Wekas vs Ducks?

Seasons over for me and I didnt get out much due to working in Oz, but I enjoyed what time I did get chasing ducks.
My boy getting his first few with his new 20g was the highlight for me.

Got out one morning last week with a good mate and his young fella. While shooting the shit between the odd pair looking over our decoys, we discussed the lack of ducks around the last few seasons on the coast.
Numbers although not as bad as last year, have been pretty low compared to what we are used to.
He mentioned there was talk among others that wekas maybe the culprits. I was amused for a start.
Weka numbers have been very noticably on the increase the last few years. When we were on the farm we had oodles around the house the last few yrs considering we had a dog and 2 cats. You heard their calls all night as well. We moved closer to town at xmas. Last week we had one strut around the garden turning it over for worms.
I would have seriously dismissed the idea normally but since he mentioned the possibility, I have noticed a lot more wekas and their calls.
Went out to shoot a local creek near the farm that night with the same crew. We split up by around 4-500 yrds. It was pretty quiet but we managed a few birds.
There were 4 wekas mooching around where my boy and I were camped and I inoticed 2 wekas work a large portion on edge of the creek we were on. They got in the water and were picking thru any cover that would hold ducks or ducklings.
The other crew had a noticed a few around where they were as well.
There have always been wekas on the coast, but it used to be almost novel to see one were we are.
Maybe there is some credibility in the theory.
I dont know much about the buggers other than they are reasonably tame, like stealing shit and I have heard, taste bloody nice.
Being protected on the mainland I doubt there can be anything done about it if there is some truth to the idea. But it would be interesting to find out for sure.