesoplodon europaeus) were investigated by measuring auditory evoked potentials. Click-evoked potentials, auditory thresholds as a function of frequency, and the modulation rate transfer function were determined. The evoked potentials and modulation rate transfer function were similar to those measured in other echolocating odontocetes; the upper limit of functional hearing was 80–90 kHz. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the feeding behavior of humpback whales in tropical waters off Brazil. It claims that it is not surprising that humpback whales occasionally utilize abundant prey resources that become available during their long residency in tropical waters in light of the energetic demands of a winter fast. The study found that juvenile humpback whales may also be less prepared to withstand a prolonged fast where they live off of stored energy reserves and that their smaller size makes it more likely that sporadic feeding on small prey patches will have a positive effect on their annual energy budget than in larger adults.

Creating a baseline understanding of communicative signals and perceptual abilities is imperative for gaining insight into a species' life history. This is especially relevant for at-risk species, as it can aid in monitoring and conservation efforts. Marine mammals communicate predominately through acoustic modalities for a variety of functions, including foraging and reproduction. The acoustic signals produced by marine mammals, and their ability to perceive signals produced by conspecifics, are directly impacted by the level of ambient noise in the underwater environment in which they inhabit. Modern ocean noise levels are considerably louder than historical levels, and noise is therefore considered to be a threat to acoustically communicating marine mammal species. This review summarizes the documented acoustic signals, hearing abilities, and responses to sound of a critically endangered baleen whale, the North Atlantic right whale (Eubalaena glacialis), highlights gaps in the current body of literature, and identifies priorities for future research. [Display omitted] • North Atlantic right whales produce a variety of sounds, including tonal and impulsive signals • Tonal sounds generally range from 50-600 Hz and are less than 5 s, though impulsive signals are much shorter and broadband • Hearing ranges from 20 Hz-22 kHz, based on vocalization frequency, anatomical modeling, and behavioral responses • Given the overlap of right whale habitat and human activities, understanding the impacts of anthropogenic noise is critical [ABSTRACT FROM AUTHOR]

As a result of the phase-out of production of perfluorooctane-sulfonyl-based compounds by a major producer, concentrations of perfluorooctanesulfonate (PFOS) in marine mammals from North American and European coastal waters have been declining since the early 2000s. Nevertheless, temporal trends in perfluorochemical (PFC) concentrations in marine mammals from Asian coastal waters have not been examined. In this study, PFCs were determined in livers of melon-headed whales (Peponocephala electra) collected along the coast of Japan, from three mass strandings that occurred during the past 25 years. Concentrations of nine PFCs were determined in livers of 48 melon-headed whales that were collected during strandings in 1982, 2001/2002, and 2006. In addition, concentrations in liver tissues obtained from two pregnant females and their fetuses were compared for determination of transplacental transfer rates of PFCs during gestation. PFOS and perfluorooctanesulfonamide (PFOSA) were the predominant PFCs found in livers of melon-headed whales collected in 1982 (n = 22). PFOS, PFOSA, perfluoroundecanoate (PFUnDA), perfluorododecanoate (PFDoDA), perfluorodecanoate (PFDA), and perfluorononanoate (PFNA) were found in whales collected in 2001/2002 (n = 21) and in 2006 (n = 5). Concentrations of PFOS and PFOSA were approximately 10-fold higher in 2001/2002 than in 1982. Whereas concentrations of PFOSA then declined by 2-fold from 2001/2002 to 2006, concentrations of PFOS and perfluorocarboxylates did not decline after 2001/2002. Conversely, concentrations of PFNA and PFDA increased significantly from 2001/2002 to 2006. The proportion of perfluoroalkylsulfonates in total PFC concentrations decreased from 75% in 1982 to 51% in 2006. Conversely, the contribution of perfluorocarboxylates to total PFC concentrations increased from 25% in 1982 to 49% in 2006. PFUnDA was the major perfluorocarboxylate found in whale livers collected after 2000. Analysis of paired samples of mother-fetus demonstrated that the transplacental transfer rates of PFCs were higher than those for PCBs and PBDEs. [ABSTRACT FROM AUTHOR]

The article discusses a new technique form refloating and releasing stranded sperm whales. The technique involved using a modified net that is used in the salmonid aquaculture industry, as well as towing vessels equipped with Cummins diesel board engines that deliver power to a Hamilton Jet propulsion system. The whale is then evenly positioned in the net while applying equal pressure from the towing vessels. The vessels should be positioned in the shallow water facing the deep-water channel. To direct whales into the navigation channels, vessels were positioned near the whale, applying periodic banging on the vessel hull in order to direct whale movement.

