This survey was started for a couple of reasons. Twenty years ago in Grafham, when walking the dog before bedtime, (about 10.00 – 11 pm) one or more hedgehogs could be seen regularly. Now they are not so regularly seen in this way, in fact it is a rather rare sight. This, combined with the reports of dramatically reducing numbers of hedgehogs in the UK (Roos et Al, 2012) was an upsetting observation. Then, whilst working with the Cambridgeshire Mammal group, I came across hedgehog tunnels. They are an invention designed to register the presence of hedgehogs through the creation of footprints at a feeding station. So the idea was born, that these tunnels could be used to monitor the presence and distribution of hedgehogs in Grafham.
An article was written in the Grafham monthly newsletter to inform residents about hedgehog natural history, to start a conversation about the plight of hedgehogs in general and to encourage villagers to think about making their gardens hedgehog friendly. At the end of this article was a plea for people to use a tunnel in their garden to help create a Grafham hedgehog map.
The response has been lovely. People obviously find hedgehogs endearing and are upset that they are in trouble. When people discover they have hedgehogs in their garden they are very excited, even honoured and become determined to help them. The map has been created through a combination of tunnel evidence and reported sightings this summer.
Tunnels were made according to a design described on Hedgehog Street. They were made from black 2mm deep Correx, which can be brought as sheets or as a 1m wide roll.
The Correx was cut and scored to create a meter long tunnel that was triangular with 22cm sides. A 2cm overlap was added in order to provide an overlap for securing the triangular configuration; this was fitted with Velcro so that tunnels could be collapsed and stored flat if needed.
The insert consisted of a cardboard square that could fit into and sit on the floor of the tunnel, to which was attached A4 paper on either side, using masking tape. Non-toxic paint was made by adding edible charcoal powder to vegetable oil. This was painted, using a pastry brush, onto the strips of masking tape either side of the cardboard square. Tinned dog meat was initially used as food, but later commercial hedgehog kibble was used for ease and cleanliness. A plant pot base dish was used as a food bowl.
A tunnel was set by each participant, each night for a week. The criteria for site choice varied. Sometimes it was placed where a hedgehog had been seen foraging. If, as was normally the case, there had not been sightings, it was placed along a fence or hedge, preferably in an area of garden that had shrubbery or some sort of plant cover. In other gardens, it was placed where residents thought they might be entering the garden.
Each participant recorded results night by night on a prepared sheet (appendix I). If footprints were found, the paper was removed and replaced. The footprint sheet was annotated with the date and place.
Initially some cat footprints were found. To prevent cats being able to enter the tunnel, triangular flaps were attached to the peak of the tunnel and this successfully eliminated cat intruders.
All records for each of 20 participants were collected and have been filed.
Positive results were added to the Grafham Hedgehog map and updates were published in the Grafham Gossip each month.
People who reported hedgehog sightings also had hedgehogs put on the map. The majority of map hedgehogs were as a result of tunnel footprint evidence.
Hedgehog footprints were recorded in all but two gardens that were monitored. These two gardens had very secure boundaries with no visible means of entry for a hedgehog.
In some cases what looked like smaller foot prints were observed alongside the larger ones; it is thought that these are young hedgehogs.
Other foot prints were often recorded as well. It is thought that some are from rat and some from field mouse or perhaps voles and even shrews in the case of the churchyard.
The presence of hedgehogs to the degree shown on the map was a pleasant surprise. Based on recent viewings by people in the village, there was a general feeling that there were not many around and this level of evidence was not expected.
The reaction of the people who took part was very encouraging as it revealed a lot of concern, not only for the hedgehog but for the environment in general; it also revealed that a lot of ordinary people are upset by what humans are doing to the planet and would love to feel empowered to do something about it.
The excitement on discovering footprints was fun to be a part of; the subsequent interest in then feeding and providing hibernation and nesting houses has been a fantastic and unforeseen development. Some are now setting camera traps and getting some good footage of hedgehogs and other smaller mammals.
The use of the Grafham gossip for regular updates of the map and information about hedgehogs reinforced the interest and more people came forward each time. The Grafham Village Facebook page was also used to ask for participants and contributed some response.
