Randall William Davis

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Randall William Davis
Randall William Davis during an expedition in Antarctica.jpg
Randall William Davis during an expedition in Antarctica (Photo by R. W. Davis)
Born (1952-05-10) May 10, 1952 (age 67)
Los Angeles, California
ResidenceUnited States
NationalityUnited States
Alma materUniversity of California, San Diego
Known forAdaptations in marine mammals for deep, prolonged diving
Animal-borne video and data recorders
Methods to rehabilitate oiled sea otters
AwardsFulbright Fellow
USGS site designation in Antarctica
Non-invasive research methods for wildlife
Scientific career
FieldsPhysiological and behavioral ecology of marine mammals and other aquatic vertebrates
InstitutionsTexas A&M University at Galveston
Doctoral advisorGerald Kooyman

Randall William Davis (born 10 May 1952 in Los Angeles, California) is an educator[1] and researcher who studies the physiology and behavioral ecology of marine mammals and other aquatic vertebrates. His physiological research focuses on adaptations of marine mammals for deep, prolonged diving.[2] Davis has continually emphasized the importance of studying aquatic animals in their natural environment and has spent many years developing animal-borne instruments that record video and monitor three-dimensional movements, swimming performance and environmental variables to better understand their behavior and ecology.[3][4] His academic endeavors and 94 research expeditions have taken him to 64 countries and territories on seven continents and all of the world's oceans.

Education and early career[edit]

Randall Davis is the oldest son of Charles Davis and Beverly Sheldon who met and married in Los Angeles after the Second World War. His father, who was from Iola, Kansas, moved to Southern California in the 1930s, and his mother was a native of Los Angeles. In 1958, at the age of five, Davis moved from Los Angeles to the nearby San Gabriel Valley. During his early childhood, he developed an interest in marine biology and diving. He kept marine aquaria, collected his own specimens of vertebrates and invertebrates, and obtained his SCUBA certification at age 15. He was the Salutatorian in his graduating Nogales High School class in 1970 and was inducted into the California Scholarship Federation. Davis attended the University of California at Riverside as a pre-medical student, but spent his third year in the Department of Physiology at the University of St. Andrews in Scotland as part of the UC Education Abroad Program. It was there that he developed his keen interest in physiology, but he also traveled across Europe and had cultural experiences that motivated him to also study art history, comparative literature, music appreciation and medieval philosophy. He graduated from the University of California with a Bachelor of Science Degree in Biology in 1974 and was inducted into the Phi Beta Kappa Honor Society because of his simultaneous interest in the Liberal Arts. Davis married Ana Maria Melgoza in 1974, and the two of them returned to St. Andrews where he continued his studies in the Department of Physiology. After one year, Davis was accepted into the Physiology and Pharmacology Doctoral Program in the School of Medicine at the University of California at San Diego.

His first graduate advisor was Dr. John B. West, the high-altitude respiratory physiologist. In early 1976, Davis conducted an internship with Dr. Gerald Kooyman,[5] a comparative physiologist working at Scripps Institution of Oceanography. Kooyman was studying the diving physiology of harbor seals and had recently developed the first animal-borne time-depth recorders (TDRs) to study the diving behavior of free-ranging marine mammals. Davis decided to study the physiology of marine mammals and became Kooyman's Doctoral student in 1976. He spent that summer attaching TDRs to northern fur seals on the Pribilof Islands in the Bering Sea, then sailed on the National Science Foundation's research vessel Hero to South Georgia Island in the Southern Ocean to study the diving behavior of Antarctic fur seals.[6] He returned to South Georgia Island in 1979 and deployed the first microprocessor-based dive recorders on King Penguins, the results of which were published in the journal Science.[7]

Davis was a member of Kooyman's 1977 Weddell seal study in McMurdo Sound, Antarctica that led to the concept of an aerobic dive limit (ADL) and transformed the field of marine mammal diving physiology.[8][9] During his five years as a doctoral student at Scripps, Davis studied the intermediary metabolism of harbor seals during forced submersion by using isotopic tracers and was one of the first researchers to use this technique with marine mammals.[10] He interacted with Per Scholander, the comparative physiologist who established the Physiological Research Laboratory at Scripps in the late 1950s.

