Population viability analyses provide key insights into how alternative conservation efforts can prevent the extinction of a marsh passerine.

Habitat degradation and loss worldwide has led to dramatic population declines in several bird species. Population Viability Analysis (PVA) is a commonly used method to assess the extinction risk of a given species that can also assist in the design of recovery plans by simulating alternative management scenarios. This study conducts a PVA for the Spanish Eastern Iberian Reed Bunting (Emberiza schoeniclus witherbyi) population, with 85% of the estimated 250 breeding pairs confined to three wetlands. Viability analyses were then applied to simulate previously proposed conservation measures with the aim of predicting their potential to improve the subspecies' critical status. Results predicted that the population will halve in the next 20 years and will be reduced to two wetlands, becoming completely extinct in the 2070s. Simulated habitat restorations and predator control succeeded in delaying the estimated extinction time but did not prevent the disappearance of many small localities. Population reinforcements and reintroductions from captive breeding programmes, combined with in situ actions, were the measures predicted to be most effective for the study species' conservation. Urgent measures are required to avoid the short-term extinction predicted, and the findings provided practical guidance for the developing national conservation strategy.