Seed Dispersal by Bats and Birds in Forest and Disturbed Habitats of Chiapas, Mexico¹

Abstract

We examined seed dispersal by bats and birds in four habitats of the Selva Lacandona tropical rain forest region, Cliiapas, Mexico. The four habitats represented a disturbance gradient: active cornfield, ten-year-old abandoned cornfield, cacao plantation, and forest. Using seed traps examined before sunrise (0400 h) and before sunset (1800 h), we compared volant vertebrate seed dispersal, assuming that seeds found at the end of the night were dispersed by bats and those found at the end of the day were dispersed by birds. We did not find seeds from other frugivores such as monkeys or opossums. In all habitats bats dispersed more seeds than birds. In most months bats also dispersed more seeds than birds, except in December when no seeds were found in the traps. Bats also consistently dispersed more species of seeds than birds, although a x2 comparison showed differences not to be significant. Fifty percent of the spccies represented in the dispersed seeds in all habitats were pioneer species. Cecropia seeds represented a high percentage (up to 87% of those dispersed by bats and up to 83% by birds) of dispersed seeds that fcll in our traps. 'I'hc influence of bars and birds on sccondary successional processes is likely to be fundamental for the establishment of vcgetation. Since bats dispersed more seeds than birds (primarily to disturbed areas and consisting primarily of pioneer species), they are likely to play an important role in successional and restoration processes among habitats as structurally and vegetationally different as cornfields, old fields, cacao plantations, and forest.

Densidade e composição florística do banco de sementes de um trecho de floresta estacional semidecidual no campus da Universidade Federal de Viçosa, Viçosa, MG

“…Sementes do gênero Cecropia têm sido encontradas em vários trabalhos com banco de sementes (FLEMING;HELTHAUS, 1981;HOLTHUIJZEN;BOERBOOM, 1982;DANIEL;JANKAUSKIS, 1989;LEAL-FILHO, 1992;GROMBONE-GUARATINI, 1994;DENSLOW, 1998;MEDLÍN;GAONA, 1999;ARAÚJO et al, 2001;SOUZA 2003) e comumente são dotadas de grande longevidade (HOLTHUIZEN; BOERBOOM 1982), refletindo sua importância no processo de regeneração dessas florestas.…”

Filling data gaps on the diversity and distribution of Amazonian bats (Chiroptera): the case of Amapá, easternmost Brazil

“…Bats, due to their ecological diversity, capacity to respond to habitat changes, and high vagility, which allows bats to move through extensive areas in fragmented landscapes, are good candidates for the evaluation of the consequences of deforestation surrounding those protected areas (e.g. MEDELLÍN & GAONA 1999, GIANNINI & KALKO 2004, THIES & KALKO 2004, ALVES DA SILVA et al 2008. Finally, bats are good models for environmental education programs, which could be executed in the several municipalities influenced by the protected areas.…”

Potencial De Fragmentos Florestais Inseridos Dentro De Floresta De Exóticas Para a Restauração Da Floresta Com Araucárias

“…Este resultado é compatível com os 76,9% de espécies zoocóricas obtidos nos demais levantamentos de FOM utilizados para a comparação do presente estudo (cacSC, pnlSC, criRS e lagSC). Aspectos relacionados à presença de agentes dispersores são fundamentais na ecologia da restauração, nesse sentido, a presença de espécies que apresentam interação com a fauna, assim como as dispersas por animais, é considerada chave para o processo da dinâmica sucessional, conforme discutido por vários autores (MARTÍNEZ-RAMOS; SOTO-CASTRO, 1993;LOISELLE;RIBBENS;VARGAS, 1996;GANADE, 2001;PARROTA;TURNBULL;JONES, 1997;WUNDERLE JUNIOR, 1997;MEDELLÍN;GAONA, 1999). Entretanto, quando levado em conta o número de indivíduos de cada espécie, ptaSC apresentou 38% dos indivíduos com síndrome de dispersão zoocórica, sendo este valor menor ao esperado a partir dos outros estudos, que registraram proporções entre 72,1 e 87,9% (Figura 2b).…”