In 1980, Davis graduated with a Doctoral Degree in Physiology and immediately departed for Antarctica where he, his wife Ana Maria, and two colleagues spent a year (including the austral winter) in a remote field camp at White Island studying the diving behavior of Weddell seals.[11][12] For his effort, Davis received an Antarctica Service Medal with Winter Ribbon and a U.S. Geological Service Antarctic Site Designation 18773 (Davis Bluff; 79°09’ S, 167°35’ E) on White Island and was inducted into the Explorers Club.[13] Upon returning to Scripps, he received a National Institutes of Health Post-Doctoral Fellowship where he continued his research on harbor seal metabolism during submerged swimming[14][15] In 1983, he became a Research Scientist at the Hubbs-SeaWorld Research Institute in San Diego under the direction of Dr. William Evans. While at Hubbs, Davis and his colleagues studied the thermoregulatory effects of oil on sea otters and developed methods to mitigate the harmful impacts.[16][17] In March 1989, he was asked by the U.S. Department of the Interior to direct an Oiled Sea Otter Rehabilitation Program following the Exxon Valdez oil spill in Prince William Sound, Alaska.[18][19][20] This program rehabilitated 225 oiled sea otters and became the basis for a book that Davis co-authored on methods for rehabilitating oiled sea otters and other fur-bearing mammals.[21]

He also designed and patented (U.S. Patent 5315965,[22]) an aquatic vivarium for sea otters and aquatic birds, of which 40 are now installed at the Marine Wildlife Veterinary Care and Research Center in Santa Cruz, California. After this one-year effort, for which he received a Distinguished Service Award from the Exxon Corporation, Davis joined the faculty in the Department of Marine Biology at Texas A&M University[1] where he has continued his teaching and research.

Teaching[edit]

Davis teaches undergraduate and graduate courses in Comparative Physiology, Physiological Ecology of Marine Mammals, Marine Science of the Pacific Rim and a field course on the Coastal Marine Biology of Alaska.[23] He advises the oil industry and state and federal agencies on oil spill contingency planning and response,[24] and teaches an annual training course on the rehabilitation of oiled sea otters for members of the public that would like to volunteer in the event of another spill in Alaska.[25] People that complete this course receive an 8-hour First Responder OSHA Certificate that allows them to work in an oiled otter rehabilitation facility. As part of this training, Davis has an open-access web site (www.wildliferesearch.com) that also includes information on the life history of sea otters for students and the general public. He has published educational articles for primary and secondary students and the general public on the effects of oil on marine mammals and methods to mitigate the harmful impacts.[26][27] Davis has been featured in or helped to produce six educational films on marine mammals, one of which received first place in the Jack Ward Competition for Non-Commercial Films.

Research[edit]

Davis participated in the first deployments of mechanical and microprocessor time-depth recorders (TDRs) on pinnipeds and penguins in the mid-to-late 1970s.[6][7] The 1980s saw the advent of more sophisticated microprocessor-based archival and satellite-monitored tags and, by 1986, thousands of dives had been recorded on many species of marine mammals, penguins and reptiles.[28] However, time-depth profiles did not provide information on what the animals were doing at depth, so any behavioral interpretations were speculative. This led Davis to partner with an electronics engineer (William Hagey) to begin developing instruments that would eventually record video as well as depth, swim speed, magnetic bearing, pitch and roll, flipper/fluke stroking, GPS location at the surface and environmental variables such as conductivity (salinity), temperature and dissolved oxygen. The first instrument they deployed in 1987 on a Weddell seal in Antarctica was a Sony camcorder in a plastic housing.[29] Although simple by modern standards, it demonstrated that animal-borne video and data recorders could provide a new approach to studying marine animals.[30][3][4][31] By mounting the camera on the head, the video recorded prey capture which could be correlated with three-dimensional movements, swim speed, flipper stroking and body orientation. During the past three decades, Davis and Hagey have developed five generations of video and data recorders that have been deployed on seals, whales, sea turtles and sharks. Each generation was smaller, had more sensors and could record video and data over longer periods of time. With these instruments, researchers can now classify and distinguish the behavioral functions of different dive types and describe foraging strategies and hunting tactics in detail.[32][33][34] This work continues to be a major focus of Davis' research.

