All Publications


  • From individual responses to population effects: Integrating a decade of multidisciplinary research on blue whales and sonar ANIMAL CONSERVATION Pirotta, E., Booth, C. G., Calambokidis, J., Costa, D. P., Fahlbusch, J. A., Friedlaender, A. S., Goldbogen, J. A., Harwood, J., Hazen, E. L., New, L., Santora, J. A., Watwood, S. L., Wertman, C., Southall, B. L. 2022

    View details for DOI 10.1111/acv.12785

    View details for Web of Science ID 000782735400001

  • Scaling of maneuvering performance in baleen whales: larger whales outperform expectations. The Journal of experimental biology Segre, P. S., Gough, W. T., Roualdes, E. A., Cade, D. E., Czapanskiy, M. F., Fahlbusch, J., Kahane-Rapport, S. R., Oestreich, W. K., Bejder, L., Bierlich, K. C., Burrows, J. A., Calambokidis, J., Chenoweth, E. M., di Clemente, J., Durban, J. W., Fearnbach, H., Fish, F. E., Friedlaender, A. S., Hegelund, P., Johnston, D. W., Nowacek, D. P., Oudejans, M. G., Penry, G. S., Potvin, J., Simon, M., Stanworth, A., Straley, J. M., Szabo, A., Videsen, S. K., Visser, F., Weir, C. R., Wiley, D. N., Goldbogen, J. A. 2022; 225 (5)

    Abstract

    Despite their enormous size, whales make their living as voracious predators. To catch their much smaller, more maneuverable prey, they have developed several unique locomotor strategies that require high energetic input, high mechanical power output and a surprising degree of agility. To better understand how body size affects maneuverability at the largest scale, we used bio-logging data, aerial photogrammetry and a high-throughput approach to quantify the maneuvering performance of seven species of free-swimming baleen whale. We found that as body size increases, absolute maneuvering performance decreases: larger whales use lower accelerations and perform slower pitch-changes, rolls and turns than smaller species. We also found that baleen whales exhibit positive allometry of maneuvering performance: relative to their body size, larger whales use higher accelerations, and perform faster pitch-changes, rolls and certain types of turns than smaller species. However, not all maneuvers were impacted by body size in the same way, and we found that larger whales behaviorally adjust for their decreased agility by using turns that they can perform more effectively. The positive allometry of maneuvering performance suggests that large whales have compensated for their increased body size by evolving more effective control surfaces and by preferentially selecting maneuvers that play to their strengths.

    View details for DOI 10.1242/jeb.243224

    View details for PubMedID 35234874

  • Integrating remote sensing methods during controlled exposure experiments to quantify group responses of dolphins to navy sonar. Marine pollution bulletin Durban, J. W., Southall, B. L., Calambokidis, J., Casey, C., Fearnbach, H., Joyce, T. W., Fahlbusch, J. A., Oudejans, M. G., Fregosi, S., Friedlaender, A. S., Kellar, N. M., Visser, F. 1800; 174: 113194

    Abstract

    Human noise can be harmful to sound-centric marine mammals. Significant research has focused on characterizing behavioral responses of protected cetacean species to navy mid-frequency active sonar (MFAS). Controlled exposure experiments (CEE) using animal-borne tags have proved valuable, but smaller dolphins are not amenable to tagging and groups of interacting individuals are more relevant behavioral units for these social species. To fill key data gaps on group responses of social delphinids that are exposed to navy MFAS in large numbers, we describe novel approaches for the coordinated collection and integrated analysis of multiple remotely-sensed datasets during CEEs. This involves real-time coordination of a sonar source, shore-based group tracking, aerial photogrammetry to measure fine-scale movements and passive acoustics to quantify vocal activity. Using an example CEE involving long-beaked common dolphins (Delphinus delphis bairdii), we demonstrate how resultant quantitative metrics can be used to estimate behavioral changes and noise exposure-response relationships.

    View details for DOI 10.1016/j.marpolbul.2021.113194

    View details for PubMedID 34902768

  • Baleen whale prey consumption based on high-resolution foraging measurements. Nature Savoca, M. S., Czapanskiy, M. F., Kahane-Rapport, S. R., Gough, W. T., Fahlbusch, J. A., Bierlich, K. C., Segre, P. S., Di Clemente, J., Penry, G. S., Wiley, D. N., Calambokidis, J., Nowacek, D. P., Johnston, D. W., Pyenson, N. D., Friedlaender, A. S., Hazen, E. L., Goldbogen, J. A. 2021; 599 (7883): 85-90

