On the Air: Track the Migration of Delta’s Radio Ringnecks
Ring-necked Duck Project: Year 2 Movement Maps
Year 2 Movement Maps — June 12, 2019
The map below shows where 15 marked ring-necked ducks settled. We suspect that almost all of these birds have initiated nests. The earliest, TWP, was nesting on April 18, while Arden was the latest to start a nest on May 26.
Of the 50 ducks that initiated migration from the wintering sites in Florida, Georgia and South Carolina, most of them moved to the western half of the breeding range to nest. Three ducks died in migration or at their nesting sites. One bird was shot by a Cree Nation man in Manitoba, while Angel and JHP are designated on the map in Saskatchewan and Alberta as stars because they died relatively early, but had been at their final sites long enough to have started nests. Nesting females are certainly most vulnerable to predation at the nest. The transmitters for the two dead hens are still giving locations, but the temperature of the transmitter is low and matches the background environmental temperature — a sure sign the bird is dead.
The map below shows four ducks that are still regularly transmitting locations, but are still on the move. These ringnecks are going to be classified as non-breeders if they don’t settle very soon. We have long suspected that some females don’t initiate nests. The transmitters might increase the probability of a non-breeding event, as has been proven in other duck studies. The most interesting traveler is HMP, a duck that went to Great Slave Lake in the Northwest Territories before heading south 540 miles to her current location in western Saskatchewan.
The map below show the ducks implanted with Ornitela transmitters that we believe are still functioning (21 hens). These newer transmitters collect location data more frequently and much more accurately (GPS accuracy) than the old-school Geotrak transmitters (exclusively used last year, half the transmitters this year). However, the downside of Ornitela transmitters for these remote, northern-nesting ducks is that they send the location data via cell phone signals, so there must be a cell tower near the bird when the transmitter turns on and tries to send location data. If there is no cell tower, then the transmitter stores the location data until the next timed transmission event. So, the map shows a lot of migration tracks, but most end where high human density civilization ends, as does the abundance of cell towers. One surprise is ringneck No. 182657, migrated to northern Ontario and stopped near one of the few cell towers in that fairly remote area.
A huge expected benefit of the Ornitela transmitters is that they last longer than Geotraks, so we are banking on our Ornitela females surviving the summer and then transmitting all the stored locations when they return south in early fall. We hope to get a goldmine of location data that shows the last parts of the spring migration, nesting sites, the sites where birds underwent their annual wing molts (flightless for three to four weeks), and the initial fall migration tracks. Of course, the ducks have to survive and the transmitters have to continue to function. This is the first use of these advanced transmitters for a northern nesting duck, so we have our fingers crossed.
Unfortunately, seven Geotrak transmitters quit reporting as the birds were migrating. These were all re-deployed transmitters, so it looks like recycling transmitters is not very effective.
Tracking maps and information are provided by Dr. Mark McConnell and graduate assistant Tori Mezebish of the University of Georgia.
Why is Delta Waterfowl studying ringnecks?
We simply don’t know much about them.
Delta’s ring-necked duck project is groundbreaking for several reasons. First, ringnecks have been studied far less than any other duck in the top 10 most-harvested species. Second, ringnecks are doing well — both expanding in numbers and in their geographic range. This may be one of the first times that waterfowl researchers are studying a duck on the upswing. We usually focus our research on species in decline, which means we are constantly in crisis management. Third, this is the first time any research team has implanted transmitters in ringnecks to track their movements. The lack of extensive banding data for ringnecks means we know little about migration routes or breeding destinations for this species, although they are an important duck for hunters. Ringnecks are the only diving duck species in the Top 10 of U.S. hunter harvest, and they rank third in the Atlantic Flyway.