Over the next month or so our primary focus in terms of habitat management will be the management of hedgerow and scrub around the nature trail and in particular along adder alley.
Although adder alley has been a nightingale (as well as a reptile) hotspot, the scrub on this area of the trail has become less suitable for nightingales (and other scrub warblers) in the past couple of years and we had no nightingale territories along this section in 2018. We’ll be undertaking hedge laying and coppicing work in this area in an attempt to re-generate the scrub and create the denser scrub and understorey that they need as nesting and feeding habitat.
Incidentally, when I started working at the reserve we never found nightingales along adder alley so they do move around the site depending on the suitability of sections of the trail. Our challenge is to maintain a mosaic of hedgerow and scrub habitat where some areas are more mature and others cut back and re-generating to ensure that there is always somewhere that provides suitable nesting conditions.
If you take a look through one of the ‘gaps’ in the hedgerow near the gate to the seasonal Wetland Discovery Trail you can clearly see how little understorey there is beneath the hawthorns and blackthorns. By hedge-laying and coppicing some of the shrubs and trees it helps to allow a little more light to the ground and stimulate the growth of other understorey plants but also encourages the tree to produce new growth from a lower level and create a nice dense structure. Cutting back also encourages suckering which will help us to develop wider, deeper hedgerows that provide a fantastic home for all sorts of wildlife, especially nightingales, scrub warblers and brown hairstreak butterflies.
We’ll be doing slightly different management along sections of adder alley:
At the western end of adder alley we’ll be creating some scallops into the bramble and the blackthorn scrub, reducing the height of the brambles in some areas. This should help to increase the light and allow for more sunny basking areas for reptiles but also for invertebrates such as butterflies and dragonflies. At the moment, as you walk along the path, it seems as though there is a wall of bramble on one side and a wall of blackthorn on the other. The intention is to increase the area of ‘edge’ habitat and have a more gradual change in vegetation height as you move away from the path. Cutting back the blackthorn always helps to generate re-growth and it is this newer growth that is favoured by the fussy brown hairstreak butterfly.
A female brown hairstreak spotted in August 2018 searching for a suitable blackthorn twig on which to lay one of her precious eggs. (Photo: Anna Allum)
At the eastern end of Adder Alley you’ll see a more dramatic change once the work is complete. Some of the hawthorns will be retained at height but the blackthorns will be cut back to the ground to create coppice stools from which we’ll hope for lots of new growth. We’ll be putting up deer fencing around this section to protect the new growth and hope that after a few years we’ll have the dense scrub and understorey, interspersed with the perching trees that has been so good for nightingales historically.
Nightingale by Mike Beck
Rather than doing the entire block of scrub in one go, it’s likely that we’ll do the cutting back in strips so alternate sections are cut back this year and the other sections completed in the next couple of years. This will give us the variation in age and structure that should suit a wider range of our species.
We’ll be cutting back some of the dead bracken (it will re-grow rapidly) but will use it to create some brash piles to create cover and raised basking areas for reptiles. We’re also planning to create a hibernaculum with some of the wood and a reptile basking area. Hopefully this will be used by our adders (in the same way as the mini-beast mansion was in 2018) and allow you to see these incredible creatures whilst ensuring that they remain undisturbed. As the adders start to emerge from hibernation we’ll be continuing with our project to identify and track their movements and behaviour, so keep your eyes open for these beautiful creatures basking on sunny days from mid February.
A juvenile adder (AA3 or 'spot') photographed by Graham Osborne
Hedgerows for the future
The network of hedgerows on the reserve create fantastic corridors for wildlife, in particular bats, and are important for a wide range of bird species, invertebrates, small mammals and reptiles so we're working on a regular management plan for our hedgerows to ensure that they are managed on a rotational basis. This will ensure that we have some hedgerows that are mature and others that are regenerating. We’ll also be aiming to restore some of the ditches that run along some of the hedgerows to help with the future management of water on the site.