Evolution of leapfrog migration: A test of competition-based hypotheses.

Area of Science:

• Ornithology
• Ecology
• Animal Migration

Background:

• Leapfrog migration, where breeding and wintering latitudes are reversed between populations, is a common avian phenomenon.
• Competition for resources is hypothesized as a driver, with theories involving body size, prior occupancy, and spring weather predictability.

Purpose of the Study:

• To test hypotheses explaining leapfrog migration in common ringed plovers.
• To investigate the roles of body size, prior occupancy, and spring predictability in driving migration patterns.

Main Methods:

• Combined morphometric, migration, and weather data from four common ringed plover populations.
• Analyzed breeding and wintering distributions, body size variation, and arrival timing of meteorological spring.

Main Results:

• Body size did not correlate with wintering distribution or explain competitive exclusion.
• Spring predictability did not align with observed wintering ranges.
• Populations wintering in Europe arrived earlier than those in Africa.

Conclusions:

• Competitive exclusion via body size does not explain leapfrog migration.
• "Spring predictability" hypothesis is not supported by the data.
• Competitive exclusion mediated by prior occupancy remains a viable hypothesis for leapfrog migration.