Unfortunately it is not possible to read the numbers on the bands so it is not possible to say for certain where the birds were trapped.
Olive-backed pipit is sometimes caught in HK and it seems likely that this bird was ringed at Mai Po.
Little Egret is rarely trapped in HK (just 12 to date!), so it is unusual to see one carrying a ring. The most recent birds banded were 2 chicks in 2005 (birds which were treated and released at Kadoorie Farm) and 3 fully-grown birds at Mai Po in 2004. I would guess this is probably one of the Mai Po birds but we will probably never know for sure.