Wlf 315 Wildlife Ecology Lab I

Wlf 315 Wildlife Ecology Lab I

Fall 2008

GIS Exercise: Analyses of Home Range and Space Use Patterns

Introduction:

In this exercise you will use the ArcGIS 9 software and the third party Home Range Tool created by A.R. Rodgers in Ontario, Canada.

Cite as: Rodgers, A.R., A.P. Carr, H.L. Beyer, L. Smith, and J.G. Kie. 2007. HRT: Home Range Tools for ArcGIS. Version 1.1. Ontario Ministry of Natural Resources, Centre for Northern Forest Ecosystem Research, Thunder Bay, Ontario, Canada.

(although we are using the 2005 version in class because I could not get the 2007 version to work!)

Getting Started and Importing Telemetry Data

1. Create an ArcGIS project with the locationsof radio-collared pygmy rabbits collected during the breeding season of 2004. The locations were collected at 2 study sites that are about 7 km apart in the Lemhi Valley of eastcentral Idaho.

-Open a new project in ArcMap: Start – ArcGIS – ArcMap

-Next, add the telemetry data to the project following directions below.

-Save your project frequently: File – Save (put it in folder c:/wlf315)

2. Import the data on rabbit radio-locations from a text file into ArcMap. The data are located in the file breeding_04_Locs.txt. Data in this file include: Animal ID#, Sex, X (the East-West coordinate), and Y (the North-South coordinate).

3. Once you have successfully added the radio location data as a layer, use the Symbology to give each individual animal’s location its own color and to rename the layer.

-Right-click on Locations.shp. Select Symbology tab. Under Categories, choose Unique Values. Under Value Field, choose ID. Click Apply and then OK.

-Name the Layer: For the Layer Name, choose General tab and type Locations to rename the layer in the ArcMap project (NOTE! The shape file on the hard drive is still named breeding_04_Locs.shp, the Layer Name is simply a label).

-Look at the data – what do you see? Zoom in and out to get a feel for the distribution of locations.

Home Range Computations

4. Calculate home ranges (95% fixed kernel and 95% minimum convex polygon) for 1 animal for practice. Display the home ranges for this animal estimated 5 different ways.

-Make sure the Home Range Tools toolbar is present in the ArcMap project: Select Toolbars in the View menu; put a check mark in front of Home Range Tool ArcGIS 9. The new toolbar will appear in the ArcMap window. Move the toolbar to a convenient location.

-To calculate the home ranges for individual animals, you need to first select the locations for that individual from the whole data set, and then calculate the home range using HRT.

-Select locations for animal #10 as follows:

First to calculate the Minimum Convex Polygon (MCP) home range, you will do so in 2 different ways: a) Fixed arithmetic mean (this method keeps 95% of the points that are closest to the geographic center of the home range, and b)area added (this method keeps 95% of the points that result in the smallest home range): Click on the MCP symbol on the Home Range Tool.

a. fixed arithmetic mean:

-At the Contour tab, type 0.95 in the Levels box.

b. area added:

-At the Contour tab, type 0.95 in the Levels box.

Your results should look like this:

-Save your project!!

-Minimize ArcMap because you’ll use another program next.

In this part of the exercise you will calculate a fixed kernel home range using 3 different ways to calculate the smoothing parameter (also called an h-factor): a) least squares cross validation (LSCVh), b)h-reference, and c)likelihood cross validation (CVh). We’ll calculate these 3 different smoothing parameters using another program, Animal Space Use.

-Open the Animal Space Use Program. Choose ‘My data are assumed to be temporally independent observations’. Click Next.

-Choose ‘Estimate Home Range’. Click Next.

-Choose ‘Text File’. Click Next.

-Choose ‘Load Input Location Files’. Navigate to the folder c:/wlf315. Select the file M_10_breed_04.txt file (there is a separate .txt file for each animal). Check the Fixed Kernel box. Click Next.

-You will see the values for the CVh, LSCVh, and h_ref. Write these numbers down to 3 decimal places.

-Close down Animal Space Use.

-Restore ArcMap, and continue with home range calculations.

Click on the K symbol on the Home Range Tool.

a. least squares cross validation:

-At the Smoothing tab, select User and enter the value for LSCVh that you got from the Animal Space Use Program. Select the Fixed for fixed kernel, and remove the check for “show h as a proportion of h_ref”

-At the Standardization tab, select None.

