Transcript Invasion of the Black Rat Rattus rattus

Invasion of the Black Rat
Rattus rattus
Alexis Roque
Karin Lisa Sirjoo
Introduction
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Species: Rattus rattus
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/doc
uments/presentation/jcudev_008406~2.3.jpg
http://www.taiko.org.nz/rat1.jpg
Physical Description
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Medium sized body
 Large ears
 Tail usually longer
than body
 Weighs between 70
to 300 grams
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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
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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
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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
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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
Black Rat Vs. Santiago Rice Rat
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Interference
Competition
 Both species share
the same interest in
food sources
 General encounters
cause confrontation
between species
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Climate factors affect
the population growth
of the Black Rat
Black Rat Vs. Deer Mice
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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
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Parasite: Whipworm Trichuris muris
 Habitat and foraging
behavior overlap
Black Rat Vs. Deer Mice
http://www.marvistavet.com/assets/images/whipworm.gif
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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
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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
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www-biology.ucsd.edu/news/images/05010704-07L
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www.ferdinando.org.uk/images/Canary%20Islands.jpg
Seven main islands
100km from NW
coast of Africa
Varied vegetation
3672 terrestrial
endemic species
Of those, 1434
introduced by man
Invading the Canary Islands
Ecological Effects of Rattus Rattus
One of the world’s100
worst invasive
species (IUCN, 2001)
 Present on all 7
islands
 Arrived with European
conquistadors in the
15th century
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http://home.earthlink.net/~cyberkiwi/soldiers/magellan.jpg
Invading the Canary Islands
Ecological Effects of Rattus Rattus
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Affects plant
regeneration and
structure
 Predator of birds,
especially eggs and
chicks
 Causes decreased
breeding success in
birds
http://www.hawaii-forest.com/_img/naturalhistory/conservation-002.jpg
Human Prevention
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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
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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. Oecologia 149:276-288.
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 (Rattus rattus) parasites to endemic deer mice (Peromyscus
maniculatus) on the California Channel Islands. Diversity distributions
12:742.
Questions?