How can habitat degradation push extreme migrants over the edge?

Activiteit: Academic presentationAcademic


Long-distance migrations are a major part of the annual cycle of many shorebird species, and often involve multi-day non-stop flights over geographic barriers. These extremely long flights are operated close to the individual’s physiological limits, and are prone to rapid changes in the environmental circumstances that they evolved. This may now be occurring in the East Asian-Australasian Flyway, where the staging mudflats of migratory shorebird, especially those in the Yellow Sea, are rapidly being degraded by human activities. To understand the effects of habitat degradation to the annual routines of great knots, an ‘Endangered’ species listed in the IUCN Red List, we tracked individual migration by satellite telemetry in 2015-2017. We also measured prey availability at major staging mudflats along the Chinese coast by grid sampling. We detected shifts to other staging sites during the northward migration, which could be a plastic response to the drastic declines in local food availability and quality. Moreover, given the current poor food situation in the Yellow Sea, we suggest that it is becoming more crucial that great knots made short fueling stops before reaching the Yellow Sea. This strategy reduces starvation risk upon arrival at the Yellow Sea, and allow time to adjust physiologically to consume prey of lower quality. We discuss how individual flexibility and variations of migration strategies within the population allow adjustments to worsening conditions at staging habitats. Understanding these adaptations and their constraints enable us to define the ‘edge’ of a population collapse.
Evenementstitel137th American Ornithological Society Annual Meeting: Birds on the Edge - Dynamic Boundaries
LocatieAnchorage, United States, AlaskaToon op kaart
Mate van erkenningInternational