Scrapes and Sluices on Grove Farm

There is some exciting progress to report on the Grove Farm HLS agreement, where 3 sluices, 5 scrapes and some perimeter bunding have been worked on over August by the landowner.  The scrapes will hopefully will entice some more waders to the area and together with sluices coming into commission next spring create a hydrological regime better for breeding waders.

The sluices will allow ditch water levels to be raised in Spring, keeping the water table close to the surface of the fields to attract nesting Snipe, Lapwing and other waders. The sluices consist of flexible plastic pipes running through earth  dams across the end of each drainage ditch. By raising the upstream ends of the pipes water can be held back in March-June, when the birds need the fields to be kept damp. The pipes are lowered for the rest of the year to allow the drain to flow through as normal.

Within the fields new wader scrapes have been excavated to further enhance the habitat for wetland birds. A scrape is a shallow, irregular depression which will hold water when the water table is near the field surface. These provide valuable feeding sites for wading birds, especially in late Spring when newly-hatched chicks hunt for invertebrates on freshly exposed damp mud. The bare mud enables them to pick off spiders and beetles without getting their downy feathers cold and wet from long, dew-laden grass.

The density of wet margin features in a field has been found to be an important factor in breeding wader success on wet grassland nature reserves such as the RSPB's Berney Marshes Reserve. The density of nests and numbers of chicks fledged were linked to the length of wet margins per hectare. For this reason scrapes need to be very gradually sloping to the centre so that as the season progresses and the fields dry out there are still wet margins for feeding. Typically scrapes will dry out in summer, to fill up again the following autumn, when migrating waders will drop in to feed en route. A wiggly outline gives lots of feeding edge and shelter whichever way the wind is blowing.

These important works on Grove Farm are prescribed and supported by the Higher Level Stewardship funding from Natural England, as part of the 10-year HLS Agreement for Grove Farm.  The progress here is an important milestone for the Cayton and Flixton Carrs Wetland Project. We wait eagerly to see how the new hydrological regime works next Spring and whether it attracts greater breeding wader success.