PIT tags are Passive Integrated Transponders that are used for tracking animals. They are small, electronic microchips that are implanted into the animal’s body and can be read by a special antenna. They do not require power or batteries, but are activated by the antenna’s signal. Each PIT tag has a unique number that identifies the animal and the time it passed by the antenna. PIT tags are useful for studying animal movement, behavior, survival, and population dynamics.

To use a PIT tag, you need to implant it into the animal you want to track and set up an antenna that can read the tag’s unique code. The antenna should be connected to a computer or a device that can record the tag’s identity and the time of detection¹. You can use a handheld scanner to check for tags in captured animals, or install an antenna array to detect any tagged animals that pass by. You can also use mobile antennas to scan a study area for tagged animals.

PIT tags are used for unique identification and tracking of individual animals, especially in wildlife and marine biology applications . They can provide valuable research data on animal movement, behavior, survival, and population dynamics. They can also be used for identifying household pets, livestock, and zoo animals .

A PIT tag works by using a radio transponder that contains a specific code, which allows individual animals to be assigned a unique identification number. The PIT tag does not require a battery, but is activated by a signal emitted from a scanner or antenna. When the PIT tag is within range of the scanner or antenna, it responds to the signal and transmits its code, which is then recorded by a device connected to the scanner or antenna. This way, the PIT tag can provide information on the presence, movement, and survival of the tagged animal.

No, a PIT tag does not have a battery. It is a passive device that is activated by a scanner’s signal.

The range of a PIT tag reader depends on the type of PIT tag and reader system used. Generally, half-duplex (HDX) tags have a longer read range than full-duplex (FDX) tags, because they emit a stronger signal. However, HDX tags are also larger and slower than FDX tags. The size and shape of the antenna also affect the read range, as well as the environmental conditions and interference from other sources. the typical read range for FDX tags is about 10-30 cm, while for HDX tags it is about20-100 cm. However, these ranges may vary depending on the specific tag and reader models used. Some readers claim to have a read range of up to 1 meter for FDX tags and up to 2 meters for HDX tags. Some large antenna arrays can detect PIT tags from several meters away.

The procedure for implanting a PIT tag depends on the size and shape of the tag and the animal. Generally, there are two methods:

injection or surgical insertion. 

Injection: This method uses a hypodermic needle to inject the PIT tag under the animal’s skin, usually into muscle or body cavity. This is suitable for small cylindrical tags and small animals, such as fish.

Surgical insertion: This method requires making an incision on the animal’s body wall, inserting the PIT tag, and then closing the wound with sutures or glue. This is suitable for larger disk-shaped tags and larger animals, such as reptiles. In both methods, the animal should be anesthetized and disinfected before the procedure, and the PIT tag should be scanned before and after implantation to ensure functionality. The wound should be monitored for signs of infection or rejection.

The cost of PIT tags varies depending on the size, shape, and performance of the tags, as well as the quantity and packaging options. According to some sources, PIT tags can cost between $2 and$0.7 each. Handheld scanners or readers can cost between $100 and $1500 each. Other types of scanners or antennas may have different prices. PIT tags are relatively cheap compared to other tracking devices that require batteries or power sources.

The cost of a PIT tag system depends on the number and type of tags, readers, antennas, and accessories needed for the specific application. RFID Tag Maker’s PIT tags cost 0.5-1 $US each, and handheld readers cost 50-100 $US

Some of the benefits of PIT tags are:

Unique identification: Each PIT tag has a unique individual identification number that can be used for accurate animal identification. This number never repeats and is as reliable as a fingerprint.

No harm or disturbance: PIT tags do not harm the animal or disturb its behavior in any way. They are encased in biocompatible glass and can be implanted in any species that needs to be tracked.

Long-term tracking: PIT tags do not need a battery or power source, so they can last for the entire lifespan of the animal. They can also be useful beyond the life of the study organism, as they are resistant to preservatives and animal decomposition.

Remote detection: PIT tags can be detected remotely by scanners or antennas, without requiring recapture of the tagged animal. This can provide valuable research data on animal movement, behavior, survival, and population dynamics.

