House Sparrows Ubiquitous in urban areas Brought over from Europe Kills native bird species actively or passively Compete for resources Graphic Pictures Follow
"Without question the most deplorable event in the history of American ornithology was the introduction of the English Sparrow." -W.L. Dawson, The Birds of Ohio, 1903
Invasive Species Are Invasive Species a Major Cause of Extinctions? have negative effects on the functional relationships between birds, their prey, and prey habitat Lehmann lovegrass Buffelgrass Out-compete native species
Invasive Plants Invasive exotic plants are a major threat to many species of wild birds. Long-term and often irreversible habitat degradation for birds and other animals. Overall bird abundance was 32% greater on native-grass sites than on exotic-grass sites (Flanders).
Climate Change Becoming a heated policy issue Public concern growing Causing rapid change in habitats Extraordinary rate of species extinction Potential effects devastating to ecosystems worldwide.
Climate Change There are examples of invasive species altering the evolutionary pathway of native species by competitive exclusion, niche displacement, hybridization, introgression, predation, and ultimately extinction (Mooney). Process accelerated by global change brought on by warming
Conclusions Must address invasive species problem. Must actively manage lands to protect them from invasive species. Greater effort to exterminate invasive species More education & research needed. Limit Global Warming
Works Cited Mooney, H. A., and E. E. Cleland. "The Evolutionary Impact of Invasive Species." Proceedings of the National Academy of Sciences of the United States of America 98 (2001): 5446-5451. Gurevitch, Jessica, and Dianna K. Padilla. "Are Invasive Species a Major Cause of Extinctions?" Trends in Ecology 19 (2004): 470-474. Flanders, Aron A., et al. " Effects of Invasive exotic grasses on south Texas rangeland breeding birds." The Auk 123 (2006): 171-182. www.sialis.org/battles.htm (Pictures)