Case Study: Managing Farmland for Grey Long-eared Bats

Author: Craig Dunton, Grey long-eared bat Project Officer, Bat Conservation Trust

Species: Grey Long-eared bat:

© Craig Dunton/www.bats.org.uk

 

Why is farmland important for this species?

With as few as 1000 individuals In the UK, the grey long-eared bat is one of our rarest mammals. Their distribution is restricted to the southern coast (Devon, Dorset, Somerset, Hampshire, Isle of Wight and Sussex) and there are only 9 known maternity colonies; meaning that this species is on the brink of extinction in this country. Currently, work is being carried out to conserve this species as part of 'Back from the Brink' – a Heritage Lottery funded conservation project aiming to save 20 species from extinction. https://naturebftb.co.uk/

Farmland is vitally important to all bat species. 70% of land in the UK is used for agriculture, so for very mobile species that utilise the whole landscape, farming practices can have significant impacts on bat populations. Some bat species are more resilient than others, but for those that have very low populations, are particularly sensitive to light and disturbance, and have very specific habitat requirements, there are significant threats to their survival.

Like all bats, the grey long-eared bat needs some key elements throughout its range in order to survive and thrive.

Grey long-eared bat (Plecotus austriacus) in flight. © Dale Sutton/www.bats.org.uk

Roosts: Bats utilise a wide variety of structures to roost in, as their requirements change throughout the year. Roosts are needed for different activities – hibernation roosts, maternity roosts, night feeding roosts (for some bats) – these are all needed at different times of the year, and different bat species choose different structures for different activities.

Many bats hibernate underground, using caves, mines, cellars and tunnels that have a cool and constant temperature that bats need to hibernate. Many farms have these types of features, so it is important to be aware of their importance for bats. Some bats roost in a variety of different tree features; cracks, splits, woodpecker holes, loose bark – so it is important to retain trees that have ‘interesting’ features.

Grey long-eared bats are mostly associated with man-made roosts – usually the roof spaces of large, traditional, stone buildings with slate roofs. There are some records of them using caves and rock crevices, but no records of them using bat boxes in England.

Many buildings on farms can provide important roosts for grey long-eared bats, particularly large stone buildings with slate roofs and large, open roof voids. These can provide vital maternity roosts, temporary day and night roosts and opportunities for hibernation. As all bat species are protected, if you are planning to carry out any work that might impact bats or their roosts, the National Bat Helpline will point you in the right direction, please email enquiries@bats.org.uk

Foraging sites: As with roosts, different species of bats have different types of habitats that they favour for foraging. All UK bat species are insectivores, and depending on their size, flight habits and other physical adaptations, different species need different insect prey and therefore different habitats for foraging in. Greater horseshoe bats are large bats and so favour large prey, particularly around the maternity period. Cockchafers and dung beetles are their food of choice. Daubenton’s bats are often seen foraging over water, trawling insects from the surface of the water with their specially adapted, large hairy feet.

© Craig Dunton/www.bats.org.uk

Grey long-eared bats have a close association with unimproved lowland grassland and riparian (wet) habitats such as meadows and marshes.

Managing permanent pasture more extensively with very low or no inputs will benefit grey long-eared bat populations, offering more opportunities for invertebrates including the moths and craneflies that grey long-eared bats favour. Managing land to maintain or increase species diversity (more flowering plants) as well as structural diversity (a range in sward height), will give insects food and shelter resources. If possible, consider transitioning land back to hay meadow management as opposed to silage production, as this allows insects and plants to complete life cycles and thrive.

In terms of cultivated land, increase pollen and nectar plots and wildflower margins, and manage by cutting or grazing to maintain plant diversity. These areas alongside trees and tall hedgerows have proven benefits for some bat species. Minimise pesticide use and consider crops that contain lots of flowering plants such as herbal leys.  Within arable land, conservation headlands or low input cereals can be beneficial if management results in increased invertebrate numbers. These are all ways of increasing foraging opportunities on less productive areas of land for grey long-eared (and other) bats.

Farming organically has many advantages, including huge benefits to biodiversity, natural resource protection and reducing greenhouse gas emissions. Following organic principles should be considered if aiming to encourage bats and other biodiversity.