Davis and his graduate students have spent over four decades studying the morphological, physiological and metabolic adaptations of marine mammals for deep, prolonged diving. Davis' research has shown that the dive response (a fundamental adaptation for breath-hold diving) is more complex than earlier recognized. Although the dive response is a primitive cardiovascular response to protect animals from asphyxia, Davis showed that it has been integrated with the equally primitive exercise (fight-or-flight) response to regulate blood flow in a manner that maintains aerobic metabolism at different levels of submerged exercise.[35][36] Additional research has revealed morphological, cellular and enzymatic adaptations in a variety of tissues and organs that maintain aerobic metabolism during hypoxia associated with breath-hold diving.[37][38][39][40][41] Davis’ research has led to new discoveries and insights into the multi-level adaptations, from biochemistry to behavior, for breath-hold diving in marine mammals and other aquatic vertebrates[42][2]

A third area of Davis’ research has focused on the thermoregulatory physiology of sea otters and the harmful effects of oil exposure. In the 1980s, Davis and his colleague Dr. Terrie Williams conducted research for the U.S, Department of the Interior that developed techniques to mitigate the effects of oil on sea otters and other fur bearing marine mammals.[16][17] In the 1980s, the primary concern of the U.S. Department of the Interior had been the potential devastation of the small California sea otter population by an oil tanker spill. However, it was during the 1989 Exxon Valdez oil spill in Prince William Sound, Alaska that their science-based techniques to clean and rehabilitate otters were first used when Davis was asked by the U.S, Department of the Interior to direct the Sea Otter Rehabilitation Program.[18][19][43] This effort, involving over 300 people, rehabilitated and released 225 oiled sea otters, the largest number ever held in captivity. Davis then co-authored a book on the methods for rehabilitating oiled sea otters, and this is still the standard among rehabilitation programs for fur bearing marine mammals.[21] This book and other information on sea otters is available to the public online: www.wildliferesearch.com.

In addition to the effects of oil on sea otters, Davis has studied the behavioral ecology of sea otters in Prince William Sound, Alaska since 2001. This long-term study has included foraging behavior and prey preference,[44] foraging mechanics,[45] female and pup activity and energy budgets,[46][47] male activity budgets and territoriality,[48][49] habitat-associations,[50] and non-invasive methods to identify individual sea otters[51] for which he received the Christine Stevens Wildlife Award in 2008. Davis has conducted additional studies on the movements, behavior and habitat associations of cetaceans in the Gulf of Mexico,[52][53] sperm whales in the Gulf of California and New Zealand,[54][55] Heaviside's dolphins off the coast of South Africa,[56] northern elephant seals in California,[57][58] southern elephant seals in Argentina, and spotted seals in Alaska.[59][60] He has also conducted research on the diving behavior, energetics and maternal strategies of fur seals,[61][62][63][64] sea lions[65][66][67] and penguins[68][69] and locomotion and thermoregulation in whale sharks.[70]

Major publications[edit]

Davis has published about 130 peer-reviewed articles and books, but the most important have focused on: 1) the development and use of animal-borne technology that has extended our understanding of the life history, behavior, ecology and evolutionary adaptations of aquatic animals at sea, 2) the morphological, physiological and metabolic adaptations of marine mammals for deep, prolonged diving and 3) the development and use of techniques to mitigate the effects of oil exposure on sea otters and other fur bearing marine mammals and 4) the behavioral ecology of sea otters.

