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Migratory connectivity describes the extent to which migratory species' populations are connected throughout the annual cycle. While recognized as critical for understanding the population dynamics of migratory species and conserving them, empirical evidence of links between migratory connectivity and population dynamics are uncommon. We analyzed associations between spatiotemporal connectivity and differential population trends in a declining and endangered migratory shorebird, the far eastern curlew (Numenius madagascariensis), with multiyear tracking data from across the Australian nonbreeding grounds. We found evidence of temporal and spatial segregation during migration and breeding: curlew from southeast Australia initiated northward migration earlier, arrived at breeding sites earlier, and bred at lower latitudes than curlew from northwest Australia. Analysis of land modification intensity revealed that populations from southeast Australia face greater human impacts compared to those from northwest Australia at both the breeding and nonbreeding grounds, a pattern that aligns with steeper population declines in southeast Australia. This alignment between migratory connectivity, human impacts, and differential population change highlights the importance of a full annual cycle approach to conservation that includes mitigating threats on the breeding grounds and better protecting nonbreeding habitats in Australia where far eastern curlew spend over half of each year. [ABSTRACT FROM AUTHOR]

Shorebird expeditions have been run in the Northern Territory sporadically since 1995 and have focussed on birds from five sites along the Top End coastline. Over the years, there has been 2510 shorebirds caught from 19 species from a combination of cannon netting and mist netting. From 2014 onwards, we applied engraved leg-flags to shorebirds and this has allowed for a more detailed understanding of site fidelity on the non-breeding grounds and migration pathway connectivity. Since that time, there has been more than 3403 leg-flag resightings from six countries in the East Asian-Australasian Flyway. In 2018, the objective of the expedition was to capture the critically endangered Far Eastern Curlew Numenius madagascariensis to attach GPS tracking devices to birds to learn about their local movements on the non-breeding grounds of Australia. One GPS tag was deployed on a Curlew during this expedition. Shorebird catching expeditions allow researchers to collect useful data on age demographics within populations, and to target species for more detailed studies such as those on movements of birds. [ABSTRACT FROM AUTHOR]

Migratory species can travel tens of thousands of kilometers each year, spending different parts of their annual cycle in geographically distinct locations. Understanding the drivers of population change is vital for conserving migratory species, yet the challenge of collecting data over entire geographic ranges has hindered attempts to identify the processes leading to observed population changes. Here, we use remotely sensed environmental data and bird count data to investigate the factors driving variability in abundance in two subspecies of a long‐distance migratory shorebird, the bar‐tailed godwit Limosa lapponica. We compiled a spatially and temporally explicit dataset of three environmental variables to identify the conditions experienced by each subspecies in each stage of their annual cycle (breeding, non‐breeding and staging). We used a Bayesian N‐mixture model to analyze 18 years of monthly count data from 21 sites across Australia and New Zealand in relation to the remote sensing data. We found that the abundance of one subspecies L. l. menzbieri in their non‐breeding range was related to climate conditions in breeding grounds, and detected sustained population declines between 1995 and 2012 in both subspecies (L. l. menzbieri, –6.7% and L. l. baueri, –2.1% year–1). To investigate the possible causes of the declines, we quantified changes in habitat extent at 22 migratory staging sites in the Yellow Sea, East Asia, over a 25‐year period and found –1.7% and –1.2% year–1 loss of habitat at staging sites used by L. l. menzbieri and L. l baueri, respectively. Our results highlight the need to identify environmental and anthropogenic drivers of population change across all stages of migration to allow the formulation of effective conservation strategies across entire migratory ranges. [ABSTRACT FROM AUTHOR]