Hourly Laying Patterns of the Pearly-eyed Thrasher (Margarops fuscatus) in Puerto Rico

摘要

Temporal aspects of egg deposition are important factors governing avian reproductive success. I report hourly egg-laying patterns of the Pearly-eyed Thrasher (Margarops fuscatus) in the Luquillo Experimental Forest in northeastern Puerto Rico during 1979-2000. Initiatory eggs were laid by early morning (median = 0642 hrs, AST) and almost half of the eggs were laid by 0723 hrs. Many penultimate and eggs completing a clutch, however, were laid later in the morning and some not until mid afternoon (1429 hrs), thus extending egg deposition to 8 hrs. Delayed laying of the last eggs in a clutch may be an adaptive strategy triggering brood reduction to ensure survival of older and more robust siblings during periods of physiological stress and food shortages.