Great Hornbill Casque Functions as a Thermoregulatory Radiator


 

THE SARAWAK MUSEUM JOURNAL
VOL LXXIX NO.100 DECEMBER 2018

 
 
Title : 
Great Hornbill Casque Functions as a Thermoregulatory Radiator

Author : 
Stephen K. Slaughter and Pilai Poonswad

Abstract:
Hornbills (Bucerotidae) are defined by their casques, structures that are extensions of the beak. The purpose of these structures, which take diverse forms, has been subject to speculation. In this study, it is asserted that a primary function of the casque is thermoregulation, its large vascularised surface area functioning as a structure to facilitate heat exchange. Infrared thermography on a Great Hornbill (Buceros bicornis) revealed that the bird’s casque exhibited significant percentage of heat loss in relation to the body's resting heat production along a temperature gradient of 19.2 to 34.2°C. The results indicate that the casque is capable of dissipating a disproportionate amount of heat in relation to the rest of its body and even comparable to major thermal windows in other animals.

DOI:
https://doi.org/10.61507/smj22-2018-M6H8-06


How to cite:
Stephen K. Slaughter and Pilai Poonswad (2018). Great Hornbill Casque Functions as a Thermoregulatory Radiator. Sarawak Museum Journal, LXXIX (100): 87-96 https://doi.org/10.61507/smj22-2018-M6H8-06

References
  1. Poonswad, P., Kemp, A. & Strange, M. 2013 Hornbills of the World. Draco Publishing, 212 p.
  2. Kinnaird, M.F. & O’Brien, T.G. 2007 The Ecology and Conservation of Asian Hornbills: Farmers of the Forest. University of Chicago Press, Chicago, 315 p.
  3. Alexander, G.D., Houston, D.C. & Campbell, M. 1994 A possible acoustic function for the casque structure in hornbills. Journal of Zoology. 233: 57–67.
  4. Tattersall, G.J., Andrade, D.V. & Abe, A.S. 2009 Heat Exchange from the Toucan Bill Reveals a Controllable Vascular Thermal Radiator, Science 325 (5939): 468–470.
  5. van de Van, T.M.F.N., Martin, F.O., Vink, T.J.F., McKechnie, A.E. & Cunningham, S.J. 2016 Regulation of Heat Exchange across the Hornbill Beak: Functional Similarities with Toucans? PLoS ONE 11(5): e0154768.
  6. McNab, B.K. 2001 Energetics of toucans, a barbet, and a hornbill: Implications for avian folivery. Auk (118): 916.
  7. Tattersall, G.J. 2016 Thermimage: Thermal Image Analysis. R package version 2.1.1. https://CRAN.R-project.org/package=Thermimage.
  8. Greenberg, R., Cadena, V., Danner, R.M. & Tattersall, G.J. 2012 Heat loss may explain bill size differences between birds occupying different habitats. PLoS ONE 7: e40933

 

 

 
 

Copyright © 2021 Sarawak Museum Department
Last Updated On 22 Nov 2024

Operating Hours (Main Office)

Monday - Thursday
8.00am to 1.00pm & 2.00pm to 5.00pm

Friday
8.00am to 11.45pm & 2.00pm to 5.00pm

Saturday, Sunday, Public Holiday
Counter Closed
image Polls
image Announcement