Exploitation by Introduced Species

28

29

Brown Tree Snake (Boiga irregularis) Introduced to Guam (mid-1940s)

31

Myiagra freycineti (Guam flycatcher)

Gallicolumba xanthonuraWhite-throated ground-dove

28

29

Zosterops conspicillatus **Bridled white-eye

Acrocephalus lusciniaNightingale reed-warbler

Rhipidura rufifrons *Rufous fantail

Ptilinopus roseicapillaMariana fruit-dove

Myzomela cardinalisCardinal honeyeater

Halcyon cinnamomina **Micronesian kingfisher

Nine of Eleven NativeForest Birds in Guam

EXTIRPATED/EXTINCT

30

SUCCESS OF SPECIESINTRODUCED OUTSIDE OF NATURALGEOGRAPHIC DISTRIBUTION

• No Coevolved Interspecific Competitors

• No Coevolved Herbivores

• No Coevolved Parasites

• No Coevolved Pathogens

Predator-Prey Dynamics

Sunspot Hypothesis(Elton 1924)

What Controls Snowshoe Hare Population Fluctuations?

Predator HypothesesFood Supply/Quality Hypotheses

Overpopulation Hypotheses

TEASING OUT THE INDIVIDUAL EFFECTS:CONTROLLED EXPERIMENT

27

Test for Effects of Predators, Plant Food Supply, Quality

Controls SupplementalFood

Fertilizer

Electric Fence/ Supplemental Food

Electrical Fence

Krebs et al. 1995

8 YEAR STUDY

TEASING OUT THE INDIVIDUAL EFFECTS:CONTROLLED EXPERIMENT

Fig. 14.15 in Molles 2006

TEASING OUT THE INDIVIDUAL EFFECTS:CONTROLLED EXPERIMENT

Underlying Processes: Predator – Prey Dynamics

Alfred Lotka (1925)

Vito Volterra (1926)

dNh/dt = rhNh – pNhNp

Modeling Population Change: Host (= Prey)

rh =

p =

Nh =

Np =

dNp/dt = cpNhNp-dpNp

Modeling Population Change: Predator

cp =

Nh =

Np =

dp =

Fig. 14.17 in Molles 2006

Fig. 14.17 in Molles 2006

2

Predator – Prey Oscillation in the Laboratory?

Fig. 14.18 in Molles 2006Bean Weevil

Parasitoid Wasp

Utida 1957

Predator – Prey Oscillation in the Laboratory?

Predator – Prey Relationships in the Lab(Paramecium – Didinium)

G. Gause (1935)Predator: DidiniumPrey: Paramecium

Predator – Prey Relationships in the Lab(Paramecium – Didinium)

Fig. 14.19 in Molles 2006

Experiment 1

PreyPredator

Fig. 14.19 in Molles 2006 Trial 2

Predator – Prey Relationships in the Lab: Refuges(Paramecium – Didinium)

Add a Refuge: Sediment

Predator – Prey Relationships in the Lab: Restock Predators(Paramecium – Didinium)

Prey Predator

Trial 3

Restock the Predator

10

Predatory Mite• Can Crawl• Feeds on Six-Spotted Mite

Six-Spotted Mite•Feeds on Oranges• Can Crawl or “Balloon” via Silk Strand

Predator – Prey Relationships in the Lab(Predatory Mite / Six-Spotted Mite)

Predator – Prey Relationships in the Lab(Predatory Mite / Six-Spotted Mite)

Fig. 12.21 in Cain et al. 2008

Huffaker (1958)

Predator – Prey Relationships in the Lab: Refuges and Complexity(Predatory Mite / Six-Spotted Mite)

Fig. 12.22 in Cain et al. 2008

Additional Complexity• Widely Spaced Oranges• Intervening Vaseline Strips• Posts Inserted on Some Oranges to Facilitate Ballooning

9

2 http://perso.orange.fr/argaud/botanique/opuntia_stricta_fruit.jpg

3 http://www.northwestweeds.nsw.gov.au/images/COMMON1.JPG

4 http://www.northwestweeds.nsw.gov.au/images/Cochineal%20on% 20common%20pear%201%20Jun%2003%20Bingara%20web.jpg

5 http://www.gri.msstate.edu/research/cmdmn/images/cactoblastis.jpg

6 http://cache.eb.com/eb/image?id=6545&rendTypeId=4

7 http://www.depts.ttu.edu/communications/news/stories/images/ saltcedar-mountains-large.jpg

8 http://www.co.morton.nd.us/vertical/Sites/%7B90CBB59C-38EA- 4D41-861A-81C9DEBD6022%7D/uploads/%7BC2C6F596-EB0D- 427F-852E-5840C1E97721%7D.JPG

9 http://www.invasive.org/eastern/images/768x512/0002030.jpg

10 http://www.cwss-scm.ca/Weeds/images/Ly1-purple-loosestrife.JPG

11 http://www.ec.gc.ca/EnviroZine/images/Issue35/zebra_mussels _DFO2_l.jpg

12 http://www.starfish.govt.nz/shared-graphics-for-download/zebra-mussel-large.jpg

14 http://www.birdfinders.co.uk/images/lesser-kestrel-2-spain-2006.jpg

15 http://www.douglloydphotography.com/mediac/400_0/media/DIR_ 9698/short~eared~owl~607.jpg

13 http://www.naturephoto-cz.com/photos/andera/common-vole-15371.jpg

16 http://www.lakesuperiorstore.com/store/images/books/warner/HBC.jpg

18 http://www.toothandclaw.org.uk/upload/files/European%20Lynx-0001.jpg

17 http://www3.nationalgeographic.com/animals/images/primary/ snowshoe-hare.jpg

19 http://www.pas.rochester.edu/~afrank/Theory/eit027.jpg

20 http://www.volunteertaskforce.org/images/aspen_seedlings.jpg

21 http://www.toothandclaw.org.uk/upload/files/European%20Lynx-0001.jpg

22 http://www.toothandclaw.org.uk/upload/files/Goshawk0003.jpg

23 http://www.alangrinberg.com/photos/NewZealand/SouthPage02/3708_ Tannin.jpg

24 http://library.thinkquest.org/11922/habitats/boreal_forest2_c-NOVA.jpg

25 http://www.wildlandsleague.org/imgup/forest.aerial.jpg

26 http://www.tpwd.state.tx.us/huntwild/wild/species/coyote/

27 http://www.wildlandsleague.org/imgup/forest.aerial.jpg

28 http://www.physorg.com/newman/gfx/news/hires/browntreesna.jpg

29 http://2.bp.blogspot.com/_3yf8gXwg-1g/SbArAtu9bBI/AAAAAAAAASw/ 8xRFAuwO1RY/s400/Brown-tree-snake-(3).jpg

29 http://media-2.web.britannica.com/eb-media/53/11953-004-2CF4FCD9.jpg

31 http://www.fort.usgs.gov/resources/education/bts/impacts/birds.asp

30 http://www.fort.usgs.gov/resources/education/bts/impacts/birds.asp

32 http://www.earlham.edu/~biol/desert/invasive.htm

33 http://www.chihuahuandesert.org/images/Salt%20Cedar%20Leaf%20Beetle.jpg