The article presents a study which describes the behaviour of a social unit of sperm whales entangled by a driftnet during the rescue operation administered by the Coast Guard scuba-diving team in Cape Palinuro, Italy. It showed that the whales tend to roll sideways when they were inside the driftnet. It also indicated that the entangled whales developed different patterns of clicks distinguished as codas and creaks. Moreover, the most obvious demonstrations of social behaviour depicted by these mammals were head rubbing and fluke contact.

Humpback whales are renowned for the complex structured songs produced by males. A second, relatively understudied area of humpback acoustic communication concerns un-patterned sounds known as “social sounds,” produced by both males and females. These include vocalizations as well as sounds produced at the surface of the water as a result of surface behaviors ( e.g., breaching, pectoral slapping). This study describes a portion of the non-song social sound repertoire of southward migrating humpbacks in Australian waters, and explores the social relevance of these sounds. On migration, humpback whales travel in social groups of varying compositions. These social groups are not stable in that humpback whales continually change group composition by splitting from, or joining with, other groups. The results of this study suggest that “breaching” and “slapping” have a communicative function. Other sounds such as “underwater blows” and “cries” were heard mainly in competitive groups while other low-frequency sounds such as “grumbles,”“snorts,”“thwops,” and “wops” may function in intra- or inter-group communication. Particular sounds (“grunts,”“groans,” and “barks”) were almost exclusive to joining pods suggesting a role in social integration. Social sounds in humpbacks may have specific social and behavioral functions relating to social group composition, and the mediation of interactions between these social groups. [ABSTRACT FROM AUTHOR]

Humpback whales were instrumented with satellite transmitters off the western Antarctic Peninsula in January of 2004–2006 to examine their movement patterns and habitat use. Whales were tracked from 4 to 80 days (mean = 36.5 days). Distance and travel rate estimates for nine individuals ranged from 223 to 4,356 km and from 17 to 75 km/day, respectively. Considerable individual variation was observed in direction, speed and range of movements. The overall pattern was characterized by short- and long-distance movements between presumed foraging areas with relatively short residency times. Travel rates were lower at these sites, characterized by erratic movements, than during traveling between them. Area usage for six individuals based on the 95% fixed kernel home range with least squares cross-validation ranged from 2,771 to 172,356 km2. The management boundary between the feeding grounds associated with Breeding Stocks G and A needs revision, as current available data suggest it should be located to the east of 50°W. This study is the first to present detailed information on the movements of humpback whales in the Southern Ocean. [ABSTRACT FROM AUTHOR]

Two test systems were developed to evaluate the influence of draw-length and tissue compliance on entanglement-induced epidermal abrasion in humpback ( Megaptera novaeangliae) and right whale ( Eubalaena glacialis) tissue samples. Under straight pull abrasion tests, an adult right whale fluke required 3.7 times the load and 15 times the draw-length of a right whale calf flipper to induce epidermal failure whereas a humpback fluke was intermediate between these extremes. A load applied tangentially to the leading edge of the fluke or flipper resulted in a substantial, but reversible, deflection of the leading edge in the direction of the applied load. The maximum possible deformation of the leading edge under shear load, prior to the line slipping relative to the skin, was defined as the tissue compliance limit. Oscillatory abrasion tests revealed that line draw-lengths exceeding the tissue compliance limit resulted in substantially increased tissue abrasion. In actual entanglements, line draw-length relative to the tissue compliance may determine if the line will cut into the body or simply press against the skin. Increasing the entangling line's ability to stretch in response to a load could potentially minimize sliding of the line relative to the skin and help mitigate entanglement injuries. [ABSTRACT FROM AUTHOR]

