Water vapour conductance of eggs during incubation
The water vapour conductance of whole eggs was significantly different
to that calculated from allometric equations using the egg’s mass
(df=19, T=3.86, p=0.001) (Figure 7A).
We compared the water vapour conductance calculated in this study for
whole incubated eggs with that reported in the literature (Table 7).
Calder (1978a) used infertile eggs and the methodology employed by Rahn
et al., (1974). Sylin-Roberts (1983) devised a method for calculating
the pore number and pore area and calculated the water vapour
conductance of the whole egg from three eggshell fragments. Both these
studies were done on Apteryx australis eggs and eggshells, but at
this time, Apteryx australis included A. mantelli ,A. rowi , and A. australis .
We plotted the resulting water vapour conductance alongside the data
published by Ar et al.,1974, where they demonstrated how the water
vapour conductance is proportional to the 0.78 power of the eggs mass
(Figure 8). Here we show how the water vapour conductance of Brown Kiwi
fits perfectly with what is observed for other species.