Breeding biology of the endangered Dupont’s Lark Chersophilus duponti in two separate Spanish shrub-steppes

Abstract

ABSTRACTCapsule: The Dupont’s Lark Chersophilus duponti in Iberia has relatively high breeding success in both core and fragmented habitats, so population declines are more likely to be the result of low juvenile or adult survival.Aims: To measure important aspects of the reproductive biology of one of the most endangered and least known larks: the Dupont’s Lark C. duponti.Methods: We monitored 36 nests in 2 Spanish shrub-steppes, one holding one of the largest European populations (250 pairs) and one composed by fragmented habitat patches holding a smaller population (50 pairs).Results: The breeding season went from late-March to early July. Overall mean (±sd) clutch size was 3.47 ± 0.56, and the number of fledglings per successful nest was 3.0 ± 1.15. Mean nestling period was short (8.2 days). Nests showed similar daily survival rate during the incubation period (0.9750 ± 0.0110) as during the nestling period (0.9545 ± 0.0168), with a mean breeding success of 50%. Predation was the main cause of complete nest failure (83.3% of failed nests in both localities).Conclusion: Breeding parameters did show no significant variation between populations. Breeding success in both sites was generally higher than recorded in previous studies of this and most other lark species, which suggests that breeding success does not compromise long-term viability of these populations. The decline of the studied populations should be explained by other causes, such as a general decrease in habitat quality, habitat loss or habitat fragmentation.