Hedgehogs, Erinaceus europaeus, Fact Sheet.

Analysis by the Bromley Biodiversity Partnership Species & Habitats Sub-group for 2017/2018.

Hedgehog photo by Judith John.
Hedgehog photo by Judith John.

Hedgehogs are solitary animals except when raising young. They are nocturnal and during spring, summer and autumn spend the daytime sleeping in nests of leaves, waking at dusk to hunt for soil invertebrates such as slugs, snails, beetles, earwigs, worms, caterpillars, and millipedes. They have poor eyesight, relying more on an acute sense of smell, touch and hearing and may travel over 2 kms/ night searching for food.

They mate in April then the male leaves the female. She gives birth to 3-5 blind, pink young about month later in a special maternity nest of leaves and grass. The babies quickly develop soft white spines, open their eyes at about 14 days old and grow more brown spines. Their mother takes them out on their first foraging trip at about 4 weeks and continues to suckle them until they can hunt for themselves. By 6 weeks they should be independent and will leave the nest area.

In winter (November to mid March) when less food is available, hedgehogs hibernate in a nest of dead leaves and grass beneath deep leaf litter in woodland or beneath hedgerows, scrub or even garden sheds. Their body temperature drops from about 35°C to 10°C or less, their heart rate slows from about 190 beats per minute to about 20 and their respiration rate to 1 breath every few minutes.

Hedgehog near Hayes Station.  Photo by Bill Welch.
Hedgehog near Hayes Station. Photo by Bill Welch.

If they weigh less than 450gms (1lb) they will not survive hibernation, so if you find a small hedgehog in autumn advice should be sought from a local expert or the British Hedgehog Preservation Society at this link: British Hedgehog Preservation Society

An adult hedgehog has 5,000-7,000 spines. When threatened it raises its spines and rolls into a tight ball. If it isn't quick enough, a dog, fox or even a cat can grab its back legs and prevent it from rolling up properly. If they survive their first year they may live for another 4-5 years. Some individuals have been recorded as reaching 10 years.

Since 2000, hedgehog populations in England have fallen by more than 50&percent; in rural areas, 33&percent; in urban areas (see 'The State of British Hedgehogs 2015' published by the People's Trust for Endangered Species).

Threats to hedgehogs in London Borough of Bromley

In Bromley, hedgehogs are now generally rarely recorded, but surveying in 2017 highlighted a few areas in the borough where records have been sent from several gardens. These recordings were generally near areas of open space, e.g. in Petts Wood near Crofton Woods and near Betts Park, Penge. An article about the hedgehog survey in The Petts Wood Gazette helped generate recordings.

In 2019, 20 hedgehog sightings were reported directly to the Bromley Biodiversity Partnership gmail address. The majority were from the West Wickham area following an article in the West Wickham Residents Newsletter, again highlighting the importance of local newsletters in helping to obtain records. Sitings were mainly from gardens around West Wickham football and cricket club, Corkscrew Hill with some closer to Langley Park Golf Course. There were also some records from gardens near Poverest Recreation Ground/Covet Wood. In 2019 contact will be made with other groups producing newsletters to see if they will take articles asking for records of Bromley's priority species.

In addition to the records submitted by members of the public, 3 sites — Downe Orchard, Jail Lane and Clockhouse Orchard — were surveyed by Sue Holland and Steven Lofting of idverde and RSPB using hedgehog footprint tunnels baited with dog food, but no hedgehog footprints were recorded. Further sites will be surveyed later in 2019.

Leaflets have been posted targeting streets where hedgehogs have been sighted, giving advice on how to help hedgehogs as they travel through their gardens and green spaces. Through this we hope to not only gain more records of sightings but to encourage residents to improve their way of gardening, and garden usage to provide more safe havens for our spikey friends.

All Bromley's records have been submitted to the London Wildlife Trust. Click on this link: LWT's Hedgehog Sightings to see London Wildlife Trust's map of hedgehog sightings, which include some of those from Bromley.

As we find out more about the location of hedgehogs in LBB, the importance of improving links between the green spaces near where they are seen, providing safe corridors along which hedgehogs can travel and forage is becoming increasingly obvious. These links can be via wildlife-friendly gardens, Churchyards, allotments, paths bordered by scrub or long grass etc. It is also important to improve the availability of information regarding how to look after hedgehogs.

Bromley Biodiversity Partnership will continue to ask for records during 2019 and will contact householders in areas where there have been several hedgehog sightings to encourage neighbours to get together and follow guidance set out in Hedgehog Street. See Hedgehog Street and click on 'highways for hedgehogs'. There are many other tips for helping hedgehogs on both this site and the British Hedgehog Preservation Society.

General advice is set out below:

For further information on how to help hedgehogs visit British Hedgehog Preservation Society.

Please continue sending records to bromleybiodiversity@gmail.com or sue.holland@idverde.co.uk.

— Bromley Biodiversity Partnership Species & Habitats Sub-group, January 2019

This article is copyright © Judith John 2019. The photographs are copyright © Bill Welch 2012 and © Judith John 2018.