-At the Contour tab, type 0.95 in the Levels box.

- Name the output home range when prompted, for example m10_leastsquare.shp for the home range for animal #10.

- To find the area of this home range, look n the attribute table. Right click on the shape file and select Attributes Table. The area for the 95% kernel home range reported in square meters.

b. h-reference:

Click on the K symbol on the Home Range Tool again.

-At the Smoothing tab, select User and enter the value for h_ref that you got from the Animal Space Use Program. Select the Fixed for fixed kernel, and remove the check for “show h as a proportion of h_ref”

-At the Standardization tab, select None.

-At the Contour tab, type 0.95 in the Levels box.

-Repeat the method for saving the home range, for example m10_href.shp

c. likelihood cross validation:

-At the Smoothing tab, select User and enter the value for CVh that you got from the Animal Space Use Program. Select the Fixed for fixed kernel, and remove the check for “show h as a proportion of h_ref”

-At the Standardization tab, select None.

-At the Contour tab, type 0.95 in the Levels box.

-Repeat the method for saving the home range, for example m10_likelihood.shp

You can display the different home ranges with different colors using the Symbology under the properties for each layer.

Your results should look like this:

5. Record the area for the 95% fixed kernel home ranges and the 95% MCP home ranges for M10 in hectares. There are 10,000 square meters in one hectare. How are they different or similar?

Now – you know how to calculate home ranges using 2 home range estimators (fixed kernel and minimum convex polygon). And, you should have an appreciation for how different user-selected software options for each method can alter the estimate of the size of the home range. NOW YOU CAN SEE WHY IT IS SO IMPORTANT TO ALWAYS REPORT YOUR EXACT METHODS WHEN REPORTING A HOME RANGE ESTIMATE!!

Lab Assignment:

Develop a hypothesis and prediction:

1. State one hypothesis (educated guess about why something is the way it is) that explains some aspect of the spatial pattern in the rabbits, and then provide a short explanation of the reasoning behind the hypothesis. You might consider asking questions about differences between sexes or study areas with respect to:
2. Size of home ranges (differences between sexes or study areas)

• Overlap between home ranges (differences between sexes or study areas)
• Sizes of home ranges using different types of home range estimators

(MCP vs. Fixed Kernel, or LSCV vs. CVh vs. h-ref smoothing parameters)

It does not matter if the hypothesis is “true” – it should be logical. Then provide a prediction, which is what you will actually measure.

Example:

Hypothesis: Home range sizes are larger for animals when resources are

spaced farther apart.

Explanation: When resources are spaced out, animals must travel further between

resource patches.

Prediction: Home ranges for pygmy rabbits will be larger at the Cedar Gulch site

than the Rocky Canyon site because the sagebrush plants are farther

apart, and rabbits use the sagebrush for food and cover from predators.

Run your ideas past one of the instructors before launching off on the exercise.

1. Make a table to display the sizes of the home ranges or number of overlapping home ranges (whatever information pertains to your hypothesis).
2. Make a map or 2 maps that display the home ranges that you used for your hypothesis. See instructions below for making maps from your GIS data.
3. Use your analyses to provide a qualitative test of your hypothesis. Briefly type a discussion about whether or not your hypothesis was supported by the analyses. You should refer to your maps and/or tables in answering this question.

Making Map Layouts:

Make a map of one or both study areas(which ever you need for your hypothesis) that shows the home ranges that you chose as part of your hypothesis.

-Zoom to the extent of one of the study areas (Cedar Gulch or Rocky Canyon)

-Click on Layout View in the View menu.

-If you prefer a Landscape view over Portrait – make the changes under Page and print setup in the File menu.

-Add a title, legend, scale bar, and north arrow using the Insert menu.

-You can choose different styles – just be sure that all of the parts are included.

Turn in for your Assignment:

-Hypothesis, Explanation, Prediction

-Table(s) with the home ranges you estimated

-Map(s) with the home ranges you estimated

-Brief discussion (in paragraph format) that evaluates your hypothesis in light of the data – was your hypothesis supported or not? Use your data (refer to tables and figures) to support your conclusion.

Due by the start of your lab next week (2:30 on Dec 8/9)– in either the TA or Instructor’s mailbox. Please have one of the administrative assistants for Fish & Wildlife (Linda or Carrie) sign & date your paper before putting in the mailbox.