Blainville’s beaked whales (Mesoplodon densirostris) use broadband, ultrasonic echolocation signals with a -10 dB bandwidth from 26 to 51 kHz to search for, localize, and approach prey that generally consist of mid-water and deep-water fishes and squid. Although it is well known that the spectral characteristics of broadband echoes from marine organisms vary as a function of size, shape, orientation, and anatomical group, there is little evidence as to whether or not free-ranging toothed whales use spectral cues in discriminating between prey and nonprey. In order to study the prey-classification process, a stereo acoustic tag was deployed on a Blainville’s beaked whale so that emitted clicks and the corresponding echoes from targets in the water could be recorded. A comparison of echoes from targets apparently selected by the whale and those from a sample of scatterers that were not selected suggests that spectral features of the echoes, target strengths, or both may have been used by the whale to discriminate between echoes. Specifically, the whale appears to favor targets with one or more nulls in the echo spectra and to seek prey with higher target strengths at deeper depths. [ABSTRACT FROM AUTHOR]

North Atlantic right whale feeding and calving behaviors provide predictable spatial and temporal windows in which to conduct surveys and facilitate collection of opportunistic sightings data. Migration behavior makes it more difficult to locate and sample marine animals systematically or to observe them opportunistically. The lack of data creates a critical gap in understanding social behavior; it also hampers the development of mitigation strategies to anthropogenic disturbances such as vessel strikes, acoustic pollution and entanglements. We employ regression analysis to fill this gap to model northerly movements of North Atlantic right whales in the coastal mid-Atlantic migratory corridor of the United States. The modeling suggests an early to mid-March departure from Jacksonville, Florida, with a 30 day departure range; an average travel time of 21–24 days to the tip of Long Island, corresponding to a mean migration/displacement rate of 1.5–1.7knots (2.8–3.1km/h). Right whales migrating with calves begin their northern migration several days after right whales migrating without calves. These statistical models can supplement the absence of migratory survey data and help direct and stratify survey efforts in migratory corridors. The combination of rigorous statistical prediction with direct observation also should facilitate the creation of more effective mitigation measures. The methods employed here can be applied to other megafauna elsewhere around the world in many situations where migratory data are sparse. [Copyright &y& Elsevier]

Despite years of study, the humpback whale mating system remains an enigma. Sustained observations of subsurface behavior may help reveal important components of the mating system. In 2005 and 2006, we deployed CRITTERCAM, an animal-borne imaging and data-logging tool, on humpback whales in their winter grounds. We focused our efforts on competitive groups, believed to be the epicenter of mate selection. Over 27 days of fieldwork in Maui waters we deployed 10 front- or rear-facing CRITTERCAMS on escorts (males) in competitive groups. This work revealed: (1) Five whales swimming to depths of over 150 m, with one animal diving down 298 m; (2) Instances of competitive behavior (inflated pleats, chasing) occurring along the seafloor; (3) The displacement of a primary escort (the whale closest to the female) by a challenger; (4) A detailed time budget of one principal escort maintaining his position over a 73-min observation window; (5) Threats and body strikes between secondary escorts; (6) Apparent affiliative behavior by females, including possible pectoral fin stroking of a principal escort and drafting in a principal escort's pressure wave; and (7) A secondary escort resting on the bottom while sculling its pectoral fins through the substrate, throwing up clouds of sand. In summary, CRITTERCAM allowed us to observe diving behavior and sustained micro-interactions between animals in competitive groups occurring far below the surface. Such observations can have significant bearing on interpretation of the mating system by assisting in uncovering behaviors that may be involved in mate guarding, dominance hierarchies, and female choice. [ABSTRACT FROM AUTHOR]

The article reports on a study of the relationship between humpback whales in New Zealand waters and known breeding sites in the Oceania region. Individual identification photographs of adult humpback have been gathered throughout the Oceania region since 1991. Results strongly indicate that there are connections between the humpback whales migrating through New Zealand waters with Breeding Stock E. However, their key wintering destination is still unknown. Data also indicate that there is a possible connection between the humpback whales in New Zealand waters and those in Fiji wintering grounds.

