Ecology, wildlife and Redland Green
Redland Green is the last remaining fragment of undeveloped space in an area that only 100 years ago was largely open fields, as pictures elsewhere on this site show. We humans tend to develop our urban areas without regard for the effect of development on wildlife. This often means that wildlife habitats, with their food sources and places to shelter and breed, are replaced by roads, housing, commerce and industry, and so places that were once rich with native wildlife become impoverished in it.
Over the last few decades, there have been catastrophic losses of biodiversity in the countryside. This is largely a result of the intensive methods of agriculture adopted in the post-war period to increase food production. There is increasing recognition that urban areas can now offer vital refuges for our native (and, indeed, non-indigenous) wildlife. (e.g. ‘Where is the UK's pollinator biodiversity? The importance of urban areas for flower-visiting insects.’) If, in our own gardens, we provide wildlife with the infrastructure that is needed to provide food and shelter, we not only do not have to lose so much wildlife, but can do much to protect species, and to provide vital corridors to connect green areas, allowing species to move from place to place. This is important for a variety of reasons: to provide new sources of food and breeding sites, and to provide access to new territories for new generations of animals.This is, in turn, important for us: the experience of nature is good for physical and mental well-being. The multiple mental and physical health enhancements offered by green spaces are of significant interest as more and more of us live highly urbanised lives, and there is particular evidence of the benefits this gives to children.
One of three veteran ash trees near the Dell, over 300 years old
Although Redland Green is surrounded by intensive development and congested roads, it is relatively rich in wildlife. Why is this?
One reason is the diversity of habitats on the Green itself: a small woodland ("the Dell", pictured below) with a variety of trees including oak, ash, elder, holly and hazel, and a large number of trees of different species all around the Green, including some very old ash trees (left), and some relatively unmanaged areas of trees, brambles and scrub around some of the perimeters. The more unmanaged areas are important for wildlife, with fallen leaves and slowly decaying wood providing the habitat infrastructure that many small species, such as invertebrates and small mammals need. Grass is important too as some species forage for food in short grass: you may see blackbirds, crows and magpies, or perhaps even a song thrush or a green woodpecker hunting on the grass for worms and grubs, listening for the sounds of movement below the surface.
Great spotted woodpecker (left)
Leaf litter as well as decaying wood on the ground and in trees (so called deadwood) provide homes for invertebrates such as insects, beetles, spiders, wood lice and many others. Deadwood is hugely important in sustaining wildlife: for example, woodpeckers both consume insects which live in trees and hollow out nests in old and dead trees. The ancient ash trees in the Green, and others, are home to great spotted woodpeckers: you can hear them drumming particularly in the early months of Spring and the sound resonates throughout the Green.
Redland was developed over several decades and consists largely of properties built from the late Victorian to pre-World War II periods. As the aerial view to the right shows, the Green is surrounded by gardens with trees and green spaces, well illustrating the point that what we choose to do with our gardens can be really significant for wildlife, providing living space and green corridors between habitat opportunities. Gardens don't need to be large to offer sanctuary for wildlife; what is important is what is provided within them. Happily, advice on what to provide is easily found today, and all the major wildlife and gardening organisations (e.g. RSBP, the Wildlife Trusts, Royal Horticultural Society) offer suggestions on how to attract wildlife to, and sustain wildlife in our gardens.
Just as important is that Redland Green is adjacent to an area of land used since the 1920s for allotments. The picture above also shows the large area occupied by the Green and the four allotments (plus the non-contiguous Birchall Field allotments on the north east side of Cranbrook Road). Between them, the Green and the allotments provide wildlife with a fairly large, and contiguous undeveloped space.
Recent research at the University of Bristol has indicated that allotments can be rich habitats for wildlife, as reported by the Guardian in 2014. The four allotment sites of Redland (Redland Green, Metford Road, Cranbrook Road and Kersteman Road) provide a large and connected area of mostly organic cultivation contiguous with the Green which greatly amplifies the wildlife value of the Green.
