Download presentation
Presentation is loading. Please wait.
Published byLauren Franklin Modified over 9 years ago
1
BIOL 4240 Field Ecology
2
Ecologists are often interested in spatial data… Plant ecologists, distribution of individuals. Animal ecologists, distribution of individuals AND movements Which way did they go?
3
What purpose can movement/telemetry studies serve? Which way did they go? * Movement patterns, migration, dispersal * Space use and home range size * Resource use and selection * Population abundance and density * Survival * Fecundity
4
Movement patterns – assumed to be random through homogenous environment Which way did they go?
5
Home ranges – Various models (polygons, parametric and non-parametric) Which way did they go?
6
Home ranges – Various models (polygons, parametric and non-parametric) Which way did they go?
7
Home ranges – Various models (polygons, parametric and non-parametric) Which way did they go?
8
Home ranges – Various models (polygons, parametric and non-parametric) Which way did they go?
9
Home ranges – 2 variables have big influence… 1)How many animals 2)How many points per animal Which way did they go? Confidence level (%) Bound (%) N necessary 9510386 952098 953045
10
Resource use/selection – Describe habitat with discrete categories… – Cover type – Vegetation types – Topography – Successional stage Which way did they go?
11
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
12
Which way did they go? Survival – – Use computer software SURVIV by White (1983) – Program MARK? – Various other methods… Mayfield, Kaplan-Meier, Cox’s
13
Which way did they go? Questions necessary to determine… – What type of study? *Observational (descriptive or correlative) *Manipulative
14
Which way did they go? Questions necessary to determine… – Hypothesis testing or Model building? *Which type of study is more appropriate for model building?
15
Which way did they go? Questions necessary to determine… – What level of inference? What is the population? Time of day? Scale?
16
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 > type I error
17
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
18
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)
19
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
20
Which way did they go? Questions necessary to determine… – Are location errors addressed? *PDOP *Remote estimation
21
Which way did they go? Questions necessary to determine… – Are biases in observation rate identified and corrected? *remote estimation (GPS collars etc.) important
22
Preliminaries… – How many dimensions do tracking data have? Which way did they go?
23
Coordinate Systems… Explain UTM and why it is preferred *Advantages of Lat./Long.? *Disadvantages? Which way did they go?
24
Coordinate Systems… Explain UTM and why it is preferred *Universal Transverse Mercator (UTM)… between 84 N and 80 S divided into 6° rectangles (zones 1-60)... Which way did they go?
25
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 Which way did they go?
26
Coordinate Systems… * N or S then Universal Polar Sterographic (UPS) used. Which way did they go?
27
Preliminaries… – What other data are important to include with location data? Which way did they go?
28
Preliminaries… – Cause and Effect can ONLY be determined through which type of experiment? Which way did they go?
29
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? Which way did they go?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.