In response to the question about whether we need more sites for avocet, the answer is yes!
Numbers in the upper Humber are certainly good but the future for them as breeders (rather than passage) is not as secure as it may appear. Read's Island - the main avocet stronghold - is being badly eroded along the northern shore to the point where the lagoons aren't functioning as they should. This has forced a lot of the avocets out on to the surrounding intertidal, leaving them more exposed to predation, weather, tides, etc. Similarly, the vegetation on Whitton Island, another decent breeding site, is starting to develop in ways that isn't ideal for avocets (or any other breeding waders). As managers of these sites, this is something that we (RSPB) are looking at tackling.
That aside, the situation in the upper Humber is not ideal anyway. Although avocets nest colonially the numbers and densities we see in the upper Humber are more a reflection of the historic lack of good breeding habitat around the Estuary. Avocets are typical of early successional stage breeders. They do great in early years on new habitat but as their colonies grow they tend to get badly hit by predation and other density dependent factors, which drive down the productivity of a colony. We're starting to see this now on a lot of the upper Humber. So what we really need on the Humber is more dynamic and smaller avocet breeding sites. This will allow the population to respond by moving themselves around and staying ahead of the pressures. It also obviously reduces the impacts on the population of failure of any one colony. While the estuary's islands are currently key to the breeding population, having more terrestrial sites also gives those of us who manage avocet breeding sites more flexibility about how we manage them in a given year, so we've got more chance of having good, dynamic wetlands spread round the Estuary.
With avocets being one of the Humber's internationally important species, those of us who manage parts of the Estuary have legal duties to make sure the population is maintained. A big part of this is thinking about the future for the species, not just their current numbers. Combined with the major benefits for wintering waders and wildfowl (both roosting and feeding) that tend to go hand in hand with avocet breeding habitat creation/management, these types of project should be great for the Estuary's wildlife throughout the year. It's fantastic to see ABP and the IDB taking a lead on this at Rosper Road.
Richard RSPB Humber Conservation Officer
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