Organically managed allotments are so good for wildlife for a number of reasons. Cultivation of fruit and vegetables provides many and varied sources of nectar from spring to autumn. Nectar is essential as an energy supply for for pollinating insects such as solitary and honey bees, bumblebees, moths, butterflies and hoverflies, and, of course, nectar-feeders require nectar throughout the months in which they are active, from spring to autumn. In the spring, the apple, plum and pear trees, and currant bushes almost universally found on allotments, are rich sources of nectar. Commonly grown vegetables such as french and runner beans, peas, broad beans, courgettes, cucumbers, pumpkins (pumpkin flower with honey bee pictured left), tomatoes and chillies are good sources of nectar in the summer months, extending into autumn.
Many allotmenteers also plant ornamental flowers, for their attractiveness or in order to attract more insects to pollinate crops: lavender (right, with bumblebee) is a particularly good plant for insects. Since many birds feed on insects, allotments can provide rich hunting grounds for them. And birds, particularly the passerines ("perching birds") in turn provide food for others, such as foxes, badgers and larger birds. Magpies, crows, jays, great spotted woodpeckers, and green woodpeckers, all of which flourish in the area, will all predate upon young birds, as well as eggs.
The Redland Green and Metford Road allotments offer a particularly diverse range of habitats, because of the river and woodland running through them, and because these areas are unused and uncultivated. Fox dens and badger setts are hidden within these uncultivated areas, and there is plenty of space for other, smaller mammals, such as wood mice, pictured left (also known as field mice).
Slow worms, one of three native species of lizard found in the UK, and the only one without legs, are often found in protected warm or sunny spots on the allotments here (such as a compost heap, under mulching mat, or in nooks and crannies at protected margins of cultivated beds). They can grow up to 50cm and can live up to 30 years in the wild. As predators of many garden pests, such as slugs and small snails, their presence is very much welcomed!
For at least the last ten years, a pair of sparrowhawks (female pictured right) has nested in a tree within the allotments: they can be seen in the locality as they hunt smaller birds, and in late July and early August, the cries of their young can be heard along the valley as their parents try to entice them away from the nest, which they re-use each year.
Female sparrowhawks (which are bigger than the males) are also big enough to take pigeons. It is not uncommon to find the plucked remains of a woodpigeon in the allotments. (This is evidence of a sparrowhawk kill rather than a fox or badger kill, as both mammals will also eat the feathers, which raptors do not). Woodpigeons are also doing well locally: there are at least four pairs living in the allotments and Dell area.
Sadly, no hedgehogs have been seen on the Green or in the allotments. Although hedgehogs have suffered very serious population declines in Great Britain since the 1950s, their absence here is more likely to be the result of the presence of the badgers, a major hedgehog predator, although the busy roads of Redland have doubtless also contributed to a more general local decline.
The UK's smallest bat, the soprano pipistrelle, may be seen at dusk. (This bat is very similar to the common pipistrelle, and most easily distinguished from it with the aid of a bat detector, a device that picks up bats' echolocation calls.) They emerge shortly after the sun has set to hunt small insects (flies, midges and mosquitos), which they catch and eat on the wing. This is known as "aerial hawking". Each bat can eat up to 3,000 insects a night! In the summer, the bats roost in tree holes and crevices in colonies of several dozen individuals. In the winter, they nest either singly or in smaller groups in tree holes and crevices. Old trees, such as the ash trees on the Green are therefore very important for bat conservation, as trees can develop holes as they age. When a tree suffers an injury, for example, such as a branch breaking, an opening is created in the bark and outer tissues which allows fungi and bacteria to attack the sapwood below. (Sapwood is the living tissue which contains the vessels which transport water and nutrition through the tree.) Over time, a hole will develop. This is one reason that old trees are particularly beneficial to wildlife, as they provide habitat to a greater extent than do young trees.
Bats also may use bat boxes: there are bat boxes in the Metford Road allotments, which the local scout group put in place several years ago.
Butterflies are species of huge conservation concern in the UK, with serious and long term declines in both their population numbers and where they might be seen.
