
Animal migration tracking is used in
wildlife biology,
conservation biology
Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an i ...
,
ecology
Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...
, and
wildlife management
Wildlife management is the management process influencing interactions among and between wildlife, its Habitat, habitats and people to achieve predefined impacts. Wildlife management can include wildlife conservation, population control, gamekeepi ...
to study animals' behavior in the wild. One of the first techniques was
bird banding
Bird ringing (UK) or bird banding (US) is the attachment of a small, individually numbered metal or plastic tag to the leg or wing of a wild bird to enable individual identification. This helps in keeping track of the movements of the bird an ...
, placing passive ID tags on birds legs, to identify the bird in a future catch-and-release. Radio tracking involves attaching a small
radio transmitter
In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an antenna with the purpose of signal transmissio ...
to the animal and following the signal with a
RDF receiver. Sophisticated modern techniques use satellites to track tagged animals, and
GPS tags which keep a log of the animal's location. With the Emergence of
IoT the ability to make devices specific to the species or what is to be tracked is possible. One of the many goals of animal migration research has been to determine where the animals are going; however, researchers also want to know why they are going "there". Researchers not only look at the animals' migration but also what is between the migration endpoints to determine if a species is moving to new locations based on food density, a change in water temperature, or other stimulus, and the animal's ability to adapt to these changes. Migration tracking is a vital tool in efforts to control the impact of human civilization on populations of wild animals, and prevent or mitigate the ongoing extinction of
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
.
Technologies

In the fall of 1803, American Naturalist
John James Audubon
John James Audubon (born Jean-Jacques Rabin, April 26, 1785 – January 27, 1851) was a French-American Autodidacticism, self-trained artist, natural history, naturalist, and ornithology, ornithologist. His combined interests in art and ornitho ...
wondered whether migrating birds returned to the same place each year. So he tied a string around the leg of a bird before it flew south. The following spring, Audubon saw the bird had indeed come back.
Scientists today still attach tags, such as metal bands, to track movement of animals. Metal bands require the re-capture of animals for the scientists to gather data; the data is thus limited to the animal's release and destination points.
Recent technologies have helped solve this problem. Some electronic tags give off repeating signals that are picked up by radio devices or
satellite
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
s while other electronic tags could include archival tags (or data loggers). Scientists can track the locations and movement of the tagged animals without recapturing them using this
RFID
Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When tri ...
technology or satellites. These electronic tags can provide a great deal of data. Modern technologies are also smaller, minimising the negative impact of the tag on the animal.
Recent advancements in tracking technology have improved the ability to monitor animal migration without the need for recapturing.
Wildlife Drones, an Australian company, developed a drone-based radio telemetry system to track small, mobile species like the Swift Parrot, one of Australia’s most endangered birds. Traditional tracking methods for such species involved very high frequency (
VHF) radio-tags and manual tracking with handheld receivers, which were labour-intensive and limited in range. The system allows researchers to collect data remotely from multiple tagged animals over large distances, increasing the efficiency and effectiveness of wildlife monitoring.
Radio tracking
Tracking an animal by radio telemetry involves two devices.
Telemetry, in general, involves the use of a
transmitter
In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an antenna (radio), antenna with the purpose of sig ...
that is attached to an animal and sends out a signal in the form of
radio waves
Radio waves (formerly called Hertzian waves) are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 gigahertz (GHz) and wavelengths ...
, just as a
radio station
Radio broadcasting is the broadcasting of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based rad ...
does.
A scientist might place the transmitter around an animal's
ankle
The ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The ...
,
neck
The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...
,
wing
A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-d ...
,
carapace, or
dorsal fin
A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...
. Alternatively, they may surgically implant it as internal radio transmitters have the advantage of remaining intact and functioning longer than traditional attachments, being protected from environmental variables and wear. The transmitter typically uses a
frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...
in the
VHF band as antennas in this band are conveniently small. To conserve battery power the transmitter usually transmits brief pulses, perhaps one per second. A specialized
radio receiver
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. ...
called a
radio direction finding
Direction finding (DF), radio direction finding (RDF), or radiogoniometry is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertent source, a natural ...
(RDF) receiver picks up the signal. The receiver is usually in a
truck
A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construct ...
, an
ATV, or an
airplane
An airplane (American English), or aeroplane (Commonwealth English), informally plane, is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a vari ...
