Once swans are fitted with VHF transmitters (above) they are relocated by scanning with a receiver and antenna.

Secondly, we are placing VHF transmitters on a select sample of swans. The VHF transmitters are attached to a plastic collar that is fitted around the swan's neck. Transmittered swans are then relocated, by scanning with a receiver and antenna. Transmitter life is approximately 18 months and will allow us to track swan for 2 consecutive winters. This phase of the study will provide a second means with which to estimate survival rates and also to track precise movements of tundra swans while they are wintering here in North Carolina.

Lastly, several tundra swans will receive state-of-the-art satellite transmitters. The satellite transmitters weigh 30 grams and like the VHF transmitters, they are also attached to a plastic neck collar. Only adult female swans will receive the satellite transmitters, as they are more likely than males to return to their place of birth to nest each year. Satellite tracking will allow us to monitor movements of swans in extremely remote locations and gain a much better understanding of when the swans make their annual spring and fall migrations. We will also learn where swans are breeding and where major migration stopover points are located. Specific locations for North Carolina wintering swans are not well documented.

The transmitters emit a signal that is picked up by 3 ARGOS satellites orbiting the earth. The signals are relayed to a processing center in France and after converting the location data to latitude and longitude, the information is then relayed to researchers here in the United States. Although the cost of each transmitter with data retrieval is about $4000, this portion of the research project is cost-effective if one considers the costs associated with trapping and field tracking swans in remote locations in Canada and Alaska.

VHF transmitter (left) and a satellite transmitter

The satellite transmitters are programmed such that the frequency of transmissions is greatest during the spring and fall migration period and lowest during the summer and winter when the swans are more stationary. Expected battery life is a minimum of 18 months and should allow for tracking through several migration periods.

In winter 2001 we placed 9 satellite transmitters on adult female swans. Follow the movements of these birds as they make their spring and fall migrations and learn where their breeding sites are located in the remote Arctic. Track their migration here! In winter 2002, we plan to mark additional swans with satellite transmitters and will be adding the movements of these swans to this site in the coming months.