La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Survival estimates for Royal Terns in southern California
Auteurs :	Charles T. Collins, Auteur ; Paul F. Doherty, Auteur
Type de document :	Article
Dans :	Journal of Field Ornithology (77(3) SUM 2006)
Article en page(s) :	310-314
Langues:	Anglais
Résumé :	Once the most abundant large tern in California, populations of Royal Terns (Thalasseus Maximus) are now greatly reduced statewide. However, these terns are still common in southern California where the population appears to be increasing. We estimated survival of this species, for which no robust estimate of survival is available, using mark-resighting data. Apparent survival of birds > 3 yr of age was estimated to be similar to 0.95; first-year survival was owe at 0.86. Re lower survival estimate for first-year birds probably reflects increased mortality, but could also be a function of permanent emigration by individuals in this age class. The adult survival probability is the highest reported among terns and suggests that survival is playing an important role in the recovery of this tern population and that the current population growth is not solely due to immigration. Improvements in resighting protocols, marking technology, and mark-recapture methods are recommended to better use live resighting, dead recovery, and multistate data.

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