A Guide to Badger Surveys
15th March 2016
The start of the survey season is a great opportunity to hone survey skills and improve our understanding of badgers before vegetation grows and starts to disguise some key signs. Practecology shares its experience from conducting badger surveys in Scotland.
Given the protection surrounding badgers it is important to glean as much information from surveys as possible, not least this information may later be used to submit licence applications. While no personal licence is needed to survey for badgers it is important that surveys are completed by experienced ecologists who can find and interpret field signs.
Following some queries from budding ecologists and wildlife enthusiasts Practecology decided to put together an article outlining what to look for when undertaking badger surveys. The article contains some useful hints and tips gleaned from over 15 years experience of badger surveys in Scotland and England and may be a useful guide to those about to venture into the world of badgers.
When should I conduct my surveys?
Badger surveys are best undertaken in the early part of the year, generally between February and March. This makes it easier to find latrines, tracks and small setts before vegetation obscures them from view. Recent snowfall can help indicate preferred pathways and crossing points of hedgerows and watercourses, but badger activity can be reduced and the number of signs limited.
At this time it is also good to do a check of the NBN gateway (https://data.nbn.org.uk) review data obtained from the local Environmental Records Centre or see if other surveys have recorded traffic fatalities. All this will help determine the presence of badgers in your survey area.
What should I wear?
Typically the weather can be unpredictable early in the year so the usual waterproofs and sturdy boots are a necessity when looking for badgers - boots are a must if investigating steep slopes or walking around spoil heaps. Wearing a few layers, even on nice days, including a thick pair of over-trousers provides some protection from gorse, brambles or conifers. Thick gloves and a hat with a peak are very useful for exploring areas of dense vegetation while it is often useful to keep a pair of safety glasses in your rucksack should the cover get very thick. Don’t do badger surveys in clothing you don’t want to get ripped or muddy!
What should I look for?
There is no quick way to do a badger survey and it is necessary to do a thorough check of areas of woodland, scrub, road verges, ditch embankments, streams and around field boundaries. Setts may exist in all of these places and outlier setts can exist at the base of field boundaries such as walls and hedgerows, irrespective of the type of crop in it.
Checking the corners of fields may also reveal badger paths or latrines thereby building a picture of how the animals move around their territory. Unfortunately badgers can often build setts in very dense cover, particularly gorse, so it may be necessary to spend considerable time conducting a search in one area. However, looking for pathways leading into the cover can help focus survey effort so don’t avoid surveying areas because they look difficult. If there is a paucity of cover in the landscape then this may be exactly where the sett is. Working as part of a team of surveyors also makes life easier and safer.
While a sett is the most obvious sign there are a number of others to always bear in mind, such as latrines, pathways, pawprints, hair in barbed wire and areas of uprooted grass or vegetation. Bare patches on moss covered walls can indicate where badgers have clambered over them while mud on the bars of gates may also indicate that a badger has passed. Holes in fences, particularly rabbit mesh, may on the whole appear to be too small for a badger to get through, but don’t underestimate the ability of a big male badger to get through the smallest of holes.
Be aware that other animals could create signs that imitate those of badgers - small scrapes dug by rabbits may be confused with foraging signs, while uprooted grass could be caused by domestic dogs or foxes marking their territory. Look at field entrances, cattle troughs and any muddy areas for badger pawprints which may confirm their presence.
There may be a thought that once a sett has been discovered the survey has been successful but it is important to get a complete picture of badger activity in your survey area. Make sure you look for latrines immediately adjacent to the sett and try to make an assessment of what the contents are as this may give an indication of the foodstuffs being ingested. For instance dung containing digested barley or maize may indicate that the badger is visiting a local farm where livestock are receiving supplementary food.
Look for paths and tracks radiating from the sett as these may lead to other setts - a useful guide if the area you are surveying contains many dense patches of woodland. Recording latrines next to these paths, even if they don’t contain fresh dung at the time, will help with future surveys, especially if it is intended to undertake a programme of bait marking.
Always investigate small mounds of exposed soil particularly if they are not in keeping with the local topography. These often form at the down slope sides of holes which may be obscured by tree roots or vegetation.
What should I record?
Firstly, it is important to make sure you have found a badger sett and not a rabbit warren! Spend time investigating each tunnel, noting its shape and dimensions, as well as the presence of pawprints or bedding. Assigning a hole as a badger sett based on the presence of some hair on the spoil heap can be misleading. A passing badger may have had a scratch when investigating the hole but not necessarily occupy it. There are far much better signs to go on so don’t be too hasty on assigning a hole as a sett - look for further evidence!
Also, bear in mind the size of a badger - they are quite chunky animals and much bigger than a rabbit so if you can’t get a clenched fist into the hole then it is unlikely to be a badger. Waving sticks in the hole to get an idea of the size of the tunnel (should your company policy prevent you from sticking your hands into possible sett) is an option but highly misleading and is best avoided. It only needs a side branch of the main tunnel to give the impression that the tunnel is quite big and lead to warrens being mis-assigned as setts. A torch is always useful to help look into tunnels and can better reveal tunnel dimensions, the presence of debris, or pawprints further inside.
Getting as much information as possible on the first visit is invaluable. Using a GPS and annotating a few notes as to the setts location will help others find the sett if operating as part of a larger team. At this stage it may be erroneous to try to classify the sett based on levels of activity (e.g. main, annex, subsidiary or outlier) as this may change but also because other larger and smaller setts may yet be undiscovered. It is also unwise to try to guess the size of setts based on the amount of spoil present at the entrance or based on the number of tunnel entrances. Large setts can have small spoil heaps but only a few entrances and vice versa. The amount of spoil can be dependent on geology, slope, the previous use of the sett as a warren and adjacent land use. Complete the survey then review your data.
Record the number of tunnel entrances, the number which appear to be active and inactive, the presence and use of any latrines, the presence of loose grass which may be used as bedding and fundamentally get some pictures of the sett entrance with a useful object for scale. Taking pictures from a number of angles, to include features which are likely to remain (e.g. fallen logs, fence posts, gates, odd shaped trees) will help both yourself and other surveyors find the sett later in the year when vegetation has grown up. Pictures showing a close up of a glove next to an entrance may be interesting in March, but exceptionally frustrating in July when trying to find the sett again!
If the sett appears to be active and if you possess one, now is a good time to deploy remote cameras. Generally there is less vegetation around to trigger the camera accidentally and the field of view may be greater, not least badgers will become increasingly active in their territory and visiting setts within their territory. If it is intended to make repeat visits, soft blocking entrances with vegetation will also help to give a good indication of occupancy, levels of activity and preferred points of entry/exit. Such information may also indicate better places to place your remote cameras or apply bait if bait marking is intended.
This is quite a lengthy article but in short, the main things to bear in mind when doing badger surveys are as follows:
- Go equipped with the right clothing and equipment
- Search everywhere even if the habitat is dense
- Make sure you spend time at each hole to gather as much information as possible - don’t make hasty judgements on sett classification at the outset
- Get decent photographs of the sett and surrounding features to facilitate additional visits
- Soft block setts with loose vegetation when you find them to build a picture of use if other visits are planned.
- Join your local badger group to get involved in national surveys, contribute to existing data sets and attend training events. Scottish badgers is a great place to start. http://www.scottishbadgers.org.uk