Hyper abundant mesopredators and bird extinction in an Atlantic forest island

Abstract

ABSTRACT. Islands can serve as model systems for understanding how biological invasions affect native species. Here we examine the negative effects of mesopredator mammals on bird richness at Anchieta Island, an 826 ha offshore island in the coast of Brazil. Anchieta Island has the highest density of mammals of the entire Atlantic forest, especially nest predators such as marmosets and coatis, introduced more than 20 years ago. This indiscriminate introduction of mammals may have affected directly the bird community, nowadays represented by 100 species comprised mainly by watercrossing birds, being 73 forest-dwelling species. A small component of these remnant bird species nests in tree holes and on the forest floor, null model analysis suggest that birds within these two nest types are under-represented on Anchieta Island. All guilds were affected negatively, but "opportunist insectivorous/omnivorous". Experiments using artificial nests showed a predation of 73% of nests on the floor while only 26% on the mainland. Camera traps recorded predation by coatis, agoutis, and opossums. The restoration of the bird community on this island is highly constrained by the high density of hyper abundant nest predators.

Two-phase extinction of “Southern Hemispheric” birds in the Cenozoic of Europe and the origin of the Neotropic avifauna

“…If a lower predation pressure in the Eocene allowed more exposed nesting sites, arboreal birds are expected to have been seriously affected by the new immigrants (e.g. Sieving 1992; Galetti et al 2009). Although this hypothesis can not be verified through the fossil record, it is notable that extant "caprimulgiform" and apodiform birds, which are among the groups with the most distinctive Southern Hemispheric pattern (Fig.…”

Prey choice of the common vampire bat on introduced species in an Atlantic forest land-bridge island

“…The island is 500-meter away from the mainland and has a long history of human occupation and was called as Ilha dos porcos (Pigs Island) in allusion to the large number of pigs that existed on island (Guillaumon et al , 1989). In the beginning of the last century, the island had a prison and, especially during the years when the prison was active (1904-1955), cattle, pigs, dogs, cats, and the domestic fowl were brought to the island (Galetti et al 2009) in order to sustain its human community that reached over 1,000 residents belonging to 420 families (Guillaumon et al , 1989). The prison and all infrastructures were expropriated and the island was transformed into a state park in 1977, and all the domestic animals were removed (Guillaumon et al , 1989).…”

Nest stolen: the first observation of nest predation by an invasive exotic marmoset (Callithrix penicillata) in an agricultural mosaic

“…Abundant mesopredators can negatively affect avian community by nest predation (Rogers & Caro 1998, Crooks & Soulé 1999, Galetti et al 2009). Nest predation is considered the main cause of nest failure in tropical birds (Skutch 1985, Wilcove 1985, Roper & Goldstein 1997, being more frequent in fragmented and urban areas (Wilcove 1985, Robinson et al 1995.…”

“…Marmosets could compete with other primate species and birds for resources (Negrão & Valladares-Pádua 2006, Ruiz-Miranda et al 2006, LyraNeves et al 2007, depredate birds and eggs (Lyra-Neves et al 2007, Begotti & Landesmann 2008, Galetti et al 2009), hybridize with conspecifics (Alonso et al 1987, Passamani et al 1997, Nunes 2006, Ruiz-Miranda et al 2006, Begotti & Landesmann 2008, and be vehicles for the introduction of new pathogens (Sales et al 2010).…”