BIOL 4240 Field Ecology

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BIOL 4240Field Ecology
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Which way did they go?
Ecologists are often interested in spatial
data Plant ecologists, distribution of
individuals. Animal ecologists, distribution of
individuals AND movements
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Which way did they go?
What purpose can movement/telemetry studies
serve?
Movement patterns, migration, dispersal Space
use and home range size Resource use and
selection Population abundance and density
Survival Fecundity
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Which way did they go?

• Movement patterns assumed to be random through
  homogenous environment

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Which way did they go?

• Home ranges Various models (polygons,
  parametric and non-parametric)

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Which way did they go?

• Home ranges Various models (polygons,
  parametric and non-parametric)

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Which way did they go?

• Home ranges Various models (polygons,
  parametric and non-parametric)

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Which way did they go?

• Home ranges Various models (polygons,
  parametric and non-parametric)

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Which way did they go?

• Home ranges 2 variables have big influence
• How many animals
• How many points per animal

Confidence level () Bound () N necessary
95 10 386
95 20 98
95 30 45
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Which way did they go?

• Resource use/selection Describe habitat with
  discrete categories
• Cover type
• Vegetation types
• Topography
• Successional stage

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Which way did they go?

• Population Abundance Density
• Use telemetered animals as marked
• Use tagged animals to determine visibility bias
  for aerial surveys helps to minimize
  underestimation that is common

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Which way did they go?

• Survival
• Use computer software SURVIV by White (1983)
• Program MARK?
• Various other methods Mayfield, Kaplan-Meier,
  Coxs

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Which way did they go?

• Questions necessary to determine
• What type of study? Observational (descriptive
  or correlative)
• Manipulative

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Which way did they go?

• Questions necessary to determine
• Hypothesis testing or Model building? Which
  type of study is more appropriate for model
  building?

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Which way did they go?

• Questions necessary to determine
• What level of inference?
• What is the population?
• Time of day?
• Scale?

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Which way did they go?

• Questions necessary to determine
• What is the sample/experimental unit? Location
  point/data
• Animal
• Social considerations
• AVOID pseudoreplication (dependence or
  correlation of sample units, and artificially
  high estimates of precision) to minimize gt type I
  error

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Which way did they go?

• Questions necessary to determine
• Sampling design?
• Sampling intensity?
• Preliminary estimates of means/variances
• Determining biological significance
• Choosing desired power
• Calculating necessary N

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Which way did they go?

• Questions necessary to determine
• Sampling design?
• Sampling intensity?
• Studies suggest that 20-25 animals with 50 pts
  necessary for determining resource selection AND
• 50-300 pts /animal necessary for home range size
• (Rowland et al. 1997, 1998)

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Which way did they go?

• Questions necessary to determine
• Are Radio-marked animals an unbiased sample?
• Effects of non-random capture
• Marking-induced or relocation-induced changes in
  behavior and survival

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Which way did they go?

• Questions necessary to determine
• Are location errors addressed?
• PDOP
• Remote estimation

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Which way did they go?

• Questions necessary to determine
• Are biases in observation rate identified and
  corrected?
• remote estimation (GPS collars etc.) important

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Which way did they go?

• Preliminaries
• How many dimensions do tracking data have?

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Which way did they go?

• Coordinate SystemsExplain UTM and why it is
  preferred
• Advantages of Lat./Long.?
• Disadvantages?

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Which way did they go?

• Coordinate Systems Explain UTM and why it is
  preferred
• Universal TransverseMercator (UTM)between 84
  N and 80 S divided into 6 rectangles (zones
  1-60)...

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Which way did they go?

• Coordinate Systems Explain UTM and why it is
  preferred
• Example zone 1 180 W Prime meridian 177 W)
• What are the units in a number AND what do they
  convey regarding precision?0291923, 4441087 vs.
  0291, 4441

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Which way did they go?

• Coordinate Systems N or S then
  UniversalPolar Sterographic (UPS) used.

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Which way did they go?

• Preliminaries
• What other data are important to include with
  location data?

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Which way did they go?

• Preliminaries
• Cause and Effect can ONLY be determined through
  which type of experiment?

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Which way did they go?

• Preliminaries
• Considerations for radio tags
• Smallest size possible
• Cryptic coloration
• Transmitter effects on behavior/fitness
• Requisite time for adaptation
• Critical life history periods to avoid
• Others?