Ground nesting by arboreal American robins (Turdus migratorius)

Abstract

Locating a site suitable for successful reproduction is an essential task of many mobile organisms. Breeding animals often need to find denning, burrowing, or other nesting locations that simultaneously provide access to nearby resources and limit resource competition while, critically, also protect both the parents and developing offspring from adverse weather/microclimates, parasites, competitors, and/or predators (Mainwaring et al., 2016). These constraints have led to many species evolving to use relatively consistent breeding sites and substrates among individuals. Accordingly, most songbird species can be readily classified into categories such as tree, ground, or cavity nesters (Nagy et al., 2019), although some species show plasticity in nest site preference depending on the shifting habitat structure (e.g., song sparrows (Melospiza melodia) raise their nest height from the ground to shrubs as the breeding season progresses: Morse Nice, 1931). Other species may shift their nest placement to avoid predators (e.g., orange-crowned warblers (Vermivora celata) place nests increasingly off the ground and into shrubs on islands where ground predators are more prevalent and avian predator pressure is reduced: Peluc et al., 2008). Observing such instances of nest-site switching allows us to address both the drivers of this behavioral plasticity and their implications for reproductive success.American robins (Turdus migratorius, hereafter "robin") are an iconic backyard songbird species in North America that build a bulky mud-lined nest off the ground in trees, shrubs, and human-made

Winged Wonders and Lush Landscapes: Exploring the Harmony between Birds and Forests

“…As a result, birds of forested lands are encountering increased habitat loss from indiscriminate destruction of forest cover through anthropogenic disturbances, including expansion of unsustainable agriculture, illegal settlements, and expansion of grazing lands [95,96].…”