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)