Correlates of the change in Ring OuzelTurdus torquatusabundance in Scotland from 1988–91 to 1999

Effects of variation in breeding habitat on Ring OuzelTurdus torquatusproductivity and chick condition

“…Burfield (2002) found Ring Ouzel breeding sites were more likely to be occupied if territory grass moor cover was high, while Sim et al (2007) found that breeding sites were more likely to remain occupied if territory heather cover remained high. Buchanan et al (2003) found occupancy was more likely to decline in areas which were initially heather-grass mosaics, which is where heather cover declines caused by grazing are most rapid (Clarke et al 1995). The same study also found occupancy declines in areas close to conifer plantations, suggesting a negative effect of predation, reduced grazing or delayed population-level effects of direct loss of breeding habitat (Buchanan et al 2003).…”

“…It is therefore possible that the cause of the recent decline in the UK is due to the particular ecology of the UK Ring Ouzel population. A recent proliferation of research into Ring Ouzels in the UK has found no single cause of the decline, however, a number of hypotheses have some support, including changes in breeding habitat (Burfield 2002, Buchanan et al 2003, Sim et al 2007, changes in wintering habitat (Ryall & Briggs 2006), changes in hunting pressure on migration (Burfield & Brooke 2005) and climate change (Beale et al 2006).…”

“…Buchanan et al (2003) found occupancy was more likely to decline in areas which were initially heather-grass mosaics, which is where heather cover declines caused by grazing are most rapid (Clarke et al 1995). The same study also found occupancy declines in areas close to conifer plantations, suggesting a negative effect of predation, reduced grazing or delayed population-level effects of direct loss of breeding habitat (Buchanan et al 2003). However, although the statistical relationships between Ring Ouzel breeding habitat and territory occupancy are well known, the mechanisms for these relationships are unstudied.…”

Anthropogenic activities influence the abandonment of Bearded Vulture (Gypaetus barbatus) territories in southern Africa

“…To address this issue, we used Caughley's (1994) declining population paradigm, postulating a series of plausible hypotheses and then testing which factors associated with these hypotheses were most closely linked to the abandonment of breeding territories. Similar approaches have been successful in elucidating important factors constraining other bird populations (e.g., Buchanan et al 2003, Lewis et al 2007, Amar et al 2011. In this study we explore the evidence for the following 3 a priori hypotheses: (1) territorial abandonment has been caused by anthropogenic activity, with abandonment occurring in areas with greater exposure to human impact; (2) territorial abandonment is the result of food shortages, with territories being abandoned in areas with insufficient food; and (3) territorial abandonment is being driven by climate change with abandonment occurring at nest locations most affected by climate change.…”

The decline of the Ring OuzelTurdus torquatusin Britain: Evidence from bird observatory data

“…This emphatically remains a possibility, although identifying the cause(s) of the decline has proved elusive (Burfield 2002b, Buchanan et al 2003. However, it is also possible that the different migration routes and timings followed by birds of the two populations expose them to different risks.…”