What causes stubby tails?

[JodanOrNoDan]

Well I have some new info. Tonight after reading the ideas here that my eggs may actually be warmer than what I have my ambient set to, I decided it's not hard to find out because I still have one remaining clutch in the incubator. I have a temperature gun so I just zapped them and yep, they are definitely warmer for whatever reason. I have my thermostat set to 88 now and the eggs still read at 90.4. Which means when I had it set to 89 they could of possibly been cooking at up to 91-92 It's sad to think just a couple degrees could have such a major affect on all my babies I'm pretty sure this is my answer though, I was incubating too warm. I just wish I would of thought to check them right away, I just thought I was good because I did have an extra egg box setup with a thermometer in it and it was reading 89 as well. I have no idea why the eggs would be warmer than the ambient but I know now I need to set my herpstat at 87.0 to get the eggs around 89.

I discovered this by accident. In the beginning I was super anal about monitoring temps and running three different probes. My readings were so flaky i thought my gauges were off but they were all within a 10th of a degree of each other. I also noticed the heating in my incubator rarely cut on, so something had to be making heat. This lead to me placing the thermostat probe between a couple eggs. It is almost always 2 degrees above the incubator's ambient. All of this led to me setting the thermostat to 87. The readings you are getting are consistent with what I found.

Also, another little tidbit of data. Once the shells begin to soften the egg temp rises. Due to this, my primary probe is always placed in the oldest clutch.