A distinct characteristic of many birds is that most of them migrate during colder periods. Before migration, many birds increase their body fats, and actually DECREASE some of their organs. For navigation, birds use different “tools”, such as internal clock, sun position, star constellations, and some species’ ability to sense the Earth’s magnetic fields.
During the First World War a post pigeon called Cher Ami even lost an eye and a leg, while doing its job. For its bravery it was awarded with a Distinguished Service Cross and it had its leg replaced with a wooden one.
Every year in the U.S.A. over 100 million birds die by crashing into windows of buildings there.
Drs. Foster and Smith. “Interesting Bird Facts.” PetEducation.com . Foster & Smith, Inc. 1997. Web. 22 Mar. 2010. < http://www.peteducation.com/article.cfm?c=15+1794&aid=179 >
“ Bald Eagle Habitat” SeaKing Adventures . SeaKing Adventures, Inc. 1994. Web. 22 Mar. 2010. http://www.seaking.ca/bald_eagle_habitat.htm
“ House Sparrow (Passer Domesticus).” Living with Wildlife in Illinois . University of Illinois Board of Trustees. 2010. Web. 22 Mar. 2010. http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=house_sparrow
“ Bird and Human Relationships.” AnimalAqua.Com . AnimalAqua. 2008. Web. 22 Mar. 2010. http://www.animalaqua.com/bird-and-human-relationships-bird/
“ Birds: Ostrich.” San Diego Zoo . Zoological Society of San Diego. 2010. Web. 22 Mar. 2010. http://www.sandiegozoo.org/animalbytes/t-ostrich.html
All about Birds . Cornell Lab of Ornithology. 2009. Web 22 Mar. 2010. http://www.allaboutbirds.org/NetCommunity/Page.aspx?pid=1189
Wikipedia: The Free Encyclopedia . Wikimedia Foundation, Inc. 2010. Web. 22 Mar. 2010. http://en.wikipedia.org/wiki/Bird