Are tortoises important seed dispersers in Amazonian forests?

Autor(es)

Jerozolimski, Adriano ^{[1, 2]} ; Ribeiro, Maria Beatriz N. ^[3] ; Martins, Marcio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Ecol, BR-05508900 Sao Paulo - Brazil

^[2] SMPW, BR-71741804 Brasilia, DF - Brazil

^[3] Inst Nacl de Pesquisas da Amazonia, Dept Ecol, BR-69060020 Manaus, Amazonas - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Oecologia; v. 161, n. 3, p. 517-528, SEP 2009.
• Citações Web of Science: 23

Resumo

According to most studies on seed dispersal in tropical forests, mammals and birds are considered the main dispersal agents and the role played by other animal groups remains poorly explored. We investigate qualitative and quantitative components of the role played by the tortoise Chelonoidis denticulata in seed dispersal in southeastern Amazon, and the influence of seasonal variation in tortoise movement patterns on resulting seed shadows. Seed shadows produced by this tortoise were estimated by combining information on seed passage times through their digestive tract, which varied from 3 to 17 days, with a robust dataset on movements obtained from 18 adult C. denticulata monitored with radio transmitters and spoon-and-line tracking devices. A total of 4,206 seeds were found in 94 collected feces, belonging to 50 seed morphotypes of, at least, 25 plant genera. Very low rates of damage to the external structure of the ingested seeds were observed. Additionally, results of germination trials suggested that passage of seeds through C. denticulata's digestive tract does not seem to negatively affect seed germination. The estimated seed shadows are likely to contribute significantly to the dispersal of seeds away from parent plants. During the dry season seeds were dispersed, on average, 174.1 m away from the location of fruit ingestion; during the rainy season, this mean dispersal distance increased to 276.7 m. Our results suggest that C. denticulata plays an important role in seed dispersal in Amazonian forests and highlight the influence of seasonal changes in movements on the resulting seed shadows. (AU)

• Processo FAPESP: 99/09988-0 - Padrões de atividade e utilização de recursos por jabutis Geocheolone denticulata (Cryptodira: Testudinidae) e o impacto da caça dos índios Kayapó sobre suas populações
• Beneficiário: Adriano Jerozolimski
• Modalidade de apoio: Bolsas no Brasil - Doutorado