Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Restoration of grasslands and nesting success of dickcissels (Spiza americana).

Abstract

We compared abundance and nesting success of dickcissels (Spiza americana) between exotic-grass and restored native-grass sites in the Blackland Prairie Region of east-central Texas during March-July 2007 and 2008. Abundance of dickcissels was 44% greater on restored than on exotic sites, but the difference was not significant. Daily survival of nests was 0.895±0.013 SE on restored and 0.930±0.017 on exotic sites; there was no significant difference between restored and exotic sites. Mean height of nest was 56% higher on restored sites, mean height of nesting substrate was 58% higher on restored sites, and detectability was greater on restored sites than on exotic sites. The relatively small restored sites we studied did not improve daily survival of nests and may have acted as ecological traps, with the result being a lower proportion of successful nests, lower daily survival of nests, and higher relative abundance of dickcissels.