Scientists have been using traditional radio telemetry to track animals for decades. Radio transmitters are deployed on animals, and transmit radio signals to a receiver; these signals provide information on where the animal is located relative to the receiver. Radio transmitters provide less precise location information than satellite or GPS transmitters, but can also be much smaller, and so can be deployed on smaller-bodied animals.

Unlike traditional radio transmitters, which send signals at different frequencies, new coded radio transmitters (brand names are “nanotags” and “lifetags”) emit signals at the same frequency, but each transmitter’s signal is uniquely identifiable. This allows receiver units to be automated and record transmissions from large numbers of transmitters. These new transmitters can weigh less than a gram (or about 20% of the weight of a penny), so they can be safely deployed on a wide range of species.

We have limited information on the offshore movements of small shorebirds, songbirds, and migratory tree bats. This makes it difficult to predict risk to these species from planned offshore wind energy development. Automated radio tracking could be used for this purpose, but there are few platforms offshore on which to place receivers (see locations of current receivers in the eastern U.S., left).

Putting receivers on offshore wind turbines, site assessment buoys, or other offshore platforms allows us to gather new information on the movements of these animals in the marine environment, including their movements relative to offshore wind farms. Building a network of offshore receivers will take time, but a key first step the development of protocols to help offshore wind developers and regulators integrate this technology into monitoring plans.

Study collaborators developed monitoring protocols for use of automated radio tracking systems at offshore wind farms. This work was conducted via a collaboration with the U.S. Fish and Wildlife Service, Biodiversity Research Institute, University of Rhode Island, and Bird Studies Canada, and was coordinated with a broad group of expert stakeholders. Project components included:

• Protocols to deploy radio transmitters and receivers to help assess risk and understand the impact of offshore wind energy development on birds and bats
• Modeling of animal movements offshore relative to receiver detection ranges, to understand the probability of transmitters being detected as animals fly by a network of receivers
• A free online study design tool to help offshore wind energy developers and regulators determine how many receivers they need to monitor a given offshore wind project, and where those receivers should be placed
• Framework for coordinating offshore monitoring with the Motus Wildlife Tracking System

This project helped make automated radio telemetry a consistent component of monitoring plans for offshore wind farms, and as a result, has greatly improved our understanding of the offshore movements and habitat use of many bird and bat species in the eastern U.S.

Further discussions to help coordinate Motus efforts in relation to offshore wind energy development may occur via the bird and bat subcommittee of the Regional Wildlife Science Collaborative. Please reach out to Pam Loring or Kate Williams for more information.

Stakeholder Workshop: Operating and Calibrating Offshore Motus Stations (July 26, 2022). In conjunction with the State of the Science Workshop on Wildlife and Offshore Wind Energy, Pam Loring (Division of Migratory Birds, U.S. Fish & Wildlife Service) and Erik Carlson (Department of Physics, University of Rhode Island) will provide hands-on demonstrations and discussions on some of the key technical aspects of operating, maintaining, and calibrating automated radio telemetry stations on offshore buoys and wind turbines in coordination with the Motus Wildlife Tracking System. State of the Science Workshop registration is required to attend.

Funding to for this project came from the New York State Energy Research and Development Authority (NYSERDA), with additional support from the U.S. Fish and Wildlife Service Migratory Bird Program. The project was initiated in spring of 2020 and was completed in early 2023.