Current Research Projects
CATS tag image from bubble-netting whale in southeastern Alaska. The tag is deployed on the dorsum and oriented forward, with the left pectoral flipper raised and a stream of bubbles appearing out of the blowhole.
Comparative Bubble-Netting Kinematics
Bubble-netting is a highly specialized foraging behavior employed by humpback whales (Megaptera novaeangliae) in multiple locations around the globe. All forms of bubble-netting involve the use of a bubble curtain to corral or startle prey into a dense aggregation for easier consumption at higher densities, thereby increasing the energetic economy of the foraging bout. Different populations of animals have developed these strategies independently over time and use their bubble curtain in different ways. Some groups forage solitarily or in pairs and create a series of successively smaller curtains before lunging, while other groups range upwards in size from ~4-16 individuals, with designated “bubble-blowers” that form the bubble curtain. Many of these bubble-netting variations have been studied individually, but our study will be the first to directly compare the kinematics and energetic economy of different bubble-netting styles using a combination of UAV drone and biologging tag data for animals from three distinct populations.
Representative annual cycle for a mysticete whale (Humpback: Megaptera Novaeangliae). The top left depicts the variables affecting daily foraging variability. The bottom left depicts a migration between a foraging ground (Western Antarctic Peninsula) and a breeding ground (Ecuador). The right side depicts the annual cycle of energy loss and energy gain.
Migration Energetics of large Whales
Long-distance migrations are one of the most energetically challenging behaviors observed within the animal kingdom. Animals migrate to track the seasonality of food sources or move between spatially distinct foraging and breeding habitats. Large body sizes, such as those seen in baleen whales (Mysticeti), are one adaptation allowing for migrations across vast distances. As capital breeders, mysticetes must also rely on the energy from a defined feeding season to last them throughout the year. Consequently, maximum migratory distance should be a function of energy gained during the feeding season. Using empirically-derived estimates of foraging and swimming energetic intake and costs for mysticetes of varying body sizes, we calculated the energy gained during a foraging season as well as the energy subsequently used during migration. For a successful foraging season, the energetic cost of migration only amounts to ~20% of foraging season energy intake across body sizes, while a poor foraging year could result in exorbitant migratory costs of ~100% or more. We also found that migratory costs are dependent on total distance, duration, and swimming speed. Combining a theoretical model with satellite tracks of individual whales, we determined that longer migrations are more costly and occur at higher speeds than shorter migrations. In a rapidly changing ocean, small differences in the distance, duration, and/or speed of a migration could have major impacts on individual fitness.
Will be presented at the Society for Integrative and Comparative Biology Annual Meeting (2024) in Seattle, WA
Previous Research Projects
Schematic trace and empirical data for a foraging lunge. The light orange and blue areas in the top portion correspond to the acceleration and deceleration phases of the lunge, respectively. Bottom shows kinematic data and corresponding camera views for paired blue whales lunge feeding on krill. The images on the right are taken from CATS biologging tags deployed on a pair of blue whales, with the data traces corresponding to the leading animal in the pair. Each set of images from top to bottom correspond to specific times during the lunge and are represented in the data traces as dotted lines. These times are 1) the point of mouth opening at the beginning of the lunge (MO), 2) the maximum gape during the lunge (MG), and 3) the mouth closure at the end of the lunge (MC).
Lunging Kinematics of Large Whales
Although gigantic body size and obligate filter feeding mechanisms have evolved in multiple vertebrate lineages (mammals and fishes), intermittent ram (lunge) filter feeding is unique to a specific family of baleen whales: rorquals. Lunge feeding is a high cost, high benefit feeding mechanism that requires the integration of unsteady locomotion (i.e., accelerations and maneuvers); the impact of scale on the biomechanics and energetics of this foraging mode continues to be the subject of intense study. The goal of our investigation was to use a combination of multi-sensor tags paired with UAS footage to determine the impact of morphometrics such as body size on kinematic lunging parameters such as fluking timing, maximum lunging speed, and deceleration during the engulfment period for a range of species from minke to blue whales. Our results show that, in the case of krill-feeding lunges and regardless of size, animals exhibit a skewed gradient between powered and fully unpowered engulfment, with fluking generally ending at the point of both the maximum lunging speed and mouth opening. In all cases, the small amounts of propulsive thrust generated by the tail were unable to overcome the high drag forces experienced during engulfment. Assuming this thrust to be minimal, we predicted the minimum speed of lunging across scale. To minimize the energetic cost of lunge feeding, hydrodynamic theory predicts slower lunge feeding speeds regardless of body size, with a lower boundary set by the ability of the prey to avoid capture. We used empirical data to test this theory and instead found that maximum foraging speeds remain constant and high (~4 m/s) across body size, even as higher speeds result in lower foraging efficiency. Regardless, we found an increasing relationship between body size and this foraging efficiency, estimated as the ratio of energetic gain from prey to energetic cost. This trend held across timescales ranging from a single lunge to a single day and suggests that larger whales are capturing more prey – and more energy – at a lower cost.
