National censuses of the Marbled Teal Marmaronetta angustirostris in Spain

National censuses of the globally threatened Marbled Teal were organized in Spain in 1994 and 1995 during the prebreeding, breeding and post-breeding periods. This is the first detailed study of the status and distribution of the species in any country. The censuses revealed a drastic decrease in Marbled Teal numbers in the Guadalquivir marshes in Andalucia (their former stronghold) but numbers in the other main subpopulation in Valencia region are not currently in decline. The average national count (excluding pulli) was 55 in 1994 and 50 in 1995. In 1994, 75% of birds and 86% of broods were recorded in Valencia region, with 23% of birds and 14% of broods in Andalucia and 3% of birds in Murcia. In 1995, 91% of birds and 95% of broods were recorded in Valencia region, with 9% of birds and 8% of broods in Andalucia. The censuses provide evidence of movements from the Guadalquivir marshes to Valencia during the breeding season, in response to severe drought in the former area.