Large-scale land use change may explain bird species declines in semi-natural areas: the case of Black Grouse population collapse in Lower Saxony, Germany

Abstract

Farmland birds in Central Europe have been heavily declining in past decades. Among them are many ground-nesting species, adapted to semi-natural but secondary habitats. A vivid example is the Black Grouse (Tetrao tetrix) in the lowlands of north-western Germany, the Netherlands and Denmark, where the species 0 populations experienced dramatic declines between the 1950s and 1970s. One explanation for these ubiquitous population declines might be large-scale changes in agricultural land use and land cover. We investigated several agricultural indices at three hierarchic administrative scales in parts of the federal state Lower Saxony, Germany, and related changes in these indicators with the Black Grouse declines. Land cover proportions remained relatively stable whereas indices of agricultural intensification heavily increased from 1952 to 1973. Multiple regression showed that change in farmland area was the best predictor of the trends across scales. Correlates of Black Grouse abundance were moor at the medium scale and pasture cover and fallow land at the smallest scale. Our results support the hypothesis that Black Grouse population dynamics in the lowlands of Central Europe were affected by land use changes. They show that Black Grouse populations in Central Europe were dependent upon extensive farming and may provide additional explanation where underlying factors on the habitat scale cannot fully explain the declines.

Changes in bird distribution in a Central European country between 1985–1989 and 2001–2003

“…The exact causes of the loss of these species remains unexplored. We can only speculate about the switch from an extensively cultivated agricultural landscape providing a heterogenous mosaic of habitats to either highly intensive agriculture or the complete abandonment of arable land in the key areas for populations of these species (Konvička et al 2006(Konvička et al , 2008Ludwig et al 2009;see also Š ťastný et al 1996). The disappearance of these highly specialized species is consistent with Kerbiriou's et al (2009) findings on the spread of tolerant species with a broad ecological niche leading to biotic homogenization of bird communities in France (Devictor et al 2008) and the Netherlands (Van Turnhout et al 2007).…”

Declining reproductive output in capercaillie and black grouse – 16 countries and 80 years

“…Capercaillie prefer older and climax conifer forest whilst black grouse prefer open forest of younger successional stages that also include peat-bogs, heaths, sub-alpine pastures, marshes and grasslands (Seiskari, 1962;Swenson & Angelstam, 1993;Ludwig et al, 2009). Given the wide distribution of capercaillie and black grouse, they can also be considered habitat generalists within their respective niches, at least in the boreal forest of Fennoscandia (Lande & Herfindal, 2010;Sirkiä et al, 2011a, b;Lande et al, 2014).…”

Abandoned military training sites are an overlooked refuge for at-risk open habitat bird species

“…These results underscore the importance of sparsely vegetated biodiversity refuges located in lowlands. In Europe, lowlands experienced extensive habitat alteration (Verburg et al 2004;Zomeni et al 2008;Hersperger and Burgi 2009), resulting in massive loss of bird biodiversity (Chamberlain et al 2000;Telleria et al 2008;Ludwig et al 2009;Reif et al 2010b) and AMTS might contribute to maintenance of habitat remnants for threatened and protected bird species. More forested or densely vegetated AMTS had lower conservation value, expressed as a proportion of protected species, in contrast to AMTS covered by sparse scrubby vegetation.…”