Breeding performance of passerines in a polluted oasis habitat in southern Tunisia.

We investigated the breeding performance of passerines nesting in the oases close to Gabès city, one of the most industrialised areas in Tunisia, in relation to habitat pollution. Using data on nest survival, clutch size and chick productivity of four insectivorous passerine species, we assessed whether the proximity to Gabès–Ghannouche factory complex of phosphate treatment was associated with reduced breeding performance. Our results show evidence of decreased breeding performance near the factory complex, but this decrease was more perceptible when comparing one oasis situated at the vicinity of the factory complex (polluted oasis) with one control oasis situated tens of kilometres faraway, than when comparing sites situated hundreds of metres apart within the polluted oasis. Overall, these results would indicate that passerines offer suitable models for biomonitoring programmes in the Gabès region and underline once more the usefulness of passerines as reliable biomonitors of terrestrial ecosystems.