Impacts of invasive exotic grasses on South Texas bird communities

Invasive, exotic species complicate wildlife management and are recognized as a significant threat to native species. Increasingly, exotic plants are causing long-term degradation of wildlife habitat. Thus, we compared the abundance and diversity of breeding birds and native flora on South Texas rangelands dominated by native grasses to rangelands dominated by the exotic grasses Lehmann lovegrass (Eragrostis lehmanniana) and buffelgrass (Cenchrus ciliaris) in 2001–2002. Results of our study indicated higher bird abundance (P < 0.05) on native grass sites. One bird species and 2 bird foraging guilds had higher abundance (P < 0.05) on native grass sites. Native grass sites had higher forb and grass species diversity and richness (P < 0.05). Land managers in South Texas should be aware that rangelands dominated by exotic grasses appear to be lower quality habitat than native rangelands for breeding birds, especially those in the ground-foraging guild.