A carrion-eating Grey Heron

The garden pond froze over for a considerable period in January 2001 (and we happened to be away, so the ice did not get broken). When the ice melted it soon became clear that many frogs which had been hibernating in the pond had suffocated, and over several days in early February I netted out about 25 dead, and some decidedly rotting and bloated, corpses. These were (I am ashamed to say) dropped just over the fence into the field, and covered with long grass, in order (or so I anticipated) that they could rot down. (I might have buried them, I suppose, but the ground was still frozen hard at this time - my excuse.) We were then most surprised to see on 17th February a Grey Heron standing in the field, and gulping down one after the other at least three of the corpses, having somehow located them - perhaps by the stench!  We did not see any further action for over two weeks (during which time we had a slight worry that the Heron had died in agony), until 4th March, when the (presumed) same bird was again eating rotting frogs, now two weeks more rotten than before. This time, after the hors d‘oeuvre, the Heron jumped over the fence, advanced into the pond, and within a few seconds had caught a huge - and very much alive - frog, dispatched and eaten that. (Although we had on occasion seen a Heron at the pond, this had previously always been at much quieter times of day, such as dawn or dusk.) On a different point, the mass suffocation of frogs may have been a result of my not having got around to clearing out the mass of vegetation from the pond, a job usually done in autumn, but in autumn 2000 not carried out, my excuse on this occasion being the atrocious weather. Thus there was a great deal of rotting vegetation caught under the ice, which would be expected to have contributed to the depletion of oxygen. Having finally had a 'clear-out‘ of vegetation in late January, there was then little cover in the pond for concealing frogs, making the Heron‘s job that much easier.  We then acquired a so-called 'frog-home‘ - a floating container with a large internal space above water level, which proved to be very popular with the frogs (and a toad), and which is advertised to - and promises to - keep open an air-hole when ice forms. Since then, the Heron has continued to be a frequent visitor, and the remaining frogs have taken to lurking in their 'home‘. In spite of an anticipated shortage of frogs, come the spawning season, we had just as much spawn as usual, although a pair of wild Mallard then started to arrive at dusk, when it was almost too dark to see them, gobbling up many of the tadpoles: we now have a distinct shortage of frogs in comparison to the usual state of affairs, but we have provided feeding opportunities for local avian life.  Jeremy Roberts