ABSTRACT
Habitat loss is a principal cause of species extinction and, therefore, a key conservation problem as the world’s human population approaches 8 billion. Plovers worldwide are affected by intensified land use, development, and climate change, with each threat posing unique conservation challenges. Understanding how species use habitats is paramount to population management. Plovers occur in open areas on coasts, rivers, lakeshores, grasslands, and tundra in habitats rich in invertebrate prey (e.g., tidal flats, river shorelines, productive grasslands). Habitat selection theory predicts that habitat choices should enhance a bird’s fitness, by increasing foraging rate and decreasing the probability of being killed by a predator. In the breeding season, plovers choose nesting sites near foraging habitat, allowing adults to readily acquire food while tending nests and giving newly hatched chicks access to foraging sites. Plovers also select habitats that allow them to escape predation, which can be difficult in open habitats. They select substrate colors and textures that camouflage them, avoid dense vegetation that can obstruct their view of predators, and select large patches of open area that increase predator search time and effort. Many plovers defend breeding territories, which may set an upper limit on density and limit local population size. Plover population irruptions that occur when new habitat is created by natural or anthropogenic processes are evidence that habitat limits populations. Habitat restoration practices, such as augmenting riverine sandbars or removing vegetation, have been attempted for several plover species with mixed results. Rigorous studies that critically address habitat selection and habitat suitability are needed to complete our understanding of plover habitat ecology. Such studies will provide a scientific underpinning needed to solve increasingly urgent, habitat-related conservation problems.
