"WILDLIFE OBSERVATIONS AT HARDKNOTT FOREST: STAR JELLY, BARN OWLS, ADDERS AND INVERTEBRATES" by John Hincks, Site Officer, January 2023
At the Restoring Hardknott Forest project there are lots of opportunities to observe the signs and activity of the wildlife that lives here. From a landscape scale to the miniature, there is always something new to see and learn about. The wildlife that inhabits the forest is a key aspect of the work we do, as species-richness is an indicator of a healthy ecosystem which is providing a variety of habitats. Some of the signs and behaviour of our wild creatures may be fairly common and familiar, others less so. Here are a few of the more unusual and infrequent encounters that may be found Hardknott Forest, such as Star jelly.
Star Jelly is found on the ground, occasionally on branches. It is a gelatinous substance that is a greyish – white to translucent colour. Star jelly has been recorded as early as the 14th century, occurring throughout Britain, as well other places across the globe. It has various names such as "Pwdre Ser" – from the Welsh for “rot from the stars”, "Stenenrotz", meaning “star snot” in German and “Caca de Luna” which is Mexican for “Moons faeces”. The old folklore stories describe the jelly as being deposited during meteor showers. The actual cause of the weird jelly “blobs” is often debated, but there is a consensus that the explanation is connected to the predation of amphibians. Star jelly is mostly found during the first months of the year – late winter/early spring. At Hardknott, amongst many other locations, it may be discovered high on the open fell. The jelly is thought to be formed within the glands of the oviducts of toads and frogs, (which are active quite early in the year). Birds such as crows, magpies, grey herons and ravens, all present at Hardknott Forest, will eat amphibians and often swallow them whole. As the body of the frog is broken apart, ovaries release the eggs that are surrounded by the jelly material. Within the body of an amphibian this jelly takes up little room. Yet when in contact with water it expands rapidly (ever stopped to wonder how a little frog can produce so much frog spawn?). As the unlucky amphibian is devoured, the predator’s stomach juices mix with the jelly during the digestive process and this expands, resulting in the meal being vomited up producing the jelly as we see it. This would explain how it is that Star jelly may be found a long way from anywhere you might expect to find a frog or toad, also the body of the regurgitated amphibian could then have been eaten.
Barn owls and peregrine falcons
Just as we are affected by the changing weather, wild creatures must adapt their behaviour according to the seasons and are impacted by extreme conditions and climate change. This was especially apparent in the behaviour of a Barn owl we observed while we were removing non – native trees in the Grassguards area of the forest. Barn owls are predominantly nocturnal, although like many other owl species they can often be seen at dusk and early in the morning. This owl was hunting right through the afternoon, flying low and scanning the ground for prey. Although aware of our presence, it was not perturbed, at times coming quite close. Working in the same location the following day, the owl was back hunting again. The previous few nights had seen some heavy rainfall, which would have prevented the owl from hunting, (downy feathers, which enable silent flight, become waterlogged; also the acute hearing of the owl is compromised). This will have led to the owl having to pick the window in the weather and consequently hunt out during the afternoon.
I would like to tell you that all went well for owl and its hunting was successful, however the following morning we discovered a pile of feathers and one foot - all that remained of the Barn owl. It was immediately apparent that it had been predated. Since then a second Barn owl corpse was discovered. The most likely suspect is the Peregrine falcon, and there a various pairs that breed within the area. The high-speed dive of a falcon is more than capable of dispatching an owl, and out in the open with its focus on hunting, the unfortunate bird would be an easy target for a larger, female Peregrine passing overhead. It may be that there is a particularly aggressive falcon present, as one of the local farmers has seen a buzzard being harassed by a Peregrine.
During the warmer months of the year there are of course many more species active and present than in the winter. Migrant birds come to breed at Hardknott and insect life buzzes, also amphibians and reptiles may be seen. Adders are not uncommon throughout the forest, with several sightings this previous spring/summer. Hibernating in the winter they may be seen from March to October, on cooler mornings basking in the sun, being quite lethargic before they warm up. As long as they are given a respectful distance, they present no harm to people, with only 14 recorded deaths from adder bites since 1876. Adders just want to be left alone and will usually disappear long before you get a chance to see one (if you are concerned you might step on one, make plenty of noise and stamp your boots). Britain’s only venomous snake, they hunt small rodents, lizards, ground nesting birds and frogs in the more open areas of the forest. Females are a reddish brown, smaller males are silvery green. They have a lifespan of up to 15 years, mature adults growing to around 60/80cm in length. In the spring males perform a “dance” to compete for females. After mating the female incubates the eggs internally, giving birth to between 3 or 25 young. While protected in the UK adders have suffered significant decline due to habitat loss and fragmentation, so we a very happy to see them occupying the naturally regenerating areas of Hardknott that were once conifer plantation.
Many of the projects undertaken by the restoring Hardknott Forest team directly benefit some of our resident invertebrates. Restored peat bog creates pools that provide habitat for species such as the Golden ringed dragonfly. One of the larger of the UK dragonflies, they are commonly found across the north and west of the country. Often seen hunting for other insects around these boggy areas, they lay their eggs in shallow pools whilst hovering in a vertical position. The majority of the dragonfly’s life cycle takes place as larvae underwater, Golden ringed only flying as adults between May and October, having spent up to five years or more as larvae. During this time the larvae may need to moult five to fourteen times as they grow. They are ferocious underwater predators, devouring other insect larvae, snails, worms, leeches, tadpoles - even small fish may be on the menu!
With the help of volunteers and our wildflower growing group, we have put in over 600 plants at Hardknott forest this year. Species include Water avens, Wild angelica, Melancholy thistle, Devils–bit scabious and Ragged-robin. The restoration of these native wildflowers benefits many invertebrates that come to feed on their nectar, such as butterflies and bees. These pollinators may in turn provide a meal for others, including some we may not be quite so familiar with that are to be found at Hardknott, for example the Gasteruption jaculator. You may find the name a bit disturbing, but then so are its habits. It belongs to the parasitic wasp family Gasteruptiidae and although these insects look like they pack a powerful sting they are not harmful to people, the adults feeding predominately on flowers. However their offspring have different tastes. The female has an incredibly long ovipositor, this is a needle – like organ extending from the abdomen that is used to lay eggs.
Solitary bees are a favourite quarry, and once the female wasp has found a bee’s nest she uses her ovipositor, pushing it into the nest to lay her eggs within. Upon hatching, the wasp larvae begin to devour the bee grubs, also consuming the bee’s pollen and nectar larder. Producing one brood per year, the young overwinter in the nest, and the larvae pupate in the spring, hatching out from May throughout the summer. We were lucky enough to have a Gasteruption jaculator fly into the car while eating lunch one day last summer, quite an unexpected surprise!
Further information available at:
Amphibian and Reptile Conservation Trust https://www.arc-trust.org/
Game and Wildlife Trust https://www.gwct.org.uk
British Dragonfly Society https://british-dragonflies.org.uk/