.
The receiver has a
directional antenna
A directional antenna or beam antenna is an antenna that radiates or receives greater radio wave power in specific directions. Directional antennas can radiate radio waves in beams, when greater concentration of radiation in a certain directio ...
(usually a simple
Yagi antenna) which receives most strongly from a single direction, and some means of indicating the strength of the received signal, either by a meter or by the loudness of the pulses in earphones. The antenna is rotated until the received radio signal is strongest; then the antenna is pointing toward the animal. To keep track of the signal, the scientist follows the animal using the receiver. This approach of using radio tracking can be used to track the animal manually but is also used when animals are equipped with other payloads. The receiver is used to home in on the animal to get the payload back.
Another form of radio tracking that can be utilized, especially in the case of small bird migration, is the use of
geolocators or "geologgers".
This technology utilizes a light sensor that tracks the
light-level data during regular intervals in order to determine a location based on the length of the day and the time of solar noon.
While there are benefits and challenges with using this method of tracking, it is one of the only practical means of tracking small birds over long distances during migration.
Passive integrated transponders (PIT) are another method of telemetry used to track the movements of a species
Passive integrated transponders, or "PIT tags", are electronic tags that allow researchers to collect data from a specimen without the need to recapture and handle the animal.
Data is captured and monitored via electronic interrogation antennae, which records the time and location of the individual.
Pit tags are a humane method of tracking that has little risk of infection or mortality due to the limited contact necessary to monitor the specimens. They are also cost-efficient in that they can be used repeatedly should the need arise to remove the tag from the animal.
Motus wildlife tracking network is a program by
Birds Canada, it was launched in 2014 in the US and Canada, by 2022 there are more than 40,000 transmitters on various animals, mostly birds, and 1,500 receiver stations have been installed in 34 countries, most receivers are concentrated in the United States and Canada.
Satellite tracking

Receivers can be placed in
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
-
orbit
In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...
ing satellites such as
ARGOS. Networks, or groups, of satellites are used to track animals. Each satellite in a network picks up electronic signals from a transmitter on an animal. Together, the signals from all satellites determine the precise
location of the animal. The satellites also track the animal's path as it moves. Satellite tracking is especially useful because the scientists do not have to follow after the animal nor do they have to recover the tag to get the data on where the animal is going or has gone. Satellite networks have tracked the migration and territorial movements of
caribou,
sea turtles,
whales
Whales are a widely distributed and diverse group of fully Aquatic animal, aquatic placental mammal, placental marine mammals. As an informal and Colloquialism, colloquial grouping, they correspond to large members of the infraorder Cetacea ...
,
great white sharks,
seals,
elephants
Elephants are the Largest and heaviest animals, largest living land animals. Three living species are currently recognised: the African bush elephant (''Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian ele ...
,
bald eagles,
osprey
The osprey (; ''Pandion haliaetus''), historically known as sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor, reaching more than in length and a wingspan of . It ...
s and
vultures. Additionally
Pop-up satellite archival tags are used on marine mammals and various species of fish. There are two main systems, the above-mentioned Argos and the
GPS.
[Northern Bald Ibis Project]
/ref>
Thanks to these systems, conservationists can find the key sites for migratory species.[ Another form of satellite tracking would be the use of acoustic telemetry. This involves the use of electronic tags that emit sound in order for the researchers to track and monitor an animal within three dimensions, which is helpful in instances when large quantities of a species are being tracked at a time.
]
IoT tracking
IoT or the internet of things proves to be a potential resource for the future of wildlife tracking and research. This technology can range from low-power wide-area LPWA sensor networks attached to wildlife by safe adhesive to cameras connected to the internet using machine learning to determine what images are interesting and categorize the photos. With LPWA, the applications are endless. All that needs to be done is to develop the sensors that attach to any animal. With the sensors' low power, changing their batteries becomes less of a problem. The program Where's The Bear is a wildlife monitoring software by the Computer Science Department at the University of California Santa Barba. They use cameras as their sensors and machine learning to quantify the photos into empty pictures triggered by wind and rain. They are instead reporting those of different species of animals. To make the training process of the algorithm rapid, they used edited photos with animals inserted in the shot of the given sensors view to sense the different animals. This training was able to make the technology more accurate with fewer false positives and false negatives. This method increased the ability to categorize animals’ photos, proving a potential new technology for vast groups of people for commercial and public use.
