Location matters: survival of artificial nests is higherin small grassland patches and near the patch edge

PRETELLI M; CAVALLI M.; CHIARADIA N; CARDONI A.; ISACCH J. P

IBIS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2022

0019-1019

Nest survival is an important part of breeding success in grassland ecosystems, and thelocation of nests can determine vulnerability to different predators. We conducted anexperiment with artificial nests to evaluate jointly the predation rate on nests at differentspatial scales (landscape, patch and tussock) and the relative abundance of potential nestpredators (small mammals and birds) in a temperate grassland area. In November 2014and 2016, we installed 288 artificial nests in Common Pampas GrassCortaderia selloanagrasslands in the southeastern Pampas region, Argentina. The nests were placed in two10-ha plots in a continuous grassland patch (c. 900 ha) within a reserve and in two smallgrassland patches (1.5 and 1.8 ha) in an agricultural matrix (landscape-scale), at thepatch edge and inside the patches (patch-scale), and at two heights within the tussockgrass (tussock-scale). In 2016, we also conducted live trapping of small mammals andsurveyed birds along strip transects at the sampling sites. Nests located in patches withinan agricultural matrix and near the edge had greater relative survival than those set inthe reserve and inside the patches, respectively. This might be explained by the lowerrelative abundance of small mammals that we found outside the reserve. Artificial nestsurvival values recorded at the landscape-scale contrasted with those previously observedfor natural nests. Our results could be partly explained by differences in nest densitybetween agro-patches and those within the reserve. Future studies could also evaluatethe role of parental nest defence on nest survival.