Moorhen vs Crayfish

I was out today, ostensibly looking for herons, when I came across something that I’d never seen before…

Yes, a common-a-garden moorhen carrying a (dead) crayfish. The moorhen took the crayfish to a slightly submerged log where it tried to make a meal of it before deciding an exposed and sunken log wasn’t the best spot. It then dragged it off through the bankside undergrowth where, presumably, it could more easily deal with it.    

A surprise to me because I’ve only ever seen or known the moorhen to be a vegetarian and it’s normally seen nibbling at river weeds. I suspect this was an opportunistic meal and that the crayfish was probably scavenged dead from the waterside. Whatever the case, the moorhen was quite enthusiastic about its find. 

On doing a bit of research, it appears that the moorhen is omnivorous and will eat whatever it can find. Clearly that includes crayfish. So, I learned something new today. 

 The crayfish is actually an american signal crayfish. This can be seen from the red underside of it’s large front claws. It uses these claws to flash / signal by opening these legs to show off the underside. These crayfish are an introduced invasive species in the UK. They are larger than the native (european) crayfish and probably outcompete the local cousin. More problematic is that they carry a crayfish plague which kills the european crayfish. Most of our waterways are heavily infested with these crayfish. The canal, where this photo was taken, carries out regular control measures of trapping them but with limited success.