Ontogenetic changes in water-vapor conductance of eggs of yellow-headed blackbirds (Xanthocephalus xanthocephalus)

✍ Scribed by Hanka, Ladislav R. ;Packard, Gary C. ;Sotherland, Paul R. ;Taigen, Theodore L. ;Boardman, Thomas J. ;Packard, Mary J.

• Book ID: 102335301
• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 241 KB
• Volume: 210
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402100121

✦ Synopsis

Abstract

Eggs of Yellow‐headed Blackbirds were incubated in a forceddraft incubator, and conductance of eggs to water vapor was determined for eggs having undergone different amounts of development. Multiple regression analysis indicated that water‐vapor conductance is related to incubation time (expressed in both linear and quadratic forms) and to the length of pores through eggshells. Studies of geographic variation in conductance within a single avian species may be subject to serious sampling error if the eggs are at different stages of incubation at the time they are collected for study. Also, pore length is a better approximation to length of the diffusion pathway through an eggshell than is shell thickness.