Final Round of Nutcracker Transmitters Deployed by Tomback Lab

This past March, University of Colorado Denver faculty, Dr. Diana Tomback, and master’s student, Karina Li, successfully deployed the final round of satellite tags on Clark’s nutcrackers in Yellowstone National Park, as part of a multi-year spatial study that began in 2019. These seven solar-powered and ultra-light tags, attached using back-pack style harnesses that allow unhindered bird movement, will contribute to the Tomback lab’s growing database of long-term and long-distance nutcracker tracking data.

Clark’s nutcrackers are considered a nomadic species, but details of long-distance movements are unclear, including the rate that birds return to areas they’ve previously left. For nutcrackers that are considered residents of a region, known seed transport distances up to 32 km indicate that these birds may require a lot of space for their normal activities throughout the year. However, little is known about nutcracker annual home range size and habitat use during the winter and early spring, when nutcrackers would typically be retrieving their cached seeds.

This uncertainty leads to questions regarding the reproductive potential of whitebark pine seeds. After all, if harvested and “pouched” by a nutcracker, the fate of a single whitebark seed depends on many factors, all of which are determined by where that bird chooses to go next. For those who believe that whitebark and nutcracker conservation go hand-in-hand, information regarding the scale of nutcracker habitat use and the frequency of emigration without return might inform future management of this important species.

The study, which also includes annual transect surveys, is a collaboration among University of Colorado Denver, Ricketts Conservation Foundation (RCF), and Yellowstone National Park resources managers. This study is supported by Yellowstone Forever.

The Tomback lab will begin processing the data from tagged birds and looks forward to hopefully providing insight into these elusive aspects of nutcracker movement. Stay tuned!