I need some help with a mixed effects model in R. I want to know if there is any effect of month on home range size. The following is my set-up and an idea of how it is laid out in an excel sheet: I have 2 parks that I have home range estimates from (labeled parks 1 and 2). There are 6 individuals in each park (individuals 1-6 in park 1 and individuals 7-12 in park 2). There are 2 years worth of data (years 1 and 2), so for each month, each individual should have two home range estimates (one for year 1 and one for year 2).
I know "ID" should be a random effect, and I currently have "park","year", and "month" as fixed effects. My first thought is that "Park", "year" and "month" should all be crossed, but I am lost as to where "ID" is nested.
I have the following in R:
How do i "fix" this bit of code so that it represents my experimental set up?