Peat extraction sites providing cavities and large areas of open soil favour a threatened songbird

The northern wheatear ( Oenanthe oenanthe ) is a songbird that is considered threatened with extinction in both the German federal state of Lower Saxony and Germany. Today, in the mainland of Lower Saxony (NW Germany), industrial peat extraction sites are the most important breeding habitat for the species. However, our knowledge regarding the detailed habitat requirements of the northern wheatear in these mining sites is still scarce. In this study, we aimed to identify the environmental drivers of nest site selection by the northern wheatear in its last distribution stronghold in the mainland of Lower Saxony. In three different raised bogs, where peat was still exploited and the northern wheatear was still breeding, we systematically surveyed wheatear nests and environmental parameters at 26 randomly selected plots with an area of 45 ha each. Our study confirmed that peat extraction sites were an important breeding habitat for the northern wheatear. However, this was only true if they provided a combination of (i) regular availability of suitable cavities for nesting and (ii) vast open areas that guaranteed easy access to arthropod prey and increased detectability of potential predators. By far, the most important structures for nesting were the cavities within the rows of cross‐ and lengthwise stacked peat sods. The availability of large open areas was particularly ensured by regular milling of the peat. Practical implication . Based on our findings, peat extraction sites used as a breeding habitat for the northern wheatear would benefit from a combination of sod cutting and peat milling to create both the required (i) nesting structures and (ii) open soil for foraging and early predator recognition. To avoid nest losses, re‐stacking of peat sods is best carried out before the breeding season starts (until mid‐April) and harvesting of the sods after the breeding season from the end of July onwards.