Great Basin Naturalist


The Yellow-headed Blackbird (Xanthocephalus xanthocephalus) nests in marshes and is dependent on emergent vegetation for nest sites. Fluctuating water levels from year to year cause an increase or decrease in the amount of emergent vegetation and affect the time required for the vegetation to become suitable for nesting. Nests built in marshes are very susceptible to wind, rainfall, vegetation growth, and predation. Many nests are abandoned before being used and the mortality of eggs and young is high. The reproductive strategy of the Yellow-headed Blackbird has been selected for flexibility and opportunism to compensate for the unpredictability of the marsh situation.