Crosswinds During Spring Migration Carryover and Influence the Time Interval Between Arrival and Laying in a...

Area of Science:

• Ecology
• Ornithology
• Animal Behavior

Background:

• Migratory birds face environmental challenges on non-breeding grounds and during migration.
• These events can significantly impact reproductive timing and success upon arrival at breeding sites.
• Carryover effects from migration influence subsequent breeding phenology in songbirds.

Purpose of the Study:

• To investigate the link between migration weather conditions and breeding onset in yellow warblers (Setophaga petechia).
• To determine if crosswinds during migration affect arrival timing, female reproductive condition, or the interval to egg laying.
• To understand how these factors influence overall reproductive success.

Main Methods:

• A 12-year study in Revelstoke, BC, Canada, focusing on yellow warblers.
• Analysis of female arrival dates, body mass, and plasma triglyceride levels.
• Correlation of breeding timing with weather data, specifically crosswind speeds during migration (May 18-31).

Main Results:

• Female yellow warbler arrival dates were not significantly affected by year, growing degree days, or crosswinds.
• Crosswinds experienced 14 days before arrival did not impact female arrival mass or reproductive state.
• Crosswinds influenced the interval between arrival and egg laying; shorter intervals were associated with elevated plasma triglycerides.

Conclusions:

• Carryover effects of migration crosswinds impact yellow warbler breeding timing and reproductive success.
• Both migration wind conditions and female physiological state on arrival independently influence the time to egg laying.
• Delayed breeding due to adverse migration conditions significantly reduces the chances of fledging young.