I only have one Russian tortoise hatched in the past couple years from 3 females that laid total of 18 eggs. I collected 7 eggs from this year around end of June and early July. So they have been in the incubator for a while (65 to 87 days). The 7 eggs are from 2 females, one laid 5 last year (none hatched and not fertile) and 4 this year. The other female laid her first ever 3 large eggs. I am really bad at candling and telling if an egg is fertile. Initially I thought I may have fertile eggs but now I am not sure. This is the set of eggs from female #1 who has also laid last year (none hatched). Picture was taken two weeks ago but I do not see any further development. The dark mass at the bottom remains almost the same. I never noticed "chalking" early on but it could be that my eyes were not trained to spot that or I missed it.