# What's the probability a rabbit will return to a (certain) forest?

Let's assume we have a forest.

And there is a breed of rabbits that is visiting that forest all the time.

It is possible to distinguish every individual rabbit.

There are devices in that forest that count the visits of every individual rabbit on a daily basis; so there are not two or more visits for a specific rabbit on one day; a rabbit stay the whole day so to say.

The information I have is e.g.:

• rabbit #343 visited the forest on May 5th 2012 for the 12th time.
• rabbit #793 visited the forest on June 2nd 2012 for the 1st time.

now the CEO of the forest wants to measure if there is a tendency of rabbits not coming back.

and I am the CEO's data guy and have to figure that out.

My question is if this "problem type" is known under a specific label - I guess it is - and if there is something like an established formula to indicate the "back out rate" or the "loyalty rate" / "probability of another visit extrapolated for all rabbits".

What I will do is to chart for multi-day-time-periods (e.g. a week)

• the number of rabbits that visited for the first time
• and the number of rabbits that visited for the last time (e.g. hindsight knowledge for six month)