Thursday, 20 January 2011

KP (2)

Radipole Lake has been punching below it's weight for many years. With the second phase of the restoration programme completed this winter, it is beginning to look fighting fit at last. The key issue has been one of habitat stability and a resultant lack of diversity, now being ably tackled by the current reserve staff, with a bit of Kick-ass Perturbation.

With restored ditches and new pools in place (see above), attention can be turned to reed management. Some of it should be simply got rid of; grazed out and replaced with swampy grassland (some of it suitable for passage Aquatic Warblers). Some short-rotation and some long-rotation cutting is required, and commercial reedcutting is not a bad option for the former. Often considered an anathema by conservationists, it all depends on scale, and small-scale regular reedcutting is undoubtedly good for Bearded Tits. BTs benefit from mosaics of different aged reed; cut reed, young reed, old reed, extensive edges next to water, pools, shallow scrapes and ditches. There are good examples of reedbeds where declining management has resulted in declining BT populations, and conversely examples where re-invigorated management has been matched by a resurgent BT population (look no further than Blacktoft Sands).

Commercially cut reed blocks will result in fixed reed clearings for a number of years but in the right size and location can provide good habitat for BTs as well as an assortment of other birds from Water Pipits through Snipe and duck to Cranes. A Dutch study found that you can remove up to 50% of the standing crop of a reedbed annually with no loss of breeding birds. On nature reserves, a maximum removal of 20% would be more appropriate.

Cut reed blocks and ditch management should increase interest for visitors as more birds become visible. Overall, continued 'disturbance' in the habitat should maintain it's diversity of wildlife.  Not much was visible today however - a Marsh Harrier, a few Bearded Tits and a Goosander, the 6+ Bitterns present managed to avoid being seen.

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