Froude efficiency versus total body length (m) for species from different morphological and taxonomic groups. Different swimming modes are presented as different shapes (● circle: drag-based paddling; ▲ triangle: undulatory swimming; ■ square: oscillatory swimming). The values for mysticete cetaceans are the mean species-level data from the present study. Silhouettes correspond to each group by rough position and color.
Swimming Hydrodynamics in Large Whales
High efficiency lunate-tail swimming with high-aspect-ratio lifting surfaces has evolved in many vertebrate lineages, from fish to cetaceans. Baleen whales (Mysticeti) are the largest swimming animals that exhibit this locomotor strategy and their extant body sizes range from 6-30m, making them an ideal study system to examine how morphology and the kinematics of swimming scale to the largest body sizes. We used data from whale-borne inertial sensors coupled with morphometric measurements from aerial drones to calculate the hydrodynamic performance of oscillatory swimming in six baleen whale species ranging in body length from 5-25m (fin whale, Balaenoptera physalus; Bryde’s whale, Balaenoptera edeni; sei whale, Balaenoptera borealis; Antarctic minke whales, Balaenoptera bonaerensis; humpback whales, Megaptera novaeangliae; and blue whales, Balaenoptera musculus). We find that mass-specific thrust increases with both swimming speed and body size. Froude efficiency, defined as the ratio of useful power output to the rate of energy input, generally increased with swimming speed but decreased on average with increasing body size. This finding is contrary to previous results in smaller animals where Froude efficiency increased with body size. Although our empirically-parameterized estimates for swimming baleen whale drag was higher than that of a simple gliding model, oscillatory locomotion at this scale exhibits generally high Froude efficiency as in other adept swimmers. Our results quantify the kinematics and estimate the hydrodynamics of routine and energetically expensive swimming modes at the largest scale.
Schematic showing our peak-to-peak amplitude measurement methods. The background is a video still from the deployment of interest. Letters correspond to the: rostrum (A), dorsal fin (B), left flipper (C), right flipper (D), peduncle (E), left fluke blade (F), right fluke blade (G).
Swimming Kinematics in Large Whales
The scale dependence of locomotor factors has long been studied in comparative biomechanics, but remains poorly understood for animals at the upper extremes of body size. Rorqual baleen whales include the largest animals, but we lack basic kinematic data about their movements and behavior below the ocean surface. Here, we combined morphometrics from aerial drone photogrammetry, whale-borne inertial sensing tag data and hydrodynamic modeling to study the locomotion of five rorqual species. We quantified changes in tail oscillatory frequency and cruising speed for individual whales spanning a threefold variation in body length, corresponding to an order of magnitude variation in estimated body mass. Our results showed that oscillatory frequency decreases with body length while cruising speed remains roughly invariant at 2 m/s. We compared these measured results for oscillatory frequency against simplified models of an oscillating cantilever beam and an optimized oscillating Strouhal vortex generator. The difference between our length-scaling exponent and the simplified models suggests that animals are often swimming non-optimally in order to feed or perform other routine behaviors. Cruising speed aligned more closely with an estimate of the optimal speed required to minimize the energetic cost of swimming. Our results are among the first to elucidate the relationships between both oscillatory frequency and cruising speed and body size for free-swimming animals at the largest scale.
Published as an Editor’s Choice in the Journal of Experimental Biology, 2019
μCT images of the mid‐span location of P. phocoena at the leading edge subsections (visualizing the chordwise sectional face). The chordline used for measurement of acute fiber angles was perpendicular to the cut edge of each tissue section.
