Free-living energy demands

Field metabolic rates

Our lab is one of the world’s leading centres for the measurement of free-living energy demands of wild animals using the doubly labelled water method. We collaborate with about 30 different groups across the globe (see map below and collaborations section on the main site for more details of individual projects). We are using the method to address a range of different questions concerning the factors that drive individual energy demands, and whether and how these demands might be limited. The work has been twice featured on the cover of Nature.

If you are interested in using the DLW method and doing analyses via our laboratory then please go to the DLW resource centre for more details of the method in general and the collaborative contracts we operate.


Since 1997 I have published a number of synthetic reviews of the available measurements of animals using the DLW method. The most recent of which was a comprehensive review including not only the energetic but also other physiological costs of reproduction in small mammals. pdfs for most of the publications listed here are available for free download here.

  • SPEAKMAN, J.R. (2008)
    The physiological cost of reproduction in small mammals.
    Philosophical transactions of the Royal Society 363: 375-398
  • SPEAKMAN, J.R. (2007)
    The energy cost of reproduction in small rodents.
    Acta theriologica sinica 27: 1-13
  • SPEAKMAN, J.R. (2000)
    The cost of living: Field metabolic rates of small mammals.
    Advances in Ecological Research 30: 177-297.
  • SPEAKMAN, J.R. (1997)
    Factors influencing daily energy expenditure of small mammals.
    Proceedings of the Nutrition Society 56: 1119-1136.

Studies of Birds

Most of our collaborative work involves mammals however we have also done a small amount of work on birds.

  • Hinsley, S.A., Hill, R.A., Bellamy, P.E., Broughton, R.K., Harrison, N.M., Mackenzie, J.A., SPEAKMAN, J.R. and Ferns, P.N. ( in press: 2009)
    Do Highly Modified Landscapes Favour Generalists at the Expense of Specialists? An Example using Woodland Birds.
    Landscape research
  • Welcker, J., Harding,A.M.A., Kitaysky, A., SPEAKMAN, J.R. and Gabrielsen, G.W. (2009)
    Daily energy expenditure increases in response to high food availability in an Arctic-breeding seabird, the little auk (Alle alle)
    Functional Ecology
  • Williams, T.D., Vézina, F., & SPEAKMAN, J.R. (2009)
    Individually-variable energy management strategies during egg production are repeatable across broods.
    Journal of Experimental Biology212: 1101-1105
  • Hinsley, S.A., Hill, R.A., Bellamy, P.E., Harrison, N.M., SPEAKMAN, J.R., Wilson, A.K.
    and Ferns, P.N. (2008)
    Effects of structural and functional habitat gaps on breeding woodland birds: working harder for less
    Landscape Ecology 23: 615-626
  • Vezina, F., SPEAKMAN, J.R., and Williams, T.D. (2006)
    Individually variable energy management strategies in relation to the costs of egg production
    Ecology 87: 2447-2458
  • Simon, A., Thomas, D.W., SPEAKMAN, J.R., Blondel, J., Perret, P. and Lambrechts, M.
    (2005) Impact of ectoparasitic blowfly larvae (Protocalliphora spp) on the behaviour and energetics of nestling blue tits (Parus caeruleus).
    Journal of Field Ornithology 76: 402-410
  • Massemin, S., Korpimäki, E., Zorn, T., Pöyri, V. & SPEAKMAN, J.R. (2004)
    Energy expenditure of nestlings in relation to food quantity and hatching span in the Eurasian Kestrel (Falco tinnunculus)
    Journal of Avian Science
  •  Thomas, D.W., Blondel, J., Perret, P., Lambrechts, M.M. and SPEAKMAN, J.R. (2001)
    Energetic and fitness costs of mismatching resource supply and demand in seasonally breeding birds.
    Science 291: 2598-2600.
  • Hawkins, P.A.J., Butler, P.J., Woakes, A.J. and SPEAKMAN, J.R. (2000)
    Estimation of the rate of oxygen consumption of the common eider duck (Somateria mollissima), with some measurements of heart rate during voluntary dives.
    Journal of Experimental Biology 203: 2819-2832.
  • Bevan, R.M., SPEAKMAN, J.R. and Butler, P.J. (1995)
    Daily energy-expenditure of tufted ducks - a comparison between indirect calorimetry, doubly
    labeled water and heart-rate.
    Functional Ecology 9: 40-47.

Studies of Mammals

The bulk of our collaborations for use of the DLW method concern studies of mammals. These include mostly small mammals but also some studies of pinnipeds that include measurements of walrus that are the largest animal ever studied using the DLW methodology.