Honors and awards[edit]

  • 2012 Fulbright Fellow
  • 2012 Smithsonian speaker
  • 2011 Regents Professor, Texas A&M University
  • 2008 First place in the Jack Ward Competition for Non-Commercial Films presented to Jesse E. Purdy and Randall W. Davis, Co-Producers of: "The World of Weddell Seals." The 45th Animal Behavior Society Meeting
  • 2008 Christine Stevens Wildlife Award for innovations in non-invasive research methods for wildlife
  • 2007 Visiting Professor, Ocean Research Institute, University of Tokyo
  • 2005 USGS Antarctic Site Designation 18773, Davis Bluff on White Island, Antarctica in honor of research on Weddell seals from 1977-2003, including the winter of 1981
  • 1990 Distinguished Service Award for the Exxon Valdez Oil Spill Response for Sea Otters
  • 1983 Inducted into the Explorer's Club
  • 1981-84 NIH Postdoctoral Fellow
  • 1977, 1981 Antarctic Service Medal with Winter Ribbon
  • 1974 Inducted into the Phi Beta Kappa Honor Society

References[edit]

  1. ^ a b "Marine Biology Faculty". Texas A&M University.
  2. ^ a b Davis RW (2014) A review of the multi-level adaptations for maximizing aerobic dive duration in marine mammals: From biochemistry to behavior. Journal of Comparative Physiology B 184:23-53
  3. ^ a b Stone R (1998) First Glimpse at Hidden Life of Seals. Science 279:657 http://science.sciencemag.org/content/279/5351/657
  4. ^ a b Kwok R (2017) Build it yourself: From custom wildlife collars to underwater recorders, a tailor-made field device is within a biologist’s grasp. Nature 545:253-255
  5. ^ "Bio". Research Profiles. Retrieved January 1, 2018.
  6. ^ a b Kooyman GL and Davis RW. (1986) Diving behavior of Antarctic fur seals. In: Fur Seals: Maternal Strategies on Land and at Sea. (RL Gentry and GL Kooyman, eds). Princeton University Press, pp 115-125
  7. ^ a b Kooyman GL, Davis RW, Croxall J, Costa DP. (1982) Diving depths and energy requirements of king penguins, Aptenodytes patagonica. Science 217:726-727
  8. ^ Kooyman GL, Wahrenbrock EA, Castellini MA, Davis RW, and Sinnett EE. (1980) Aerobic and anaerobic metabolism during voluntary diving in Weddell seals: evidence of preferred pathways from blood chemistry and behavior. Journal of Comparative Physiology 138:335-346
  9. ^ Kooyman G (2015) Marine mammals and Emperor penguins: a few applications of the Krogh principle. American Journal of Physiology 308:R96-R104
  10. ^ Davis RW. (1983) Lactate and glucose metabolism in the resting and diving harbor seal (Phoca vitulina). Journal of Comparative Physiology 153:275-288
  11. ^ Japenga A (January 2, 1981) The Long, Dark Winter Way Down Under. Los Angeles Times, Part IV, pp 1,10-11
  12. ^ Castellini MA, Davis RW, Kooyman GL (1992) Annual Cycles of Diving Behavior and Ecology of Weddell Seals. Volume 28. University of California Press, 54 pp
  13. ^ The Explorers Club Handbook (2008) Membership Roster, p 123
  14. ^ Davis RW, Williams TM, Kooyman GL. (1985) Swimming metabolism of yearling and adult harbor seals (Phoca vitulina). Physiological Zoology 58:590-596
  15. ^ Davis RW, Castellini MA, Kooyman GL. (1991) Fuel homeostasis in harbor seals during submerged swimming. Journal of Comparative Physiology 160:627-635
  16. ^ a b Davis RW, Williams TM, Thomas JA, Kastelein RA, Cornell LH. (1988) The effects of oil contamination and cleaning on sea otters II: metabolism, thermoregulation and behavior. Canadian Journal of Zoology 66:2782-2790
