VARIATION DES EFFECTIFS NICHEURS DE HÉRONS POURPRÉS Ardea purpurea SUR LE LITTORAL MÉDITERRANÉEN FRANÇAIS EN RELATION AVEC LA PLUVIOMÉTRIE SUR LES QUARTIERS D’HIVERNAGE

Christophe Barbraud (1) , Heinz Hafner (2)

1 CEBC - Centre d'Études Biologiques de Chizé
2 Station Biologique de la Tour du Valat

An increasing number of studies have demonstrated a link between some demographic parameters and rainfall indices for some Palearctic- African migrant. Such relationships have been shown for the Purple heron in several European populations except in France, where variations in the population size seem not to depend on African wintering conditions. Here, we reanalyse long term population data on the Purple heron breeding in southern France in relation to a Sahel rainfall index in the light of recent findings on factors affecting breeding numbers on the breeding grounds. After taking into account these factors in the analysis, there was a positive relationship between interannual population variation and the Sahel rainfall index in September (r = 0.653, n = 15, P = 0.008) and October (r = 0.643, n = 15, P = 0.01) over the period 1981-1998. The breeding population increased following high automnal rainfall in the Sahel. These findings are in agreement with previous studies on this species and highlight the necessity to take into account local confounding factors when investigating such broadscale relationships.

Domaines: Biodiversité et Ecologie

Christophe Barbraud, Heinz Hafner. VARIATION DES EFFECTIFS NICHEURS DE HÉRONS POURPRÉS Ardea purpurea SUR LE LITTORAL MÉDITERRANÉEN FRANÇAIS EN RELATION AVEC LA PLUVIOMÉTRIE SUR LES QUARTIERS D’HIVERNAGE. Alauda, 2001. ⟨hal-01312423⟩