Skip to main content
Springer Nature Link
Log in

Thermoregulation in a large bird, the emu (Dromaius novaehollandiae)

  • Published:
Save article
View saved research
Journal of Comparative Physiology B Aims and scope Submit manuscript

Abstract

The emu is a large, flightless bird native to Australia. Its habitats range from the high snow country to the arid interior of the continent. Our experiments show that the emu maintains a constant body temperature within the ambient temperature range-5 to 45°C. The males regulate their body temperature about 0.5°C lower than the females. With falling ambient temperature the emu regulates its body temperature initially by reducing conductance and then by increasing heat production. At-5°C the cost of maintaining thermal balance is 2.6 times basal metabolic rate. By sitting down and reducing heat loss from the legs the cost of homeothermy at-5°C is reduced to 1.5 times basal metabolic rate. At high ambient temperatures the emu utilises cutaneous evaporative water loss in addition to panting. At 45°C evaporation is equal to 160% of heat production. Panting accounts for 70% of total evaporation at 45°C. The cost of utilising cutaneous evaporation for the other 30% appears to be an increase in dry conductance.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+
from $39.99 /Month
  • Starting from 10 chapters or articles per month
  • Access and download chapters and articles from more than 300k books and 2,500 journals
  • Cancel anytime
View plans

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Explore related subjects

Discover the latest articles, books and news in related subjects, suggested using machine learning.

Abbreviations

A r :

Effective radiating surface area

BMR:

basal metabolic rate

C dry :

dry conductance

CEWL:

cutaneous evaporative water loss

EHL:

evaporative heat loss

EWL:

evaporative water loss

FECO2 :

fractional concentration of CO2 in excurrent air

FFH2O :

water content of chamber excurrent air

FEO2 :

fractional concentration of O2 in chamber excurrent air

FICO2 :

fractional concentration of CO2 in incurrent air

FIO2 :

fractional concentration of O2 in chamber incurrent air

MHP:

metabolic heat production

MR:

metabolic rate

REWL:

respiratory evaporative water loss

RH:

relative humidity

RQ:

respiratory quotient\((\dot VCO_2 /\dot VO_2 )\);

SA:

surface area

SEM:

standard error of the mean

SNK:

Student-Newman-Keuls multiple range test

STPD:

standard temperature and pressure dry

T a :

ambient temperature(s)

T b :

body temperature(s)

T e :

surface temperature(s)

\(\dot V\) :

flow rate of air into the chamber

\(\dot VCO_2\) :

carbon dioxide production

\(\dot VO_2\) :

oxygen consumption

\(VP_{H_2 O}\) :

vapour pressure of water

References

  • Arad Z, Gavrieli-Levin I, Eylath U, Marder J (1987) Effect of dehydration on cutancous water evaporation in heat-exposed pigeons (Columba livia). Physiol Zool 60:623–630

    Google Scholar 

  • Arad Z, Midtgård U, Bernstein MH (1989) Thermoregulation in turkey vultures: vascular anatomy, arteriovenous heat exchange, and behaviour. Condor 91:505–514

    Google Scholar 

  • Aschoff J (1981) Thermal conductance in mammals and birds: its dependence on body size and circadian phase. Comp Biochem Physiol 69A:611619

    Google Scholar 

  • Bech C (1980) Body temperature, metabolic rate, and insulation in winter and summer acclimatized mute swans (Cygnus olor). J Comp Physiol 136:61–66

    Google Scholar 

  • Bernstein MH, Samiengo FC (1981) Ventilation and acid-base status during thermal panting in pigeons (Columba livia). Physiol Zool 54:303–315

    Google Scholar 

  • Brück K (1986) Basic mechanisms in thermal long-term and shortterm adaptation. J Therm Biol 11:73–77

    Google Scholar 

  • Calder WA, Schmidt-Nielsen K (1968) Panting and blood carbon dioxide in birds. Am J Physiol 215:477–482

