Connect Plus / Case studies
Enhancing our environment
Species focused ecology projects
This year we have delivered species-focused ecology projects around the network for several species, this has included plot enhancements, planting of herbaceous plants, installation of nest boxes and surveying for nationally scarce/rare species.
In the summer of 2023, we undertook regular surveys of the land below the Dartford Bridge focussing on rare bee species, particularly the endangered Shrill Carder Bee. In August we were pleased to be accompanied by a representative from the Bumblebee Conservation Trust, and whilst we didn’t find any bees during the survey, Bumblebee Conservation confirmed the site was ideal habitat and, because of recordings in surrounding areas, it was highly likely the Shrill Carder was present there. The Trust will be assisting us as we continue to survey the site throughout the year.
Despite not seeing the Shrill Carder Bee, we did record several scarce species of solitary and social Bee over the summer at this site, affirming the site’s biodiversity.
These included:
- Moss Carder Bee (Bombus muscorum) - Nationally Rare
- Brown-banded Carder Bee (Bombus humilis) - Nationally Rare
- Pantaloon Bee (Dasypoda altercator) - Nationally Scarce
- Silvery Leaf-cutter Bee (Megachile leachella) - Nationally Scarce
Additionally, this year saw diligent monitoring of our Small Blue (Cupido minimus) butterfly site, located within a balancing pond site between junctions 22 and 21a on the M25. Despite initial setbacks with Kidney Vetch planting in 2022, we have now replanted with larger, sturdier plants. Kidney vetch is the only larval food plant of the near-threatened small blue, the smallest butterfly in the UK and it is incredibly important that we continue with our work to attract them to the site.
At junction 16 on the M25, our focus shifted to creating habitat for the Striped Lychnis Moth, in the UK Biodiversity Action Plan as a priority species and as Nationally Scarce A. It is only found in Oxfordshire, Buckinghamshire, Berkshire, Hampshire, West Sussex and, recently, a single sighting in Wiltshire. The nearest colony to our site is six miles to the North.
Despite initial challenges such as premature mowing in 2023, we replanted Dark Mullein, it’s only larval food plant, and implemented protective measures to ensure the survival of this rare moth species. Later this year we’ll inspect the flower spikes for the stripey larvae.
In Dartford, our initiative to plant Marsh Mallow Plants aimed to create suitable habitat for the Red Data Book species, the Marsh Mallow Moth. This moth is one of the UKs rarest and is found at only a limited number of sites in Southeast Essex and Kent. With an abundance of its only larval food plant, we remain optimistic about attracting this rare moth to the site.
We also enhanced the biodiversity of a woodland area and ditch within an off-network adjacent area, close to J11. The woodland is close to a canal and, as it is damp year-round, we’ve planted wetland herbs, sedges and rushes close to the ditch area. These species will both enhance diversity and, potentially, suppress Bramble growth making inspections easier and safer. In addition to felling the invasive Cherry Laurel, we also thinned the wet woodland and planted trees that were more suitable to this habitat, such as Alder Buckthorn and Elder.
These enhancements should also support the declining Downy Emerald Dragonfly (Cordulia aenea), which has been recorded nearby. In the drier areas at the woodland edges, we have planted Common Dog Violets (Viola riviniana), the only larval food plant of the silver-washed fritillary (Argynnis paphia).
To assess moth populations at our improvement sites, we have invested in a moth trap. The trap works by attracting the moth via light, which then falls into a gap at the top of the trap and settles in amongst egg cartons placed within. The following morning, we open the trap and record the moths or any other insects, before safely releasing them, unharmed.
We've implemented a recording system for invertebrates on our GIS platform and are currently expanding it to include a dedicated layer for moth trapping records, and a botanical survey recording system. Anticipating comprehensive data collection, we expect to document over 300 moth species across our network throughout the year.
We've strategically positioned five Kestrel (Falco tinnunculus) nesting boxes across our network, carefully selecting locations with rough grassland ideal for these birds to hunt small rodents. As the year progresses, we'll closely monitor these sites, with the hope of seeing some fledglings later in the year. Our chosen locations include:
- A1M – J4-5
- M25 J28
- M25 J20-21a
- M25 J22-21a
- M23
Additionally, at the M25 J11 enhancement site, we've installed 15 smaller nest boxes, with five specifically designed to accommodate Tree Creepers (Certhia familiaris), further enriching the habitat diversity and supporting avian biodiversity in the area.