Concept: Eurasian Spoonbill
Local recruitment and immigration play an important part in the dynamics and growth of animal populations. However, their estimation and incorporation into open populations models is, in most cases, problematic. We studied factors affecting the growth of a recently established colony of Eurasian spoonbill (Platalea leucorodia) and assessed the contribution of local recruits, i.e. birds born in the colony, and immigrants, i.e. birds of unknown origin, to colony growth. We applied an integrated population model that accounts for uncertainty in breeding state assignment and merges population surveys, local fecundity and individual longitudinal data of breeding and non-breeding birds, to estimate demographic rates and the relative role of recruitment and immigration in driving the local dynamics. We also used this analytical framework to assess the degree of support for the ‘performance-based’ and ‘conspecific attraction’ hypotheses as possible mechanisms of colony growth. Among the demographic rates, only immigration was positively and significantly correlated with population growth rate. In addition, the number of immigrants settling in the colony was positively correlated with colony size in the previous and current year, but was not correlated with fecundity of the previous year. Our results suggest that the variation in immigration affected colony dynamics and that conspecific attraction likely triggered the relevant role of immigration in the growth of a recently formed waterbird colony, supporting the need of including immigration in population analysis. This article is protected by copyright. All rights reserved.
The parasitic quill mites of the family Syringophilidae (Acariformes: Prostigmata) are recorded on ibises and spoonbills (Pelecaniformes: Threskiornithidae) for the first time. Four new species of the genus Stibarokris Kethley, 1970 are described: 1) S. theristicus Skoracki, Zmudzinski & Unsoeld sp. nov. ex Theristicus caudatus (Boddaert, 1783) from Brazil, 2) S. geronticus Skoracki, Zmudzinski & Unsoeld sp. nov. ex Geronticus calvus (Boddaert, 1783) from South Africa, 3) S. brevisetosus Skoracki & Zmudzinski sp. nov. ex Plegadis falcinellus (L., 1766) from Turkey, and 4) S. plataleus Skoracki & Zmudzinski sp. nov. ex Platalea leucorodia L., 1758 from Austria. Additionally, a key to all described species in the genus is presented, and hypothesis of the Gondwanan origin of syringophilids associated with ibises and spoonbills is briefly discussed.