Natural Selection

I had a day off today and among other walking and birding activity on a crisp and sunny January day watched the tide come in at the exotically named Burglar’s Alley, on the Wyre estuary south of Fleetwood. My plan was to look for Rock Pipits and Snipe displaced by the high tide and search through the Teal and Wigeon flocks. When a Grey Heron swooped through the panorama above and landed on the flooding saltmarsh I had an inkling what was going to happen, and I was proved to be right.

Flashback to November 2020 and a heron appeared at roughly the same state of the tide. Through my binoculars I see it struggling with extremely large prey. Checking through my scope I was somewhat surprised to see it despatching a very large rat. Unfortunately I was rather taken by surprise, and the images I got by holding my mobile phone to my telescope left a lot to be desired.

Today I should have been more prepared, but I wasn’t because the heron struck so quickly. I had barely gazed elsewhere to look back and see groundhog day. In keeping with groundhog day my images capturing the event were as grim as in 2020.

It’s obviously well known that Grey Herons are opportunists, and will eat anything that they can catch. Nevertheless I am very much minded that this is the same bird exploiting a food source that only occurs on the bigger tides. On both occasions a heron has appeared as spring tide conditions began, quickly found and killed a rat, rested on the marsh for a while to digest its catch and left before the tide is fully in. Presumably catching and eating a rat is a very efficient strategy for a heron compared with multiple fishing attempts or taking smaller rodent prey like shrews and voles.