In migratory animals, high mobility may reduce population structure through increased dispersal and enable adaptive responses to environmental change, whereas rigid migratory routines predict low dispersal, increased structure, and limited flexibility to respond to change. We explore the global population structure and phylogeographic history of the bar-tailed godwit, Limosa lapponica, a migratory shorebird known for making the longest non-stop flights of any landbird. Using nextRAD sequencing of 14,318 single-nucleotide polymorphisms and scenario-testing in an Approximate Bayesian Computation framework, we infer that bar-tailed godwits existed in two main lineages at the last glacial maximum, when much of their present-day breeding range persisted in a vast, unglaciated Siberian-Beringian refugium, followed by admixture of these lineages in the eastern Palearctic.
View Article and Find Full Text PDFThe pace and scale of environmental change represent major challenges to many organisms. Animals that move long distances, such as migratory birds, are especially vulnerable to change since they need chains of intact habitat along their migratory routes. Estimating the resilience of such species to environmental changes assists in targeting conservation efforts.
View Article and Find Full Text PDFPresent-day ecology and population structure are the legacies of past climate and habitat perturbations, and this is particularly true for species that are widely distributed at high latitudes. The red knot, Calidris canutus, is an arctic-breeding, long-distance migratory shorebird with six recognized subspecies defined by differences in morphology, migration behavior, and annual cycle phenology, in a global distribution thought to have arisen just since the last glacial maximum (LGM). We used nextRAD sequencing of 10,881 single-nucleotide polymorphisms (SNPs) to assess the neutral genetic structure and phylogeographic history of 172 red knots representing all known global breeding populations.
View Article and Find Full Text PDFGlobally, bird migration is occurring earlier in the year, consistent with climate-related changes in breeding resources. Although often attributed to phenotypic plasticity, there is no clear demonstration of long-term population advancement in avian migration through individual plasticity. Using direct observations of bar-tailed godwits (Limosa lapponica) departing New Zealand on a 16,000-km journey to Alaska, we show that migration advanced by six days during 2008-2020, and that within-individual advancement was sufficient to explain this population-level change.
View Article and Find Full Text PDFThe gene Clock is a key part of the Core Circadian Oscillator, and the length of the polyglutamine (poly-Q) repeat sequence in Clock (ClkpolyQcds) has been proposed to be associated with the timing of annual cycle events in birds. We tested whether variation in ClkpolyQcds corresponds to variation in migration timing in the bar-tailed godwit (Limosa lapponica baueri), a species in which individuals show strong annual consistency in their migration timing despite the New Zealand population migrating across a 5-week period. We describe allelic variation of the ClkpolyQcds in 135 godwits over-wintering in New Zealand (N.
View Article and Find Full Text PDFKubelka (Reports, 9 November 2018, p. 680) claim that climate change has disrupted patterns of nest predation in shorebirds. They report that predation rates have increased since the 1950s, especially in the Arctic.
View Article and Find Full Text PDFThe behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring).
View Article and Find Full Text PDFBackground: Geolocators are useful for tracking movements of long-distance migrants, but potential negative effects on birds have not been well studied. We tested for effects of geolocators (0.8-2.
View Article and Find Full Text PDFPhenotypic differences among individuals can arise during any stage of life. Although several distinct processes underlying individual differences have been defined and studied (e.g.
View Article and Find Full Text PDFFlexibility in scheduling varies throughout an organism's annual cycle, reflecting relative temporal constraints and fitness consequences among life-history stages. Time-selection can act at different scales, either by limiting the range of alternative strategies in the population, or by increasing the precision of individual performance. We tracked individual bar-tailed godwits Limosa lapponica baueri for two full years (including direct observation during non-breeding seasons in New Zealand and geolocator tracking of round-trip migrations to Alaska) to present a full annual-cycle view of molt, breeding, and migration schedules.
View Article and Find Full Text PDFCapture myopathy is a complication of capture and handling in many species of birds and mammals. Muscular necrosis leads to ataxia, paralysis, and pain, whereas metabolic disturbances can result in death. We conducted an opportunistic clinical trial on Bar-tailed Godwits (Limosa lapponica baueri) that developed capture myopathy after a cannon-net capture in New Zealand in October 2008.
View Article and Find Full Text PDFDespite clear benefits of optimal arrival time on breeding grounds, migration schedules may vary with an individual bird's innate quality, non-breeding habitat or breeding destination. Here, we show that for the bar-tailed godwit (Limosa lapponica baueri), a shorebird that makes the longest known non-stop migratory flights of any bird, timing of migration for individual birds from a non-breeding site in New Zealand was strongly correlated with their specific breeding latitudes in Alaska, USA, a 16,000-18,000 km journey away. Furthermore, this variation carried over even to the southbound return migration, 6 months later, with birds returning to New Zealand in approximately the same order in which they departed.
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