Presentation on theme: "Using radio tags to study the physiology, behavior, and demography of animals Telemetry- the transmission of information through the atmosphere usually."— Presentation transcript:
Using radio tags to study the physiology, behavior, and demography of animals Telemetry- the transmission of information through the atmosphere usually by radio waves
Before radio-tracking, the study of animal movements depended on live-trapping and tagging animals and then hoping to recapture them somewhere else Using color-coded collars that allowed observers to identify animals from afar. Biased results
1.A transmitting subsystem consisting of a radio transmitter, a power source and a propagating antenna 2.A receiving subsystem including a "pick-up" antenna, a signal receiver with reception indicator (speaker and/or display) and a power source. Three types of radio tracking: 1.Very-high-frequency (VHF) radio tracking- 1963 2.Satellite tracking 3.Global Positioning System (GPS) tracking
Researchers can track animals in the field through: homing in (either by ground or aerial tracking) Triangulating Passive remote tracking is accomplished through automatic tracking systems
Used for- location data, to tell if an animal is active (or feeding, walking, running, resting) and the time spent in mortality from death until the transmitter is recovered. Microphone-containing transmitters allow researchers to listen to a creature's vocalizations Advantages- relatively low cost reasonable accuracy for most purposes long life Disadvantages- labor-intensive weather-dependent if aircraft-based
Argos System- estimates a vector from a passing satellite to a PTT (platform transmitter terminal) by the Doppler Shift of a controlled frequency. If there are two or more satellites, the tag’s location can be calculated Satellite tracking- uses a higher-powered transmitter attached to an animal. Ideal for- studying long-distance movements in remote areas (marine animals) Disadvantages: higher initial cost, less accurate (mean accuracy = 480 meters)
GPS- uses a radio receiver (rather than a transmitter) in an animal's collar. Usage Types: store the data and drop off the animal when expired to allow data retrieval others transmit the data to another set of satellites that deliver it to the researchers send the data on a programmed schedule to biologists who must be in the field to receive them.
Disadvantages- high initial costs relatively short-lived and applicable to mammals the size of a wolf or larger or to birds on which solar cells can be used Advantages- highly accurate suited for studies where intensive and frequent data are needed may not require frequent field visits.
The ability to program radio-collars to transmit only at certain times ("duty cycling") rather than continually. This refinement can double or triple transmitter life, thus reducing or eliminating the need to recapture an animal for replacing an expired collar. For example, using duty cycling, batteries in elk collars could now last 8 years or more. (VHF) Reduction in weight of GPS collars- used on smaller species, add batteries to larger specie collars GPS transmitters powered by solar cells are now available for birds Condor
necks, large ears, or horns/antlers Expandable collars allowing for growth of young animals have also been applied successfully to mountain lions, bobcats, black bears, caribou calves, elk calves, white-tailed deer fawns mammals with non-prominent necks (e.g. hedgehogs)- backpack harnesses. Surgically implanted transmitters such as subcutaneous transmitters, abdominal transmitters, or rumen transmitters represent other attachment alternatives (beavers, sea otters, yellow-bellied marmots, bears) Two considerations when using implanted transmitters are greatly reduced signal range (sometimes < 50%) and increased invasiveness to the animal that may result in greater data bias and potentially require subsequent veterinary procedures
Attachment methods for fitting transmitters to birds vary widely. Examples include transmitters with whip antennas fitted to backpacks with attachment loops under the wings ; loops meeting near the breast, or loops under the legs; loop-antenna harness- chest packs; whip antennas adhered directly to tail feathers, collars, neck band mounts, or necklaces, leg-band transmitters Vulture chick
Snakes have been fitted with internal transmitters that still allow the snake to move through small openings and to shed its skin Transmitter-fitted anesthetic darts have been placed in penguin nests for remote activation to capture the birds
Location positions of the white-tailed eagle, from August 5 - October 25, 2004
Fewer than 30,000 remain Goals: to devise lion conservation strategies to protect livestock from predators to ensure that local people gain significant economic value from lions and other wildlife, to offset the cost of living with them.
After three months of GPS data taken every hour during the night Two female lions from two prides resident on Ol Jogi Ranch in Laikipia District, Kenya. Results: Lions in Laikipia live largely on commercial ranches (white background) avoiding communal areas (brown backgrounds) with large numbers of livestock and humans.
The use of hairs plucked from free-ranging animals The use of scats, both for DNA analyses. Purpose- To tell presence/absence of a species and population estimates Disadvantages- 1)would require considerable field effort, 2)lab analyses of scat-derived DNA are problematic 3)The scat technique would provide little of the complementary data that radio-tracking yields such as behavioral observations, mortality rates and causes, dispersal, and various other data depending on the amount and frequency of tracking time. Red Wolf Scat