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Emu Emu Society
Journal of BirdLife Australia
RESEARCH ARTICLE

Microclimate of nesting burrows of the Rainbow Bee-eater

Alan Lill A B C and Peter J. Fell A
+ Author Affiliations
- Author Affiliations

A Wildlife Ecology Research Group, School of Biological Sciences, Monash University, Clayton Campus, Vic. 3800, Australia.

B School of Psychology, Psychiatry and Psychological Medicine, Monash University, Clayton Campus, Vic. 3800, Australia.

C Corresponding author. Email: Alan.Lill@sci.monash.edu.au

Emu 107(2) 108-114 https://doi.org/10.1071/MU06046
Submitted: 11 December 2006  Accepted: 8 May 2007   Published: 13 June 2007

Abstract

Burrow-nesting affords protection from predators and climatic extremes, but potentially can pose physiological ‘problems’ for developing birds and attendant adults. Microclimate parameters of burrows of breeding Rainbow Bee-eaters (Merops ornatus) were measured to assess whether they presented such difficulties for young and adults. Estimated mean volume of the brood-chamber was ~4.5 L. Relative humidity was typically 100% in the brood-chamber and chamber air temperature was constant, averaging 4–6°C above ambient levels. The temperature regime of the burrow probably resulted in low thermoregulatory costs for attendant adults and endothermic nestlings. The chamber oxygen (O2) fraction (mean 19.35%) was always lower than ambient values, but mostly not sufficiently low to be problematic for the growing young. Mean pre-internal pipping absolute oxygen consumption rate of embryos (62.9 ± 13.8 mL O2 day–1) did not appear to be strongly influenced by either the protracted incubation period or the reduced O2 partial pressure of the chamber atmosphere. Mean eggshell water-vapour conductance (8.95 mg day–1 kPa–1) was tuned to egg mass rather than egg mass/incubation period. However, eggs still lost ~15% of their mass during incubation because the influence of the small water-vapour pressure difference across the shell (2.91 kPa) and the protraction of the incubation period apparently counteracted each other.


Acknowledgements

We gratefully acknowledge the assistance of George and (the late) Dorothy Merritt, David and Thelma Basselot-Hall, Bob Wood, Frank Devlin, the Victorian Department of Sustainability and Environment, Peter Domelow and Max Hart. Approval for the investigation was obtained from the Monash University School of Biological Sciences Animal Ethics Committee. Three anonymous referees provided some useful comments on the manuscript.


References

Ackerman, R. A. , Whittow, G. C. , Paganelli, C. V. , and Pettit, T. N. (1980). Oxygen consumption, gas exchange and growth of embryonic wedge-tailed shearwaters (Puffinus pacificus chlorhynchus). Physiological Zoology 53, 210–221.
Ar A., and Sidis Y. (2002). Nest microclimate during incubation. In ‘Avian Incubation: Behaviour, Environment, and Evolution’. (Ed. D. C. Deeming.) pp.143–160. (Oxford University Press: Oxford, UK.)

Ar, A. , Paganelli, C. V. , Reeves, R. B. , Greene, D. G. , and Rahn, H. (1974). The avian egg: water vapour conductance, shell thickness and functional pore area. Condor 76, 153–158.
Crossref | GoogleScholarGoogle Scholar | Carey C. (2002). Incubation in extreme environments. In ‘Avian Incubation: Behaviour, Environment, and Evolution’. (Ed. D. C. Deeming.) pp. 238–253. (Oxford University Press: Oxford, UK.)

Colby, C. , Kilgore, D. L. , and Howe, S. (1987). Effects of hypoxia and hypercapnia on VT, f and VI of nestling and adult bank swallows. American Journal of Physiology 253, R854–R860.
PubMed | Deeming D. C. (2002). Functional characteristics of eggs. In ‘Avian Incubation: Behaviour, Environment, and Evolution’. (Ed. D. C. Deeming.) pp. 28–42. (Oxford University Press: Oxford, UK.)

