Influence of surrounding land cover on marsh-breeding birds: Implications for wetland restoration and conservation planning

Marsh-breeding birds are valuable components of healthy ecosystems and are useful indicators of successful wetland restorations. The occurrence of these species, however, is influenced by the surrounding landscape. To aid decision-makers, we used data from the Great Lakes Marsh Monitoring Program of Birds Canada at 521 sites across four time periods (2000–2001, 2005–2006, 2010–2011, 2015–2016) throughout southern Ontario, Canada, to quantify how initial occupancy and subsequent local extinction or colonization of 13 marsh-breeding bird indicator species (or species groups) was influenced by the composition of, and concurrent changes in, surrounding remotely-sensed land cover within 200–6,400 m. For six species (46 %) initial occupancy was higher or extinction was lower where surrounding wetland/open water land cover was higher. By contrast, initial occupancy was lower, extinction was higher, and/or colonization was lower: 1) where surrounding anthropogenic (predominantly urban) land cover was higher (four species, 31 %), 2) in Great Lakes coastal compared to inland landscapes (five species, 38 %), and 3) where loss of surrounding wetland/open water land cover increased, depending on whether surrounding wetland/open water land cover was initially low or high (seven species, 54 %). We recommend that decision-makers consider the influence of the surrounding landscape during conservation planning and when measuring success of wetland restorations based on marsh-breeding bird indicator species, particularly in Great Lakes coastal landscapes and landscapes with high urban land cover and/or low wetland/open water land cover.