—North American waterfowl winter throughout a large geographic area, and the choice of wintering site has a direct impact on survival and fitness. Climatic and food variables are the most commonly cited factors influencing abundance and distribution of wintering migratory birds, including waterfowl. We conducted stratified aerial surveys at a northern latitude wintering site, Great Salt Lake (G...

Regional and intraseasonal patterns of food use influence populations through impacts on breeding success, survival, and distribution of individuals. We used both traditional foregut content analysis and stable carbon and nitrogen isotopes in liver and leg muscle to determine intraseasonal patterns in the diet of Atlantic brant geese (Branta bernicla hrota) from early winter through spring stag...

The geographic structuring of parasite communities across the range of a single host species can illuminate patterns of host-population connectivity. To determine the location of parasite transmission in a Neotropical migrant bird species, we sampled adult and hatch-year (HY) birds across the breeding and wintering range of the Swainson's thrush (SWTH), an abundant passerine with a migratory di...

The main Hawaiian Islands (MHI) are the principal breeding ground for humpback whales in the North Pacific. Over the past 3 decades, population recovery from whaling-era losses has resulted in a steady increase in the number of whales wintering in Hawaiian waters and a geographic expansion of their distribution in the MHI. Until recently, no existing evidence showed that this expansion included...

There is growing interest in understanding patterns of seasonal migratory connectivity between breeding and wintering sites, both because differences in migratory behaviour can be associated with population differentiation and because knowledge of migratory connectivity is essential for understanding the ecology, evolution and conservation of migratory species. We present the first broad survey...

Temperate ectotherms are expected to benefit from climate change (e.g., increased activity time), but the impacts of climate warming during the winter have mostly been overlooked. Milder winters are expected to decrease body condition upon emergence, and thus to affect crucial life-history traits, such as survival and reproduction. Mild winter temperature could also trigger a state of chronic p...

Determining the factors that influence migratory population abundance has been constrained by the inability to connect events in different periods of the annual cycle. Carry-over effects are events that occur in one season but influence individual success the following season and recent empirical evidence suggests that they may play an important role in migratory population dynamics. Using a lo...

Seasonal migratory birds return to the same breeding and wintering grounds year after year, and migratory long-distance shorebirds are good examples of this. These tasks require learning and long-term spatial memory abilities that are integrated into a navigational system for repeatedly locating breeding, wintering, and stopover sites. Previous investigations focused on the neurobiological basi...