animal movement and home range lab - claremont...
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Animal Movement and home Range Lab Donald McFarlane and Warren Roberts
Pacas (Agouti paca) are large neotropical rodents that were formerly
widespread in Costa Rica but suffer intense hunting as a favored food
animal. They occur on the Firestone Reserve, but have not been
studied there; the following data is conjectural.
The data set consists of a set of GPS locations for two pacas, such as
would be derived from animals fitted with radio-collars. In addition, GIS
data has been provided for you to save you (a lot of) time.
Map Layers provided
1. Without any base map layers your display of points will have no
context to other features in the landscape such as proximity to
water, slope, aspect, vegetation, watersheds, etc. Shown below are
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Pica collected locations displayed alone without basemap layers.
2. Unlike projects in the US, projects in remote locations in other parts
of the world have limited map resources. The layers provided were
mostly generated from field data collection and further generation
using ArcGIS.
3. GPS collected locations are collected in the field or tracked remotely
(tagged turtles). The following displays the requirements of such
data when displayed in Excel. Many GPS units today will directly
export directly into GIS layers. The following considers that you have
raw data of locations in table format.
Prepare lesson
4. Start ArcMAP (dismiss initial dialog box)
5. Select menu Customize
6. Select ArcMAP Options
7. Select Sharing Tab
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8. Change Use User Specified Folder to c:\gis-data .. select OK
9. Close ArcMAP
Obtain Data
10. log in to the http:///www.ArcGIS.com
a. login pitzercollege password student
11. select Groups and All Content as shown below
12. Select to download the lesson data
13. Once ArcMAP opens, select File Menu > SaveAs > save into the
folder c:\gis\Paca folder
Examine GPS Data Format (for GIS)
GPS provides the tool to easily collect location ‘address’ of features in
the field. The latitude longitude of the following locations perhaps were
collected using a Garmin GPS (approximately 80 dollars) and
transferred to excel (either by a download using free software online
(DNRGarmin) or simply by transferring the locations displayed in the
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GPS by typing the coordinates into Excel in the following format (the
longer way)
14. Display the table of contents to show ‘List by Source’
15. Examine the table PACAA001$ (right mouse on the table and
select open)
The locations can be either in Longitude Latitude (DD / Decimal
Degrees only) as opposed to DMS (Degrees Minutes and Seconds).
The location can also be collected in XY but you must be familiar
with what coordinate system your GPS is configured (in this case,
the data is display XY using UTM 17N for Costa Rica). The first field
identifies which PICA was found at each of the location. Each record
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in the table is one PICA finding. How many locations where
recorded?
Create (GIS) layer of PICA locations
16. Right mouse on the PACA001$ in the table of contents
17. Select Display XY Data
18. Select OK. Good?
19. OK, now repeat to display the PICA002$ collection.
Fortunately we have basemap layers to show the points above and see
their location relative to other features and aspects on the landscape
such as slope or proximity to water or circulation.
20. Change the display of the points as shown below
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Visualize the movements.
How does the movement of the Paca look if you were to connect the
locations in order? We'll use a tool that simply connects the points in
the order they were collected. The paths will show the ‘path’ it takes
across the landscape..
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Search and select the tool 'Point to Line' and provide the information
requested. Repeat for each of the paca (001 and 002)
Describe and characterize movements
If locations are sorted chronologically, then you get a quick calculation
of lengths and turn angles of the animal movement between each
location. These are added point by point to the attribute table (see next
page). These can be summarized quickly by clicking on the column in
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the attribute table, right clicking, and then clicking on statistics (see
below).
We can now answer the following questions / statistics of movement
for the Paca001.
● What is the minimum distance travelled between locations?
● What is the maximum distance travelled between locations?
● What is the total distance travelled between locations?
What is the home range?
Home range is determined using various tools. I provided you the tool
you need in the toolbox rather than searching for the correct tool to use
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'Minimum Bounding Geometry'
You can display the new Home Range polygon layer to be displayed
‘hollow’ and make outline thicker.
What is the home range overlap? The next page we will determine
what percentage of overlap if we look at 100% of the home range.
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What is the % Home Range Overlap?
To save time a completed Home Range layer is provided with the
percentage of overlap for both Paca 01 and Paca 02.
21. In ArcCatalog, navigate to the folder ‘results’ and locate the
homerangestudy.shp layer and add to ArcMAP. You can identify
each of the 3 areas (one is the overlap) to determine area and
percentage coverage.
What is the % coverage overlapping both Paca 01 and 02 home range?
Calculate the Fixed Kernel home range estimate
Using ‘density’ functions we should progressively separate our two
animals to show the home range concentration.
22. Select bookmark and select both pacas (zooms to display extents
of both)
23. In ArcMAP, select the menu Customize > Extensions > check on
‘spatial analysis’ .. Close
24. set the environments .. the extents of our analysis (we are not
examining the whole bloody planet)
a. Geoprocessing menu > Environments>Processing extent ..
select same as extent. Select OK
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25. Select the tool 'kernel density'
● input is the Paca001
● provide output name (no spaces and
less than 13 characters
● radius 50 meters (determined how
many others sightings within 50
meters)
● output in numbers of sightings per
square kilometer
● Select OK
26. Repeat Kernel Density Estimator for Paca002
point collections.
Looking at each of the 50% concentrations you can
see there is no overlap unlike using the Home
Range Analysis on that exhibits 50% overlap!
[end of lesson]
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