Low cost: PIT tags are relatively cheap compared to other tracking devices that require batteries or power sources. They can also be deployed in large numbers without spending a lot of money.

PIT tags are Passive Integrated Transponder tags that are used to track fish movement, survival, and growth over time. They are small, pill-shaped devices that contain a radio transponder with a unique code. They are injected into fish using a syringe and can be detected by antennas installed along the river. PIT tags are useful for fish monitoring because they do not require batteries or recapture of the tagged fish. They can provide information on the life cycle and migration patterns of fish, especially for species like salmon that move between freshwater and saltwater¹. PIT tags can also help researchers evaluate the effects of environmental factors, such as dams, water temperature, and predators, on fish survival and behavior.

Some of the downsides to using PIT tags are:

Limited detection range: PIT tags can only be detected when they are within a few meters of a scanner or antenna, which limits the spatial and temporal resolution of the data. Researchers need to install and maintain multiple scanners or antennas to cover a large study area or track long-distance movements.

Tag loss or failure: PIT tags may be lost or expelled from the animal’s body due to tag migration, infection, rejection, or predation. PIT tags may also fail to transmit their code due to damage, interference, or malfunction.

Ethical and welfare issues: PIT tagging may cause some stress, pain, or injury to the animal during implantation or recovery¹². Researchers need to follow ethical and welfare guidelines to minimize the risks and impacts of PIT tagging on the animal’s health and behavior.

A PIT tag conveys a specific code that identifies the tagged animal. The code is usually a 10 or 15 digit alphanumeric sequence that is unique and never repeats. The code can be linked to other information about the animal, such as its species, sex, age, origin, or health status. The code can also provide information on the time and location of the animal’s detection by a scanner or antenna.

PIT tags and GPS trackers are different in several ways. Some of the main differences are:

Power source: PIT tags do not need batteries or power, but GPS trackers do. PIT tags are activated by a scanner’s signal, while GPS trackers use satellites to locate the animal.
Detection range: PIT tags can be detected only when they are within a few meters of a scanner or antenna, while GPS trackers can be detected anywhere with satellite coverage. PIT tags rely on fixed or mobile scanners to record the animal’s presence, while GPS trackers can send real-time updates to a smartphone or computer.
Size and weight: PIT tags are much smaller and lighter than GPS trackers, and can be implanted in very small animals. GPS trackers are usually attached to a collar or harness, and may be too bulky or heavy for some animals.
Cost and subscription: PIT tags are relatively cheap and do not require a subscription fee, but GPS trackers are more expensive and usually require a monthly or yearly fee for data service.

PIT tags can last for the entire lifespan of the animal, as they do not need any internal source of power and are encased in biocompatible glass. They are as reliable as a fingerprint and can be scanned anytime. However, some factors may affect the longevity or functionality of PIT tags, such as tag migration, tag loss, tag failure, or interference from other devices.

Researchers track animals that have migrated to different locations by using various methods, depending on the species, distance, and research question. Some of the methods are: – **Satellite telemetry**: This method uses tags that transmit signals to satellites orbiting the Earth, which then relay the data to ground stations or researchers’ computers. Satellite telemetry can provide global coverage and high-resolution data on animal location, speed, direction, and altitude. – **Radio telemetry**: This method uses tags that emit radio signals that can be detected by receivers or antennas on the ground, on aircrafts, or on satellites. Radio telemetry can provide local or regional coverage and data on animal location and movement. – **GPS telemetry**: This method uses tags that receive signals from GPS satellites and store or transmit the data to receivers or satellites. GPS telemetry can provide high-accuracy data on animal location and movement, but requires more power and may have limited coverage in some areas. – **Light-level geolocation**: This method uses tags that record light levels and time, which can be used to estimate animal location based on sunrise and sunset times. Light-level geolocation can provide coarse data on animal location and movement over long distances, but requires calibration and may have errors due to weather or habitat conditions.

