Intraspecific variation in exploratory behavior and elevational affinity in a widely distributed songbird.

Area of Science:

• Ecology
• Evolutionary Biology
• Behavioral Ecology

Background:

• Species populations can exhibit significant behavioral and morphometric variations due to differing environmental pressures.
• These variations can lead to the development of distinct adaptive strategies within the same species.
• Understanding these adaptations is crucial for comprehending species' responses to environmental gradients.

Purpose of the Study:

• To quantify variations in exploratory behavior and morphometric traits between low and high elevation rufous-collared sparrow populations in central Chile.
• To evaluate migratory patterns using census data and stable isotope analysis (δ²H) in feather and blood.
• To investigate if differing environmental pressures drive distinct adaptive strategies in these populations.

Main Methods:

• Comparative analysis of exploratory behavior and morphometric traits (e.g., size) between high and low elevation sparrow populations.
• Winter and summer abundance surveys to assess population dynamics.
• Stable isotope analysis (δ²H) of feather and blood samples to infer migratory behavior and habitat use.

Main Results:

• Sparrows at higher elevations were larger and exhibited more intense exploratory behavior compared to those at lower elevations.
• A decline in sparrow abundance was observed during winter at the high-elevation site.
• Similar δ²H values in winter and summer blood samples at the high-elevation site, significantly lower than at the low-elevation site, suggest limited long-distance winter migration.

Conclusions:

• Results support the existence of different adaptive strategies between high and low elevation rufous-collared sparrow populations.
• The findings suggest that high-elevation sparrows likely remain in refuge habitats at similar elevations during winter.
• Integrating behavioral, morphometric, and stable isotope data provides a robust approach to assessing adaptive differences across environmental gradients.