1984/02/01 by Ian C. T. Nisbet, Melinda J. Welton · 2 citations
Environmental Science · Agricultural and Biological Sciences · #Avian ecology and behavior #Plant and animal studies #Animal Behavior and Reproduction
paper · doi:10.2307/1367345
openalex publication_date 1984/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We studied the breeding of 125 pairs of Common Terns (Sterna hirundo) in a large colony at Monomoy, Massaschusetts, in 1979. The colony was subjected to predation by one or more Great Horned Owls (Bubo virginianus). The adult terns deserted the colony for 6.5-8 hours each night throughout the season. Although the owl(s) took no adults and only about 20 chicks from our study plots, the terns suffered unusually heavy losses from other causes, including breakage and disappearance of eggs, hatching failures, attacks by ants (Lasius neoniger), chilling of newly-hatched chicks, and predation by Black-crowned Night-Herons (Nycticorax nycticorax). In a 10-year study, most of these causes of egg and chick loss have been associated with nocturnal desertion and predation by Great Horned Owls. Although nocturnal desertion is effective in minimizing owl predation on adults, it leaves the eggs and chicks vulnerable to chilling and predation. In 1979, both direct and indirect effects of predation fell more heavily on terns that laid in May than on terns that laid in June. Differential predation on early nesters tends to offset other factors that presumably favor early nesting.