    Google Scholar 

  • Calder WA, Dawson TJ (1978) Resting metabolic rates of ratite birds: the kiwis and the emu. Comp Biochem Physiol 60A:479–481

    Google Scholar 

  • Cracraft J (1974) Phylogeny and evolution of the ratite birds. Ibis 116:494–521

    Google Scholar 

  • Crawford EC, Schmidt-Nielsen K (1967) Temperature regulation and evaporative cooling in the ostrich. Am J Physiol 212:347–353

    Google Scholar 

  • Crawford EC, Lasiewski RC (1968) Oxygen consumption and respiratory evaporation of the emu and rhea. Condor 70:333–339

    Google Scholar 

  • Dawson TJ, Schmidt-Nielsen K (1966) Effect of thermal conductance on water economy in the antelope jack rabbit,Lepus alleni. J Cell Physiol 67:463–472

    Google Scholar 

  • Dawson TJ, Read D, Russell EM, Herd RM (1984) Seasonal variation in daily activity patterns, water relations and diet of emus. Emu 84:93–102

    Google Scholar 

  • Dmi'el R, Tel-Tzur D (1985) Heat balance of two starling species (Sturnus vulgaris andOnychognathus tristrami) from temperate and desert habitats. J Comp Physiol B 155:395–402

    Google Scholar 

  • Drent RH, Stonehouse B (1971) Thermoregulatory responses of the Peruvian penguin,Spheniscus humboldti. Comp Biochem Physiol 40A:689–710

    Google Scholar 

  • Folkow LP, Mercer JB (1986) Partition of heat loss in resting and exercising winter- and summer-insulated reindeer. Am J Physiol 251:R32-R40

    Google Scholar 

  • Frumkin R, Pinshow B, Weinstein Y (1986) Metabolic heat production and evaporative heat loss in desert phasianids: chukar and sand partridge. Physiol Zool 59:592–605

    Google Scholar 

  • Grice D, Caughley G, Short J (1985) Density and distribution of emus. Aust Wildl Res 12:69–73

    Google Scholar 

  • Hayes JP, Speakman JR, Racey PA (1992) Sampling bias in respirometry. Physiol Zool 65:604–619

    Google Scholar 

  • Herreid CF, Kessel B (1967) Thermal conductance in birds and mammals. Comp Biochem Physiol 21:405–414

    Google Scholar 

  • Hill RW (1972) Determination of oxygen consumption by use of the paramagnetic oxygen analyzer. J Appl Physiol 33:261–263

    Google Scholar 

  • Hinds DS, Calder WA (1973) Temperature regulation of the pyrrhuloxia and the Arizona cardinal. Physiol Zool 46:55–71

    Google Scholar 

  • Hurlbert SH (1984) Pseudoreplication and the design of ecological field experiments. Ecol Monogr 54:187–211

    Google Scholar 

  • Hyrtl J (1863) Neue Wundernetze und Geflechte bei Vögeln und Säugetieren. Denkschr Mathem Naturw Classe 22:113–152

    Google Scholar 

  • Jones JH, Grubb B, Schmidt-Nielsen K (1983) Panting in the emu causes arterial hypoxemia. Respir Physiol 54:189–195

    Google Scholar 

  • Louw GN, Belonje PC, Coetzee HJ (1969) Renal function, respiration, heart rate, and thermoregulation in the ostrich (Struthio camelus). Sci Pap Namib Desert Res Stn 42:43–54

    Google Scholar 

  • Maloney SK, Dawson TJ (1993) Sexual dimorphism in basal metabolism and body temperature of a large bird, the emu. Condor 95:1034–1037

    Google Scholar 

  • Maloney SK, Dawson TJ (1994) Ventilatory accommodation of oxygen demand and respiratory water loss in a large bird, the emu (Dromaius novaehollandiae), and a re-examination of ventilatory allometry for birds. J Comp Physiol B (in Press)

  • Marder J, Gavrieli-Levin I (1987) The heat-acclimated pigeon: an ideal physiological model for a desert bird. J Appl Physiol 62:952–958