Fitzherbert K. (1985). The role of energetic factors in the evolution of the breeding biology of the short-tailed shearwater (Puffinus tenuirostris, Temminck). Ph.D. Thesis, Monash University, Melbourne.

Fry C. H. (2004). Family Meropidae (Bee-eaters). In ‘Handbook of the Birds of the World. Vol. 6. Mousebirds to Hornbills’. (Eds J. del Hoyo, A. Elliott and J. Sargatal.) pp. 286–341. (Lynx Edicions: Barcelona.)

Hainsworth F. R., and Voss M. A. (2002). Intermittent incubation: predictions and tests for time and heat allocations. In ‘Avian Incubation: Behaviour, Environment, and Evolution’. (Ed. D. C. Deeming.) pp. 223–237. (Oxford University Press: Oxford, UK.)

Higgins P. J. (Ed.) (1999). ‘Handbook of Australian, New Zealand and Antarctic Birds. Vol. 4: Parrots to Dollarbird.’ (Oxford University Press: Melbourne.)

Hilbert D., and Cohn-Vossen S. (1999). ‘Geometry and the Imagination.’ (Chelsea: New York.)

Hoyt, D. F. (1976). The effect of shape on the surface–volume relationships of birds’ eggs. Condor 78, 343–349.
Crossref | GoogleScholarGoogle Scholar | Kendeigh S. C., Dol’nik V. R., and Gavrilov V. M. (1977). Avian energetics. In ‘Granivorous Birds in Ecosystems’. (Eds J. Pinowski and S. C. Kendeigh.) pp. 129–205. (Cambridge University Press: Cambridge, UK.)

Lill, A. (1993). Breeding of rainbow bee-eaters in southern Victoria. Corella 17, 100–106.
Martin T. E. (1992). Interaction of nest predation and food limitation in reproductive strategies. In ‘Current Ornithology. Vol. 9’. (Ed. D. M. Power.) pp. 163–197. (Plenum Press: New York.)

Prinzinger, R. , and Dietz, V. (1995). Qualitative course of embryonic oxygen consumption in altricial and precocial birds. Respiration Physiology 100, 289–294.
Crossref | GoogleScholarGoogle Scholar | PubMed | Pywell S. R. (1990). The behavioural energetics of foraging in the Rainbow Bird (Merops ornatus). B.Sc.(Honours) Thesis, Monash University, Melbourne.

Rahn, H. , and Whittow, G. C. (1988). Adaptations to a pelagic life: eggs of the albatross, shearwater and petrel. Comparative Biochemistry and Physiology Part A: Physiology 91, 415–423.
Crossref | GoogleScholarGoogle Scholar | Tenney S. M., and Boggs D. F. (1983). Comparative mammalian respiratory control. In ‘The Handbook of Physiology: Section 3: The Respiratory System, Vol II Control of Breathing’. (Eds N. S. Cherniack and J. G. Widdicombe.) pp. 833–855. (American Physiological Society: Bethesda, MD.)

Tinbergen J. M., and Williams J. B. (2002). Energetics of incubation. In ‘Avian Incubation: Behaviour, Environment, and Evolution’. (Ed. D. C. Deeming.) pp. 219–313. (Oxford University Press: Oxford, UK.)

Vleck, C. M. , and Kenagy, G. J. (1980). Embryonic metabolism of the fork-tailed storm petrel: physiological patterns during prolonged and interrupted incubation. Physiological Zoology 53, 32–42.


Webb, D. R. (1987). Thermal tolerance of avian embryos: a review. Condor 89, 874–898.
Crossref | GoogleScholarGoogle Scholar |

White, F. N. , Bartholomew, G. A. , and Kinney, J. L. (1978). Physiological and ecological correlates of tunnel nesting in the European bee-eater, Merops apiaster. Physiological Zoology 54, 140–154.


Wickler, S. J. , and Marsh, R. L. (1981). Effects of nestling age and burrow depth on CO2 and O2 concentrations in the burrows of bank swallows (Riparia riparia). Physiological Zoology 54, 132–136.


Withers, P. C. (1976). Models of diffusion-mediated gas exchange in animal burrows. American Naturalist 112, 1101–1112.