Morphology of The Cetacean Tail Fluke
The cetacean tail fluke blades are not supported by any vertebral elements. Instead, the majority of the blades are composed of a densely packed collagenous fiber matrix known as the core layer. Fluke blades from six species of odontocete cetaceans were examined to compare the morphology and orientation of fibers at different locations along the spanwise and chordwise fluke blade axes. The general fiber morphology was consistent with a three‐dimensional structure comprised of two‐dimensional sheets of fibers aligned tightly in a laminated configuration along the spanwise axis. The laminated configuration of the fluke blades helps to maintain spanwise rigidity while allowing partial flexibility during swimming. When viewing the chordwise sectional face at the leading edge and mid‐chord regions, fibers displayed a crossing pattern. This configuration relates to bending and structural support of the fluke blade. The trailing edge core was found to have parallel fibers arranged more dorso‐ventrally. The fiber morphology of the fluke blades was dorso‐ventrally symmetrical and similar in all species except the pygmy sperm whale (Kogia breviceps), which was found to have additional core layer fiber bundles running along the span of the fluke blade. These additional fibers may increase stiffness of the structure by resisting tension along their long spanwise axis.
Eider Duck sea-surface Escape Kinematics
Common eiders (Somateria mollissima) are heavy sea-ducks that spend a large portion of their time swimming at the water surface. Surface swimming generates a bow and hull wave that can constructively interfere and produce wave drag. The speed at which the wavelengths of these waves equal the waterline length of the swimming animal is the hull speed. To increase surface swimming speed beyond the hull speed, an animal must overtake the bow wave. This study found two distinct behaviors that eider ducks used to exceed the hull speed: (1) ‘steaming’, which involved rapid oaring with the wings to propel the duck along the surface of the water, and (2) ‘paddle-assisted flying’, during which the ducks lifted their bodies out of the water and used their feet to paddle against the surface while flapping their wings in the air. An average hull speed (0.732±0.046 m s−1) was calculated for S. mollissima by measuring maximum waterline length from museum specimens. On average, steaming ducks swam 5.5 times faster and paddle-assisted flying ducks moved 6.8 times faster than the hull speed. During steaming, ducks exceeded the hull speed by increasing their body angle and generating dynamic lift to overcome wave drag and hydroplane along the water surface. During paddle-assisted flying, ducks kept their bodies out of the water, thereby avoiding the limitations of wave drag altogether. Both behaviors provided alternatives to flight for these ducks by allowing them to exceed the hull speed while staying at or near the water surface.
Dog Urinary Posture and Motor Laterality
Motor laterality is the preference shown for using one limb or lateral half of the body over the other. In domestic dogs, most laterality studies have examined forelimb preferences during staged tasks. We focused instead on hindlimb preferences during urination when males use the raised-leg posture and females the squat-raise. We observed individual dogs during walks at two shelters and recorded posture used for each urination and hindlimb raised, if any. Our study confirms and extends for shelter dogs the effects of sex and age on urinary postures previously reported for dogs living under other conditions. Lack of a population bias with respect to hindlimb raised is consistent with findings of most motor laterality studies in dogs. However, our finding that most dogs were ambilateral differs from results obtained from studies using staged forelimb tasks. Assessing motor laterality for a natural hindlimb behavior has both advantages and disadvantages.
Published in Applied Animal Behaviour Science with follow-up work in the Journal of Veterinary Behavior
Percentage of urinations by dogs that involved a raised hindlimb as a function of age as a continuous variable. Data are shown for male dogs (A; two shelters pooled) and female dogs (B; two shelters pooled). Vertical dashed lines indicate the approximate separation between juvenily and adult age classes (dashed line on left) and the separation between adult and senior age classes (dashed line on right).
Curriculum Vitae (PDF)
Selected Excerpts
JOURNAL PUBLICATIONS
1) Fish, F.E., Nicastro, A.J., Cardenas, K.L., Segre, P.S., Gough, W.T., Kahane-Rapport, S.R., St. Leger, J., Goldbogen, J.A. (2023) Spin-leap performance by cetaceans is influenced by moment of inertia. In Prep. (Data creation)
2) Cade, D.E., Kahane-Rapport, S.R., Gough, W.T., Bierlich, K.C., Linsky, J.M.J., Calambokidis, J., Johnston, D.W., Goldbogen, J.A. and Friedlaender, A.S. (2023). Minke whale feeding rate limitations suggest constraints on the minimum body size for engulfment filtration feeding. Nature Ecology & Evolution 7: 535-546.