    Google Scholar 

  • Marder J, Arad Z (1989) Panting and acid-base regulation in heat stressed birds. Comp Biochem Physiol 94A:395–400

    Google Scholar 

  • Marder J, Raber P (1989) Beta-adrenergic control of trans-cutaneous evaporative cooling mechanisms in birds. J Comp Physiol B 159:97–103

    Google Scholar 

  • Marder J, Arieli Y, Ben-Asher J (1989) Defense strategies against environmental heat stress in birds. Isr J Zool 36:61–75

    Google Scholar 

  • Midtgård U (1980) Heat loss from the feet of mallardsAnas platyrhynchos and arterio-venous heat exchange in the rete tibiotarsale. Ibis 122:354–359

    Google Scholar 

  • Midtgård U (1981) The rete tibiotarsale and arteriovenous association in the hind limb of birds: a comparative morphological study on counter-current heat exchange systems. Acta Zool (Stockholm) 62:67–87

    Google Scholar 

  • Phillips PK, Heath JE (1992) Heat exchange by the pinna of the African elephant (Loxodonta africana). Comp Biochem Physiol 101A:693–699

    Google Scholar 

  • Porter WP (1969) Thermal radiation in metabolic chambers. Science 166:115–117

    Google Scholar 

  • Schmidt-Nielsen K (1979) Animal Physiology: adaptation and environment, 2nd edn. Cambridge University Press, Cambridge, UK

    Google Scholar 

  • Schmidt-Nielsen K, Schmidt-Nielsen B (1952) Water metabolism of desert mammals. Physiol Rev 32:135–166

    Google Scholar 

  • Schmidt-Nielsen K, Kanwisher J, Lasiewski RC, Cohn JE, Bretz WL (1969) Temperature regulation and respiration in the ostrich. Condor 71:341–352

    Google Scholar 

  • Steen I, Steen JB (1965) The importance of the legs in the thermoregulation of wading birds. Acta Physiol Scand 63:285–291

    Google Scholar 

  • Taylor CR, Dmi'el R, Fedak M, Schmidt-Nielsen K (1978) Energetic cost of running and heat balance in a large bird, the rhea. Am J Physiol 221:596–601

    Google Scholar 

  • Walsberg GA, King JR (1978) The relationship between external surface area of birds to skin surface area and body mass. J Exp Biol 76:185–189

    Google Scholar 

  • Weast RC, Astle MJ (1983) CRC handbook of chemistry and physics. CRC Press, Boca Raton, Florida

    Google Scholar 

  • Winston PW, Bates DH (1960) Saturated solutions for the control of humidity in biological research. Ecology 41:232–237

    Google Scholar 

  • Withers PC (1983) Energy, water and solute balance of the ostrich,Struthio camelus. Physiol Zool 56:568–579

    Google Scholar 

  • Withers PC, Williams JB (1990) Metabolic and respiratory physiology of an arid-adapted Australian bird, the spinifex pigeon. Condor 92:961–969

    Google Scholar 

  • Young BA, Fenton TW, McLean JA (1984) Calibration methods in respiratory calorimetry. J Appl Physiol 56:1120–1125

    Google Scholar 

Download references

Author information

Author notes

  1. S. K. Maloney

    Present address: Brain Function Research Unit, University of the Witwatersrand, 7 York Road, 2193, Parktown, South Africa

Authors and Affiliations

  1. School of Biological Science, University of New South Wales, PO Box 1, 2033, Kensington, Australia

    S. K. Maloney & T. J. Dawson

Authors
  1. S. K. Maloney
    View author publications

    Search author on:PubMed Google Scholar

  2. T. J. Dawson
    View author publications

    Search author on:PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Maloney, S.K., Dawson, T.J. Thermoregulation in a large bird, the emu (Dromaius novaehollandiae). J Comp Physiol B 164, 464–472 (1994). https://doi.org/10.1007/BF00714584

Download citation

  • Accepted:

  • Issue date:

  • DOI: https://doi.org/10.1007/BF00714584

Key words