    Abstract

    Baleen whales influence their ecosystems through immense prey consumption and nutrient recycling1-3. It is difficult to accurately gauge the magnitude of their current or historic ecosystem role without measuring feeding rates and prey consumed. To date, prey consumption of the largest species has been estimated using metabolic models3-9 based on extrapolations that lack empirical validation. Here, we used tags deployed on seven baleen whale (Mysticeti) species (n=321 tag deployments) in conjunction with acoustic measurements of prey density to calculate prey consumption at daily to annual scales from the Atlantic, Pacific, and Southern Oceans. Our results suggest that previous studies3-9 have underestimated baleen whale prey consumption by threefold or more in some ecosystems. In the Southern Ocean alone, we calculate that pre-whaling populations of mysticetes annually consumed 430million tonnes of Antarctic krill (Euphausia superba), twice the current estimated total biomass of E. superba10, and more than twice the global catch of marine fisheries today11. Larger whale populations may have supported higher productivity in large marine regions through enhanced nutrient recycling: our findings suggest mysticetes recycled 1.2*104tonnesironyr-1 in the Southern Ocean before whaling compared to 1.2*103tonnesironyr-1 recycled by whales today. The recovery of baleen whales and their nutrient recycling services2,3,7 could augment productivity and restore ecosystem function lost during 20th century whaling12,13.

    View details for DOI 10.1038/s41586-021-03991-5

    View details for PubMedID 34732868

  • Tools for integrating inertial sensor data with video bio-loggers, including estimation of animal orientation, motion, and position ANIMAL BIOTELEMETRY Cade, D. E., Gough, W. T., Czapanskiy, M. F., Fahlbusch, J. A., Kahane-Rapport, S. R., Linsky, J. J., Nichols, R. C., Oestreich, W. K., Wisniewska, D. M., Friedlaender, A. S., Goldbogen, J. A. 2021; 9 (1)
  • Context-dependent variability in the predicted daily energetic costs of disturbance for blue whales. Conservation physiology Pirotta, E. n., Booth, C. G., Cade, D. E., Calambokidis, J. n., Costa, D. P., Fahlbusch, J. A., Friedlaender, A. S., Goldbogen, J. A., Harwood, J. n., Hazen, E. L., New, L. n., Southall, B. L. 2021; 9 (1): coaa137

    Abstract

    Assessing the long-term consequences of sub-lethal anthropogenic disturbance on wildlife populations requires integrating data on fine-scale individual behavior and physiology into spatially and temporally broader, population-level inference. A typical behavioral response to disturbance is the cessation of foraging, which can be translated into a common metric of energetic cost. However, this necessitates detailed empirical information on baseline movements, activity budgets, feeding rates and energy intake, as well as the probability of an individual responding to the disturbance-inducing stressor within different exposure contexts. Here, we integrated data from blue whales (Balaenoptera musculus) experimentally exposed to military active sonar signals with fine-scale measurements of baseline behavior over multiple days or weeks obtained from accelerometry loggers, telemetry tracking and prey sampling. Specifically, we developed daily simulations of movement, feeding behavior and exposure to localized sonar events of increasing duration and intensity and predicted the effects of this disturbance source on the daily energy intake of an individual. Activity budgets and movements were highly variable in space and time and among individuals, resulting in large variability in predicted energetic intake and costs. In half of our simulations, an individual's energy intake was unaffected by the simulated source. However, some individuals lost their entire daily energy intake under brief or weak exposure scenarios. Given this large variation, population-level models will have to assess the consequences of the entire distribution of energetic costs, rather than only consider single summary statistics. The shape of the exposure-response functions also strongly influenced predictions, reinforcing the need for contextually explicit experiments and improved mechanistic understanding of the processes driving behavioral and physiological responses to disturbance. This study presents a robust approach for integrating different types of empirical information to assess the effects of disturbance at spatio-temporal and ecological scales that are relevant to management and conservation.

    View details for DOI 10.1093/conphys/coaa137

    View details for PubMedID 33505702

    View details for PubMedCentralID PMC7816799

  • Social exploitation of extensive, ephemeral, environmentally controlled prey patches by supergroups of rorqual whales Animal Behaviour Cade, D. E., Fahlbusch, J. A., et al 2021; 182: 251-266
  • Predator‐scale spatial analysis of intra‐patch prey distribution reveals the energetic drivers of rorqual whale super‐group formation Functional Ecology Cade, D. E., Seakamela , M., Findlay, K. P., Fukunaga , J., Kahane‐Rapport, S. R., Warren, J. D., Calambokidis, J., Fahlbusch, J. A., Friedlaender , A. S., Hazen, E. L., Kotze , D., McCue, S., Meÿer , M., Oestreich , W. K., Oudejans, M. G., Wilke, C., Goldbogen, J. A. 2021

    View details for DOI 10.1111/1365-2435.13763

  • Animal-Borne Metrics Enable Acoustic Detection of Blue Whale Migration. Current biology : CB Oestreich, W. K., Fahlbusch, J. A., Cade, D. E., Calambokidis, J., Margolina, T., Joseph, J., Friedlaender, A. S., McKenna, M. F., Stimpert, A. K., Southall, B. L., Goldbogen, J. A., Ryan, J. P. 2020

