In situ adaptive response to climate and habitat quality variation: spatial and temporal variation in European badger (Meles meles) body weight

Abstract

Variation in climatic and habitat conditions can affect populations through a variety of mechanisms, and these relationships can act at different temporal and spatial scales. Using post-mortem badger body weight records from 15 878 individuals captured across the Republic of Ireland (7224 setts across ca. 15 000 km(2) ; 2009-2012), we employed a hierarchical multilevel mixed model to evaluate the effects of climate (rainfall and temperature) and habitat quality (landscape suitability), while controlling for local abundance (unique badgers caught/sett/year). Body weight was affected strongly by temperature across a number of temporal scales (preceding month or season), with badgers being heavier if preceding temperatures (particularly during winter/spring) were warmer than the long-term seasonal mean. There was less support for rainfall across different temporal scales, although badgers did exhibit heavier weights when greater rainfall occurred one or 2 months prior to capture. Badgers were also heavier in areas with higher landscape habitat quality, modulated by the number of individuals captured per sett, consistent with density-dependent effects reducing weights. Overall, the mean badger body weight of culled individuals rose during the study period (2009-2012), more so for males than for females. With predicted increases in temperature, and rainfall, augmented by ongoing agricultural land conversion in this region, we project heavier individual badger body weights in the future. Increased body weight has been associated with higher fecundity, recruitment and survival rates in badgers, due to improved food availability and energetic budgets. We thus predict that climate change could increase the badger population across the Republic of Ireland. Nevertheless, we emphasize that, locally, populations could still be vulnerable to extreme weather variability coupled with detrimental agricultural practice, including population management.

Climate and anthropogenic factors determine site occupancy in Scotland's Northern‐range badger population: implications of context‐dependent responses under environmental change

“…Badgers do not exhibit any specific annual pulse in mortality, or migration (Macdonald, Newman, Nouvellet, & Buesching, 2009); thus outside of the cub rearing season (Fell, Buesching, & Macdonald, 2006), it is unlikely that demographic changes could account for heterogeneity in detectability. Badgers are strongly influenced by temperature and rainfall patterns (Byrne et al, 2015;Macdonald & Newman, 2002;Macdonald et al, 2010;Nouvellet et al, 2013); therefore, variation in their aboveground activity regimes (Noonan et al, 2014) provides the most likely source of variation in detection rates. Noonan et al (2015)…”

“…This is the north‐western margin of the species’ distribution, which extends from the Mediterranean to the Arctic (Johnson, Jetz, & Macdonald, ). Badgers are territorial and central place foragers, not prone to moving in response to tracking food supply (Byrne, Fogarty, O'Keeffe, & Newman, ). Furthermore, climatic conditions have proven influential on badger population dynamics (Macdonald & Newman, ; Macdonald et al., ; Nouvellet, Newman, Buesching, & Macdonald, ; see also Newman, Buesching, & Macdonald, in press) and regional population densities (Byrne et al., ; Johnson et al., ).…”

“…Badgers are territorial and central place foragers, not prone to moving in response to tracking food supply (Byrne, Fogarty, O'Keeffe, & Newman, ). Furthermore, climatic conditions have proven influential on badger population dynamics (Macdonald & Newman, ; Macdonald et al., ; Nouvellet, Newman, Buesching, & Macdonald, ; see also Newman, Buesching, & Macdonald, in press) and regional population densities (Byrne et al., ; Johnson et al., ). Long, unproductive winter conditions (see Macdonald & Newman, ), associated with less suitable high‐latitude and high‐elevation weather and habitats, generally limit badgers’ northern distribution (Bevanger & Lindström, ).…”

“…Within this framework, we used Autumn-Winter occupancy data, that is, covering a critical phase of the badger life cycle, when food availability and environmental conditions are likely to be limiting (Noonan et al, 2014;Nouvellet et al, 2013), to test how badger occupancy is influenced by: (1) climatic conditions (and associated elevation effects), which define the species' climatic niche and thus directly affect its survival and recruitment patterns (Byrne et al, 2015;Macdonald et al, 2010;Noonan et al, 2015;Nouvellet et al, 2013;Thornton, 1988); (2) development of human infrastructures, as measures of anthropogenic disturbance (Elliott, O'Brien, & Hayden, 2015;Grilo, Bissonette, & Santos-Reis, 2009;Hipólito, Santos-Reis, & Rosalino, 2016); (3) forested versus un-forested habitats, because these relate to food availability and suitable sett sites (Virgós, 2001(Virgós, , 2002; and (4) structural complexity of the landscape matrix, as a surrogate for resource richness and diversity (Santos, Rosalino, Santos-Reis, & Ustin, 2016;Virgós, 2001). We then investigated how distinct topo-climatic contexts (i.e., temperature and elevation) interact with habitat type, human infrastructural development and modification of the landscape for agriculture.…”

Altitude shapes the environmental drivers of large‐scale variation in abundance of a widespread mammal species

“…Spatial and temporal environmental heterogeneity can determine the population trends of wild populations, either a population decrease or extinction, or the ability of some species to become overabundant. Species interactions and environmental factors are usually the most important factors limiting distribution and abundance (Boyce et al, 2016;Hoffmann & Blows, 1994), but may act at different temporal and spatial scales, environmental factors being preponderant at large scales (Byrne, Fogarty, O'Keeffe, & Newman, 2015).…”