Exploring fall migratory patterns of American black ducks using eight decades of band-recovery data

Abstract

As regions of habitat used by migratory waterfowl are subjected to rising anthropogenic pressures, establishing patterns of landscape use during migratory cycles is becoming increasingly important for managing and maintaining populations. Although data collection strategies such as global positioning system (GPS) telemetry promise high‐resolution insight on geographic use of contemporary populations, decades of available band recovery records on many species can provide a low‐cost, multi‐generational alternative for defining broad, historically informed patterns of landscape use. We used nearly a century of band‐recovery data to reconstruct patterns of fall migratory landscape use for American black ducks in the Mississippi and Atlantic flyways. We partitioned band recovery positions by month from September to February and spatially analyzed positions using kernel density estimates (KDEs) to delineate geographic regions used by American black ducks and track changes in landscape use during migration. Additionally, we considered the appropriateness of current management strategies, which treat American black ducks as a single population, by testing for differences in month‐specific landscape use between ducks banded in the Mississippi and Atlantic flyways, and between international management units (ducks banded in Canada or the U.S.). We found that geographic distributions during peak migration faithfully recovered regions previously hypothesized as migratory corridors. Furthermore, regardless of banding origin, we found highly similar distributions and strong flyway fidelity in Atlantic flyway American black ducks. Conversely, American black ducks banded in the Mississippi flyway displayed differences in landscape use between Canadian and U.S. populations, with Canadian ducks significantly more likely to winter in areas within the Atlantic flyway (i.e., migrate between flyways). Flyway‐ and population‐specific patterns of black duck landscape use indicate populations behave more independently than currently treated by management models (including the Adaptive Harvest Management plan), and that population maintenance may be advanced by managing stocks separately. © 2014 The Wildlife Society.

Identifying hybrids & the genomics of hybridization: Mallards & American black ducks of Eastern North America

“…We present the most comprehensive molecular study of mallards and black ducks to date, and are able to differentiate between these two previously closely related and genetically undiagnosable species (Figures and ; Lavretsky, Hernández Baños et al, ). First, whereas recent work identified migratory structure within black ducks (Lavretsky, Miller, Bahn, & Peters, ), we report no identifiable genetic structure within black ducks and suggest this species to be treated as a single genetic population. Conversely, we find evidence for two genetically distinct mallard stocks (Figures and ), which we characterize as western and non‐western.…”

Flyway structure in the circumpolar greater white‐fronted goose

“…Banding, telemetry, bird counts throughout the year, and morphological data have led to the identification of major migratory flyways, which are an integral part of management strategies, particularly in North America. However, the boundaries between these flyways are not always discrete and fidelity to these migratory flyways varies within and across taxonomic groups (Baldassarre, ; Ely & Scribner, ; Guillemain, Sadoul, & Simon, ; Lavretsky, Miller, Bahn, & Peters, ; Madsen, Tjørnløv, Frederiksen, Mitchell, & Sigfússon, ). Although observational data, such as the distribution of band recoveries, frequently suggest high migratory connectivity, it is relatively unknown in many waterfowl species if fidelity to migration flyway reflects philopatry (natal‐ and breeding‐site fidelity), which would promote genetic structure.…”

“…Banding, telemetry, bird counts throughout the year, and morphological data have led to the identification of major migratory flyways, which are an integral part of management strategies, particularly in North America. However, the boundaries between these flyways are not always discrete and fidelity to these migratory flyways varies within and across taxonomic groups (Baldassarre, 2014;Ely & Scribner, 1994;Guillemain, Sadoul, & Simon, 2005;Lavretsky, Miller, Bahn, & Peters, 2014;Madsen, Tjørnløv, Frederiksen, Mitchell, & Sigfússon, 2014).…”

Predicting the initial spread of novel Asian origin influenza A viruses in the continental USA by wild waterfowl

“…As recovery data for waterfowl in North America is primarily collected from hunter harvested birds, our density estimates may be biased by hunter attributes and behaviour and may not completely represent waterfowl movement (Lavretsky, Miller, Bahn, & Peters, 2014). Thus, an underlying assumption in using band-recovery data is that areas and seasons for waterfowl hunting also correspond to waterfowl concentration areas (Buhnerkempe et al, 2016;Farnsworth et al, 2011).…”