A Killer Whale attack on Narwhals was observed at Kakiak Point in Admiralty Inlet, Nunavut, Canada, in August 2005. Behavioral responses of both Narwhals and Killer Whales were documented by direct observation. Data collected from Narwhals instrumented with satellite-linked transmitters 5 days prior to the arrival of Killer Whales were used to examine changes in Narwhal movement patterns (e.g., dispersal and clumping) five days before the attack, during the attack, and five days after Killer Whales left the area. A minimum of four Narwhals were killed by 12-15 Killer Whales in a period of 6 hours. Narwhals showed a suite of behavioral changes in the immediate presence of Killer Whales including slow, quiet movements, travel close to the beach (<2 m from shore), use of very shallow water, and formation of tight groups at the surface. These behavioral changes are consistent with Inuit accounts of Killer Whale attacks on Narwhals. During the attack, Narwhals dispersed broadly, the groups were less clumped (standard deviation of inter-whale mean latitudes and longitudes), Narwhal space-use doubled from pre-attack home ranges of 347 km2 to 767 km2 (kemel 50% probability), and Narwhals shifted their distribution further south of the attack site. After the disappearance of Killer Whales, north-south dispersal of Narwhals contracted and was similar to pre-attack levels, total space use decreased slightly (599 km2), yet west-east dispersal remained high. Narwhals were distributed significantly (P<0.001) more broadly offshore in areas not used before the occurrence of Killer Whales. In general, short-term reactions of Narwhals to Killer Whale presence were obvious; yet normal behavior (as observed from shore) resumed shortly after Killer Whales left the area. Long-term (five day) Narwhal behavioral responses included increased dispersal of Narwhal groups over large offshore areas. This is among the few reports of eyewitness Killer Whale attacks on Narwhals in the high Arctic and is the first time changes in Narwhal behavior have been documented in response to a predation event through the use of satellite telemetry. [ABSTRACT FROM AUTHOR]

ABSTRACT: We examined the stomach contents of 26 Baird's beaked whales caught off the coast of Japan by small-type coastal whalers. The main prey for these whales was rat-tails and hakes in the western North Pacific. Pollock and squids were also important food in the whales collected from the southern Sea of Okhotsk. The prey species found in the stomachs of the whales were almost identical to those caught in bottom-trawl nets at depths greater than about 1000 m in the western North Pacific, which suggests that the Baird's beaked whale forages for prey at depths of about 1000 m or more. Baird's beaked whales in the western North Pacific migrate to waters of 1000–3000 m in depth, where demersal fish are abundant. This implies that Baird's beaked whales migrate to waters where demersal fish, especially rat-tails and hakes, are abundant. Although there is limited information on the feeding habits of ziphiid whales, they are generally thought to prefer squid. The present data suggest that demersal fish are also important prey for ziphiid whales. [ABSTRACT FROM AUTHOR]

During mark-recapture studies of open populations, animals often temporarily emigrate from study areas. Such temporary emigration can cause biased estimates of survival probabilities. We present a new statistical method to estimate survival probability from the capture histories of marked individuals in the presence of temporary emigration. This method uses stage-structured models that include one or more stages representing the individuals that have temporarily emigrated. Although not all parameters can be estimated in such stage structures, some important parameters are still estimable. Here, we determined the estimability of parameter values from the rank of the Jacobian of the likelihood function. We applied the temporary-emigration mark-recapture method to artificial data, representing various life histories and demonstrated consistency between actual and estimated values. As an example, we used the method to analyze data on reproductive female North Atlantic right whales. The method presented in this paper will be especially useful for studies of seabird, sea turtle, and marine-mammal populations where individuals are sampled only on their breeding grounds. [ABSTRACT FROM AUTHOR]

Investigate the ecophysiological and communicative function of various click types from male sperm whales (Physeter macrocephalus) in a high-latitude habitat; Details of study conducted in northern Norway; Data indicating that sperm whales in this habitat produce usual clicks, creak clicks and slow clicks; Characteristics of usual clicks and creak clicks suggesting a profound directionality and a frequency content suited for echolocation on meso- and bathypelagic fish and squids; Data suggesting that echolocation is an important sensory cue in prey location; Characteristics of slow clicks suggesting that this click type is more suited for communication than for echolocation; View that sperm whales producing slow clicks may represent an odontocete species that utilizes long-range sound communication.