  17. ^ a b Williams TM, Kastelein RA, Davis RW, Thomas JA. (1988) The effects of oil contamination and cleaning on sea otters I: thermoregulatory implications based on pelt studies. Canadian Journal of Zoology 66:2776-2781
  18. ^ a b Fan M (1989) Los Angeles Times, Sea World Scientists to Put Disaster Study on Sea Otters to Use http://articles.latimes.com/1989-03-31/local/me-616_1_sea-otter
  19. ^ a b Fan M (1989) Los Angeles Times, Sea World Experts Hope to Save Last of 5 Otters Sent From Alaska Oil Spill http://articles.latimes.com/1989-04-13/local/me-1639_1_otter-population-five-otters-oiled-otters
  20. ^ Browne, Malcolm W. (October 2, 1990). "Untitled". The New York Times - Breaking News, World News & Multimedia. Retrieved December 1, 2017.
  21. ^ a b Williams TM, Davis RW, (eds) (1995) Emergency Care and Rehabilitation of Oiled Sea Otters: A Guide for Large and Small Oil Spills Involving Fur-bearing Marine Mammals. University of Alaska Press, 279 pp
  22. ^ "Patent US5315965 - Aquatic fur-bearing mammal and bird vivarium". Google Books. May 31, 1994. Retrieved December 1, 2017.
  23. ^ "Courses, Department of Marine Biology". Texas A&M University.
  24. ^ Berg C (2014) Getting the Band Back Together: Rescuing Sea Otters. Office of Response and Restoration, National Oceanographic and Atmospheric Administration, U.S. Government http://response.restoration.noaa.gov/about/media/getting-band-back-together-rescuing-sea-otters.html
  25. ^ Cejnar J (2008) Sea otter rehab training offered. Peninsula Clarion, Kenai, Alaska http://peninsulaclarion.com/stories/022808/news_4418.shtml
  26. ^ Davis RW (1991) Advances in Rehabilitating Oiled Sea Otters: The Valdez Experience. Wildlife Journal 13:30-41
  27. ^ Davis RW, Williams TM (1991) The Saga of Alaska Sea Otters. World and I Magazine. 6(3):314-319
  28. ^ Le Boeuf BJ, Costa DP, Huntley AC, Kooyman GL, Davis RW. (1986) Pattern and depth of dives in northern elephant seals, Mirounga angustirostris. Journal of Zoology, London. 208:1-7
  29. ^ Davis RW, Wartzok D, Elsner R, Stone H. (1992) Attaching a small video camera to a Weddell seal: A new way to observe diving behavior. In: Marine Mammal Sensory Systems. (J Thomas, R Kastelein and AY Supin, eds). Plenum Press, New York pp 631-642
  30. ^ Davis RW, Fuiman L, Williams TM, Collier S, Hagey W, Kanatous, SB, Kohin S, Horning M. (1999) Hunting behavior of a marine mammal beneath the Antarctic fast-ice. Science 283:993-996
  31. ^ Rejcek P (2010) Night Hunt: Scientists track seal predation behavior through the dark of Antarctica. http://antarcticsun.usap.gov/science/contentHandler.cfm?id=2248
  32. ^ Davis RW, Fuiman L, Williams TM, Le Boeuf BJ. (2001) Three-dimensional movements and swimming activity of a female northern elephant seal. Comparative Biochemistry and Physiology. Part A 129:759-770
  33. ^ Davis RW, Fuiman LA, Williams TM, Horning M, Hagey W. (2003) Classification of Weddell seal dives based on three-dimensional movements and video recorded observations. Marine Ecology Progress Series 264:109-122
  34. ^ Davis RW, Fuiman LA, Madden K, Williams TM (2013) Classification and behavior of free-ranging Weddell seal dives based on three-dimensional movements and video-recorded observations. Deep Sea Research Part II 88:65-77
  35. ^ Davis RW and Kanatous SB. (1999) Convective oxygen transport and tissue oxygen consumption in Weddell seals during aerobic dives. Journal of Experimental Biology 202:1091-1113
