Climate and land‐use change drive habitat loss in a mountain bird species

Abstract

Mountain areas still feature remnants of traditional land use and consequently constitute a large proportion of the remaining species-rich habitats in Central Europe. However, their biodiversity is increasingly threatened by changes in climate and land use. The Alpine Ring Ouzel Turdus torquatus alpestris is a typical mountain bird that has recently declined in most of its breeding range. In this study we compared the historical (1986)(1987) and recent (2017) distribution of breeding Ring Ouzels in 62 randomly selected 750 × 750 -m plots and analysed local colonization and extinction patterns in 558 subunits (= 'grid cells') in the southern Black Forest (south-western Germany). Our study revealed that habitat occupancy has decreased by about one-third, mainly at lower elevations and in depressed landforms, during the past three decades. Local colonization amounted to 25% and extinction to 66% of the previously vacant or occupied grid cells, respectively. Habitat occupancy and local colonization and extinction were driven by climate and habitat parameters. The Ring Ouzel preferred convex landscape formations such as mountain peaks and ridges with long snow-cover duration for breeding. Sites with high proportions of deciduous forest and abandoned pasture were avoided. Local colonization was higher at convex landscape formations and by high coniferous forest coverage and forest-edge length. Local extinction, on the other hand, was lower at convex landscape formations and high-elevation sites. Our results suggest that shorter persistence of snow fields caused by climate change and degradation of feeding grounds through land-use abandonment might severely deteriorate food availability for the species, which is likely to have contributed to the observed decline. For conservation of the Alpine Ring Ouzel, we recommend adopting measures to mitigate the negative effects of climate warming and improve habitat quality. The creation of small-scale mosaics of sparse conifer forests and regularly grazed pastures, especially on north-and east-facing slopes on the lee sides of hills, mountain peaks or ridges, should be supported.

Effects of local climate and habitat heterogeneity on breeding-bird assemblages of semi-natural grasslands

“…In general, birds depend on (i) suitable foraging habitats with high prey accessibility and (ii) breeding habitats that provide shelter from potential nest predators (Benton et al 2003;Moorcroft et al 2002;Fartmann et al 2018). Prey accessibility in grassland birds is granted by patches of low-growing vegetation and bare ground (Tagmann-Ioset et al 2012;Kämpfer and Fartmann 2019;Fumy and Fartmann 2021). Taller vegetation is thought to reduce the predation risk of eggs and chicks in ground nests (Baines 1990;Schwarz et al 2018).…”

“…They are mainly affected by changes in food supply and breeding habitats caused by altered farmland-management practices (Benton et al 2002;Newton 2004). Additionally, temperature is another important driver of bird species richness and density (Pearce-Higgins and Green 2014; Keller et al 2020;Fumy and Fartmann 2021).…”

Impacts of Changing Livestock Farming Practices on the Biocultural Heritage and Landscape Configuration of Italian Anti-Apennine

“…The discontinuation of traditional agro-pastoral methods also results in the forfeiture of several ecosystem services [9], including those related to the maintenance of biodiversity [10] (e.g., habitats [11], plant [12][13][14] and wildlife [15][16][17] species and communities [18,19]), landscape attractiveness [20], biocultural heritage [21][22][23], the accompanying viable economic models [24,25], as well as the pastoral knowledge, as it plays a crucial role in the management and sustainability of pastoralism-based systems [26][27][28].…”

Forest Dynamic in the Italian Apennines

“…As a consequence of landscape homogenization, the extent of such ecotones has been greatly reduced in Central Europe. Although not so much is known about the effects of ecotone loss on biodiversity in general, however, it seems obvious that the numerous species specialized on these complex habitats-such as the Ring Ouzel-may be negatively affected by the expansion of forests [32]. Recently established forests remain different from ancient forests in terms of herbaceous plant species composition even hundreds of years after re-establishment [33].…”