They can eat surprisingly big animals. I was loosing a duck each week for several weeks. First the young ducklings - I thought some kind of big fish in the lake was eating them. When they were all gone I started loosing the adults - first couple I thought had got lost - then I thought someone was stealing them as more vanished. NO feathers or signs of a struggle. My ducks were free range on a small lake in my housing estate.
Then one night my neighbour was knocking on my door frantically and told me a snake was eating one of my ducks. We ran out to the lake to see a huge python wrapped around a duck. Our torch and noise disturbed it and it swam away. While I was looking for new homes for the remaining ducks about a week later I was walking home and noticed a strange 'log' on the lake bank. Walking back I saw it was huge python sneaking up to my sleeping ducks. Only a few inches away from them. I shone my torch on it - it was very impressive and very beautiful, its skin shining with iridescence. I threw a palm leaf at it and it shot into the lake in a split second.,... so fast - not like on TV. My heart was racing and I will never forget the experience of seeing such an impressive wild animal so close.
This snake was very long - over 7 foot, but not very wide. My big fat ducks must have been difficult to swallow. Poor things. I have re homes most of my ducks now and just keep my favs as pets in my back yard - and lock them in a dog crate at night. Now they have to swim in a metal bath and I am sure they miss the lake with all its plants and snails to eat.