As Victoria Burton, lead scientist for Earthworm Watch recently reported, earthworms are a vital source of food for many small invertebrates including flies, beetles, slugs and leeches. Without earthworms in our garden soils mammals such as badgers, moles and our beloved hedgehogs would struggle at certain times of the year to find enough food. Earthworms are active for most of the year and are packed with protein, iron and similar levels of calcium that you would find in fresh cheese or milk. It is therefore no surprise that earthworms are on the dinner menu of many a British mammal and enthusiastically eaten by the wildlife that may visit your garden.  

Badgers with their keen sense of smell love to feed on earthworms in woodlands, parks and gardens. Badgers are highly social and live together, often in extended family groups underground in interlocking tunnels called setts with several entrances. Earthworms make up to 80% of their diet and badgers can eat hundreds of them in a single night. Earthworms are important not only for protein but are 90% water and during periods of hot, dry weather they are a vital source of water in a barren landscape that can prevent badgers from dehydrating.  

Wytham Woods (close to where Earthwatch is based and where scientists such as Dr. Alan Jones are studying how trees are responding to climate change) is home to one of the most dense populations of Badgers in the world and have been one of the longest studied of all carnivores with research by the Wildlife Conservation Research Unit going back to the 1970’s. They also run Badger Watch at certain times of the year allowing you to get up close to these charismatic mammals. You could also contact your local mammal group to find out how you can help our native mammals.

Whilst earthworms make up a huge part of their diet, Badgers are omnivores and opportunistically will scavenge. Badgers forage for insect grubs, fruit, flower bulbs and will eat frogs, toads and hedgehogs. Although Badgers do predate hedgehogs, our spiny friends have seen a marked decline in their populations in rural and urban areas.

According to the 2015 Report on the State of Britain’s Hedgehogs by The British Hedgehog Preservation Society and The People’s Trust for Endangered Species hedgehogs have declined from an estimated 1.55 million hedgehogs in the 1990’s to less than 1 million in 2010. This cannot be attributed to increased badger activity alone. The 2016 State of Nature report cites the changing landscape of Britain with the intensification of agriculture and reduction of habitat in rural areas which has led to parks and gardens becoming a refuge for hedgehogs (just like many species of birds and amphibians). The recent BBC programme The British Garden presented by Chris Packham which intensively studied 5 suburban gardens for a year with experts from The Natural History Museum (partners in Earthworm Watch) clearly demonstrated the value your garden has as a refuge for British wildlife. The team recorded over 683 species, including 13 mammals, 490 invertebrates, with 9 earthworm species found in a single garden.

Hedgehogs like badgers eat earthworms as a food source along with slugs, beetles, caterpillars, millipedes and other insects, fruits and fungi. Hedgehogs emerge at night often when certain earthworm species are at their most active, dragging down leaves into their burrows. Earthworm Watch is trying to understand the abundance of earthworms and the impact that their activities have in urban green spaces and if there is to be a future for hedgehogs, than understanding how to improve both their habitat and their insectivorous food is key to this.

I recently have been supporting the Royal Park’s Mission Invertebrate project team at Regents Park who are trying to turn around the fortunes of the only resident breeding population of hedgehogs in a London park. The Spiny Supper survey allows volunteers to help the team using soil corers, quadrats and pitfall traps to capture and identify the hedgehogs’ invertebrate food. The team want to answer important questions about the health of the habitat in Regents Park and whether declines in populations are a response to changes in their invertebrate food. By better understanding the invertebrate food of our native wildlife and the habitats which we share our wildlife with, we will be in a better position to improve, protect and conserve it.

A few actions you can take to help Hedgehogs and their habitats:

1. Sign up to Earthworm Watch and/or join the Earthworm Society of Britain to help scientists record the abundance and diversity of earthworms in different soils across the UK which are an important food source of food for Hedgehogs and other mammals.

2. Help the People’s Trust for Endangered Species and The British Hedgehog Preservation Society by taking part in monitoring hedgehogs near you with The Big Hedgehog Map.

3. Contact your local mammal group to find out how you can help Hedgehogs and other mammals near you:

4. Make a safe space for hedgehogs in your garden with RSPB’S Give a Hog a Home as part of their Giving Nature a Home campaign.

5. Do you live in or near London? Get involved with The Spiny Supper survey or other Citizen Science Projects for Mission Invertebrate – visit the website here to find out you can get involved.

Earthworm Watch has been developed by Earthwatch (Europe)The Natural History Museum and the Earthworm Society of Britain to better understand the ecosystem benefits of earthworms. Earthworm Watch allows the public to help scientists map their abundance, better understand the human impact on their populations and with further research measure the services these ‘ecosystem engineers’ provide.  If you want to get involved, then sign up here, or if you have received a pack, but yet to do it, please complete your survey as soon as possible as earthworms will begin to retreat underground as it becomes too hot and dry. If you haven’t submitted your data, then please submit data here.