Jackson ratio question
 

Should the Jackson ratio be applied AFTER the tortoise has been wound down and is empty? After winding down my ones I notice they have lost weight during the process, they come out closer to the top line on the graph..

Of course your tortoise will have lost weight, as either three or four weeks without food this happens. Especially as they are active in at least the first one and half weeks:0)
The Jackson Ratio is only a guide to use before you start to windown your tortoise:0)
As long as they have been a normal tortoise eating and drinking throughout the year, and they have a dry nose, clear bright eyes then they are ready to hibernate:0)

As Sandy has said the JR is only a guid, at the start of wind down, weight is important , but so are many other things, as Sandy has said. Observing your tortoise over the summer is so important and getting to know their normal behaviour, because they are individuals. If your tort has been ill over the summer, it is probably best not to hibernate that year. If you have just got a new tortoise , it's best not to hibernate that year. So a number of things need to be taken into consideration.

In my opinion it's a basic flaw in the standard wind-down advice. There is a big difference between the weights before and after wind down nobody seems sure of the answer to this question.

Although it's rarely mentioned there is a better calculator than the Jackson and that's the Hailey. It's more sensitive for example you can dial up for a male or female animal. And it's based on much more recent studies.

Worth checking out for those who find these things useful. This widget will do the sum online for you:

http://www.ahailey.f9.co.uk/cond.htm

I use this for my margies, much more accurate .

I am getting this on the JR Graphhttp://i819.photobucket.com/albums/z...srben4yuz.jpeg

C for example is Cordelia who is wound down and 247mm long and weighs 2700 grams ..(2749 before wind down) looks ok on the graph but comes out low on the calculator ... am I doing it wrong?
M is Matilda 218mm and 2266g.. (2295 before wind down)
B is Betty 220mm and 2048g..(2061 before wind down)

photobucket charges for 3rd party hosting now which is probably why the photo doesn't come up. it will accept your download but wont 'host' onto another site unless you cough up the beans. Try tiny pic or imgur who will host free of charge.

I would say from the weights they are safe to hibernate subject to any health concerns. Don't worry too much about the decrease in weight - when they are that size 10, 20 30 40 50 even 80 grammes is quite small. If you compare what 80 grammes feels like in your hand its minimal. (clearly proportionate with tortoise size though) ! CB