title: Aggregation of Cricket Activity in Response to Resource Addition Increases Local Diversity.
abstract: Crickets are often found feeding on fallen fruits among forest litter. Fruits and other sugar-rich resources are not homogeneously distributed, nor are they always available. We therefore expect that crickets dwelling in forest litter have a limited supply of sugar-rich resource, and will perceive this and displace towards resource-supplemented sites. Here we evaluate how sugar availability affects cricket species richness and abundance in old-growth Atlantic forest by spraying sugarcane syrup on leaf litter, simulating increasing availability, and collecting crickets via pitfall trapping. We found an asymptotic positive association between resource addition and species richness, and an interaction between resource addition and species identity on cricket abundance, which indicates differential effects of resource addition among cricket species. Our results indicate that 12 of the 13 cricket species present in forest litter are maintained at low densities by resource scarcity; this highlights sugar-rich resource as a short-term driver of litter cricket community structure in tropical forests. When resource was experimentally increased, species richness increased due to behavioral displacement. We present evidence that the density of many species is limited by resource scarcity and, when resources are added, behavioral displacement promotes increased species packing and alters species composition. Further, our findings have technical applicability for increasing sampling efficiency of local cricket diversity in studies aiming to estimate species richness, but with no regard to local environmental drivers or species-abundance characteristics.
authors.affiliation: Programa de Pós-Graduação em Conservação e Manejo de Recursos Naturais, Universidade Estadual do Oeste do Paraná, Cascavel, Paraná, Brazil.
authors.forename: Neucir
authors.initials: N
authors.lastname: Szinwelski
authors.affiliation: Universidade Federal do Triângulo Mineiro, Iturama, Minas Gerais, Brazil.
authors.forename: Cassiano Sousa
authors.initials: CS
authors.lastname: Rosa
authors.affiliation: Programa de Pós-Graduação em Ecologia, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Ricardo Ribeiro de Castro
authors.initials: RR
authors.lastname: Solar
authors.affiliation: Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
authors.forename: Carlos Frankl
authors.initials: CF
authors.lastname: Sperber
mesh_terms: D063147:Animal Distribution; D000818:Animals; D044822:Biodiversity; D001938:Brazil; D004032:Diet; D017753:Ecosystem; D005247:Feeding Behavior; D005518:Food Preferences; D065928:Forests; D006135:Gryllidae / Q000145:classification / Q000502:physiology*; D018515:Plant Leaves; D013045:Species Specificity; D013395:Sucrose
chemical_list: D013395:Sucrose