There was a lot of conversation. especially on Facebook, as to the possible effect on hatchability of poultry eggs when heavy thunder is experienced during incubation. During the second half of December Dunedin experienced very heavy weather with lots of thunder, especially in North East Valley. During this time I had a batch of 120 Quail eggs in the incubator, which hatched  on 4 January and the results are that  I had 57% live birds at 17 days old of all eggs placed. This compared with the running average for the year of 59% is a negligible difference and disproves the theory that heavy  weather effects hatchability. It may be small numbers to be statistically significant and the weather may not have been bad enough (I would hate to experience  more severe storms), but at least I have some results. Will continue to monitor this  in future.