This project has established a good presence of hedgehogs in the village and begun to involve the people of Grafham in helping to care for them by taking care of their environment. It has also raised awareness of the importance of keeping garden boundaries open enough for hedgehog access.
However it has not established numbers, which is a recognised limitation of the tunnels. It just could be that are only a few, increasingly fat hedgehogs waddling around the village as a result of this study!
Six participants are now monitoring their gardens, once a week, to see when the hedgehogs go into hibernation. The literature generally says October is the month for hibernation. Footprints and film of hedgehogs have been recorded in the last week of October and so, with climate change, it will be interesting to see how long they remain active. The record is going to be kept each week over winter to see if they wake up at all. The recording sheet and instructions for this are in appendix II.
The plan for next year is to continue to monitor presence and distribution next year using foot print tunneIs, to establish a trend. Monitoring in May and then again in September, using the regime devised by Gurnell et Al (2018), for their study of the Regents Park Hedgehog population.
Further investigation could be to look for and compare presence and distribution in the surrounding arable land; and, if permission could be obtained from the Wild Life Trust, Brampton Woods would be interesting as this is just behind the village and joined by a wildlife corridor of trees planted by the local farmer some years ago.
Finally, if the study can involve marking the hedgehogs along the lines of Reeve et Al (2019) in the Regents Park Study, then numbers can be estimated, making the study even more valuable. This needs some research and consultation before it could be done.
If, because of this study, the residents of Grafham become more aware of requirements of hedgehogs and provide more appropriate environments in their gardens, maybe Grafham can become a model for how to help some degree of recovery for this rather endearing, native animal.
Gurnell, J.,Reeve, N., Bowen, C., Pettinger, T. (2018). A Study of Hedgehogs in The Regent’s Park Year 4 May and September 2017. https://www.royalparks.org.uk/__data/assets/pdf_file/0006/99645/A-Study-of-Hedgehogs-in-The-Regents-Park-2017-FINAL.pdf [Date Accessed: 14/09/2019]
Hedgehog street, Guidance for detecting hedgehogs using footprint tracking tunnels, Version 2 October 2016 https://ptes.org/wp-content/uploads/2014/06/Guidance-for-detecting-hedgehogs-using-tracking-tunnels.pdf [Date accessed: 08/06/2019]
Hedgehog Street, Hedgehog Hibernation. https://www.hedgehogstreet.org/about-hedgehogs/hibernation/##targetText=Hedgehogs%20usually%20hibernate%20from%20October,well%20into%20November%20and%20December. [Date accessed: 28/10/2019]
Reeve,N., Bowden, C. and Gurnell, J. (2019). An Improved Identification Marking Method for Hedgehogs. Mammal Communications Vol 5, ISSN 2056-872X (online). The Mammal Society. https://www.mammal.org.uk/wp-content/uploads/2019/01/HedgehogMarking.pdf [Date accessed: 08/09/2019]
Roos, S., Johnston, A. & Noble, D. (2012) UK Hedgehog Datasets and their Potential for Long-Term Monitoring, BTO Research Report No. 598. Report for work carried out by The British Trust for Ornithology, commissioned and funded by the People’s Trust for Endangered Species and the British Hedgehog Preservation Society. https://ptes.org/wp-content/uploads/2015/11/Roos-et-al-2012-Hedgehog-BTO-UK-trends.pdf [ Date accessed: 02/11/2019]
Grafham Hedgehog Survey Recording Sheet
Protocol for winter survey.
- Set up the tunnel on night 1.
- If there are foot prints, stop for a week. Take the footprint sheet, label with your name, address and date and file.
- If no foot prints, repaint if needed and leave tunnel out each night for up to a week.
- As soon as footprints appear, stop setting the tunnel, label and file the sheet. Set tunnel a week later with the same regime.
- If there are no footprints for a week. Reset tunnel a week later for up to a week as above.
The aim of this is to see
- when everyone stops getting footprints as an indicator as to when the Grafham hedgehogs go into hibernation
- Whether they wake up on occasion (which has been reported)
- When they come out of hibernation
Grafham Hedgehog Winter Survey Recording Sheet