Examines the songs of whales breeding off Hawaii and Mexico to determine changes in whale songs during the coarse of a breeding season. Measurement of acoustic variables depicting all known levels of song structure for each singer group; Occurrence of changes in the structure of song patterns in each area; Hypotheses influencing the changes in song patterns; Open-ocean singing; Adaptive significance of the song.

Vessel traffic is prevalent throughout marine environments. However, we often have a limited understanding of vessel impacts on marine wildlife, particularly cetaceans, due to challenges of studying fully-aquatic species. To investigate vessel and acoustic effects on cetacean foraging behavior, we attached suction-cup sound and movement tags to endangered Southern Resident killer whales in their summer habitat while collecting geo-referenced proximate vessel data. We identified prey capture dives using whale kinematic signatures and found that the probability of capturing prey increased as salmon abundance increased, but decreased as vessel speed increased. When vessels emitted navigational sonar, whales made longer dives to capture prey and descended more slowly when they initiated these dives. Finally, whales descended more quickly when noise levels were higher and vessel approaches were closer. These findings advance a growing understanding of vessel and sound impacts on marine wildlife and inform efforts to manage vessel impacts on endangered populations. • We examined vessel traffic threats on endangered killer whale foraging behavior. • Prey capture probability decreased as speed of proximate vessels increased. • Prey capture probability increased as estimates of preferred prey increased. • Vessel distance, noise and echosounders also influenced prey capture behavior. • Findings inform efforts to manage threats to endangered cetacean populations. [ABSTRACT FROM AUTHOR]

The distribution of the Bering-Chukchi-Beaufort Sea population of bowhead whales (Balaena mysticetus) is largely centered in the Chukchi Sea in autumn (September–November), which is also when sea ice is at minimum extent allowing for increased ship traffic and industrial activity. Prior work paired autumn movements of bowhead whales in the Chukchi Sea with simulated hydrographic information and concluded whales followed relatively cold, saline waters of Pacific origin during migration (<0 °C, 31.5–34.25 psu). We attached six Satellite Relay Data Logger (SRDLs) that included miniaturized Conductivity, Temperature, and Depth (CTD) sensors capable of collecting temperature (T) and salinity (S) profiles as whales dove, allowing us to verify and expand upon prior habitat studies. Areas where transiting whales stopped and lingered (presumably to feed) were associated with colder surface temperatures and lingering behavior peaked where seafloor salinity was ~33 psu. Whales were also more likely to linger in areas where density gradients were lower at the seafloor. Whales targeted colder, more saline waters of Pacific origin, in agreement with our prior work. Surface and dive behavior of whales tagged in this and other studies suggests that most feeding in the central Chukchi Sea is occurring at depths below the surface, and that surface temperature is indicative of (a proxy for) other processes occurring at depth. We suggest that colder surface temperatures are indicative of the main pathway(s) by which zooplankton are advected through the Chukchi Sea. However, because similar movement patterns in other stocks of bowhead whales have been interpreted as the avoidance of thermal stress, we suggest more research is needed on thermoregulation before this question can be resolved. • Bering-Chukchi-Beaufort Sea stock bowhead whales were tagged with Conductivity, Depth, and Temperature (CTD) sensors. • Data from CTD tags were used to examine physical oceanography and bowhead whale habitat use in the Chukchi Sea in autumn. • Areas where whales lingered had colder surface and seafloor temperatures, indicative of colder waters of Pacific origin. • We suggest colder surface temperatures indicate the pathway(s) by which zooplankton are advected through the Chukchi Sea. [ABSTRACT FROM AUTHOR]

