Fig 1.
The distribution of research on elevational shifts in birds.
Countries are coloured by the number of studies from 1 (dark purple) to 7 (yellow), with 0 studies in grey. A single study (Peh 2007) was conducted across Southeast Asia, including Myanmar, Cambodia, Laos, peninsular Malaysia, Thailand, and Vietnam.
Fig 2.
A conceptual framework of elevational ranges and range shifts.
Elevational ranges can be shaped by abiotic factors acting directly or acting indirectly via biotic factors. All of these factors affect the realized niche of a species including its current and future distributions. In addition, intrinsic and extrinsic constraints such as dispersal ability and area availability can prevent species from reaching their predicted elevational ranges.
Fig 3.
Multiple factors shape the elevational ranges of Black-headed Nightingale-Thrush (Catharus mexicanus).
While habitat associations appear to drive the elevational distributions of C. mexicanus, the species is also aggressively dominant over its higher elevation congener Ruddy-capped Nightingale-Thrush (C. frantzii), displaying the importance of interactions between habitat selection and interspecific competition for elevational ranges [141]. Photo credit: Samuel Jones.