Is commercial reed harvesting compatible with breeding purple herons Ardeapurpurea in the Camargue, southern France

Reedbeds of the Rhone river delta, southern France, constitute an important breeding habitat for purple herons (Ardea purpurea) in Europe. However, th e area of reed harvested commercially has increased in recent years and, si nce 1997, a European Union agri-environmental policy has been implemented t o reconcile economic development with conservation goals for harvested reed beds. Here, we investigate trends in breeding numbers of purple herons and the effect of reed harvesting on reedbed occupancy by herons. A regression model indicates that reedbed use by breeding herons was negatively affected by the reed harvesting pressure. An increase of nearly 50% in the harveste d area following the implementation of the policy was probably caused by su bsidies (from 67 to 100 US$/ha/year) proposed to reed harvesters, although associated with harvesting constraints intended to conserve heron colonies. The difference between the payments with and without colonies does not app ear to have been sufficient to convince reed harvesters to conserve colonie s. A case study showed that one heron colony located in a reserve area pers isted, while another split into smaller colonies following modifications of reedbeds for future reed harvesting. Results suggest that the agri-environ mental policy in its present form has failed to accomplish its primary obje ctive of improving conditions for breeding purple herons in the Camargue. P otential breeding habitat for purple herons have decreased and urgent actio n is needed to protect some reedbeds from intense reed cutting.