Feeding visit time of fruit-eating birds in Cerrado plants: revisiting the predation risk model

Abstract

Fruiting plants that attract frequent visits by fruit-eating birds tend to be predictable patches for a predator. Consequently, the risk of a predator attack increases the longer a bird stays on a fruiting plant. We tested whether large and cryptic species of fruit-eating birds spend more time per feeding visit than smaller and conspicuous ones in fruiting plants of the Brazilian Cerrado. Data were obtained from the literature for eight fruiting plant species and from field observations of birds feeding on fruits of Zanthoxylum rhoifolium (Rutaceae). We searched for a positive linear relationship between the mean visit time and the total length of the species, considering bird color as a covariate. Feeding visits of the large and cryptic bird species lasted longer than feeding visits of small and conspicuous species. Large birds may be safer from predators because large predators are less common. Cryptic birds may be difficult to be detected by predators and, consequently, may be less likely to be attacked by predators than conspicuous birds. Thus, our results provide support to the hypothesis that vulnerable bird species spend less time foraging in fruiting plants.

Frugivory by birds on Miconia albicans (MELASTOMATACEAE), in a fragment of cerrado in São Carlos, southeastern Brazil

“…The fruiting period coincides with the wet season, when many fruits of other ornithocoric dispersion syndrome plants are available in the same area, like: Davila rugosa Poiret (Dilleniaceae) (Francisco and Galetti, 2002a), Ocotea pulchella (Nees) Mez (Lauraceae) (Francisco and Galetti, 2002b), Pera glabrata (Schott) Baill (Euphorbiaceae) (Francisco et al, 2007), Rapanea lancifolia (Ruiz and Pavon) Mez (Francisco and Galetti, 2001) and Zanthoxylum rhoifolium Lam. (Rutaceae) (Silva et al, 2008).…”

“…Large and cryptic birds are less vulnerable to predators, spending more time on fruiting plants (Pratt and Stiles, 1983;Silva et al, 2008). The heaviest bird observed consuming M. albicans fruits, P. picazuro, showed the largest average visit duration (410,64 ± 222,48 seconds).…”

Anurans of a riparian forest in Sao Carlos, state of Sao Paulo, Brazil

“…The Cerrado fragment at the Universidade Federal de São Carlos is relatively well known in terms of flora (see Oliveira & Batalha 2005, Valenti et al 2008) and fauna (see Roque et al 2003, Motta-Júnior 2006, Silva et al 2008). However, no study has surveyed the local anuran fauna.…”

Dispersión de semillas por aves residentes en bosque ribereño urbano del río Torres, San José, Costa Rica

“…Otros estudios han comprobado la importancia de los tiránidos para la dispersión de semillas en diferentes escenarios latinoamericanos (Leck, 1969;Howe & DeSteven, 1979;Howe & VandeKerckhove, 1979;Barrantes & Pereira, 2002;Amico & Aizen, 2005;Guix, 2007;Silva, Figueiredo & DaSilva, 2008;MorenoVelázquez, 2010;Hernández-Ladrón de Guevara et al, 2012).…”

“…El aporte a la dispersión de semillas por los mirlos o zorzales del género Turdus, ha sido ampliamente documentado (Rougés & Blake, 2001;Barrantes & Pereira, 2002;Amico & Aizen, 2005;Guix, 2007;Silva et al, 2008;Salvande et al, 2011, Hernández-Ladrón de Guevara et al, 2012.…”