3) Segre, P.S., di Clemente, J., Kahane-Rapport, S.R., Gough, W.T., Meÿer, M.A., Lombard, A.T., Goldbogen, J.A. and Penry, G.S. (2022). High-speed chases along the seafloor put Bryde’s whales at risk of entanglement. Conservation Science and Practice 4: e12646.
4) Gough, W.T., Cade, D.E., Czapanskiy, M.F., Potvin, J., Fish, F.E., Kahane-Rapport, S.R., Savoca, M.S., Bierlich, KC, Johnston, D.W., Friedlaender, A.S., Szabo, A., Bejder, L. and Goldbogen, J.A. (2022). Fast and furious: energetic tradeoffs and scaling of high-speed foraging in rorqual whales. Integrative and Organismal Biology 4: obac038.
5) 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.A., Visser, F., Weir, C.R., Wiley, D.N. and Goldbogen, J.A. (2022). Scaling of maneuvering performance in baleen whales: larger whales outperform expectations. Journal of Experimental Biology 225: jeb243224.
6) Cade, D.E., Gough, W.T., Czapanskiy, M.F., Fahlbusch, J.A., Kahane-Rapport, S.R., Linsky, J.M.J., Nichols, R.C., Oestreich, W.K., Wisniewska, D.M., Friedlaender, A.S. and Goldbogen, J.A. (2021). Tools for integrating inertial sensor data with video bio-loggers, including estimation of animal orientation, motion, and position. Animal Biotelemetry 9: 1-21.
7) Savoca, M.S., Czapanskiy, M.F., Kahane-Rapport, S.R., Gough, W.T., Fahlbusch, J.A., Bierlich, KC, 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. and Goldbogen, J.A. (2021). Baleen whale prey consumption based on high resolution foraging measurements. Nature 599: 85-90.
8) Modest, M., Irvine, L., Andrews-Goff, V., Gough, W.T., Johnston, D., Nowacek, D., Pallin, L., Read, A., Moore, R.T. and Friedlaender, A. (2021). First description of migratory behavior of humpback whales from an Antarctic feeding ground to a tropical calving ground. Animal Biotelemetry 9: 42.
9) Czapanskiy, M.F., Savoca, M.S., Gough, W.T., Segre, P.S., Wisniewska, D.M., Cade, D.E. and Goldbogen, J.A. (2021). Modelling short-term energetic costs of sonar disturbance to cetaceans using high-resolution foraging data. Journal of Applied Ecology 58: 1643-1657.
10) Fish, F.E., Sheehan, M.J., Adams, D.S., Tennett, K.A. and Gough, W.T. (2021). A 60:40 split: differential mass support in dogs. Anatomical Record 304: 78-89.
11) Gough, W.T., Smith, H.J., Savoca, M.S., Czapanskiy, M.F., Fish, F.E., Potvin, J., Bierlich, KC, Cade, D.E., Di Clemente, J., Kennedy, J., Segre, P.S., Stanworth, A., Weir, C.R. and Goldbogen, J.A. (2021). Scaling of oscillatory kinematics and Froude efficiency in baleen whales. Journal of Experimental Biology 224: jeb237586.
12) Segre, P.S., Potvin, J., Cade, D.E., Calambokidis, J., Di Clemente, J., Fish, F.E., Friedlaender, A.S., Gough, W.T., Kahane-Rapport, S.R., Oliveira, C., Parks, S.E., Penry, G.S., Simon, M., Stimpert, A.K., Wiley, D.N., Bierlick, KC, Madsen, P.T. and Goldbogen, J.A. (2020). Energetic and physical limitations on the breaching performance of large whales. eLife 9.
13) Goldbogen, J.A., Cade, D.E., Wisniewska, D.M., Potvin, J., Segre, P.S., Savoca, M.S., Hazen, E.L., Czapanskiy, M.F., Kahane-Rapport, S.R., DeRuiter, S.L., Gero, S., Tønnesen, P., Gough, W.T., Hanson, M.B., Holt, M.M., Jensen, F.H., Simon, M., Stimpert, A.K., Arranz, P., Johnston, D.W., Nowacek, D.P., Parks, S.E., Visser, F., Friedlaender, A.S., Tyack, P.L., Madsen, P.T. and Pyenson, N.D. (2019). Why whales are big but not bigger: Physiological drivers and ecological limits in the age of ocean giants. Science 366: 1367–1372.
