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.

Do preschool children appreciate numerical value as an abstract property of a set of objects? We tested the influence of stimulus features such as size, shape, and color on preschool children's developing nonverbal numerical abilities. Children between 3 and 5 years of age were tested on their ability to estimate number when the sizes, shapes, and colors of the elements in an array were varied (heterogeneous condition) versus when they did not vary (homogeneous condition). One group of children was tested on an ordinal task in which the goal was to select the smaller of two arrays while another group of children was tested on a match-to-sample task in which the goal was to choose one of two visual arrays that matched the sample in number. Children performed above chance on both homogeneous and heterogeneous stimuli in both tasks. However, while children showed no impairment on heterogeneous relative to homogeneous arrays in the ordering task, performance was impaired by heterogeneity in the matching task. We suggest that nonverbal numerical abstraction occurs early in development, but specific task objectives may prevent children from engaging in numerical abstraction.