The role of hornbill casques : fancy ornamentation or integral thermoregulatory apparatus?
Issued Date
2018
Copyright Date
2018
Resource Type
Language
eng
File Type
application/pdf
No. of Pages/File Size
xii, 69 leaves : ill. (some col.)
Access Rights
open access
Rights
ผลงานนี้เป็นลิขสิทธิ์ของมหาวิทยาลัยมหิดล ขอสงวนไว้สำหรับเพื่อการศึกษาเท่านั้น ต้องอ้างอิงแหล่งที่มา ห้ามดัดแปลงเนื้อหา และห้ามนำไปใช้เพื่อการค้า
Rights Holder(s)
Mahidol University
Bibliographic Citation
Thesis (M.Sc. (Environmental Biology))--Mahidol University, 2018
Suggested Citation
Slaughter, Stephen Kendall The role of hornbill casques : fancy ornamentation or integral thermoregulatory apparatus?. Thesis (M.Sc. (Environmental Biology))--Mahidol University, 2018. Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/92308
Title
The role of hornbill casques : fancy ornamentation or integral thermoregulatory apparatus?
Author(s)
Advisor(s)
Abstract
Various hypotheses have been formed to explain the function of casques in hornbills (Fam Bucerotidae), especially in large-casqued hornbill species. This study hypothesized that large-casqued hornbill species use their casques for thermoregulation by dissipating heat from the surface of the body to the surrounding air through convection and radiation. This study was conducted with a captive male Great Hornbill (Buceros bicornis), female Rhinoceros Hornbill (Buceros rhinoceros), male and female Oriental Pied Hornbills (Anthracoceros albirostris), male and female Wreathed Hornbills (Rhyticeros undulatus), and male and female White-crowned Hornbills (Berenicornis comatus), with the Great Hornbill being the principal focal subject. Infrared thermography was used to record surface temperatures from various body parts of all subjects in relation to ambient temperature, and heat loss was calculated from the values obtained. The average combined heat loss through convection and radiation from the casque of the Great Hornbill was 6 .16±1.24 W, with the average percentage loss of the bird's resting heat production (RHP) of 3.1 W being 199%. Other large-casqued hornbills also exhibited high heat loss through the casque, the Rhinoceros Hornbill losing 126% heat of its RHP, and male and female Oriental Pied Hornbills losing 55% and 27% of the RHP, respectively through their casques. It is speculated that the casques of large-casqued hornbills may serve the primary function of thermoregulation.
Description
Environmental Biology (Mahidol University 2018)
Degree Name
Master of Science
Degree Level
Master's degree
Degree Department
Faculty of Science
Degree Discipline
Environmental Biology
Degree Grantor(s)
Mahidol University