Abstract
Auxiliary markers play an essential role in understanding migration, movement, demography, and behavior of migratory birds. Use of such markers relies on the assumption that the markers do not affect the traits of interest. Neck collars, among the most conspicuous of markers, substantially affect risk of harvest, and survival even in the absence of harvest. Effects of less-conspicuous markers, such as colored plastic tarsal bands, are not well understood. We used 30 years (1986–2015) of banding, recovery, and recapture data from the Yukon-Kuskokwim Delta in Alaska, USA, to assess differences in direct band recovery rates (DRRs) between black plastic and brightly colored plastic bands applied to black brant (Branta bernicla nigricans). We also assessed the effect of the color of plastic tarsal bands on annual survival, risks of natural mortality harvest, and fidelity to the breeding colony of adult female black brant. When assessing only DRRs we found that brightly colored bands were recovered at higher rates than black plastic bands in the early 2000s, but DRRs for black bands increased more rapidly through time, resulting in similar DRRs for the 2 band colors at the end of the study. Using a Burnham model structure, our results demonstrated that individuals fitted with colored bands had slightly lower hazards of dying from natural causes or hunting than individuals carrying less-conspicuous black tarsal bands. Differences on annual probability scales were small and credible intervals broadly overlapped between band types, indicating minimal differences between individuals with different band types; however, we could not resolve all confounding in our study design and we suggest that specific studies directed at assessing marker effects are warranted. We encourage education of hunters about their roles as citizen scientists and the potentially detrimental effect of targeting birds with auxiliary markers.
| Original language | English |
|---|---|
| Article number | e22172 |
| Journal | Journal of Wildlife Management |
| Volume | 86 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2022 |
Funding
We thank the numerous individuals that have been involved in banding brant over the last 4 decades and the scores of hunters that reported their bands to the Bird Banding Laboratory. We sincerely appreciate the friendship and logistic support provided by the residents of Chevak, Alaska, for our work on the Yukon‐Kuskokwim Delta. G. C. White, J. Pierce, and V. Patil provided helpful comments on the manuscript. Banding activities were supported by the United States Fish and Wildlife Service, United States Geological Survey Alaska Science Center, the United States Geological Survey Changing Arctic Ecosystem Initiative, Canadian Wildlife Service, Alaska Biological Research, Ducks Unlimited, Phil Jebbia, in memory of Marnie Shepherd, and the National Science Foundation (OPP 9214970, DEB 9815383, OPP 9985931, OPP 0196406, DEB 0743152, DEB 1252656), the Arctic Office of the Bureau of Land Management, and the North Slope Borough departments of Planning and Community Services and Wildlife Management. The Arctic Goose Joint Venture is supporting ongoing efforts to estimate abundance of maritime geese using Lincoln estimators, which in part supported our efforts here. DNK was supported by the James C. Kennedy Wetland and Waterfowl Conservation Endowment.
| Funders | Funder number |
|---|---|
| DEB 1252656, DEB 0743152, OPP 0196406, OPP 9214970, OPP 9985931, DEB 9815383 | |
| Bureau of Land Management | |
Keywords
- Branta bernicla nigricans
- auxiliary marker
- band recovery
- black brant
- harvest
- population dynamics
- population estimation
- survival
- targeting