    Abstract

    Linking individual and population scales is fundamental to many concepts in ecology [1], including migration [2, 3]. This behavior is a critical [4] yet increasingly threatened [5] part of the life history of diverse organisms. Research on migratory behavior is constrained by observational scale [2], limiting ecological understanding and precise management of migratory populations in expansive, inaccessible marine ecosystems [6]. This knowledge gap is magnified for dispersed oceanic predators such as endangered blue whales (Balaenoptera musculus). As capital breeders, blue whales migrate vast distances annually between foraging and breeding grounds, and their population fitness depends on synchrony of migration with phenology of prey populations [7, 8]. Despite previous studies of individual-level blue whale vocal behavior via bio-logging [9, 10] and population-level acoustic presence via passive acoustic monitoring [11], detection of the life history transition from foraging to migration remains challenging. Here, we integrate direct high-resolution measures of individual behavior and continuous broad-scale acoustic monitoring of regional song production (Figure1A) to identify an acoustic signature of the transition from foraging to migration in the Northeast Pacific population. We find that foraging blue whales sing primarily at night, whereas migratory whales sing primarily during the day. The ability to acoustically detect population-level transitions in behavior provides a tool to more comprehensively study the life history, fitness, and plasticity of population behavior in a dispersed, capital breeding population. Real-time detection of this behavioral signal can also inform dynamic management efforts [12] to mitigate anthropogenic threats to this endangered population [13, 14]).

    View details for DOI 10.1016/j.cub.2020.08.105

    View details for PubMedID 33007246

  • Lunge filter feeding biomechanics constrain rorqual foraging ecology across scale. The Journal of experimental biology Kahane-Rapport, S. R., Savoca, M. S., Cade, D. E., Segre, P. S., Bierlich, K. C., Calambokidis, J., Dale, J., Fahlbusch, J. A., Friedlaender, A. S., Johnston, D. W., Werth, A. J., Goldbogen, J. A. 2020

    Abstract

    Fundamental scaling relationships influence the physiology of vital rates, which in turn shape the ecology and evolution of organisms. For diving mammals, benefits conferred by large body size include reduced transport costs and enhanced breath-holding capacity, thereby increasing overall foraging efficiency. Rorqual whales feed by engulfing a large mass of prey-laden water at high speed and filtering it through baleen plates. However, as engulfment capacity increases with body length (Engulfment Volume Body Length 3.57), the surface area of the baleen filter does not increase proportionally (Baleen Area Body Length1.82), and thus the filtration time of larger rorquals predictably increases as the baleen surface area must filter a disproportionally large amount of water. We predicted that filtration time should scale with body length to the power of 1.75 (Filter Time Body Length1.75 ) We tested this hypothesis on four rorqual species using multi-sensor tags with corresponding unoccupied aircraft systems (UAS) -based body length estimates. We found that filter time scales with body length to the power of 1.79 (95% CI: 1.61 - 1.97). This result highlights a scale-dependent trade-off between engulfment capacity and baleen area that creates a biomechanical constraint to foraging through increased filtration time. Consequently, larger whales must target high density prey patches commensurate to the gulp size to meet their increased energetic demands. If these optimal patches are absent, larger rorquals may experience reduced foraging efficiency compared to smaller whales if they do not match their engulfment capacity to the size of targeted prey aggregations.

    View details for DOI 10.1242/jeb.224196

    View details for PubMedID 32820028

  • Seasonal activity levels of a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands Animal Biotelemetry Harrington, K. J., Fahlbusch, J. A., Langrock, R., Therrien, J., Houtz, J. L., McDonald , B. I. 2020; 8
  • A Case Study of a Near Vessel Strike of a Blue Whale: Perceptual Cues and Fine-Scale Aspects of Behavioral Avoidance FRONTIERS IN MARINE SCIENCE Szesciorka, A. R., Allen, A. N., Calambokidis, J., Fahlbusch, J., McKenna, M. F., Southall, B. 2019; 6
  • Extreme bradycardia and tachycardia in the world's largest animal PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Goldbogen, J. A., Cade, D. E., Calambokidis, J., Czapanskiy, M. F., Fahlbusch, J., Friedlaender, A. S., Gough, W. T., Kahane-Rapport, S. R., Savoca, M. S., Ponganis, K. V., Ponganis, P. J. 2019; 116 (50): 25329–32