Many of the papers were featured on the front cover of the journals (see below)

  • Sale, M., SPEAKMAN, J.R. and Arnould, J. (in press: 2009)
    Energy expenditure, water flux and activity budgets of Swamp Antechinuses in contrasting habitats.
    Journal of Mammalogy 90:
  • Sheriff, M.J.,SPEAKMAN, J.R.,Kuchel, L.,Boutin, S. andHumphries, M.M. (in press:
    The cold shoulder: free-ranging snowshoe hares maintain a low cost of living in cold climates.
    Canadian Journal of Zoology
  • Lane, J.E., Boutin, S., SPEAKMAN, J.R., and Humphries, M.M. (2009: in press)
    Energetic costs of male reproduction in a scramble competition mating system
    Journal of Animal Ecology
  • Schmid, J. and SPEAKMAN, J.R. (2009)
    Torpor and energetic consequences in free ranging gray mouse lemurs (Microcebus murinus): a comparison of dry and wet forests.
    Naturwissenschaften 96: 609-20
  • Zub K., Szafrańska P. A., Konarzewski M., Redman P., SPEAKMAN, J.R. (2009)
    Tradeoffs between activity and thermoregulation in a small carnivore, the least weasel Mustela nivalis
    Proceedings of the Royal Society B 276: 1921-1927
    This paper was featured on the front cover of the journal
  • Scantlebury, M., Waterman, J.M., Hillegrass, M., SPEAKMAN, J.R. & Bennett, N.C.
    Energetic costs of parasitism in the Cape ground squirrel Xerus inauris
    Proceedings of the Royal Society of London B 274: 2169-2177
  • Aquarone, M., Born, E.W. and SPEAKMAN, J.R. (2006)
    Field metabolic rates of Walrus (Odobenus rosmarus) measured by the doubly-labelled water
    Aquatic mammals 32: 363-369.

Walrus, the largest animals on which DLW has been used to date.

