>I am assuming those percentages are based off of average package/nuc purchases that come from treated (non-survivor) stock. But let's say I was willing to suffer the losses and work this plan for 10 years, keeping only "survivors." What can I expect my percentages to be in ten years? In 10 years, how many hives would I need to go into winter with to have a 99% chance of coming out with a single colony?
A lot of places have losses in the range of 50% but mostly I picked it because it's easy to do the math.
>You have been treatment free for 40 years. What are your loss percentages each year?
It depends on the winter. In a "normal" winter about 80% survive (20% losses). In a very nice winter (cold enough to keep them from being too active but not a lot of sub zero weather) it probably runs 90% survival. But then I also try to overwinter smaller colonies than I used to since some of them do survive. I could cut that number by doing fall combines of the smaller colonies.
>I believe you when you say that "treating is not a long term solution." But losing 1/2 or more of my hives every Fall/Winter is not a long term solution for me.
If you split enough to make up the loses then you are staying even.
>When should I start seeing the "survivor effect" in my apiaries and my tf losses start moving down?
A lot of winter survival is good beekeeping and that takes both practice and study. For instance, you need to always insure you get that last batch of young bees going into winter. Some years there is not enough of a fall flow for this to happen. Some years it happens quite naturally. I'm not saying you are a bad beekeeper, but experience is a great asset to keeping bees alive.
>I know there is no formula for this, but I am just trying to get an idea of what I could reasonably expect.
Every year is different. Your other beekeeping practices have a lot to do with survival. A lot of people are treating and losing half or more of their bees. Sometimes all of them. Between viruses, mites, poor genetics, small gene pool, poor queens, getting bees through the winter has gotten hard. Check out the Bee Informed Partnership to compare treating with not treating and get average losses for your location under both circumstances. Then take into account that as you get more experience and as you make good decisions, like local treatment free stock, natural cell size, etc. you can improve on those numbers.