Do eggs create their own heat?

[Stockwell]

Well, this is all interesting.
Its all news to me.
Eggs producing their own heat...?? Maybe, I really don't know. Certainly decomposition produces heat, as does fermentation, but normal developing ectotherms producing heat.. Maybe, I've never investigated that before, and can't say I've noticed any such effect in my years of incubation.

The only comments I can make involves the thermodynamics and instrumentation.
To start with, most thermometers are not accurate, so extreme care must be taken to utilize the same thermometer in all experiments. I assume this is being done, but even battery voltage will effect the reading on all electronic thermometers.
I discovered that several years back.
I have a big collection of thermometers,and tend to collect them, and most indoor/ outdoor probe type read higher as the battery gets weaker. This can vary by almost 2 degrees F.Somewhat opposite to what one might think.
Lab grade spirit or mercury thermometers(non electronic) can be used for all tests but also have intrinsic problems, primarily that they have too much mass to respond quickly.
Another consideration is that adding eggs to an egg box, compeletely changes the thermal dynamics of the box, because of the increased mass.
All incubators will have heat up and cool down curves,(think of a temp vs time graph) which is based on the differential of the thermostat, and the BTU output of the heat source vs the outside ambient loss factor.
Most thermometers won't accurately reflect the heat up and cool down curve, because the response time of the thermometers will be different than that of the air in the controlled space.
Adding mass to any system has the effect of dampening and averaging the extremes.
Depending on the overshoot and differential of the system, the egg mass might read higher than the same box full of air if the air temp spikes after T stat turns off due to the overshoot effect(heat still being emited after switch off)
If this spike is rather quick but high, it may not have been detected by the thermometer in the initial tests with a bare box. The egg mass however will tend to increase to the mean of the curve, creating the appearance of the eggs adding heat.
But are they creating their own heat, or simply storing part of the overshoot that was previously unmeasurable with thermal response time of the measuring instrument.??

This hypothesis of eggs producing internal heat should be easy to confirm.
I suggest someone take some measurements of an empty egg box fully loaded with moist egg media over a period of days.
Then simply fill the space with chicken eggs, known to be dead but approximating the mass of a live egg clutch.
See if your reading goes up!!
If it does, the phenomenon has nothing to due with life in the shell, but is an artifact of the measurement instrumentation and thermal response time(and changes in rates of evaporation)