Does egg location in the
incubator affect a chick’s time of hatch and hatchability? In
still air incubators, you’ll find relatively wide temperature
variations throughout the incubator, but even our top of the line Brinsea
Octagon 20 Advance Incubator shows differences in hatch
rate related to egg location in the tray. The picture to the
right is the summary of my results from two hatches, suggesting that
eggs in the center are less likely to hatch than those around the
edges, and my notes show that central eggs also tend to hatch later.
The fan in our incubator keeps air moving, so you would think that all
of the eggs would be equally warm. However, a reader on our homesteading blog suggested
that radiant heat from the central heating element preferentially warms
the eggs directly underneath. His hypothesis makes a lot of
sense, as does his solution of using some kind of barrier like aluminum
foil below the heating unit to block the radiant heat while allowing
the fans to continue to circulate warmed air. It looks like I’m
going to have to do some experiments with moving thermometers around
inside the incubator to find out whether there really are high
temperature pockets and how to fix them.