Habitat and weather conditions effects on long-term breeding population dynamics of five species of herons (Ardeidae) and Glossy ibis (Threskiornithidae) in the Valencian Community, Spain

Valencian wetlands include 65 % of the region's priority habitats and most are protected areas. Waterfowl populations are used as indicators of the state of these environments. We calculated the linear population trend by species, per wetland, of five Ardeidae and Plegadis falcinellus (Threskiornitidae) species using data from the annual census between 1984-2015 for 11 selected wetlands. We constructed a matrix with 42 habitat and meteorological variables, and evaluated the relation between these variables and population trends by a Correspondence Analysis. We found an increasing trend for most species. The populations of the L'Albufera de Valencia Natural Park (NP) differed significantly from the rest. Ardea cinerea, E. garzetta, B. ibis and A. ralloides would be associated with large areas, and also with swamps and rice fields, while A. purpurea and P. falcinellus would be related to environments characterised by rainfall and the level of protection in the area. Rice fields and water management have been important for establishing breeding colonies.