Understanding distribution patterns and multitrophic interactions is critical for managing bat‐ and bird‐mediated ecosystem services such as the suppression of pest and non‐pest arthropods. Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest, a systematic review of their impact is still missing. A growing number of bird and bat exclosure experiments has improved our knowledge allowing new conclusions regarding their roles in food webs and associated ecosystem services. Here, we review the distribution patterns of insectivorous birds and bats, their local and landscape drivers, and their effects on trophic cascades in tropical ecosystems. We report that for birds but not bats community composition and relative importance of functional groups changes conspicuously from forests to habitats including both agricultural areas and forests, here termed ‘forest‐agri’ habitats, with reduced representation of insectivores in the latter. In contrast to previous theory regarding trophic cascade strength, we find that birds and bats reduce the density and biomass of arthropods in the tropics with effect sizes similar to those in temperate and boreal communities. The relative importance of birds versus bats in regulating pest abundances varies with season, geography and management. Birds and bats may even suppress tropical arthropod outbreaks, although positive effects on plant growth are not always reported. As both bats and birds are major agents of pest suppression, a better understanding of the local and landscape factors driving the variability of their impact is needed.

Active and passive restoration are two important strategies to aid the recovery of large areas of deforested and degraded tropical lands. Active restoration is where management techniques such as planting seeds or seedlings are implemented, and passive restoration is when no action is taken except to cease environmental stressors such as agriculture or grazing. We compared the habitat quality of active and passive restoration sites with similar landuse histories and times since abandonment for insectivorous birds by measuring vegetation structure, arthropod biomass, and the foraging behavior of three resident bird species in southern Costa Rica. Although vegetation measures such as amount of understory cover and tree species richness and density differed between the two restoration strategies, arthropod biomass and foraging behavioral measures were similar. Our results suggest that while active and passive restoration strategies may lead to different vegetation structures, they may support similar biomass of foliage-dwelling arthropods and be similarly used by foraging insectivorous birds. Passive restoration is generally less costlier than active restoration and, if local and landscape characteristics do not impede recovery, may be a viable alternative from the perspective of birds using the sites.

Both birds and bats are important insect predators in tropical systems. However, the relative influence of birds and bats on insect populations and their indirect effects on leaf damage have not previously been investigated in tropical forest restoration sites. Leaf damage by herbivorous insects can negatively affect the growth and survival of tropical plants and thus can influence the success of tropical forest restoration efforts. We used an exclosure experiment to examine the top-down effects of birds and bats on insects and leaf damage in a large-scale forest restoration experiment. Given the potential influence of tree planting design on bird and bat abundances, we also investigated planting design effects on bird and bat insectivory and leaf damage. The experiment included two planting treatment plots: islands, where trees were planted in patches, and plantations, where trees were planted in rows to create continuous cover. In both types of plots, insect biomass was highest on tree branches where both birds and bats were excluded from foraging and lowest on branches without exclosures where both birds and bats were present. In the island plots, birds and bats had approximately equal impacts on insect populations, while in plantations bats appeared to have a slightly stronger effect on insects than did birds. In plantations, the levels of leaf damage were higher on branches where birds and bats were excluded than on branches where both had access. In island plots, no significant differences in leaf damage were found between exclosure treatments although potential patterns were in the same direction as in the plantations. Our results suggest that both birds and bats play important roles as top predators in restoration systems by reducing herbivorous insects and their damage to planted trees. Tropical restoration projects should include efforts to attract and provide suitable habitat for birds and bats, given their demonstrated ecological importance.

Efforts to restore tropical forest in abandoned pasture are likely to be more successful when bird visitation is promoted because birds disperse seeds and eat herbivorous arthropods that damage leaves. Thus, it is critical to understand bird behavior in relation to different restoration strategies. We measured the likelihood of visitation, number of visits, and duration of visits for all birds and for Cherrie's Tanager (Ramphocelus costaricensis), a common seed disperser, in five sizes of forest restoration patches planted with four tree species in southern Costa Rica. We predicted that the largest patches, and the tree species with the greatest canopy cover, would be visited most frequently and have the longest visits because we assumed that these patch types had the greatest food resources and the lowest predation risk. We found that birds were more likely to visit large patches and the tree species with the highest canopy cover (Inga edulis). Birds visited Inga trees more often and stayed in Inga and Erythrina poeppigiana trees for longer periods of time than in other tree species. We found similar results for Cherrie's Tanagers. Thus, we identified two factors, tree species and patch size, which may be manipulated in restoration projects to increase bird visitation.

Summary1. Active restoration to rehabilitate degraded tropical lands often involves planting tree seedlings, an effective but expensive approach if large areas are planted. Planting small patches of vegetation (tens to a few hundred square metres) has recently been suggested as a more economical restoration technique that mimics natural regeneration processes. However, few studies have examined the consequences of restoration patch size on animals, whose presence and activities are often key to successful ecosystem recovery. 2. We examined the effects of patch size on the foraging behaviour of four resident tropical bird species in a replicated forest restoration experiment in southern Costa Rica. We also measured arthropod abundance and anti-predator vigilance behaviour to assess whether variation in food availability or predation risk could explain patch size effects on foraging behaviour. 3. Prey attack rates were highest, and the effort required to find prey was lowest, in larger patches for three of the four bird species. Arthropod density was approximately twice as great in larger patches (>3500 m 2 ) compared with smaller patches (<350 m 2 ). Evidence for patch size differences in predation risk was more limited but risk may be higher in smaller patches. The results indicate that food availability is the primary mechanism driving patch size effects on foraging behaviour, with predation risk being an additional influence for some species in some years. 4. Synthesis and applications. As demonstrated in this study, patches of tens to a few hundreds of metres squared are likely to provide fewer food resources and potentially less cover from predators for vertebrates that use woody habitat, compared with patches of a few thousand square metres. The more limited resources in smaller patches are likely to have short-term and, potentially, longterm consequences for the fitness of organisms. When considering restoration project design, the potential economic and other benefits of planting in smaller patches must be weighed with the potentially negative ecological effects on some taxonomic groups. To increase the probability that patches provide adequate habitat for the largest number of species, we recommend that when financial resources are available, patches of at least a few thousand square metres be planted.