Motus bird tracking is a collaborative research network that tracks the movements of birds across continents using automated radio telemetry. Researchers from all over the world contribute automated radio receiving stations to the Motus network to track nanotags that have been attached to birds. This allows researchers to gain insights into bird migration, behavior, survival, and habitat use that were not possible before.
How does Motus bird tracking work?
Motus bird tracking relies on automated radio telemetry technology. Researchers first capture a bird they want to track and fit it with a tiny radio transmitter called a nanotag. The nanotag weighs less than 2 grams so it does not hamper the bird’s movement. It emits a unique coded radio signal that allows each bird to be individually identified.
The researchers then release the bird. As the bird flies around, its movements are tracked by hundreds of automated radio receiver stations set up by researchers around the world. These stations form the Motus wildlife tracking system. Whenever the tagged bird flies within 15 km of a receiver station, the station detects its unique coded signal. The station records the transmissions and sends the data to researchers via satellite or internet connectivity.
By looking at the signal data from multiple receiving stations, researchers can map out the migratory routes and movements of each tagged bird. The more receiver stations there are, the better the coverage and the more detailed the tracks.
What are the key components of Motus?
There are three key components that make up the Motus wildlife tracking system:
- Nanotags – Tiny radio transmitters that emit coded signals. They are attached to birds to track their movements.
- Automated radio telemetry receivers – Hundreds of automated receiving stations set up around the world to detect signals from tags.
- Motus data platform – Central database that compiles and analyzes data from receivers to generate bird tracks.
What are the advantages of Motus?
Some key advantages of Motus bird tracking include:
- Provides more detailed and extensive bird migration tracks than ever before possible.
- Can track individual birds throughout their annual cycles across continents.
- Low cost – Nanotags are inexpensive compared to satellite tags.
- Can track small songbirds that could not previously be tracked.
- Collaborative network allows data sharing between researchers.
- Can track birds in near real-time throughout their migrations.
How small are the nanotags used in Motus?
The nanotags used in the Motus system are incredibly tiny radio transmitters. They weigh only 0.29 grams to 1.6 grams depending on the model. This is light enough that they can be fitted on birds as small as 10-12 grams, such as many migrating songbirds. The tags represent only 1-5% of the bird’s body weight, so they do not hamper the bird’s movement.
To give an idea of scale, some of the smallest Motus tags are only 8.5 mm long, about the size of a grain of rice. They are far smaller and lighter than satellite tags and allow researchers to track bird species at a finer scale than ever before.
How long do the nanotags last?
The battery life and longevity of Motus nanotags varies by model. Some last for months while the longest-lasting models can continue transmitting for over a year. This provides enough power to track a bird throughout an entire annual migration cycle from breeding to wintering grounds and back again.
Here are the typical lifespans of some common Motus tag models:
Tag model | Battery life |
---|---|
NTQB-6-2 | 50 days |
NTQB-9-2 | 100 days |
NTQB-12-2 | 150 days |
NTQ1-18-1.6 | 365 days |
The lifespan allows collection of data throughout critical periods of a bird’s annual cycle. Researchers select the tag model best suited for the planned duration of the study.
How are nanotags attached to birds?
Attaching the tiny nanotags to birds requires specialized techniques. Most Motus tags are designed to be glued on using a non-toxic latex-based glue. The tag is glued on the bird’s back between the wings in an area with minimal feathers.
Tagging is done by trained researchers when the birds are captured in fine mist nets. The attachment area is first cleaned before applying the fast-drying glue. The tag is positioned and held in place for about a minute until the glue sets. The bird is then released.
The glue is designed to fall off along with the tag after the battery expires and the transmitter stops working. The tag and glue come off when the bird molts that section of feathers. There is no need to recapture the bird to remove the tag.
How many birds are currently tracked by Motus?
The Motus wildlife tracking network has grown rapidly since its beginnings in 2013. As of October 2022, over 850 automated telemetry stations have been set up across 26 countries. More than 4,000 individual birds of over 100 species have been tagged with Motus nanotags.
Some of the major species tracked by Motus include:
- Purple martin
- Bobolink
- Barn swallow
- Wood thrush
- Scarlet tanager
- Long-tailed jaeger
- American golden plover
- Peregrine falcon
The number of birds and receiver stations on the Motus network continues to grow each year as more researchers join the collaborative initiative and tagging expands to new regions.
What are some key findings from Motus research?
The Motus tracking network has led to many new discoveries about bird migration routes and timing, behavior, and survival. Some highlights include:
- Bobolinks were found to take diverse migration routes based on breeding origin, with two main parallel paths over the Americas.
- Purple martins time their migrations to exploit peaks in food resources at stopover sites.
- Wood thrush exhibited lower survival when forced to detour around sites impacted by hurricanes.
- Barn swallows showed high breeding site fidelity but dispersed across Sourth America during winter.
- Golden plovers made rapid long flights direct from Nova Scotia to South America.
These discoveries have only been made possible by higher resolution data from Motus tracking unachievable through other methods. The findings inform conservation efforts for vulnerable migratory species.
What are the limitations of Motus?
While Motus represents a major advance in bird tracking, there are some limitations to be aware of:
- Detection range restricted to about 15 km from a receiver station.
- Less comprehensive coverage across some remote regions.
- Provides less data than GPS tags (only detects presence, not precise locations).
- Does not work well for tracking marine birds far from land.
- Shorter battery life than satellite tags.
Despite this, Motus fills an important niche by allowing large-scale automated tracking of small bird species that could not carry satellite tags. The network coverage and technology continues to improve over time as more users contribute stations.
How can I join the Motus network?
Joining Motus is open and free to interested researchers and wildlife enthusiasts. Simple receiving stations can be set up to expand the coverage of the collaborative tracking network. There are resources on motus.org with guidance to get started tracking birds.
Some ways to join include:
- Setting up your own automated radio telemetry receiving station.
- Applying for training workshops on bird tagging and telemetry.
- Purchasing your own nanotags to tag local birds.
- Volunteering to help established Motus researchers.
- Making monetary donations to support expansion of the Motus system.
With its open collaborative ethos, Motus provides an opportunity for people from many backgrounds to contribute to and learn from an extremely powerful global bird research network.
Conclusion
Motus bird tracking represents a revolutionary system for studying the detailed migrations and movements of birds across continents. The collaborative automated radio telemetry network produces data at scales never before possible. It allows researchers to uncover new insights into the amazing global journeys of small migratory birds.
As tagging expands and more receiver stations are added, Motus will continue to grow as an open research platform. Its discoveries will inform conservation of threatened bird species across the Americas and beyond. With its inclusive open access approach, Motus provides opportunities for people everywhere to engage with and contribute to cutting-edge bird research and conservation.