I have 6 sites with 3 sites as constant food in a feeder and 3 sites as pulsed food in a feeder. For the pulsed food sites, there are days with food and without food.So, I have 2 treatments: constant, pulsed with food, pulsed without food.
I counted birds at 2 locations(near and far from feeder) at each site multiple times. I want to know if treatment predicts the difference in the number seen near and far. So I want to know, is there a significant difference between the differences?
I've thought about doing this problem in a mixed models approach: (number of birds) ~ treatment*location + (1|site)
or
(number of birds near - number of birds far) ~ treatment + (1|site)
Any advice/guidance on this?