Habitats for Hedgehogs

Hedgehog (Erinaceus europaeus) © Lucy Smith

Article written by Taras Bains

Hedgehogs! Who doesn’t love them? These small, prickly mammals are one of the most well-known and beloved members of our local British fauna. However, their populations are declining at increasing rates and it is now more important than ever to better understand the ecology of hedgehogs in order to better conserve them.

TVERC currently has around 215 hedgehog records across Oxford and many more within the surrounding counties of Oxfordshire and Berkshire. These records come from many different places; from local mammal and wildlife groups, to general members of the public who have seen a hedgehog in their garden. In this project we wanted to explore in which habitats hedgehogs might be found and how easy it is for them to move around Oxford between different patches of habitat.

In this map the red areas represent those which have suitable habitat that is well connected. In general, TVERC’s records reflect this. The map shows a couple of key things: First, there are some isolated patches of suitable habitat within the city that have hedgehog records in but are surrounded by barriers or other unsuitable habitat. This may suggest that there could be populations of hedgehogs that don’t interact with each other. Second, it also shows there are some key barriers within the city that may act to limit hedgehog dispersal and movement. The two rivers which run through the city may act as a barrier in some places, but the main barrier is the railway line which can be seen as the grey line running through the city from the top left vertically down exiting at the bottom left. The major road network also acts a barrier as seen at the top of the red areas where there is an empty space where the 3 major roads come together.

These three maps also show habitat suitability for the hedgehogs, with the hedgehog records being shown by black dots. Figure 2 is a land-use map showing how land is used within Oxford and shows which types of habitats hedgehogs have been recorded in. Most of the records seem to occur in urban areas (orange on the map) and there are a few records in grassland (red on the map, which also includes parks and playing-fields, etc). Although at first this may suggest that hedgehogs prefer urban zones other factors must also be considered which may explain this. For example; there is a recorder bias and certain areas are more likely to have been surveyed than others, e.g. people are often encouraged to look for hedgehogs in their gardens and therefore this may explain why there are a lot more records for urban areas. Hedgehogs are also generally much easier to see in urban areas and are more likely to be encountered by people than in non-urban areas, particularly as the majority only come out at night. Consequently, we cannot be sure whether this distribution is due to a real pattern or an artefact of the data that is available and more recording is required in areas which are generally under-represented and other suitable habitats.

Figure 3 was created as a result of a species distribution model and the colour represents the suitability of the habitat present there for hedgehogs. The darker oranges represent the least suitable habitat and as it gets lighter it gets more suitable with the white and then purple representing the most suitable habitat based on the data we already have. The areas surrounding Oxford is generally shown as orange and is dominated by cultivated arable land showing that this habitat is not suitable for hedgehogs. It would also be beneficial to increase surveying and recording in those areas signified in the model as more suitable to see if the model is correct and to give us a better understanding of habitat preferences. Figure 4 is also interesting as it shows the presence of floodplains in Oxford with the light blue representing the floodplains. This is very interesting as none of the hedgehog records, we have occur on these floodplains and it would be an interesting avenue of research in the future.  

We also made a light map which showed that the majority of TVERC records were in areas which were well lit and in comparison, many dark areas lacked hedgehog records all together. One of the main explanations for this could be that well-lit areas tend to be urban and it is much easier to see hedgehogs. Our records also show that in lightest areas there are some records, but the majority are in areas with lots of light but not too much.

There are a number of things that members of the public could do to try and reduce these barriers to hedgehogs. For example; gardens are often good habitat for hedgehogs, but garden fences are often barriers to their movement. This can mean that hedgehogs can’t forage enough or travel the distances they require to find mates or suitable nesting sites meaning they either become isolated in particular gardens or end up moving along roads which increase their risks of being hit by cars.

There are many campaigns such as the hedgehog highway project which aims to create little holes at the bottom of fences to make sure that they can pass freely through your garden. More information about some of these can be found here:

https://www.hedgehogstreet.org/help-hedgehogs/link-your-garden/

https://www.wildlifetrusts.org/actions/how-create-hedgehog-hole

 

Posted: January 23, 2020