The blue whale is the largest animal ever. This gigantism probably evolved to exploit seasonal krill blooms, where massive feasts allow for accumulation of large blubber reserves that can fuel their low mass specific metabolism during prolonged periods of fasting. Until recently, the physiology and biomechanics of blue whales could only be inferred from anatomical inspections, but the recent development of biologging tags now provide unique insights into how these ocean giants function and interact with their environment. Their mandibles, the largest bones ever to evolve, along with a highly expandable buccal cavity, enable an extreme and dynamic bulk feeding behavior. During a lunge feeding event, blue whales accelerate up to 5 m/s to engulf a volume prey laden water that is commensurate with the whale's gigantic body size. Perhaps due to the costs of such extreme foraging, their dive times of 10-15 min are much shorter than scaling would predict for their size. Like other diving animals, blue whales display a dive response with heart rates down to 4 BPM to prolong dive times and perhaps mitigate decompression sickness. Blue whales make the lowest and most energetic calls of any mammal with ocean traversing potential under natural ambient noise conditions. However, communication space may be severely reduced due to pervasive shipping noise. We hope that an increasing ability to study the physiology and behavior of blue whales and other marine megafauna will enable informed decisions and ensure our permanent co-existence in the face of increasing human encroachment into marine habitats. Unlabelled Image • Blue whale are bulk filter feeders that engulf their own body weight in prey laden water. • Short dive times of less than 15 min are probably driven by the energetic foraging style and proximate prey. • Blue whale invoke a dramatic dive response involving heart rates down to 2 beats per minute. • Their infrasonic and loud calls with ocean traversing potential are prone to masking from vessel noise. [ABSTRACT FROM AUTHOR]

Studies the ecology and behavior of whales by developing a sonic/radio tag to monitor their dive depths and underwater movements. Tag design; Tag deployment; Whale responses to approaches and tagging; Tracking and monitoring tagged whales; Longevity of tag attachment.

Focuses on the vocalizations of marine animals. Sophistication on dolphin communication; Sounds whales make when alone; Complexity in the sound of baleen whales.

Interactions of singing humpback whales, Megaptera novaeangliae, with conspecifics nearby were studied during the breeding season off the west coast of Maui, Hawaii. On 35 occasions singing humpbacks were followed by boats (Table 1). The movement patterns of these singing whales and other conspecifics nearby were recorded by observers on land using a theodolite. Thirteen of 35 singers stopped singing and joined with nonsinging whales either simultaneously or within a few minutes after ceasing to sing. Another 15 also stopped singing while under observation and were not seen to join with another whale, but all singing whales that joined with other whales stopped singing. Singing whales often pursue nonsinging whales, while nonsinging whales usually turn away from singers (Figs. 4, 5). When a singer joined with a female and calf unaccompanied by another adult, behavior tentatively associated with courtship and mating was observed (Fig. 7). Such behavior also occurred during several interactions between singers and individuals of unknown sex. Aggressive behavior was observed during three interactions between singers and individuals of unknown sex (Fig. 4) and it predominated whenever more than one adult accompanied a cow and calf. During the other occasions when a singer joined another whale, we could not determine the nature of the interaction. Many times the singers and joiner would surface together only once and would then separate. However, on several occasions the singer and joiner would remain together for as long as we could follow them, up to 1.5 h. The roles of singer and joiner can be interchangeable. For instance, on two occasions a singer joined with a whale that either had been singing or started singing later in the day (Fig. 3). Furthermore, on several occasions, a nonsinging whale appeared to displace the singer. Individual singing humpbacks are not strictly territorial, although singers appear to avoid other singers. As the breeding season progressed, singers sang for longer periods of time (Fig. 2). In addition, the probability of a whale joining with the singer decreased by 42% from the first half of the observation period to the second half. Furthermore, this increase in duration of song bouts occurred during that section of the season when female reproductive activity as measured by rate of ovulation is reported to be decreasing in other areas. Our observations support the hypothesis that humpback song plays a reproductive role similar to that of bird song. Humpbacks sing only during the breeding season. If, as seems likely, most singing humpbacks are male, then singing humpbacks probably communicate their species, sex, location, readiness to mate with females, and readiness to engage in agonistic behavior with other whales. [ABSTRACT FROM AUTHOR]