On arrival it was obvious that the landfill site was operational, as thousands of gulls were present. After settling down, having had an hour or more scanning and also having walked across to the enclosed lagoons, the time came to estimate those numbers present. My gut reaction was to plump for a total larid mass of, lets say, seven or eight thousand individuals, based on nothing more than educated guesswork. However, when I tried to add a little bit of common sense to the process, it only helped to prove that my initial estimate was woefully short. I was quite happy to claim a fairly positive count of 375 Lesser Black-backed Gulls. So I used this as a starting point - a number not estimated but actually counted out, one gull at a time. I reckoned that there were at least double the number of Common Gulls present, so I arrived at a total of 750 for them. Pete, Johnny and Frank now joined in. For every Common Gull we had seen there were at least 15, maybe even 20 Black-headed present. Taking the lower figure of 15 and multiplying this by the number of Common Gulls we reached a total of 11,250 Black-headed. Herring Gulls were plentiful, but not as numerous as Black-heads, so we settled on a total of 4,500. Other gull species present were: Great Black-backed (15), Yellow-legged (2), Mediterranean (1) plus a rather fine first-winter Iceland. So, the gull grand total was in fact 16,894, rather more than my initial hunch.