The evolution of the avian bill as a thermoregulatory organ
© 2016 Cambridge Philosophical Society The avian bill is a textbook example of how evolution shapes morphology in response to changing environments. Bills of seed-specialist finches in particular have been the focus of intense study demonstrating how climatic fluctuations acting on food availability...
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| Format: | Journal Article |
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Wiley-Blackwell Publishing Ltd.
2017
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| Online Access: | http://hdl.handle.net/20.500.11937/69001 |
| _version_ | 1848761942087303168 |
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| author | Tattersall, Glenn Arnaout, B. Symonds, M. |
| author_facet | Tattersall, Glenn Arnaout, B. Symonds, M. |
| author_sort | Tattersall, Glenn |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © 2016 Cambridge Philosophical Society The avian bill is a textbook example of how evolution shapes morphology in response to changing environments. Bills of seed-specialist finches in particular have been the focus of intense study demonstrating how climatic fluctuations acting on food availability drive bill size and shape. The avian bill also plays an important but under-appreciated role in body temperature regulation, and therefore in energetics. Birds are endothermic and rely on numerous mechanisms for balancing internal heat production with biophysical constraints of the environment. The bill is highly vascularised and heat exchange with the environment can vary substantially, ranging from around 2% to as high as 400% of basal heat production in certain species. This heat exchange may impact how birds respond to heat stress, substitute for evaporative water loss at elevated temperatures or environments of altered water availability, or be an energetic liability at low environmental temperatures. As a result, in numerous taxa, there is evidence for a positive association between bill size and environmental temperatures, both within and among species. Therefore, bill size is both developmentally flexible and evolutionarily adaptive in response to temperature. Understanding the evolution of variation in bill size however, requires explanations of all potential mechanisms. The purpose of this review, therefore, is to promote a greater understanding of the role of temperature on shaping bill size over spatial gradients as well as developmental, seasonal, and evolutionary timescales. |
| first_indexed | 2025-11-14T10:39:41Z |
| format | Journal Article |
| id | curtin-20.500.11937-69001 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:39:41Z |
| publishDate | 2017 |
| publisher | Wiley-Blackwell Publishing Ltd. |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-690012018-06-29T12:35:37Z The evolution of the avian bill as a thermoregulatory organ Tattersall, Glenn Arnaout, B. Symonds, M. © 2016 Cambridge Philosophical Society The avian bill is a textbook example of how evolution shapes morphology in response to changing environments. Bills of seed-specialist finches in particular have been the focus of intense study demonstrating how climatic fluctuations acting on food availability drive bill size and shape. The avian bill also plays an important but under-appreciated role in body temperature regulation, and therefore in energetics. Birds are endothermic and rely on numerous mechanisms for balancing internal heat production with biophysical constraints of the environment. The bill is highly vascularised and heat exchange with the environment can vary substantially, ranging from around 2% to as high as 400% of basal heat production in certain species. This heat exchange may impact how birds respond to heat stress, substitute for evaporative water loss at elevated temperatures or environments of altered water availability, or be an energetic liability at low environmental temperatures. As a result, in numerous taxa, there is evidence for a positive association between bill size and environmental temperatures, both within and among species. Therefore, bill size is both developmentally flexible and evolutionarily adaptive in response to temperature. Understanding the evolution of variation in bill size however, requires explanations of all potential mechanisms. The purpose of this review, therefore, is to promote a greater understanding of the role of temperature on shaping bill size over spatial gradients as well as developmental, seasonal, and evolutionary timescales. 2017 Journal Article http://hdl.handle.net/20.500.11937/69001 10.1111/brv.12299 Wiley-Blackwell Publishing Ltd. restricted |
| spellingShingle | Tattersall, Glenn Arnaout, B. Symonds, M. The evolution of the avian bill as a thermoregulatory organ |
| title | The evolution of the avian bill as a thermoregulatory organ |
| title_full | The evolution of the avian bill as a thermoregulatory organ |
| title_fullStr | The evolution of the avian bill as a thermoregulatory organ |
| title_full_unstemmed | The evolution of the avian bill as a thermoregulatory organ |
| title_short | The evolution of the avian bill as a thermoregulatory organ |
| title_sort | evolution of the avian bill as a thermoregulatory organ |
| url | http://hdl.handle.net/20.500.11937/69001 |