Scottish Animal Welfare Commission - badger sett definition: letters

To: Jim Fairlie MSP
From: Professor Cathy Dwyer, Chair, Scottish Animal Welfare Commission 

I received a letter dated 23rd February from the Wildlife Management Team requesting the views of SAWC on the definition of a badger sett. In addressing this issue, we have considered in particular the potential welfare costs or benefits to badgers of the different types of sett they may access.

In this regard we support the alternative definition provided by Scottish Badgers that a sett should be defined as ‘a sett within an occupied badger territory regardless of when it may have last been used. A sett in an occupied territory is classified in current use even if it is only used seasonally or occasionally by badgers and is afforded the same protection by law’.

The expression “in current use”  in the present definition is open to interpretation which may, or may not, favour the welfare of badgers. Advice from the Forestry Commission as long ago as 1995 was that “Whilst ‘current use’ is subject to interpretation by the courts, the licensing authorities take the view that it includes recent or seasonal use and does not mean that badgers have to be present when the sett is inspected.” [1]  It should not be necessary to refer a statutory definition to the courts for interpretation and therefore the proposed new definition is desirable in the interests of clarity.

Badgers have been described to make use of the main sett as well as a number of other outlier setts (also referred to as annexes, secondary setts or subsidiaries), although greatest use is made of the main sett. Rural main setts can have an average of nearly 20 entrances, and an average of 4 outliers setts, with 1-3 entrance holes.  Individual badgers vary in their use of outlier setts, with some animals never observed using these resources, whereas other badgers spent nearly 50% of their time in an outlier sett (overall mean time in outlier setts = 8% [2]). Although the research base is incomplete, there is evidence that the outlier sett may have a number of functions including avoiding harassment whilst in the main sett, reducing the costs of travelling between resting and foraging areas, territorial defence, dealing with ectoparasite loads and as an emergency refuge [3]. Badger setts also play an important role in thermoregulation and have been related to cub development by providing a more consistent temperature [4]. Secondary or outlier setts may be used by subordinate females to raise their young at specific times of the year, when the main sett is occupied by the dominant female.

Although the main sett is in continual use by at least some of the badger group, secondary, outlier or annexe setts can vary in their use according to season, sex and age, with greater use in the summer [5]. Males also spend more time in the subsidiary setts than females. A review of the ways in which badgers use setts, and an analysis of the legislation, concluded that badgers use setts in rotation as an important part of their normal behavioural repertoire throughout the year [6]. This review concluded that definition based on ‘current use’, interpreted narrowly as at the current time, ‘does not provide adequate protection of setts which has implications for badger welfare.’  

Thus, although the main sett may be the most frequently used part of the badger’s habitat, the evidence suggests that the other outlier setts play important roles in the overall habitat use by badgers and may be particularly important for specific individuals within the group. Although there is no evidence that we can find that removal of these outlier setts will have a direct impact on badger welfare, extrapolating from the hypothesised uses of these setts suggests that badger welfare will be impacted. It seems likely that there would be a potential increase in disease, stress from social impacts, an inability for badgers to adequately forage in their home range with costs on their energy expenditure and a possible reduction in their ability to evade predation or capture.

Yours sincerely,

Wildlife Management Team

References

1.  Forestry Commission, 1995 Forestry Practice Guide 9 Forest Operations and Badger Setts
2. Davison, Huck, Delahay, Roper, (2008) Urban badger setts: characteristics, patterns of use, and management implications. Journal of Zoology, 275, 190-200.
3. Davison, Huck, Delahay, Roper, (2008) Urban badger setts: characteristics, patterns of use, and management implications. Journal of Zoology, 275, 190-200. 
   Roper, Ostler, Schmid, Christian (2001) Sett use in European badgers Meles meles. Behavior, 138, 173-187.
4. Tsunoda, Newman, Buesching, MacDonald, Kaneko (2018) Badgers setts provide thermal refugia, buffering changeable surface weather conditions. Journal of Thermal Biology, 74, 226-233.
5. Kowalczyk, Zalewski, Jedrzejewska (2004) Seasonal and spatial patterns of shelter use by badgers Meles meles in Bialowieza primeval forest (Poland), Acta Theriologica, 49, 75-92.
6. Agnew, Agnew (2016) Protecting badger setts - Where law and science clash. Environmental Law Review, 18, 8-24.