Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.

Breeding is a key component of the life history of birds. Documenting diverse aspects of their breeding biology provides valuable natural history data that can be used to address questions of evolutionary, ecological, or conservation significance. Despite its importance, this information is scarce for most Neotropical species. We compiled 1180 breeding records corresponding to 325 bird species for the period 2000–2021, through an in‐depth review of photo or video records from Peru, sourced from Macaulay Library and iNaturalist platforms. We determined the geographical distribution of the breeding records, described patterns of activity and nesting behavior (i.e., host plant preference and clutch size), and explored the timing of breeding. Our study represents one of the few efforts to provide nationwide data on breeding birds in the Neotropical region. We also offer broad taxonomic coverage for further studies interested in testing hypotheses on the variation of reproductive traits and timing at both local and regional scales. The complete data set for this abstract published in the Data Article section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2024-07.1/jalter-en .

Leaf and wood functional traits of trees are related to growth, reproduction, and survival, but the degree of phylogenetic conservatism in these relationships is largely unknown. In this study, we describe the variability of strategies involving leaf, wood and demographic characteristics for tree genera distributed across the Amazon Region, and quantify phylogenetic signal for the characteristics and their relationships. Leaf and wood traits are aligned with demographic variables along two main axes of variation. The first axis represents the coordination of leaf traits describing resource uptake and use, wood density, seed mass, and survival. The second axis represents the coordination between size and growth. Both axes show strong phylogenetic signal, suggesting a constrained evolution influenced by ancestral values, yet the second axis also has an additional, substantial portion of its variation that is driven by functional correlations unrelated to phylogeny, suggesting simultaneously higher evolutionary lability and coordination. Synthesis. Our results suggest that life history strategies of tropical trees are generally phylogenetically conserved, but that tree lineages may have some capability of responding to environmental changes by modulating their growth and size. Overall, we provide the largest‐scale synopsis of functional characteristics of Amazonian trees, showing substantial nuance in the evolutionary patterns of individual characteristics and their relationships. Read the free Plain Language Summary for this article on the Journal blog.

El presente trabajo informa sobre las plantas alimenticias utilizadas por 19 especies de mariposas diurnas (Lepidoptera) que ocurren en el Centro de Investigaciones Allpahuayo-Mishana y la Comunidad Campesina de San Rafael, Loreto, Perú. Se reportan 23 especies y 1 híbrido de angiospermas empleadas por las mariposas investigadas. Veintiún plantas eran hospedadoras de las larvas y 5 nectaríferas de los adultos; Passiflora coccinea Aubl. y Passiflora edulis Sims eran a la vez hospederas y nectaríferas. Las familias de plantas más utilizadas por las mariposas en estado larval fueron Solanaceae, Passifloraceae, Fabaceae y Aristolochiaceae.

Dominance of neotropical tree communities by a few species is widely documented, but dominant trees show a variety of distributional patterns still poorly understood. Here, we used 503 forest inventory plots (93,719 individuals ≥2.5 cm diameter, 2609 species) to explore the relationships between local abundance, regional frequency and spatial aggregation of dominant species in four main habitat types in western Amazonia. Although the abundance‐occupancy relationship is positive for the full dataset, we found that among dominant Amazonian tree species, there is a strong negative relationship between local abundance and regional frequency and/or spatial aggregation across habitat types. Our findings suggest an ecological trade‐off whereby dominant species can be locally abundant (local dominants) or regionally widespread (widespread dominants), but rarely both (oligarchs). Given the importance of dominant species as drivers of diversity and ecosystem functioning, unravelling different dominance patterns is a research priority to direct conservation efforts in Amazonian forests.