  • Scantlebury, M., SPEAKMAN, J.R., Oosthuizen, M.K., Roper, T., & Bennett, N.C. (2006)
    Energetics reveals physiologically distinct castes in a eusocial mammal.
    Nature.440: 795-797
  • Humphries M.M., Boutin S., Thomas D.W., Ryan J.D., Selman C., McAdam A.G., Berteaux
    D., SPEAKMAN, J.R. (2005)
    Expenditure freeze: the metabolic response of small mammals to cold environments
    Ecology letters 8: 1326-1333
  • Scantlebury, M., Bennett, N.C., SPEAKMAN, J.R., Pillay, N. and Schradin, C. (2006)
    The energetics of huddling in group-living African four-striped field mice Rhabdomys pumilio
    Functional Ecology 20: 166-173
  • Scantlebury, M., SPEAKMAN, J.R., and Bennett, N. (2006)
    The costs of sexual dimorphism in mole rats are morphological not behavioural.
    Proceedings of the Royal Society Series B: Biologial Sciences 273: 57-63.
  • Scantlebury, M., M.K. Oosthuizen SPEAKMAN, J.R., C.R. Jackson and Bennett, N.C.
    Seasonal energetics of the Hottentot golden mole (Ambysomus hottentottus longiceps) at High altitude (1500m)
    Physiology and behaviour 84: 739-745
  • D.M. Scantlebury, Shanas, U., Kupshtein, H., SPEAKMAN, J.R. and Haim, A.(2004)
    Differential energy costs of winter acclimatized common spiny mice Acomys
    cahirinus from two adjacent habitats
    Comparative Physiology and Biochemistry A 137: 419-423
  • SPEAKMAN, J.R., Ergon, T.E., Scantlebury, M., Reid, K.A., Cavagne, L. and Lambin, X.
    Resting metabolic rate is correlated with daily energy expenditure in free-living voles (Microtus
    agrestis) but reflects extrinsic rather than intrinsic limits.
    Proceedings of the National Academy of Sciences of the United States of America100: 14057-14062
  • Schmidt, J., Andersen, N.A, SPEAKMAN, J.R. and Nicol, S.C. (2003)
    Field energetics of free-living, lactating and non-lactating echidnas (Tachyglossus aculeatus)
    Comparative Physiology and Biochemistry A 136: 903-909
  • Korine, C., SPEAKMAN, J.R. & Arad, Z. (2004)
    Reproductive energetics of captive and free-ranging Egyptian fruit bats (Rousettus aegyptiacus)
    Ecology 85: 220-230
  • Scantlebury, M, Shanas, U., SPEAKMAN, J.R., Kupshtein, H., Afik, D. and Haim, A. (2003).
    Energetics and water economy of common spiny mice Acomys cahirinus from two adjacent
    Functional ecology 17: 178-185
  • Scantlebury, M., Russell, A.F., McIlrath, G.M., SPEAKMAN, J.R. and Clutton-Brock, T.H.
    The energetics of lactation in cooperative breeding meerkats Suricata suricatta.
    Proceedings of the Royal Society of London Series B-Biological Sciences 269: 2147-2153
    This paper was featured on the front cover of the issue.
  • Humphries, M.M., Thomas, D.W., Hall, C.L.,SPEAKMAN, J.R.., and Kramer, D.L. (2002)
    The energetics of autumn mast hoarding in eastern chipmunks
    Oecologia 133: 30-37
  • Bryce, J.M., SPEAKMAN, J.R., Johnson, P.J.and MacDonald, D.W. (2001)
    Competition between Eurasian red and introduced Eastern grey squirrels: the energetics significance of body-mass differences.
    Proceedings of the Royal Society of London Series B-Biological Sciences 268 1731-1736.
  • Schmid, J. and SPEAKMAN, J.R. (2000)
    Gender related variation in the daily energy expenditure of the grey mouse lemur (Microcebus murinus): a small primate that uses torpor.
    Journal of Comparative Physiology B – Biochemical Systemic and Environmental Physiology 170: 633-641.
  • Scantlebury, D.M., Butterwick, R. and SPEAKMAN, J.R. (2000)
    Energetics of lactation in domestic dog (Canis familiaris) breeds of two sizes.
    Comparative Biochemistry and Physiology A – Molecular and Integrative Physiology 125 Iss 2:197-210.
  • Corp, N., Gorman, M.L. and SPEAKMAN, J.R. (1999)
    Daily energy expenditure of free-living male Wood Mice in different habitats and seasons.
    Functional Ecology 13: 585-593.
  • Gorman, M.L., Mills, M.G., Raath, J.P. and
    SPEAKMAN, J.R. (1998)
    High hunting costs make African wild dogs vulnerable
    to kleptoparasitism by hyenas.
    Nature 391: 479-481.**
    This paper was featured on the front cover of the issue.
  • Arnould, J.P.Y., Boyd, I.L. and SPEAKMAN, J.R. (1996)
    The relationship between foraging behaviour and energy expenditure in Antarctic fur seals.
    Journal of Zoology 239: 769-782.
  • Poppitt, S.D., SPEAKMAN, J.R. and Racey, P.A. (1994)
    Energetics of reproduction in the lesser hedgehog tenrec, Echinops telfairi (Martin).
    Physiological Zoology 67 Iss 4: 976-994.
  • SPEAKMAN, J.R., Racey, P.A., Haim, A., Webb, P.I., Ellison, G.T.H. and Skinner, J.D. (1994)
    Interindividual and intraindividual variation in daily energy-expenditure of the pouched mouse (Saccostomus-campestris).
    Functional Ecology 8: 336-342.
  • Stephenson, P.J., SPEAKMAN, J.R. and Racey, P.A. (1994)
    Field metabolic-rate in 2 species of shrew-tenrec, Microgal- dobsoni and M-talazaci.
    Comparative Biochemistry and Physiology A - Physiology 107 Iss 2: 283-287.
  • Poppitt, S.D., SPEAKMAN, J.R. and Racey, P.A. (1993)
    The energetics of reproduction in the common shrew (Sorex-araneus) - a comparison of indirect calorimetry and the doubly labeled water method.
    Physiological Zoology 66: 964-982.
  • SPEAKMAN, J.R., Racey, P.A., Haim, A., Webb, P.I., Ellison, G.T.H. and Skinner, J.D. (1992)
    Daily energy-expenditure in the pouched mouse (Saccostomus-campestris Peters 1896).
    Israel Journal of Zoology 38: 341-351.
  • SPEAKMAN, J.R. and Racey, P.A. (1991)
    No cost of echolocation for bats in flight.
    Nature 350: 421-423.
    This paper was featured on the front cover of the issue

Studies on reptiles

  • Brown, R.P., Perez-Mellado, V., Diego-Rasilla, J., Garcia, J.A., Naranjo, A. and SPEAKMAN, J.R. (1992)
    Individual and population energetics of a lizard on a Mediterranean islet.
    Oecologia 91 Iss 4: 500-504.
  • Brown, R.B., Thorpe, R.S. and SPEAKMAN, J.R. (1992)
    Comparisons of body size, field energetics, and water flux among populations of the skink Chalcides-sexlineatus.
    Canadian Journal of Zoology 70 Iss 5: 1001-1006