| Autor: |
Hermann Rahn, Charles V. Paganelli, Ralph A. Ackerman |
| Rok vydání: |
1977 |
| Předmět: |
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| Zdroj: |
Physiological Zoology. 50:269-283 |
| ISSN: |
0031-935X |
| DOI: |
10.1086/physzool.50.4.30155731 |
| Popis: |
An egg diffusion hygrometer is described for measurement of absolute humidity in the nest air immediately surrounding bird eggs during natural incubation. The empty eggshell of the species under study is filled with a drying agent and calibrated by observing its weight change in time upon exposure to known water vapor tensions. Such an egg is then placed in the nest for several days and its rate of gain in weight recorded, from which the mean vapor pressure during exposure can be calculated. The vapor pressure in the nest microclimate of eight species varied from 18 to 26 torr. An indirect method for predicting nest air vapor pressure without the use of a hygrometer is also presented, and for 10 other species yields values similar to those of the diffusion hygrometer. The vapor pressure of nest air is always greater than that of ambient air; from the difference and the known rate of water loss of the egg, nest ventilation can be calculated. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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