    Abstract

    The biology of the blue whale has long fascinated physiologists because of the animal's extreme size. Despite high energetic demands from a large body, low mass-specific metabolic rates are likely powered by low heart rates. Diving bradycardia should slow blood oxygen depletion and enhance dive time available for foraging at depth. However, blue whales exhibit a high-cost feeding mechanism, lunge feeding, whereby large volumes of prey-laden water are intermittently engulfed and filtered during dives. This paradox of such a large, slowly beating heart and the high cost of lunge feeding represents a unique test of our understanding of cardiac function, hemodynamics, and physiological limits to body size. Here, we used an electrocardiogram (ECG)-depth recorder tag to measure blue whale heart rates during foraging dives as deep as 184 m and as long as 16.5 min. Heart rates during dives were typically 4 to 8 beats min-1 (bpm) and as low as 2 bpm, while after-dive surface heart rates were 25 to 37 bpm, near the estimated maximum heart rate possible. Despite extreme bradycardia, we recorded a 2.5-fold increase above diving heart rate minima during the powered ascent phase of feeding lunges followed by a gradual decrease of heart rate during the prolonged glide as engulfed water is filtered. These heart rate dynamics explain the unique hemodynamic design in rorqual whales consisting of a large-diameter, highly compliant, elastic aortic arch that allows the aorta to accommodate blood ejected by the heart and maintain blood flow during the long and variable pauses between heartbeats.

    View details for DOI 10.1073/pnas.1914273116

    View details for Web of Science ID 000502577500056

    View details for PubMedID 31767746

    View details for PubMedCentralID PMC6911174

  • A low-cost, open-source inertial movement GPS logger for eco-physiology applications. The Journal of experimental biology Fahlbusch, J. A., Harrington, K. J. 2019

    Abstract

    Open-source technology has been increasingly used for developing low-cost animal-borne bio-loggers, however, a gap remains for a bio-logger that records both inertial movement and GPS positions. We address this need with the Tapered Wings Logger (TWLogger), an archival bio-logger that records high-resolution (e.g. 50-Hz) tri-axial accelerometry and magnetometry, temperature, and GPS. The TWLogger can be built for 90 USD, accepts user-defined sampling parameters, and with a 500-mAh battery weighs 25-g. We provide publicly available build instructions and custom analysis scripts. Bench tests recorded 50-Hz inertial movement and 2-min GPS for 31.8 ± 2.2 h (mean±SD, n=6) with GPS accuracy within 10.9±13.6 m. Field deployments on a medium-sized bird of prey in the wild achieved similar results (n=13). The customizable TWLogger has wide-ranging application across systems and thus offers a practical solution for eco-physiology applications.

    View details for DOI 10.1242/jeb.211136

    View details for PubMedID 31753906

  • The advantages of diving deep: Fin whales quadruple their energy intake when targeting deep krill patches FUNCTIONAL ECOLOGY Friedlaender, A. S., Bowers, M. T., Cade, D., Hazen, E. L., Stimpert, A. K., Allen, A. N., Calambokidis, J., Fahlbusch, J., Segre, P., Visser, F., Southall, B. L., Goldbogen, J. A. 2019
  • Differential Vulnerability to Ship Strikes Between Day and Night for Blue, Fin, and Humpback Whales Based on Dive and Movement Data From Medium Duration Archival Tags FRONTIERS IN MARINE SCIENCE Calambokidis, J., Fahlbusch, J. A., Szesciorka, A. R., Southall, B. L., Cade, D. E., Friedlaender, A. S., Goldbogen, J. A. 2019; 6
  • Context-dependent variability in blue whale acoustic behaviour ROYAL SOCIETY OPEN SCIENCE Lewis, L. A., Calambokidis, J., Stimpert, A. K., Fahlbusch, J., Friedlaender, A. S., McKenna, M. F., Mesnick, S. L., Oleson, E. M., Southall, B. L., Szesciorka, A. R., Sirovic, A. 2018; 5 (8): 180241

    Abstract

    Acoustic communication is an important aspect of reproductive, foraging and social behaviours for many marine species. Northeast Pacific blue whales (Balaenoptera musculus) produce three different call types-A, B and D calls. All may be produced as singular calls, but A and B calls also occur in phrases to form songs. To evaluate the behavioural context of singular call and phrase production in blue whales, the acoustic and dive profile data from tags deployed on individuals off southern California were assessed using generalized estimating equations. Only 22% of all deployments contained sounds attributed to the tagged animal. A larger proportion of tagged animals were female (47%) than male (13%), with 40% of unknown sex. Fifty per cent of tags deployed on males contained sounds attributed to the tagged whale, while only a few (5%) deployed on females did. Most calls were produced at shallow depths (less than 30 m). Repetitive phrasing (singing) and production of singular calls were most common during shallow, non-lunging dives, with the latter also common during surface behaviour. Higher sound production rates occurred during autumn than summer and they varied with time-of-day: singular call rates were higher at dawn and dusk, while phrase production rates were highest at dusk and night.

    View details for DOI 10.1098/rsos.180241

    View details for Web of Science ID 000443443000040

    View details for PubMedID 30225013

    View details for PubMedCentralID PMC6124089