Exam 2- Measure of Resource Selection Flashcards
What is the scale of selection?
First order selection
Second order selection
Third order selection
Fourth order selection
First order selection
Selection of geographical range
Second order selection
Selection of a home range within that geographical range
Third order selection
Differential use of sites within the home range
Fourth order selection
Procurement of food items from among those available at a feeding site.
Use
An animal or species occupies a vegetation type or consumes a resource.
Availability
Quantity of vegetation type or resource accessible for the animal.
Selection
A resource is used in a way that is disproportionate to its availability
Preference
Selection independent of availability
There are 3 way to go about measuring resource use, what are they?
- Direct observation
- Radiotelemetry
- Indirect measure
What is included under direct observation as a method of measuring resource use?
- Must have good visibility
- Potential bias due to differential visibility
- Photos
What is included under radiotelemetry as a method of measuring resource use?
- Most common method
2. Error assessment must be done to determine if accuracy is good enough.
What is included under indirect measure as a method of measuring resource use?
- Use presence of sign (tracks, feces, browse/feeding) in various habitats to assess use.
- Bias due to differential production or visibility of sign among habitats.
What is a good method of measuring habitat availability?
Some sort of mapping activity; GIS/Remote sensing
What are some challenges to analyzing resource use?
- Lack of independence in use data
- Lack of independence in habitat use proportions
- Arbitrary definition of availability
Steps under second order selection (example)
- Construct home ranges
-Minimum convex polygon (MCP)
-Kernel Method - Define availability
- Statistically compare used areas to available areas
-Compositional Analysis based on Multivariate
Analysis of Variance
What do you do when using a Minimum Convex Polygon?
Connect the dots around telemetry points.
More locations=greater area
What type of statistical estimate is the Kernel method?
Probability-based
More locations doesn’t mean greater area
Steps under third order selection (example)
- Plot points used
- Overlay on vegetation cover map
- Generate non-use points
- Compare used vs. non-used points
Methods of measuring food use
- Direct observation
- Feeding site investigations
- Post-ingestion studies
a) . Fecal or pellet analysis
b) . Digestive tract analysis
What do you need when using direct observation as a method of measuring food use?
- Make direct observations of feeding activity
- Need highly visible animals in open habitat
- biases due to visibility differences possible
What do you need when using Feeding Site Investigations as a method of measuring food use?
- Measure use of vegetation between grazed and ungrazed plots.
- Use exclosures
- Clip and weigh vegetation of various species
Which is the most common type of food analysis?
Post-Ingestion studies
What are two types of post-ingestion studies?
- fecal or pellet analysis
2. digestive tract analysis
Fecal or pellet analysis
includes both carnivores & herbivores
noninvasive
potential bias bc remains can be hard to ID
What is the difference in digestive tract analysis of mammals and birds? What may be necessary in order to ID?
Mammals: stomach contents
Birds: crop contents
-microscopic analysis of food items
What are some techniques for measuring availability of vegetation as food?
- Many sampling techniques
- Line-Intercept
- Daubenmire square
- Ungulate browse surveying
- Mast traps
What technique is used to determine abundance in terms of carnivore food availability?
Trapping
