Nestled within the Norfolk Broads lies an unassuming and vibrant nature reserve. A maze of habitats ranging from reedbed where marsh harriers nest and roost, to wildflower meadows from which the rare and unique swallowtail butterfly enters the world.
RSPB Strumpshaw Fen is alive with the sights and sounds of nature all year round and none more so than the summer through to autumn. This is a time when the winds of change dictate the movement of wildlife, some arriving, some leaving and others existing for a short time within its realm.
As the days become that little bit shorter, with still a current of warmth in the air, it’s just enough for a rare and unusual species of damselfly. The willow emerald damselfly was first recorded in East Anglia in 2009 and is a European species that has slowly begun to populate parts of eastern England. While this unique species may still be difficult to see in flight, it leaves a clear and visible record of where it has been and where the next generation will arise from the following year. This startling metallic green damselfly lays its eggs in tracks it makes in branches of willow and alder trees, leaving what is known as ‘egg scars’ in the bark. The trees overhanging the river on returning to the visitor centre on the Fen Trail route is a great place to search for these egg scars.
As with all dragon and damselflies, the life of the willow emerald damselfly is relatively short lived. Flying between June to October, it is one of the few species whose life crosses over two seasons.
Continuing along the insect theme, the rare and striking swallowtail butterfly takes to the wing again in August. The first generation of swallowtails emerge from chrysalis that have laid dormant through the winter months, awaiting the warmth of the first summer sun in May and early June. This first generation will mate and lay eggs as soon as possible. The hatching caterpillars feed on a particular plant called milk parsley. It’s still possible to see these large green caterpillars feeding through to August. If conditions are right, there will be a second emergence of the butterflies in early August and what a sight they are to behold. As the UK’s largest butterfly they are magnificent in eye-catching yellow and black with two red ‘eye-spots’ amidst a dusting of blue. Strumpshaw Fen is one of the remaining strongholds of this butterfly, however, their future is uncertain, being under threat from rising sea levels associated with climate change. The reserve is working hard to ensure this threat is minimised as much as possible. Planting milk parsley in new areas less prone to flooding is one of the few remaining lifelines being trialled for this species.
It's not all micro though. Autumn sees large movements of marsh harriers across the country. Juvenile birds disperse from their nest sites and birds breeding further north move south. Up until recently nearly all UK breeding marsh harriers would spend the winter in Europe. However, many now choose to stay in the UK. They’re in search of vast reedbeds in which to roost at night. The reed bed at Strumpshaw Fen attracts 25-30 birds each autumn evening. It’s quite the spectacle. Marsh harriers are a true marker of conservation success, with a single breeding pair in the UK in 1971 growing to over 590 when last surveyed in 2016. Thanks to reedbed habitat regeneration and creation works, they have once again become a more frequent sight in our skies. As well as attracting a significant number of birds to roost in the autumn, Strumpshaw Fen also attracts nesting pairs in the spring and summer.
As the summer foliage changes colour with the bright, bold orange and red palette of autumn, other characters return to the stage. Autumn is often a great time to catch otters, these playful mammals and their cubs become more visible as the cubs embark on new adventures into the big wide world, splashing and frolicking in the water. They are streamlined and graceful swimmers with the ability to dive to depths of up to 60 metres. With large, webbed feet, their tracks in the mud are often a telltale sign they have been around. With up to eight females around within the Mid Yare Valley, autumn presents a good opportunity to catch a glimpse into their secret world. At Strumpshaw, Reception Hide is a great place to watch the otters from, with a family frequently observed playfully exploring, the bank in front of the hide also appears to be the area of choice for dining.
A flash of bright blue is also a frequent sight. The high-pitched whistle of a kingfisher is often the first sign there is one nearby, followed by a bright blue streak zipping past to seek out low overhanging branches to perch and survey the water from. While their branch may move and sway in the wind, the kingfisher’s head remains static in a fixed position as it focuses on its prey beneath the surface, like a dart it shoots into the water, returning with a stickleback or similar small fish if it’s lucky. Fen Hide remains one of the best kingfisher observation spots, the shallow pool attracting the birds for easy prey opportunities.
RSPB Strumpshaw Fen nature reserve really does have something for everyone. From the macro to the micro, and solo naturalist to family, the reserve attracts a wide range of visitors. Families can get to grips with a spot of pond dipping or bug hunting, with a range of equipment for hire, allowing younger visitors to get hands-on and delve into another world. There’s a den building area and family trails on offer each month. The reserve also offers a unique range of wildlife experience guided walks with a warden to help get to know the wide range of wildlife onsite, dusky bat walks and fungi forays are a particular highlight of the autumn.
Find our more at rspb.org.uk/days-out/reserves/strumpshaw-fen