Stable isotopes
Stable isotopes are one of the intrinsic markers used for studying migration
Migration, migratory, or migrate may refer to: Human migration
* Human migration, physical movement by humans from one region to another
** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...
of animals. One of the benefits of intrinsic markers in general, including stable isotope analysis, is that it does not require an organism to be captured and tagged and then recaptured at a later time. Each capture of an organism provides information on where it has been based on diet. The three types of intrinsic markers that can be used as tools for animal migration studies are: (1) contaminants, parasites and pathogen
In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...
s, (2) trace elements, and (3) stable isotopes. Certain geographic regions have specific stable isotope ratios that affect the chemistry of organisms foraging in those locations, this creates "isoscapes" that scientists can use to understand where the organism has been eating. A couple prerequisites must be met in order to use stable isotope analysis successfully: (1) the animal must have at least one light isotope of interest in specific tissues that can be sampled (this condition is almost always met since these light isotopes are building blocks of most animal tissues), and (2) the organism needs to migrate between isotopically different regions and these isotopes must be retained in the tissue in order for the differences to be measured.
Stable isotope analysis has a lot of benefits and has been used in terrestrial and aquatic organisms. For example, stable isotope analysis has been confirmed to work in determining foraging locations of nesting loggerhead sea turtle
The loggerhead sea turtle (''Caretta caretta'') is a species of sea turtle, oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the Family (biology), family Cheloniidae. The average loggerhead measures around ...
s. Satellite telemetry was used to confirm that the location derived from the analysis were accurate to where these turtles actually traveled. This is important because it allows for greater sample sizes to be used in migration studies, since satellite telemetry is expensive and tissue, blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells.
Blood is com ...
, and egg samples can be taken from the female turtles laying eggs.
Importance
Electronic tags are giving scientists a complete, accurate picture of migration patterns. For example, when scientists used radio transmitters to track one herd
A herd is a social group of certain animals of the same species, either wild or domestic. The form of collective animal behavior associated with this is called '' herding''. These animals are known as gregarious animals.
The term ''herd'' ...
of caribou, they learned two important things. First, they learned that the herd moves much more than previously thought. Second, they learned that each year the herd returns to about the same place to give birth
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...
. This information would have been difficult or impossible to obtain with "low tech" tags.
Tracking migrations is an important tool to better understand and protect species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
. For example, Florida
Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
manatees are an endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
, and therefore they need protection. Radio tracking showed that Florida manatees may travel as far as Rhode Island when they migrate. This information suggests that the manatees may need protection along much of the Atlantic Coast of the United States. Previously, protection efforts focused mainly in the Florida area.
In the wake of the BP oil spill, efforts in tracking animals has increased in the Gulf. Most researchers who use electronic tags have only a few options: pop-up satellite tags, archival tags, or satellite tags. Historically these tags were generally expensive and could cost several thousands of dollars per tag. However, with current advancements in technology prices are now allowing researchers to tag more animals. With this increase in the number of species and individuals that can be tagged it is important to record and acknowledge the potential negative effects these devices might have.
See also
* Acoustic tag
* Bird ringing
Bird ringing (UK) or bird banding (US) is the attachment of a small, individually numbered metal or plastic tag to the leg or wing of a wild bird to enable individual identification. This helps in keeping track of the movements of the bird an ...
* Data storage tag
* History of wildlife tracking technology
* Light level geolocator
* GIS and aquatic science
* Pop-up satellite archival tag
* Tracking collar
* Coded wire tag
* Motus (wildlife tracking network)
References
External links
"Satellite Tracking."
''Space Today''.
* Tomkiewicz Jr, Stanley
telonics.
* Zanoni, Mary
Klamath Basin.
Audubon. National Audubon Society, Inc.
"Satellite Tracking Migratory Birds."
Western Ecological Research Center.
''Space Today''.
Save The Manatee Club.
Journey North. Learner.
Radio interview
Robert and Kirk Miner remember their grandfather, Jack Miner, and talk about the Jack Miner Migratory Bird Sanctuary. Originally aired February 1, 2008.
{{Authority control
Zoology
Animal migration
Geopositioning