Wintering Together: Do Migrants Impact Residents? A Literature Review

Area of Science:

• Ecology
• Ornithology
• Conservation Biology

Background:

• Tropical ecosystems host both resident and migratory birds during the dry season.
• Overlapping habitat and resource use suggest potential interspecific competition.
• Previous research has focused on migrants, neglecting the impact on resident birds.

Purpose of the Study:

• To critically evaluate and summarize literature on interactions between migratory and resident birds in tropical ecosystems.
• To assess interspecific competition using Dhondt's criteria.
• To identify knowledge gaps and propose future research directions.

Main Methods:

• Literature review and synthesis.
• Application of criteria for assessing interspecific competition.
• Analysis of impacts on resident bird behavior, diet, and habitat use.

Main Results:

• Resident birds experience interference competition (territoriality, aggression) and altered foraging behavior and microhabitat use.
• Evidence for exploitation competition exists due to dietary overlap, but is not fully understood.
• Methodological inconsistencies and inadequate scales hinder comprehensive understanding.

Conclusions:

• Interspecific competition significantly impacts resident tropical birds.
• Long-term studies are crucial to understand seasonal effects and competitive pressures.
• Understanding these dynamics is vital for conserving resident tropical avifauna, especially endemic species, amidst climate change.