I have not seen this done well and look forward to seeing the answers you get and your own results if you go ahead with it! Dispersal syndromes are based on the assumption - and some evidence - that particular fruits traits are associated with particular major frugivores, but it is big jump from this to dispersal effectiveness.
Hi dear Ning Li. As R.T. Corlett mentioned the traits of birds and fruits could be explain the efectiveness of seed dispersal.
The best way to know if an animal is a good disperser is capture the animal and colect their excretes or stomach contents . Followed by test of viability of these seeds by the emergence of seedlings. If the animal is a good disperser most of seeds founded in the excretes should germinate.