Landscape contexts shape the effects of local factors on the predation of artificial bird nests in cocoa agroforests

Nest predation represents the pivotal threat to bird reproduction in disturbed environments. Although some agricultural systems, such as agroforests, are considered biodiversity-friendly, there is still a lack of information on how factors acting at different spatial scales shape nest predation in these environments. We assessed the effects of landscape (native forest cover and total forest cover) and local factors (number of shade trees, cocoa trees, understory plants, and canopy openness) on the number of predated bird nests in cocoa agroforests. Artificial nests were placed on the ground and in the understory of 30 agroforests located in the Brazilian Atlantic Forest. The agroforests were embedded in three regions with different amounts of native forest remnants and areas designated for cocoa agroforests and cattle pastures. Using GLMM models and the Akaike information criterion, we identified which environmental predictors can determine nest predation in agroforests. We detected that ground nests are more vulnerable to predation than understory nests. We also observed higher nest predation in the region dominated by cocoa agroforestry systems than in the region with high forest cover. Our statistical models evidenced an increase in the number of predated nests in agroforests presenting a high number of understory plants and cocoa trees, particularly when located in deforested landscapes. Our study highlighted that the landscape context in which the cocoa agroforests are situated can modulate the effect of local characteristics on the predation of artificial nests.