The following is a general background into my data analysis problem:

• I am working with count data that is non-normal.
• Data was collected at 2 time periods.
• I am interested in comparisons of species counts between treatments.
• There are 4 treatments.

Data were initially analyzed using the Kruskal-Wallis rank sum test (a non-parametric ANOVA counterpart). A reviewer of my manuscript suggested using a Poisson distribution. How can I perform a repeated measures ANOVA with a Poisson distribution in R?