British dung beetles – here to help

Author: Ceri Watkins, Co-Founder of Dung beetle UK Mapping Project

Species: Dung beetles

Why is farmland important for these species?

There are approximately 60 species of dung beetle in the UK. They are not the ‘ball rollers’ seen in warmer countries and on TV, instead they live inside the dung pile (dwellers) or in the soil beneath it (tunnellers). Livestock grazing provides much of the dung required for the survival of these beetles, although other animals such deer and badgers also contribute. Some species are rather specialised and require exacting conditions. For example, Volinus sticticus prefers horse or sheep dung in the shade and Onthophagus joannae is a sun loving beetle that favours sheep dung on light soils. Others are less fussy and have few specific requirements.

It is possible to find dung beetles at work all year round. Several species are winter active, although the vast majority are found in the spring, summer and autumn. Given the right conditions, dung beetles can decimate a pile of horse poo or a cow pat in just a couple of days.

Volinus sticticus (c) Katherine Child  

Onthophagus joannae (c) Katherine Child

How do dung beetles benefit farms?

Dung beetles provide a wide range of ecosystem services that help to maintain healthy pastures and soils. These include the most obvious, the consumption of dung thereby removing it from the fields thus reducing pasture fouling, but also some that you may not have considered. As the beetles tunnel down through the soil, burying the dung for breeding purposes, essential nutrients are recycled within the soil profile. This improves grass growth and provides a direct benefit to grazing animals. The larger species such as the Minotaur beetle (Typhaeus typhoeus) can tunnel a metre or more, this action breaks up the ground and improves drainage, especially useful on clay soils.

In addition, dung beetles also reduce nuisance fly populations by transporting phoretic mites that eat fly eggs and help control intestinal parasites by reducing dung suitability for worm larvae. The beetles are also an important food source for many other farmland favourites such as bats and birds.

 

Onthophagus similis with phoretic mites (c) Ceri Watkins

Habitat management

Continuity of the dung supply and diversity of habitat are key factors in supporting a diverse range of dung beetle species on the farm. If possible, maintain some outdoor grazing year-round, even if only a few animals. Planting a group of trees and grazing within them will provide variety of forage and shelter for livestock and support the shade loving dung beetles too.

Broad spectrum livestock wormers such as avermectin are detrimental to beneficial dung invertebrates. These chemicals are excreted in the dung for many weeks after treatment and a range of lethal and sub-lethal effects occur depending on the concentration. Such effects include slowing beetle larvae development, reducing the size attained at adulthood and reduced breeding capacity.

Dung beetle larvae (dwellers) (c) Darren Mann

Cutting down the use of chemicals on the farm with a sustainable worm control policy that includes monitoring with faecal egg counts will help. Treating animals only when necessary will save money and also slow the rate of anthelmintic resistance. As a natural alternative in a rotational system, consider using herbal leys. Sainfoin, birdsfoot trefoil and chicory all have anthelmintic properties. The latter has been shown to reduce worm burden in sheep by as much as 40%. In permanent grasslands, mixing up cattle and sheep grazing works by reducing the stocking density of the parasite host – cattle and sheep worms are different species.

Benefits

Supporting dung beetles on your farm not only helps keep pasture and livestock healthy, it also represents good economic sense. It has been estimated that dung beetles save the UK cattle industry £367 million per annum through the provision of ecosystem services (Beynon et al., 2015). So, it really does pay to look after these useful little creatures.

For further information and dung beetle identification resources, please visit the Dung beetle UK Mapping Project website or get in touch via email or twitter.

Case Study: Managing for wildlife in Caithness

Author: Katy Malone
Farm: Todholes Farm, Caithness

Todholes Farm is a 170ha lowland livestock farm in Caithness, where Ian Campbell raises prize winning beef cattle and sheep.

Ian Campbell took over the 170ha holding around 1990. Previously his father had managed the farm, having moved to Caithness in 1951. Since then, Ian has built up a herd of prize winning livestock, and won many rosettes for his Beef Shorthorn cattle as well as Lleyn and Texel sheep at a county level and further afield.

Aims:

Caithness holds nationally important populations of breeding waders such as lapwings, curlews, redshanks and snipe as well as twite, which have suffered from long-term declines in their breeding numbers across the UK. It is also a stronghold for the biodiversity action plan (BAP) priority species great yellow bumblebee which was previously widespread in the UK but is now one of our rarest native bumblebees. Populations of all these species have been maintained in Caithness thanks to high nature value farming systems. Todholes Farm is a typical example of these systems, which has been further enhanced through the tailoring of management for the benefit of key species.

The majority of the farm is grazed, with smaller areas of arable for livestock feed: spring barley for cattle feed, fodder rape for fattening lambs, and fodder turnips for wintering sheep.

Much of the farm is directly adjacent to the River Thurso, a Special Area of Conservation for Atlantic Salmon and a Site of Special Scientific Interest for a number of nationally rare or scarce plants.

Management:

Management advice was provided by the RSPB Scotland, specifically in relation to breeding waders and seed eating birds. Scottish Natural Heritage advised on management relating to designated sections of the site, and the Bumblebee Conservation Trust advised on the provision of pollen and nectar sources.

Of the options available for the non-designated parts of the farm, Ian opted for:

– Open Grazed Grassland for Wildlife (29ha)

– Management of Habitat mosaics (16ha)

– Management of Species Rich Grassland (4.5ha)

Open Grazed Grassland for Wildlife

Stock are excluded for six consecutive weeks between 15th March and 15th June, to restrict trampling of nests of waders such as lapwing and curlew. This could have had a high impact on the farm business, particularly in late spring, so the timing of the exclusions are calculated to allow two areas to be shut off while a third is opened up. This works well and has little detrimental impact on the economics of the business.

Management of Habitat Mosaics

This is an area of bog and heath with scattered rush and gorse bushes. Grazing is kept low between May to August to avoid trampling of wader nests and at the same time to avoid the vegetation becoming too rank.

Species Rich Grassland

Three areas of species rich grassland are managed on the farm. Wildflowers were relatively abundant right into early September, providing a much-needed late nectar source to bumblebees. In particular, the nationally rare great yellow bumblebee has been found on Todholes, and lapwings and curlews nest on the other areas of species rich grasslands.

There are some small areas of wetland within the habitat mosaics field, which were of concern to Ian in case they presented a problem with liver fluke. These areas were fenced off to address this. However, to prevent them from becoming rank, the wetlands still need to be grazed and cattle have access to them through the autumn/winter months. The cattle are dosed for fluke three times annually and Ian has not noticed any detrimental effect of fluke on his livestock as a result of grazing in these wetland areas.

Achievements:

It is still early days for the created species rich area and other taller more nutrient-loving species such as thistle currently dominate the field. Species that we hope will flourish here include vetches (e.g. tufted vetch and meadow vetchling), bird’s-foot trefoil and flag iris. Livestock are excluded between April and August but by the time the field is opened up again, the level of grazing is not sufficient to control the ‘weeds’. The grazing plan will be adjusted over time e.g. to increase grazing or allow for cutting so that a greater variety of plants can flourish. Some scarification and reseeding may also take place.