Researchers use various methods to ensure that the data from PIT tags is accurate and reliable. Some of them are: – **Choosing the appropriate tag size and implantation site**: Researchers should select the PIT tag size that is suitable for the study animal, based on its body size, shape, and life history. The tag should not exceed a certain percentage of the animal’s body weight or length, to avoid negative effects on survival, growth, and behavior. The implantation site should also be chosen carefully, to minimize tag migration, loss, or infection. – **Scanning the tags before and after implantation**: Researchers should scan the PIT tags before implantation to verify their functionality and uniqueness. They should also scan the tags after implantation to confirm that they are still working and detectable. – **Using standardized protocols and quality control**: Researchers should follow standardized protocols for PIT tagging procedures, such as anesthesia, disinfection, injection, wound care, and data recording. They should also implement quality control measures, such as checking for duplicate tags, erroneous readings, missing data, or tag failure. – **Using appropriate detection systems and data analysis**: Researchers should use detection systems that are compatible with the PIT tag frequency and performance. They should also calibrate and test the detection systems regularly, to ensure optimal sensitivity and accuracy. They should also use appropriate data analysis methods, such as meta-analysis or meta-regression, to account for heterogeneity and confounding factors among studies.

Researchers use various methods to analyze data from PIT tags, depending on their research questions and objectives. Some of them are: – **Meta-analysis and meta-regression**: These are statistical methods that combine and compare data from multiple studies on the same topic, to estimate the overall effect size and identify sources of heterogeneity or bias. For example, a meta-analysis and meta-regression of PIT tagging effects on mortality and growth of juvenile salmonids was conducted to evaluate the appropriate tag:fish size ratio when tagging salmonids. – **DART PIT Tag Adult Fish Ladders Fallback**: This is a web-based tool that allows users to query and visualize data on adult fish ladder fallback at various dams in the Columbia River Basin. Fallback is defined as the movement of a fish downstream past a dam after having ascended the fish ladder. The tool provides graphics and text summaries of fallback rates, conversion rates, mean travel times, and historical run timing for different species, runs, and rear types. – **Three visualization approaches for communicating and exploring PIT tag data**: This is a report that describes three examples of visualization approaches for PIT tag data: (1) an interactive map that shows the spatial distribution and movement patterns of PIT tagged fish in the Columbia River Basin; (2) an interactive dashboard that allows users to filter and explore data on survival, migration timing, and travel time of PIT tagged fish; and (3) a narrative visualization that tells a story about the life cycle and migration challenges of PIT tagged salmon.

The size of the salmon that can get PIT tagged depends on the size of the PIT tag and the recommended tag-to-body ratio. PIT tags come in different sizes, but the most common ones are 12 mm and 23 mm long. The tag-to-body ratio is the percentage of the tag length relative to the fish total length. A lower ratio is preferable to minimize the potential negative effects of tagging on fish survival and growth. Researchers can follow best practices for tagging juvenile salmonids with tags that are not greater than 17.5% of fish total length (TL). This equates a minimum size threshold of **131 mm TL** for tagging salmonids with 23-mm PIT tags, and 69 mm TL with 12-mm PIT tags.

To install a PIT tag, you need a PIT tag injector, a PIT tag, and a fish to tag. Here are the steps to follow: – Prepare the injector by loading the PIT tag into the needle or cartridge. Make sure the tag is oriented correctly and the needle is sharp and clean. – Anesthetize the fish using an approved anesthetic agent, such as MS-222 or clove oil. Make sure the fish is fully sedated before proceeding. – Hold the fish gently in one hand and locate the injection site on the ventral side of the fish, slightly posterior to the pectoral fins. Avoid injecting near the spine, internal organs, or blood vessels. – Insert the needle into the body cavity at a 45-degree angle and press the plunger to release the tag. Withdraw the needle quickly and smoothly. – Check that the tag is properly implanted by scanning it with a handheld reader. If the tag is not detected, repeat the injection with a new tag. – Record the tag number and any other relevant information about the fish, such as species, length, weight, marks, etc. – Place the fish in clean water to recover from anesthesia. Monitor the fish for any signs of stress or infection. – Dispose of the used needle or cartridge properly.