14) Goldbogen, J.A., Cade, D.E., Calambokidis, J., Czapanskiy, M.F., Fahlbusch, J.A., Friedlaender, A.S., Gough, W.T., Kahane-Rapport, S.R., Savoca, M.S., Ponganis, K.V. and Ponganis, P.J. (2019). Extreme bradycardia and tachycardia in the world’s largest animal. Proceedings of the National Academy of Sciences 4: 25329-25332.
15) Gough, W.T., Segre, P.S., Bierlich, KC, Cade, D.E., Potvin, J., Fish, F.E., Dale, J., Di Clemente, J., Friedlaender, A.S., Johnston, D.W., Kahane-Rapport, S.R., Kennedy, J., Long, J.H., Oudejans, M., Penry, G., Savoca, M.S., Simon, M., Videsen, S.KA., Visser, F., Wiley, D.N. and Goldbogen, J.A. (2019). Scaling of swimming performance in baleen whales. Journal of Experimental Biology 222: jeb204172.
16) Gough, W.T., Fish, F.E., Wainwright, D.K. and Bart-Smith, H. (2018). Morphology of the core fibrous layer of the cetacean tail fluke. Journal of Morphology 279: 757-765.
17) McGuire, B. and Gough, W.T. (2017). Body size influences urinary posture but not hindlimb laterality in shelter dogs. Journal of Veterinary Behavior: Clinical Applications and Research 21: 38-44.
18) Gough, W.T. and McGuire, B. (2015). Urinary Posture and Motor Laterality in Dogs (Canis lupus familiaris) at Two Shelters. Applied Animal Behaviour Science 168: 61-70.
19) Gough, W.T., Farina, S.C. and Fish, F.E. (2015). Aquatic Burst Locomotion by Hydroplaning and Paddling in Common Eiders (Somateria mollissima). Journal of Experimental Biology 218: 1632-1638.
TEACHING
Marine Mammal Science and Conservation (MBIO 650) (~6 students) – 2023
• University of Hawaii at Manoa (HIMB) led by Dr. Lars Bejder
• Led two days of teaching / training related to the history and modern usage of biologging technologies.
Biologging Tag Data Processing Workshop (~50 attendees) – (2020)
• Stanford University / UC Santa Cruz in collaboration with Dr. David Cade.
• Co-designed / co-instructed a week-long workshop to train members of the scientific community to 1) properly setup and deploy archival biologging tags, 2) process the resulting data into useable formats, and 3) design experiments to answer novel biomechanical, behavioral, or physiological questions.
Biologging and Biotelemetry (BIOHOPK 234H) (~10 students) – (2018)
• Stanford University (Hopkins Marine Station) led by Dr. Jeremy Goldbogen.
• Assisted with class preparation and activities to train students on the proper use and potential utility of biologging devices.
Animal and Plant Physiology (BIO 84) (~40 students) – (2018)
• Stanford University led by Drs. Craig Heller, Robert Sapolsky, and Jose Dinneny.
• Led two weekly discussion sessions to reinforce lecture material focused on multiple physiological processes in plant and animal systems.
• Proctored exams and assisted with grading of all class materials.
Anatomy and Function of Marine Vertebrates (BIOSM 3210) – (2013 – 2014)
• Cornell University (Shoals Marine Laboratory) led by Dr. Frank Fish
• Helped students develop and complete individual, research-based final projects pertaining to multiple marine vertebrate lineages.
• Prepared lab and dissection materials and assisted with grading class materials.
Vertebrate Anatomy, Physiology, and Evolution (BIOEE 2740) – (2013)
• Cornell University led by Dr. Betty McGuire.
• Assisted with lab material preparation and proctoring of laboratory examinations.
OUTREACH
Stanford University – Salinas High School Internship Program – (2019 – 2022)
• Co-led design and logistics for a partnered internship between Hopkins Marine Station and Salinas High School.
• Managed pairings of 8-10 high school interns per year with graduate student / post-doctoral mentors.
• Designed final seminars to give interns a chance to present their work to their peers and parents.
Pacific Grove Natural History Museum – Science Saturday – (2019)
• Presented cetacean research to a public audience of adults and children
American Museum of Natural History – Milstein Science Series – (2015)
• Presented simple marine biomechanics and locomotion concepts to a public audience of adults and children.
Cornell University – Expand Your Horizons – (2013 – 2014)
• Assisted and led scientific activities for a group of 15-20 7th grade girls.