Signal Crayfish and a fish skeleton

Signal Crayfish ClawFish Skeleton

I came across these 2 specimens on the track that runs parallel to the river at the end of Trehafren. There were 2 Crayfish claws, which where about 5 meters apart and I assume that they were from the same animal, but there were no signs of any other remains.
(The 20p piece might give Paula some idea of the actual size of the original animal).
The fish carcase was found about 50 meters down stream of the Crayfish claws and it is not the remains of an Otter kill because I am sure that it would have been more crunched up if Otters had been feeding off it.
The Crayfish claws were actually first spotted by a colleague and he suggested that perhaps rats were the culprits, with a little extra help from some birds, in the case of the fish.
Interestingly, the Crayfish claws were in the exact location where I had my first encounter with the Otters in 2012 and they were probably feeding on Signal Crayfish at that time.
If anyone has further suggestions on the type of predator that may have taken these ‘kills’ then I would be pleased to hear from you.