title: Contrasting effects of tropical cyclones on the annual survival of a pelagic seabird in the Indian Ocean.
abstract: Tropical cyclones are renowned for their destructive nature and are an important feature of marine and coastal tropical ecosystems. Over the last 40 years, their intensity, frequency and tracks have changed, partly in response to ocean warming, and future predictions indicate that these trends are likely to continue with potential consequences for human populations and coastal ecosystems. However, our understanding of how tropical cyclones currently affect marine biodiversity, and pelagic species in particular, is limited. For seabirds, the impacts of cyclones are known to be detrimental at breeding colonies, but impacts on the annual survival of pelagic adults and juveniles remain largely unexplored and no study has simultaneously explored the direct impacts of cyclones on different life-history stages across the annual life cycle. We used a 20-year data set on tropical cyclones in the Indian Ocean, tracking data from 122 Round Island petrels and long-term capture-mark-recapture data to explore the impacts of tropical cyclones on the survival of adult and juvenile (first year) petrels during both the breeding and migration periods. The tracking data showed that juvenile and adult Round Island petrels utilize the three cyclone regions of the Indian Ocean and were potentially exposed to cyclones for a substantial part of their annual cycle. However, only juvenile petrel survival was affected by cyclone activity; negatively by a strong cyclone in the vicinity of the breeding colony and positively by increasing cyclone activity in the Northern Indian Ocean where they spend the majority of their first year at sea. These contrasting effects raise the intriguing prospect that the projected changes in cyclones under current climate change scenarios may have positive as well as the more commonly perceived negative impacts on marine biodiversity.
authors.affiliation: Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
authors.forename: Malcolm A C
authors.initials: MA
authors.lastname: Nicoll
authors.affiliation: INRA, UMR Ecologie et Santé des Ecosystèmes, Equipe Conservation et Restauration des Ecosystèmes Aquatiques, 65 rue de Saint-Brieuc, 35042, Rennes Cedex, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Nevoux
authors.affiliation: Durrell Wildlife Conservation Trust, Les Augres Manor, Trinity, Jersey, UK.|Mauritian Wildlife Foundation, Grannum Road, Vacoas, Mauritius.
authors.forename: Carl G
authors.initials: CG
authors.lastname: Jones
authors.affiliation: British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
authors.forename: Norman
authors.initials: N
authors.lastname: Ratcliffe
authors.affiliation: National Parks and Conservation Service (Government of Mauritius), Reduit, Mauritius.
authors.forename: Kevin
authors.initials: K
authors.lastname: Ruhomaun
authors.affiliation: Mauritian Wildlife Foundation, Grannum Road, Vacoas, Mauritius.
authors.forename: Vikash
authors.initials: V
authors.lastname: Tatayah
authors.affiliation: Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
authors.forename: Ken
authors.initials: K
authors.lastname: Norris
mesh_terms: D000818:Animals; D044822:Biodiversity; D001717:Birds; D057231:Climate Change; D055867:Cyclonic Storms; D017753:Ecosystem; D006801:Humans; D019156:Indian Ocean
keywords: 
  Pterodroma
  ; adult survival; climate change; hurricane; juvenile survival; migration; mortality; petrel; typhoon