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Invasion of the Black Rat Rattus rattus. Alexis Roque Karin Lisa Sirjoo. Introduction. Species: Rattus rattus Also Know as Ship Rat and Roof Rat Originated in Asia Found primarily around human habitations Mainly vegetarian diet.
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Invasion of the Black Rat Rattus rattus Alexis Roque Karin Lisa Sirjoo
Introduction • Species: Rattusrattus • Also Know as Ship Rat and Roof Rat • Originated in Asia • Found primarily around human habitations • Mainly vegetarian diet http://www.jcu.edu.au/discovernature/idc/groups/public/documents/presentation/jcudev_008406~2.3.jpg http://www.taiko.org.nz/rat1.jpg
Physical Description • Medium sized body • Large ears • Tail usually longer than body • Weighs between 70 to 300 grams • Usually black • Can be any combination of black, white or grey • Males longer and heavier than females http://lavieavec.unblog.fr/2007/07/03/la-beste-suite/
Lifestyle • Black Rats are nocturnal and omnivorous • Breed and reproduce throughout the year • Live together in large groups http://www.michaelspornanimation.com/splog/wp-content/e/ratatouille06.jpg
Geographic Distribution • Found on all continents especially tropical regions • Most common in coastal areas • Agile climber – often lives in high places like top floors of buildings or in trees • Rarely swims • Spreads disease http://www.biokleen.co.uk/gif/rat.gif
Black Rat Vs. Santiago Rice Rat • The Black Rat negatively affects the population of the Rice Rats • Interference of population by aggression • Removal of R. rattus slowed population decline of N. swarthi http://www.hear.org/galapagos/invasives/images/nswarthi.jpg
Interference Competition Both species share the same interest in food sources General encounters cause confrontation between species Climate factors affect the population growth of the Black Rat Black Rat Vs. Santiago Rice Rat
Deer mice is native to the California Channel Islands Black Rat affects Deer Mice in 2 ways: 1. Increasing Predation & Competition 2. Introducing new parasites & diseases Parasite: Whipworm - Trichuris muris Habitat and foraging behavior overlap Black Rat Vs. Deer Mice
Black Rat Vs. Deer Mice http://www.marvistavet.com/assets/images/whipworm.gif http://share3.esd105.wednet.edu/rsandelin/NWnature/Photos/Deer%20mouse.jpg • Whipworm is transferred through contaminated materials and foods • Eggs of the worm are infectious within 3 weeks of being passed from the system
Black Rat Vs. Sea Birds • Black rat is largest contributor to seabird extinction • Prey mostly on on small burrow nesters • Smaller birds are more vulnerable http://www.flickr.com/photos/cuba_photos/510171343/
Invading the Canary Islands • Seven main islands • 100km from NW coast of Africa • Varied vegetation • 3672 terrestrial endemic species • Of those, 1434 introduced by man www-biology.ucsd.edu/news/images/05010704-07L www.ferdinando.org.uk/images/Canary%20Islands.jpg
Invading the Canary IslandsEcological Effects of RattusRattus • One of the world’s100 worst invasive species (IUCN, 2001) • Present on all 7 islands • Arrived with European conquistadors in the 15th century http://home.earthlink.net/~cyberkiwi/soldiers/magellan.jpg
Invading the Canary IslandsEcological Effects of RattusRattus • Affects plant regeneration and structure • Predator of birds, especially eggs and chicks • Causes decreased breeding success in birds http://www.hawaii-forest.com/_img/natural-history/conservation-002.jpg
Human Prevention • Sanitation • Traps & Poison baits • Sound & Electronic devices • Control by cats & dogs • Eradication http://www.orlandorats.com/images/cheese.jpg http://www.mitchamcouncil.sa.gov.au/webdata/resources/images/rat1.jpg
References • Harris, Donna B., Gregory, S.H., Macdonald, D.W. 2006. Space invaders? A search for patterns underlying the coexistence of alien black rats and Galápagos rice rats. Oecologia149:276-288. • Harris, Donna B., Macdonald, D.W. 2007. Interference competition between introduced black rats and endemic Galapagos rice rats. Ecology 88:2330. • Jones. 2007. Severity of the Effects of Invasive Rats on Seabirds: A Global Review. Conservation Biology 22:16-26. • Nogales, M., Rodriguez, J.L., Marrero, P. 2006. Ecological effects and distribution of invasive non-native mammals on the Canary Islands. Mammal Society 36:49-65. • Smith, Katherine F., Carpenter, S.M. 2006. Potential spread of introduced black rat (Rattusrattus) parasites to endemic deer mice (Peromyscusmaniculatus) on the California Channel Islands. Diversity distributions 12:742.