  36. ^ Davis RW, Williams TM. (2012) The dive response is exercise modulated to maximize aerobic dive duration. Journal of Comparative Physiology A 198:583-591
  37. ^ Polasek L, Davis RW. (2001) Heterogeneity of myoglobin distribution in the locomotory muscles of five cetacean species. Journal of Experimental Biology 204:209-215
  38. ^ Kanatous SB, Davis RW, Watson R, Polasek L, Williams TM, Mathieu-Costello O. (2002) Aerobic capacities in the skeletal muscles of Weddell seals: key to longer dive durations? Journal of Experimental Biology 205:3601-3608.
  39. ^ Fuson AL, Cowan DF, Kanatous SB, Polasek LK, Davis RW. (2003) Adaptations to diving hypoxia in the heart, kidneys and splanchnic organs of harbor seals (Phoca vitulina). Journal of Experimental Biology 206:4139-4154
  40. ^ Watson RR, Miller TA, Davis RW. (2003) Immunohistochemical fiber typing of harbor seal skeletal muscle. Journal of Experimental Biology 206:4105-4111
  41. ^ Polasek L, Dickson KA, Davis RW. (2006) Spatial heterogeneity of aerobic and glycolytic enzyme activities and myoglobin concentration in the epaxial swimming muscles of the harbor seal (Phoca vitulina). American Journal of Physiology: Regulatory, Integrative and Comparative Physiology 290:R1720-R1727
  42. ^ Davis RW, Polasek L, Watson RR, Fuson A, Williams TM, Kanatous SB. (2004) The diving paradox: New insights into the role of the dive response in air-breathing vertebrates. Journal Comparative Biochemistry and Physiology, Part A 138:263-268
  43. ^ Browne M (1990) New York Times, Science Section, Oiled sea otter rehabilitation project https://www.nytimes.com/1990/10/02/science/492190.html?pagewanted=all
  44. ^ Wolt R, Gelwick FP, Weltz F, Davis RW. (2012) Foraging behavior and prey preference of sea otters (Enhydra lutris kenyoni) in a predominantly soft sediment habitat in Alaska. Mammalian Biology 77:271-280
  45. ^ Timm-Davis LL, Davis RW, Marshall CD (2018) Durophagous biting in sea otters (Enhydra lutris) differs kinematically from raptorial biting of other marine mammals. Journal of Experimental Biology
  46. ^ Cortez M, Wolt R, Davis RW (2016a) Development of an altricial mammal at sea I: Activity budgets of female sea otters and their pups in Simpson Bay, Alaska. Journal of Experimental Marine Biology and Ecology 481:71-80
  47. ^ Cortez M, Wolt R, Davis RW (2016b) Development of an altricial mammal at sea II: Energy budgets of female sea otters and their pups in Simpson Bay, Alaska. Journal of Experimental Marine Biology and Ecology 481:81-91
  48. ^ Pearson HC, Davis RW. (2005) Behavior of territorial male sea otters (Enhydra lutris) in Prince William Sound, Alaska. Aquatic Mammals 31:226-233
  49. ^ Finerty SE, Pearson HC, Davis RW. (2009) Summer activity pattern and field metabolic rate of adult male sea otters (Enhydra lutris) in a soft sediment habitat in Alaska. Journal of Experimental Marine Biology and Ecology 377:36-42
  50. ^ Gilkinson AK, Finerty SE, Weltz F, Dellapenna, T.M., Davis RW. (2011) Habitat associations of sea otters (Enhydra lutris) in a soft- and mixed-sediment benthos in Alaska. Journal of Mammalogy 92:1278-1286
  51. ^ Gilkinson AK, Pearson HC, Weltz F, Davis RW. (2007) Photo-identification of sea otters using nose scars. Journal of Wildlife Management 71:2045–2051.
  52. ^ Davis RW, Worthy GAJ, Würsig B, Lynn SK, Townsend FI. (1996) Diving behavior and at-sea movements of an Atlantic spotted dolphin in the Gulf of Mexico. Marine Mammal Science 12:569-581
