Correct statistical test to use for my data (correlation/regression)

Hello everyone,

Potentially a silly question (but I am new to all of this):

I have collected data from a focal animal study on Naked mole-rats. I calculated their hierarchical positions for the entire colony of 18 individuals. In the focal studies, I counted frequencies of different locomotion types (8 behaviours in total) for 30mins and repeated this three times. So I have this rank (1:18) and a mean frequency (from three repeats) for each of the 8 behaviors for all the individuals.

I believe then I should conduct a correlation (Pearson's product-moment) for each of the behaviours (y-axis) compared to rank (x-axis) and plot a regression line to highlight the relationship whether significant or not? (p.s. I am working in R)

I just wanted to ensure this is the correct method of working before I go forward to do this? Is this the most appropriate way of looking at my data? Can anyone suggest any more appropriate ways of looking at it that aren't too fancy but will allow me to infer that the rank has a significant effect on the frequencies of different motions conducted?

Thank you all for reading this!