Comparative study on the consequences of culling badgers (Meles meles) on biometrics, population dynamics and movement

Abstract

Summary1. Capture±mark±recapture data were used to describe the process of recovery from a typical badger removal operation (BRO) at North Nibley, Gloucestershire, UK, which was carried out as part of the government's strategy to control bovine tuberculosis. Data on biometrics, demographics and movement from this low-density disturbed population were compared with those of two nearby high-density undisturbed populations (Wytham Woods and Woodchester Park, UK) in order to study fundamental principles of population dynamics and density-dependence. 2. Badgers moved more between social groups at North Nibley than in the other study areas, particularly in the immediate aftermath of the removal operation. 3. Recolonization of the vacated habitat occurred in the ®rst instance by young females. 4. Although in the ®rst year after the BRO no cubs had been reared in any of the culled groups, and although the shortage of sexually mature boars may have limited the reproductive output of sows in the following year, the population took only 3 years to recover to its (already lowered) preremoval density. 5. Losses from the adult (and cub) population due to mortality or emigration were smaller at North Nibley than at the other sites. 6. There was much evidence that during 1995 and 1996 density-dependent eects constrained the reproductive output of the high-density populations, and some support for the hypothesis that badgers exhibit the non-linear`large mammal' type of functional response to density. 7. Badgers at North Nibley were younger, heavier and in better condition than badgers at Wytham Woods and Woodchester Park. 8. We argue that the disease dynamics are likely to be dierent in disturbed compared with undisturbed badger populations, and that this could aect the eectiveness of BROs.

Effects of Culling on Mesopredator Population Dynamics

“…However, neither the rate nor demographic patterns of patch colonization were influenced by the composition nor configuration of landscape attributes. These results build upon the growing body of evidence that population manipulation alone may be insufficient to control the spread of infectious disease in mesopredators [10], [15], [16], [18].…”

“…Although epidemiological impacts were not explicitly tested in this study, the demographic changes we noted in recolonizing raccoon populations may have strong implications for disease transmission dynamics in human-modified landscapes [18], [49]. For example, rabies [50] and Baylisascaris [19] infections are highest in young raccoons.…”

“…However, colonizing adults up to 12 years old were captured in experimental patches, suggesting some range expansion or shifting did occur. Among mesopredators the roles of range shifting and natal dispersal in patch recolonization appear to vary as a function of the size of the area depopulated, landscape characteristics, and behavioral attributes of individual species [18], [22], [44]. Thus, the efficacy of culling to mitigate spread of disease likely varies among species and across landscapes.…”

“…natal dispersal vs. home range expansion) due to intersexual and age-specific differences in communicability of diseases [18], [19]. In mammals, short-term population recovery may occur through natal dispersal (often by males; [20]), or by migration of adults into depopulated areas due to reduced resource competition (vacuum effect; [21], [22]).…”

Freshwater goby life history in a Mediterranean stream

“…On the contrary, determination of the age and assessment of dynamic potentialities are to be considered a crucial tool in fisheries biology for the management strategy formulation (Britton et al, 2004). In fact, understanding demography and population regulation to the theory of sustainable exploitation (Freckleton et al, 2003;Jones & Coulson, 2006;Scalici et al, 2008) and biological control (e.g., Tuyttens et al, 2000;Scalici & Gherardi, 2007; becomes a fundamental aspect of monitoring activities in aquatic ecosystems, being also expected by the Water Framework Directive 2000/60 ECC in action plans for the preservation of water and its resources. In particular, understanding aspects in life history characteristics appears critical for the conservation of goby populations living in fragmented habitats, as a consequence of its restricted ecological habit (Zerunian et al, 1988).…”