How to count unique points within a polygon

Hi,
First to apologize if this question has already been answered. I have spent an important amount of time trying to answer the question before posting it but I might have failed!

I have a population of a species within a island. Each individual has been located a number of times. Each individual belongs to a "band", for example Band1 has 10 individuals, Band2 has 7 individuals and so on... I have created a number of buffers and now I am interested in counting the number of UNIQUE Bands happening within each buffer and adding the number as a new field to the buffers file. I have already counted the number of locations contained within each buffer but now I want to know how many different BANDS have been located within each buffer.

Example of desired output:

BUFFER............Attributex.................PointCount....... NumUniqueBand
Buffer1.............. white ................... 2305 ....... 25
Buffer2.............. brown ................. 707 ....... 13
Buffer3.............. black .................. 47 ...... 7


Any suggestion about how to proceed? Your help will be much appreciated.

Regards

Antonio. UK-Canada