Connectivity: For so much of our wildlife, good habitat connectivity is critically important. Linear features in the landscape such as hedgerows, watercourses and ditches, enable different species to flow freely through the landscape, enabling opportunities for feeding, interacting and breeding. For bats, good connectivity is vital, as many bats use linear features to navigate through the landscape, using their echolocation to move from roosting sites to foraging sites. When these features are well managed, they can also provide foraging opportunities as well as providing obvious features to allow free movement. Extensive hedgerow management (2-3 year cutting cycle) allows hedgerow plants to flower and fruit, providing vital resources for insects. Buffer strips along streams and rivers not only provides increased opportunities for foraging, but can also protect watercourses from nutrient and pesticide run off, protecting aquatic flora and fauna.

For more information on land management for grey long-eared bats contact Craig Dunton (Grey long-eared bat project officer) on cdunton@bats.org.uk

 

 

 

Case Study: Helping hedgehogs on farmland

Author: Nida Al-Fulaij, Grants Manager, People’s Trust for Endangered Species

Species: Hedgehog

Why is farmland important for this species?

Hedgehogs are found throughout the UK in all habitats. They have historically been associated with farmland for centuries. Hedgehogs are insectivores, foraging in fields and on grassland for worms, and along field margins and at the base of hedgerows for beetles, snails and other invertebrates. They are considered a generalist species, inhabiting most areas of our countryside, our villages and many areas of our towns too. However, as the dominant habitat in the UK, farmland is particularly important for hedgehogs.

Hedgehogs, like all animals, need to feed, hide from predators and find mates. A variety of habitats that provide foraging areas and secure nesting sites is ideal. Both arable and pasture land can support healthy hedgehog populations. Wide, species-rich hedgerows with buffers of grassy margins on either side provide safe ‘highways’ for hedgehogs to move around the landscape. Hedgerows with wide bases that are managed on rotation should have healthy invertebrate populations for hedgehogs to feed on. Old hedges with dense root systems and lots of deciduous leaves are ideal for them to use as nesting sites, both during the summer and in winter as hibernation spots.

The denser the network of hedges, the more securely hedgehogs can move around, and the higher the availability of prey species for them to feed on.

Recently ploughed fields can provide a bounty of earthworms and other prey; hedgehogs can be found in-field taking the opportunity to feed on invertebrates once crops have been harvested.

Recent studies show hedgehogs are found nearer to farm buildings. These areas could be providing safety from predators on farmland with less robust and fewer hedgerows, and larger fields.

Hedgehog (c) Ben Andrew (rspb-images.com)

Habitat management

Hedgerows:

Increasing hedgerow availability provides more nesting and foraging areas for hedgehogs. Ensure that hedgerows are species-rich, contain native trees and are as wide, high and dense as possible. Maintaining hedge bases at least 2m wide with minimal or no gaps provides secure safe nesting sites. Managing hedgerows on a 3 year rotation ensures that hedges remain diverse and robust.

Field margins:

Field margins provide buffer zones to protect hedgerow bases. 2m margins in arable fields and 3-6m margins in pasture ensures the hedges are protected from trampling and grazing, whilst the grassland provides extra invertebrate prey. Beetle banks also provide buffer zones and extra foraging areas.

Fields:

Smaller field sizes with a mixed crop provides greater variety, and therefore greater food security, for hedgehogs and other wildlife. Increasing hedges and field margins on farms with fewer, larger fields, provides habitat for hedgehogs. Reducing tillage or moving to no-till or conservation agriculture reduces soil compaction, increases soil invertebrates and improves and increases the depth and quality of the soil organic layer.

Pesticide & herbicide use:

Reducing pesticide and herbicide use means that more invertebrate prey, in particular earthworms, will be available on farmland for hedgehogs to feed on.

The above management measures recommended to provide a healthy landscape for hedgehogs are typically those associated with traditional farming practices. There should be no problems, though many of the measures may be more time-consuming than those associated with farming on a larger scale.

Hedgerow with grassy margin (c) Gethin Davies

Peoples Trust for Endangered Species (PTES) and British Hedgehog Preservation Society (BHPS) have created an advice note detailing management and stewardship options that will benefit not only hedgehogs but other wildlife too (see link below).

Benefits and costs

Creating and managing hedgerows sensitively has financial costs but there are stewardship options available; individual ones for the management regimes listed above are detailed in the attached advice note.

Managing a farm for a species such as a hedgehog involves looking at the farm as a whole. Unlike species that fly, such as butterflies, hedgehogs needs the entire landscape to be suitable in order to thrive. Consequently, many of the management techniques recommended to improve habitats for hedgehogs will also provide a healthier landscape. A denser proportion of hedges and associated smaller field sizes both help to reduce soil erosion. Reducing tillage improves soil organic matter and reduces soil compaction.

