| Comments | Curriculum |
Radio Tracking
Uses
-Useful on many different species
-Determines location of animals using:
*radio receiver
*directional receiver
*radio transmitter
Advantages
-Allows precise identification of individual animals.
-Allows relocations at researcher’s discretion.
Ecological questions that telemetry helps answer
-Locations and Movements
*Where does the animal live?
*How much area does it roam(need)?
*How often does it move and how far?
*Which migration route is used?
*What time of the day does the animal move the most?
*Are certain areas used more than others?
-Behavior
*What is the animal doing?
*What behavior is displayed at what time of the day?
*What does the animal eat?
*How much?
-Mortality and Survival
*How long does the animal live?
*How did it die?
-Miscellaneous
*Where is the den or nest?
*How accurate is a census method?
*Where did the animal go after it was shot with a dart?
Radio-Tracking Techniques
-High directional antennas are the best
-Error of systems must be checked
-Gain should be adjusted for the best
Triangulation
-Bearings from 2 different Locations are needed
-Simultaneous fixes are the best but may not be possible
-Intersection of the bearings = assumed animal location
-Bearing should ideally intersect at 90 degree angle
Homing
-Users portable system to walk up to animal or radio
-Walk in direction of loudest signal reducing the gain
-When extremely close the antenna can be removed
Aerial
-Homing in an airplane
-Switch from one side to the other to determine direction
-Turn plan to direction of strongest signal
-Switch sides every pulse of radio
-When close drop altitude more precise location
-Search Pattern is spiral from last location at 10,000 ft.
Self
-contained Remote Monitors
-Allows for determination of presence or absence at site
-Must have recording Instrument and power source
-Scanning receivers can monitor numerous animals
Errors and Accuracy
-Error Polygon
-Each bearing has a small error on either side of line.
-A plot of both errors gives a diamond-shaped polygon.
-Animal could be anywhere within the error polygon
-Shape and size of error polygon depends on:
*Accuracy of antenna
*Distance between the 2 receiving points
*Distance from receiving points to transmitter
*The angle of 2 bearings
*Taking 3 bearing can allow more accurate location
Maps
-In construction and reading
Signal Bounce
-Signal reflects off of rocks, trees, water
-More common in the higher frequencies
-Numerous bearings will reveal problem areas
Adverse Effects of Radio-Tracking
-Radio package could change animals behavior
-Capture process could severely affect animal
-Monitoring procedures could influence behavior