Dear Damien,

i suggest to you links and attached files in topics.

- Aggregation Behaviour and Interspecific Responses in Three Species ...

www.scielo.br/scielo.php?script=sci_arttext&pid=S0074...

- Intra- and interspecific aggregation among dung beetles - Cambridge ...

https://www.cambridge.org/.../intra-and-interspecific-aggregation-a

Best regards

Dear Damien,

Did you think about using the SADIE index? Spatial Analysis by Distance Indices (SADIE) (Perry et al. 1999).

This method is used to detect quadrats of below-average and above-average abundance. To calculate distance to regularity (D), SADIE uses the transportation algorithm (Kennington and Helgason 1980), measuring the total distance involved in passing, based on the observed spatial arrangement of counts to move to a regular arrangement, in which all units have the same value of the variable under study (see Perry et al. 1999);

also used to assess the degree of association among species or anything. The method produces an overall measure of association (X - mean of local values of spatial association), which is based on the degree of overlap between spatial patterns (see Perry and Dixon 2002).

kind regards

The more aggregated the distribution, the greater the variance among quadrat counts. To standardize measurements for different populations, divide the variance by the mean number of individuals per quadrat. This gives a reliable way to measure aggregation.

The variance/mean ratio yields a value close to 1 in a randomly dispersed population, because in samples from a random distribution the variance is equal to the mean. Any ratio significantly greater than 1 indicates aggregation, and a ratio less than 1 indicates a trend toward uniformity. 

Make sure your quadrant size is optimal in order to detect aggregation i.e. not too small or too large.