  53. ^ Davis RW, Ortega-Ortiz J, Ribic CA, Evans WE, Biggs DC, Ressler PH, Cady RB, Harris EJ, Leben RR, Mullin KD, Würsig B. (2002) Cetacean habitat in the northern Gulf of Mexico. Deep-Sea Research, Part I 49:121-142
  54. ^ Davis RW, Jaquet N, Gendron D, Bazzino G, Markaida U, Gilly W. (2007) Diving behavior of sperm whales in relation to the behavior of their main prey, jumbo squid in the Gulf of California, Mexico. Marine Ecology Progress Series 333:291-302
  55. ^ Morrissey M (March 12, 1997) Whale not fazed by closeness. The Kaikoura Star, Kaikoura, New Zealand
  56. ^ Davis RW, David JHM, Meÿer MA Sekiguchi K, Best PB, Rodríguez D, Dassis M (2014) Home Range and Diving Behaviour of Heaviside's Dolphins monitored by satellite on the West Coast of South Africa. African Journal of Marine Science 36:455-466
  57. ^ Davis RW, Weihs D. (2007) Locomotion in deep diving elephant seals: Physical and physiological constraints. Philosophical Transactions of the Royal Society B 362:2141-2150
  58. ^ McGovern KA, Marshall CD, Davis RW (2015) Are vibrissae viable sensory structures for prey capture in northern elephant seals, Mirounga angustirostris? Anatomical Record 298:750-760
  59. ^ Lowry LF, Frost KJ, Davis RW, DeMaster DP, Suydam RS. (1998) Movements of spotted seals (Phoca largha) in the Bering and Chukchi Seas. Polar Biology 19:221-230
  60. ^ Lowry LF, Burkanov VN, Frost, KJ, Simpkins MA, Davis RW, DeMaster DP, Suydam R, Springer A. (2000) Habitat use and habitat selection by spotted seals (Phoca largha) in the Bering Sea. Canadian Journal of Zoology 78:1959-1971
  61. ^ Croxall JP, Everson I, Kooyman GL, Davis RW. (1985) Fur seal diving behavior relates to vertical distribution of krill. (1985) Journal of Animal Ecology 54:1-8
  62. ^ Gamel CM, Davis RW, David JHM, Meyer M. (2005) Reproductive energetics and female attendance patterns of Cape fur seals during early lactation. American Midland Naturalist 153:152-170
  63. ^ Lee OA, Andrews R, Burkanov V, F, Davis RW. (2014) Ontogeny of early diving and foraging behavior of northern fur seal (Callorhinus ursinus) pups from Bering Island, Russia. Marine Biology 61:1165–1178
  64. ^ Belonovich OA, Fomin SV, Burkanov VN, Andrews RD, Davis RW (2015) Foraging behavior of lactating northern fur seals (Callorhinus ursinus) in the Commander Islands, Russia. Polar Biology doi:10.1007/s00300-015-1786-9
  65. ^ Brandon EAA, Davis RW, Calkins DG, Loughlin TR. (2005) Neonatal growth of Steller’s sea lion pups. Fisheries Bulletin 103:246-257
  66. ^ Rodríguez DH, Dassis M, Ponce de León A, Barreiro C, Farenga M., Bastida RO, Davis RW (2013) Foraging strategies of Southern sea lion females in La Plata River Estuary (Argentina-Uruguay). Deep Sea Research Part II 88:120-130
  67. ^ Dassis M, Rodríguez D, Leno EN, Davis RW (2013) Submerged swimming and resting metabolic rates in Southern sea lions. Journal Experimental Marine Biology and Ecology 432-433:106-112
  68. ^ Davis RW, Kooyman GL, Croxall J. (1983) Water flux and estimated metabolism of free-ranging gentoo and macaroni penguins at South Georgia. Polar Biology 2:41-46
  69. ^ Davis RW, Croxall JP, O'Connell MJ. (1989) Reproductive energetics of gentoo and macaroni penguins on South Georgia Island. Journal of Animal Ecology 58:59-74
  70. ^ Meekan MG, Fuiman L, Davis RW, Berger Y, Thums M (2015) Swimming strategy and body plan of the world’s largest fish: implications for foraging efficiency and thermoregulation. Frontiers of Science doi:10.3389/fmars.2015.00064

External links[edit]