A bird’s eye view: Flamingos and the Scientific Method Marita Davison Ph.D Student Cornell...

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A bird’s eye view: Flamingos and the Scientific Method Marita Davison Ph.D Student Cornell Universit

Transcript of A bird’s eye view: Flamingos and the Scientific Method Marita Davison Ph.D Student Cornell...

Page 1: A bird’s eye view: Flamingos and the Scientific Method Marita Davison Ph.D Student Cornell University.

A bird’s eye view: Flamingos and the Scientific

Method

Marita DavisonPh.D StudentCornell University

Page 2: A bird’s eye view: Flamingos and the Scientific Method Marita Davison Ph.D Student Cornell University.

Past Present

1996

Environmental ScienceEcology, Conservation, Sociology, Economics, Anthropology

2000

Smithsonian National Museum of Natural

HistoryCurriculum Development

2001

2002

Field collectionsCloud Forest

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I am...

Ornithologist Limnologist

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A few definitions...ECOLOGY“oikos” = house (i.e. the planet, our home)“logos” = study or knowledgeThe study of the relationship between living organisms & their environmentORNITHOLOGY“ornithos” = birdThe study of birds

LIMNOLOGY“limne” = lakeThe study of lakes, ponds, & other standing waters

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And a few more...

Community: a group of interacting organisms living in the same place

Ecosystem: a community of organisms and their physical environment interacting as an ecological unit

Coral Reef Sonoran Desert

How does predatorabundance affect thenumber of species?

How does nutrient availability affect primary production?

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test your hypothesis

The S

cienti

fic

Meth

od

make an observation

ask a question

do background research

construct a hypothesis

analyze & report results

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1. Observations

•Flamingos are the most conspicuous organisms in Altiplano salt lakes

•Flamingos spend most of their time eating by grazing algae that has settled on the lake sediment surface

•Flamingos are the most abundant grazers in Altiplano salt lakes

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2. Questions

What effect do flamingos have on Altiplano salt lakes? Sub-questions:

1. Do flamingos influence community structure? 2. Do flamingos influence ecosystem processes?

What would happen (ecologically) if flamingos disappear?

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3. Background research

A. Library searchecological journals, books, popular articles

B. Internet searchactive researchers, photographs, videos, maps

C. Make contactsexperts in the field, potential collaborators

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3. Background research

From Hurlbert & Chang 1983

Algae >2x more abundant when

flamingos absent

Protozoa >6x more abundant when

flamingos absent

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4. Constructing a hypothesis

Hypothesis: a working explanation of observed facts that

leads to testable predictionsHypotheses must address your question of

interest, they are NOT questions themselves!

Prediction: a specific forecast of the expected outcome in the situation described in your hypothesis

Predictions must be measurable, and should result in either: (1) acceptance or (2) rejection

of the hypothesis

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Question 1: Do flamingos influence community structure?

Hypotheses vs Predictions

Biodiversity will be higher when flamingos are present and lower when flamingos are absent

Flamingos impact biodiversity of their lake habitats

Question 2: Do flamingos influence ecosystem processes?

Flamingos affect the growth of algae in Altiplano salt lakes

Growth of algae will be higher when flamingos are absent and lower when flamingos are present

Find the hypothesis!

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How to test a hypothesis

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5. Hypothesis testing

Experimental design:Simulate extinction of flamingos by excluding them from certain areas in the lake

2 types of experimental plots:

Exclosure plots: flamingos excluded

Control plots: flamingos presentEach plot: 4x4 meters, 5 of

each type placed at 2 locations in the lake

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5 pairs of plots (exclosure & control)

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x4

Sampling

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Samples obtained from each plot (E & C)

Community structureAlgae for identificationInvertebrates for identification

Ecosystem processesBiomass of algae (chlorophyll a)Biomass of of invertebrates