PTES guide - How to help rural hedgehogs

Case Study: Using unharvested cereal headlands combined with cultivated margins on heavy land

Author: Martin Lines
Farm: Papley Grove Farm, Cambridgeshire

Aims:

Using options that need spring establishment can be difficult on heavy land. We wanted to find a way of providing conservation management without needing a great deal of work in the spring and without causing undue problems to the crop following it.

I grow winter wheat, winter beans and oil seed rape. Because of my heavy soils we thought this combination would be ideal for using ground for two full cropping years, allowing me to follow it with another winter established crop and avoiding the need for trying to get a crop going in the spring. I worked with Niki Williamson of the RSPB, who gives free nature-friendly farming advice in the Fens area, to design the combination.

Management:

I plant a winter wheat crop as normal, leaving a headland as a conservation headland. This receives limited fertiliser, no insecticides after 15 March, and I apply limited fungicide (only when absolutely necessary to stop crop failure). This provides insect-rich habitat all summer, helping birds like grey partridges and corn buntings. The headland is left unharvested the following autumn, so provides winter seed food as well.

From 21 March, I cultivate the headland by ploughing or discing to form a cultivated margin. Problems with working the heavy soil at this time are not so important as I am trying to create a reasonably fine fallow, but not required to create a seedbed to establish a mix or a crop.

If there is blackgrass residue once I’ve cultivated I use a herbicide to control it. That needs doing as soon as cultivation is completed, to give as long a window as possible to allow the intended weeds to grow on the plot, forming cover and food sources for wildlife.

On my land there is no rare arable flora! But the plants that do grow will flower and set seed in time for turtle doves arriving back on the farm in late April, providing a much needed food source. It also provides a fallow, weedy area for other insects and birds to use during the summer months.

From 31 July I spray off the area to clean it up and cultivate it in time to follow it with autumn sowing.

In any one year there are two areas like this on the farm, one in each option. They are rotated around the farm to keep the weed burden in check.

Achievements:

This year we followed the cultivated margin with oil seed rape and I found that this was the best bit of rape in the field. It’s cleaner because of the seedbed preparation and it’s established better because there are less slugs where there are no stubbles.

On my soils blackgrass is an issue, and would normally make things like conservation headlands and summer fallows a no-no. However this management has not increased my weed burden any worse than the rest of the farmed field. There are two opportunities to cultivate the option and bury the blackgrass, one in March and one in July. There is also nearly 2 months across August and September that can be used to germinate weeds and spray them off to create stale seed beds before drilling, giving you plenty of opportunities to address blackgrass problems.

The seed from the unharvested headlands was being depleted by pigeons and crows really early, so I had to put out deterrents to make sure it lasted further into the winter for the smaller birds we were trying to target. In the end there were still big flocks of birds in it right up until March, finding something to eat. I also have other wild bird seed mixes on the farm, which are designed to retain seed through the winter months to make sure there’s a winter-long food source.

We noted that in shaded areas, wheat tended to stay in the ear and germinate there, making it inaccessible to birds. Although it’s clearly beneficial to site it near a hedge for birds to hop in and out, I think you need to avoid the north side of tall hedges or woodland s to avoid loss of seed in this way.

The plots are rotated around the farm, so this year it will be sited in a different place. The unharvested headland will be near woodland rather than hedge. Having observed it this winter, I now wonder if it will be as popular without the hedge for the birds to use as a base to feed from. Otherwise I am very happy with the option as it stands. It fits in well with our system and delivers what we wanted for wildlife.

I found the options very easy to manage. It needs an extra operation in March to create the cultivated margin but nothing onerous.

I do what it takes to make the margin work in terms of balancing wildlife benefits with weed control. Some years it takes more, sometimes less. Although I haven’t done the detailed costings, I’m confident it balances out overall and does not leave me out of pocket.

The hedge alongside the option was teeming with yellowhammers, corn buntings, reed buntings and sparrows for as long as there was seed left in the headland. There were still birds using it when I came to cultivate it in March. There are breeding turtle doves on the farm, which I hope would benefit from the early seed source the cultivated margin provides. I saw loads of starlings and blackbirds rummaging around in spring and summer, which must show how many insects there are in there.

You can also see areas where partridge have used the fallow as a sunbathing/dusting area.

It adds another feature to the farm that wouldn’t usually be there. It’s not common to find fallow areas on heavy land, so this adds to the diversity of our system.

It’s a simple straightforward combination option that has worked well for me in my farming system.