I currently have 64 live eggs from numerous female Easterns that are in various stages of incubation. I posted photos of the first clutch of 13 eggs a couple months ago (12 are still alive).
This first clutch is now at 106 days, much longer than previous years where the incubation time was typically 96 days. I am using a cooler incubation temperature, and this is undoubtedly the explanantion for at least part of this added time.
For the first half of the incubation, I had the eggs on Scott Foam, a very large pore open cell foam. I had done this to small numbers of eggs in previous years as a test. If there is water at the bottom of the buckets (I use clear food industry buckets) then the eggs will absorb the moisture they need from the air. This only works for the first half of incubation.
For the second half of the incubation, I transferred the eggs to 1:1 vermiculite:water by weight, although for the first time, this year I used deionized water (basically distilled water).
The last month of the incubation is characterized by greatly increased condensation on the inside of the buckets (see my response to Mike Meade's post below). This increased condensation has started, albeit late also, for the first clutch I mentioned. These eggs have been supersaturating the air for maybe three weeks now.
I was worried that they may be dead, but the eggs are all very tight (firm) i.e. under internal pressure (normal, and also a sign that they are alive). None are collapsed, discolored, molding or smelling bad. In years past, just days before hatching the eggs have lost their internal pressure (as felt using my fingers to essentially pinch an egg ever so slightly). My first clutch isn't there yet.
I can't figure out why they are going so long. According to biochemical theory, metabolic rates are usually halved or doubled for every 10 degree C raise or drop in temperature. This works out to 6.5% less incubation time per increased degree C and 7% greater incubation time per decreased degree C. My mean temperature is maybe 24.5 compared to 26.5 in years past, so ten days longer is more than I would expect.
Nothing I can do except stare at the darned eggs. I have other thoughts about why they may be taking longer, but I don't want to write a book here. There is nothing worse than waiting for eggs to hatch that are late.
I was curious if anyone else has had Eastern eggs that took so long. From the looks of it, these eggs are still at least a week from hatching. I will keep everyone posted.
Robert Bruce
robert.bruce@sbcglobal.net (310) 502-6311
