Thanks for commenting.

I guess wheather the shutter speed is high enough depends on the distance/zoom length and the scope of the attention. In my case I agree with you that speed may be ok considering that (1)the focal length is only 285mm as compared with the long lens most birders here use; (2)I tried capture the whole flock of geese instead of details of one goose:)   I also agree that the pics lack of a center of attention because of messy background. Anyway, I am trying to learn and had a lot of fun so far:)