Our RSPB Site Manager Andrew Gouldstone wanted to share with you a little bit about our breeding wader success this year...
Take it away Andrew:
Anyone who is a regular visitor to Rainham is likely to have overheard lots of talk from staff and volunteers, each year, about our breeding waders.
But why are these so important ? Any why do we get so excited about the excellent results that we have had here in recent years ?
Well, one good reason – I can’t imagine a spring without tumbling and calling lapwing, and piping redshank shouting from a post or tussock.
I’m sure many people will be familiar with the fact that sadly, both lapwing and redshank have declined massively in the UK as breeding birds. The wet, splashy grassland and marshes that these breeding waders nest on have been drained and lost. And so this has made them a priority for the RSPB, both on and off our nature reserves.
Lapwings by Russ Sherriff
Lapwing, a bird once so common that they occurred on pretty much every field on every farm, and were familiar throughout Britain and Ireland in the 19th Century, have undergone a substantial decline that began in the 1960s. Between 1995 and 2012 lapwing declined by 42% in the UK (Breeding Bird Survey 2013). The longer term trend shows a decline of 64% from 1970-2012 (The State of the UK's Birds 2014).
Redshank too have undergone a similar decline - dropping by 44% in the UK from 1995-2012 (Breeding Bird Survey 2013).
When Rainham was acquired by the RSPB, there was a real debate as to whether, in the face of climate change in southern England, and a big fox population, breeding waders could ever be successful on this site. But the remnant population that still existed was seen as being a real priority for the reserve, and they continue to be the priority to this day.
With hardwork and very focussed habitat management, the reserve is seeing some excellent results for these two species. The last three years have seen the populations more than double, and lapwing productivity has exceeded the 0.7 young per pair threshold required to ensure a stable and increasing population – in 2014 we achieved 1.55 young per pair, and in 2015, our record 61 pairs produced 66 young, giving a productivity of 1.08 young per pair. In 2015, the density of nesting lapwing (ie the numbers of pairs per hectare) was the second highest that the RSPB has recorded on any of our reserves, anywhere.
The productivity figures are really important – we could have 200 pairs of lapwing, but if they aren’t producing any young, we might as well have no pairs.
Achieving these great results means careful habitat management. Judging the grazing levels is vital, to get the sward height and structure that both lapwing and redshank like – predominantly less than 5cm tall for lapwing, and scattered rushes and tussocks for redshank. The numbers of cattle and the timing of this grazing is also important, to try and reduce the risk of nests being trampled.
Maintaining damp areas is crucial if adults and chicks are to find food. Winter flooding sets us up nicely for the coming breeding season, but we have to control these levels and retain as much water as possible, using the network of ditches and pipe valves on the reserve to keep the marsh damp until well into June. Topping some areas up with pumps becomes necessary if key feeding areas dry out too soon.
Lapwing chick by Bill Crooks
Managing the anti-fox fence is the third important task. This fence massively helps reduce predation on wader nests and chicks. Routinely checking nearly 4km of fence, diagnosing problems when the fence stops working, keeping the vegetation cut back, and monitoring for signs of fox inside the fence, is no small task.
Most of this success so far has been on the Aveley Marsh part of the reserve. Replicating this success on Wennington Marsh is our next challenge, and given the size of Wennington, this could allow the numbers of our breeding waders to double again.
Other RSPB sites around the Thames are also seeing good results for breeding waders, so at least on nature reserves in south-east England, the sight of displaying lapwing and redshank in the spring seems secure for the foreseeable future.