Food supplementation protects Magnificent frigatebird chicks against a fatal viral disease

Published source details Sebastiano M., Eens M., Pineau K., Chastel O. & Costantini D. (2019) Food supplementation protects Magnificent frigatebird chicks against a fatal viral disease. Conservation Letters, 12, e12630.
Share Tweet Email

Summary

Provide supplementary food for gannets and boobies to increase reproductive success

A replicated, controlled, before-and-after study in 2017 on Grand Connétable Island, French Guiana (Sebastiano et al. 2019) found that magnificent frigatebird Fregata magnificens chicks provided with supplementary food were less likely to develop a viral infection and less likely to die than unfed chicks, and that supplementary feeding prevented a decline in body condition of initially healthy chicks. Amongst initially healthy individuals, fed chicks were less likely to develop visible signs of herpesvirus infection (0 of 8 chicks) than unfed chicks (7 of 12 initially healthy chicks). The body condition of fed chicks did not significantly change over the feeding period, whilst the body condition of unfed chicks declined (data reported as a body condition index). Amongst initially infected individuals, fed chicks were less likely to die (0 of 18 chicks) than unfed chicks (3 of 15 chicks). The body condition of these chicks did not significantly change over time, whether they were fed or not. Sixty four-month-old frigatebird chicks were studied. Approximately half were provided with supplementary food (shop-bought mackerel mackerel Trachurus trachurus; six times over two-week period). The other half were handled but not fed. The study suggests that food limitation may be driving a herpesvirus outbreak in the focal population. Survival, visible signs of infection, mass and beak length were recorded immediately before and after the feeding period.