Thanks to the money raised by National Lottery players, Data for Nature volunteers have been able to carry out a series of skylark territory mapping surveys at the Sheffield and Rotherham Wildlife Trust Woodhouse Washlands Nature Reserve.
Woodhouse Washlands reserve sits on the eastern edge of Sheffield on the border between Sheffield and Rotherham. These 53 hectares of land were once floodplains for the River Rother, but a flood alleviation scheme put in place in the 1950s saw the river straightened, flood banks built, and ditches dug to control river flow. This scheme transformed Woodhouse Washlands from a homogenous marshland habitat to a mosaic of wet and dry grasslands, swamp, ponds, wet ditches and scrub. The assortment of habitat types now found at the reserve hosts a diverse range of species – a bird survey in 2017 found around 60 species use the site, including the Skylark.
Recent management has focused on improving the reserve for breeding pairs of Skylark. This has included fencing off parts of the reserve to reduce disturbance by dogs and cattle for ground nesting birds like Skylark. This will hopefully facilitate an increase in the number of breeding pairs using the reserve. Since April, Data for Nature volunteers have visited the site four times to map the activity of male skylarks in the reserve, following techniques derived from the BTO’s Common Bird Census (CBC). The aim was to estimate the number of male skylarks holding territory during the breeding season. This can be used as a proxy to estimate the number of breeding pairs using the reserve.
The Trust estimate there are at least five pairs of breeding Skylark actively using Woodhouse Washlands reserve. These were all concentrated in the small part of the site previously fenced off by the land management team. Fencing work has clearly been successful in minimising disturbances to ground nesting birds during the breeding season. In the last survey, juvenile birds and parents carrying food were recorded, indicating that skylarks are successfully breeding on site.
Volunteers also measured the average sward height in the breeding zone to see whether optimal breeding conditions are being maintained in the reserve. Skylarks prefer to breed in grasslands where sward height is between 20 and 50 centimetres. Results showed that sward height was within this range in all but two of the grid cell areas surveyed, suggesting there is sufficient suitable breeding habitat for skylarks in the reserve.
Nabil Abbas, Reserve Manager at Woodhouse Washlands, said:
“The data generated by the Data for Nature project has already been very helpful in demonstrating the effectiveness of our nature reserve management. At Woodhouse Washlands the grassland compartment that we fenced off to prevent disturbance to ground-nesting birds has provided habitat for at least five pairs of Skylark, whilst our survey found hardly any evidence of skylark breeding in the unfenced areas of the reserve.”
The Trust will continue to survey the skylark populations at Woodhouse Washlands, monitoring the effectiveness of our work to restore the floodplain. The results of this monitoring clearly demonstrate how disturbance can be a limiting factor on skylark populations, so the Trust are keen to encourage responsible enjoyment of the site, including keeping dogs under control and ideally on a lead, during peak bird breeding season.
(c) Skylark – Luke Nelson
Volunteers – Isabel Commerford