The Redland allotments also help to provide an oasis of food and shelter for butterflies. Species seen (although not every year) in the Redland allotments have included: Meadow Brown, Speckled Wood, Large and Small Cabbage White (of course!), Red Admiral, Small Tortoiseshell, Comma, Common Blue, Holly Blue, Peacock, Gatekeeper, Ringlet, Brimstone, Painted Lady, Marbled White and Orange Tip. (To learn more about these species, have a look at Butterfly Conservation’s website.)
common blue (female)
The Redland Green and Metford Road allotment sites also benefit from the river Cran, which runs between them at the base of the valley, and is fringed with mature trees. In Redland, and in the Green, this watercourse is mostly channelled underground today. In fact, the stretch of the river Cran which runs through the allotments is the only remaining unculverted stretch of this river in the area. Although the river sometimes dries up in particularly dry summers, its running and standing water is valuable for drinking, bathing and breeding for many different types of animal. The trees along the river (which include oak, ash, sycamore and cherry laurel) are important contributors to available habitat and food sources. Oaks are particularly good for wildlife: it is estimated that they harbour more than 400 species of insect, and that if a pair of blue tits nest in an oak, they might be able to raise a brood of chicks solely on the insects they find within the confines of the tree!
Without nectar sources, the Green has not been a particularly beneficial place for butterflies and other pollinating insects. This is one of the reasons that Redland Green Community Group has been keen to instigate flowering meadows in different parts of the Green. There are now three: the oldest one runs parallel to the wall bordering the houses of St Oswald’s Road; a second runs along the north-east boundary of the Green between St Oswald’s and Cossins Roads; and the third and newest in the triangle of grass by the steps leading down from the top of Metford Road, and one devoted to native wild flowers. It has been wonderful to find aerial visitors taking nectar from the wildflowers!
In the countryside, hedgerows - rows of shrubs and trees, often of mixed native spacies - are an extremely important habitat for a huge variety of insects, birds, mammals and other animals. Traditionally, hedgerows were planted to mark the boundaries between fields and parishes. They may also be the remnants of ancient forests, and they were also planted in the nineteenth century when the Enclosure Act resulted in the subdividing of fields and common land. As areas of woodland shrunk over the centuries, hedgerows assumed a vital role in providing some replacement for lost habitat, and in providing corridors through the countryside.
To increase the value and species diversity of Redland Green, a hedgerow was planted in February 2012 along the south west perimeter wall of the Green, running parallel to St Oswald's Road. This contains a mix of traditional hedgerow species, including hawthorn, hazel, holly, wych elm, guelder and dog rose, spindle, dogwood and wayfaring tree.
The hedgerow, just after planting in 2011
The hedgerow after 2 years' growth
Dogwood berries in the hedge
The wildlife value of hedgerows is greatly increased if a hedgerow is laid. Over time, the shrubs and trees in the hedge develop weak growth, develop openings at the base, and become top heavy. For this reason, as they often served to keep livestock within fields, hedges were laid, which promotes thick growth from the base. This means trimming the tree, making a diagonal cut in the main trunk and laying the trunk along the ground: different counties developed different styles of laying. The tree will sprout new growth from the trunk, the new base of the hedgerow. It can look rather alarming after the hedgerow has just been laid, but in time new growth will sprout vigorously from the base, and the longevity of the hedgerow will also have been enhanced. And the hedge will become a great wildlife habitat.
An older hedge, which runs along the boundary between the Green and the Metford Road Allotments, and which consists exclusively of field maple trees, would also benefit from being laid, as it is now becoming very "gappy". This hedge is cut back every few years by Council contractors.
In the winter of 2018, RGCG laid the mixed species hedge in the North Somerset style, under the tuition of experienced local hedgerow layer, Malcolm Dowling (a.k.a "Grandad"). He lays hedges in the traditional styles of many different counties and also train local volunteers in this ancient skill. Later in the same winter, it is planned to lay the field maple hedge.
Over the years, members of the local community have also planted many early flowering bulbs around the Green, to enhance the visual appeal of the Green in spring, and to add early sources of nectar. In November 2017, members of the Group planted 500 Fritillaria meleagris bulbs and 150 cowslip plants along the wall of the church hall and vicarage, and hope these will provide both an attractive spring display of colour and a source of early nectar for foraging insects.
The trees, vegetation and less managed areas of the Green and the allotments together provide a varied and substantial range of habitats and food sources for a surprising variety of wildlife, and, of course, since human boundaries have no meaning for wildlife, some species found within the allotments move quite freely between them. We hope that over time, the hedgerows, meadows and other plants we have added to the Green will make the Green a much richer and more sympathetic environment to humans and wildlife alike.
Click here to see lists of birds and mammals seen on and around Redland Green, and which you could see. If you see something on the Green that isn't on this list, please email firstname.lastname@example.org.
All photographs on this page have been taken in Redland Green and the Redland allotments