Hoping for a red and green invasion

Common Crossbill

So it’s 2019. 5 years ago there was a big invasion of Common Crossbill into Hakodate. They were everywhere. 20014 was a Crossbill year when the above photo was taken. 5 years before that in 2009 we had another big Crossbill invasion when the following pic was taken.

Common Crossbill

5 years before that there was another big invasion. I didn’t have a camera in 2004 though. So do they erupt at 5 year intervals? In all those years flocks appeared in the local parks in mid February. I hope this year will be a repeat. There are precious few small birds around so far this winter ……….

Here’s another one from 5 years ago.

Common Crossbill

They occur most years in smallish numbers, I suspect those may be resident birds moving around Hokkaido and the big flocks in invasion years may be from the Asian mainland. But I may be wrong.