Sett

Abstract: From 1996 to 2001 we studied the spatial organization and demography of Eurasian badgers, Meles meles, in Biaowiea Primeval Forest in eastern Poland, one of the best preserved woodlands in temperate Europe. Badger density estimated on the basis of main sett distribution (0.54 sett/10 km 2 ) and group size (3.9 individuals per sett, on average) was 2.11 badgers/10 km 2 . Average annual productivity of the population was 64% and the mortality rate of badgers >1 year old was 22-38% per annum. The size of territories of badger groups (n = 7), estimated by radiotelem- etry, varied from 8.4 to 25.5 km 2 (mean 12.8 km 2 ). Individual home ranges of badgers (n = 13) covered, on average, 9.3 km 2 , and varied seasonally and among animals of different age and sex classes (from 4.0 to 24.4 km 2 ). Home ranges of adult badgers were significantly larger than those of subadults. Badgers occupied larger home ranges in sum- mer, when earthworm availability was low. The size of both group territories and individual home ranges was influ- enced by the distribution of oak-lime-hornbeam (OLH) forests, habitats rich in earthworms. Based on our findings and a review of literature, we propose that the standing crop of biomass of earthworms (Lumbricus spp.), the main food of badgers in a large part of their geographic range, and mean annual temperature are crucial factors shaping the densities of badgers in the European temperate and boreal zones. We also suggest that abundance of food resources is the essen- tial factor underlying the great variation in badger sociality (from pairs to large groups).

Abstract: 2 . In the whole BPF, badger main setts were spaced regularly, with the nearest neighbour distance between active setts varying from 2.2 to 13.3 km (mean = 5.3 km, SD = 2.1). Surveys of 21 main setts during 1979-1999 (totally 171 sett-years) revealed that badgers occupied the setts in 68.4% of cases, raccoon dogs Nyctereutes procyonoides in 12.9%, and red foxes Vulpes vulpes in 7%. Joint utilisation of the same setts by badgers and raccoon dogs was recorded in 5.3% of cases. Reviewing the literature on badger densities in 35 localities in the Palaeartic region showed that badgers attained rather high densities on the British Isles (14.9 setts/10 km 2 , range 1.1-45.5; and 93.8 ind/10 km 2 , range 8.6-307.0) compared to continental Eurasia (1.7 setts/10 km 2 , range 0.4-6.5; and 6.3 ind/10 km 2 , range 1.6-15.2). The number of badgers inhabiting a sett increased with log density of setts. Densities of badger setts did not depend on latitude but were negatively correlated with forest cover

Abstract: Badger setts vary considerably in size, ranging from simple single-entrance burrows to complex tunnel systems hundreds of metres long with multiple entrances and underground chambers. Data from 19 excavated setts show that main setts are larger than other setts in terms of area and volume, and contain more chambers, nests and latrines; but setts of different sizes and types are built according to the same basic architectural principles. Little is known about the environmental conditions within setts, other than that temperature and humidity are constant in parts of a sett that are at least 7 m from the nearest entrance. Setts are used for breeding and as sleeping places and refuges, but a question remains as to the functional value of large setts. It is suggested that large main setts allow members of a social group to avoid one another underground, especially when breeding. Little is known about the use of other types of sett.

Abstract: Many mammals, both potential competitors and preys, have been reported to use the complex burrow system of European badger Meles meles setts as shelter, mainly in northern Europe and during winter, when badgers are lethargic. Nonetheless, until recent times observations of den sharing have been largely restricted to anecdotal information, because of the mainly nocturnal activity of most sett occupants. Using camera-trapping, we investigated both the mammal fauna associated with 24 badger setts located in northern and central Italy, and seasonal variation in the composition of specific assemblages, without interfering with the occupants’ activity. Trapping effort was 1,605 camera trap-days from December 2010 to December 2013. Badgers (two to six individuals per sett) shared their setts with a total of eight mammal species: crested porcupine Hystrix cristata, Eastern cottontail Sylvilagus floridanus, red fox Vulpes vulpes, pine marten Martes martes, stone marten Martes foina, wood mouse Apodemus sp., brown rat Rattus norvegicus and coypu Myocastor coypus. Den sharing was observed throughout the year, with a significant reduction of sharing during winter, when badgers were probably induced to move to alternative setts to avoid breeding porcupines. Eastern cottontails used badger burrows permanently and, at least in one occasion, reared their pups inside, although they can be easily preyed upon by badgers. Badger sett sharing may have favoured both the recent northward expansion of crested porcupines and settling of introduced cottontails in agricultural habitats.