Distribution of the community of frugivorous birds along a successional gradient in a tropical dry forest in south-western Mexico

Abstract

Abstract:Few reports have described the relationship between the distribution of frugivorous birds and vegetation successional changes in dry forests. We assessed the abundance and behaviour of frugivorous birds in early, intermediate and mature dry forests in the Balsas river basin, Guerrero, Mexico. We selected nine dry-forest fragments, three fragments per stage, in these three stages of succession. We analysed the vegetation, estimated bird abundances in 10-min count periods, and recorded the way birds process fruits in circular plots (11–15 plots per fragment, 123 plots in total). Birds were classified as seed predators (15% of all individuals in this study), pulp consumers (15%) or legitimate dispersers (70%). Bird abundance was higher in mature forests in the dry season, while abundance and richness of legitimate dispersers and seed predators were positively related to vegetation complexity. Mature forests have a high vegetation complexity and a high cover of Bursera species that produce fruit during the dry season. During the rains, abundance was higher in early-successional sites when the zoochorous plants produced fruit. Legitimate disperser migrants (i.e. Tyrannus vociferans, Myiarchus cinerascens and M. tyrannulus) were widespread, helping the establishment of zoochorous trees such as Bursera spp. in early-successional forests.

Myiarchus flycatchers are the primary seed dispersers of Bursera longipes in a Mexican dry forest: An overlooked coevolutionary process?

“…Although the number of frugivorous birds was lower in the earlier successional stages (Almazán-Núñez et al, 2015), the presence of dispersers that can tolerate disturbed sites ultimately contributes to the regeneration of these forests (Griscom et al, 2007). At a lesser density, the number of seedlings recruited underneath mother plants in the early site was greater.…”

“…The vegetation of the Balsas basin in southwestern Mexico consists mainly of TDF (Rzedowski, 1978), and the dominant arboreal elements belong to the genus Bursera, Burseraceae (Rzedowski, Medina & Calderón de Rzedowski, 2005;Almazán-Núnez et al, 2012), whose fruits are a source of food for resident and migratory frugivorous and insectivorous birds during the dry season (Ortiz-Pulido & Rico-Gray, 2006;Ramos-Ordoñez & Arizmendi, 2011). Furthermore, the distribution of these birds in different successional stages of TDF is related to the presence of these trees (Almazán-Núñez et al, 2015). Although the role of insectivorous birds, such as flycatchers and vireos, as consumers and dispersers of Bursera spp.…”

Peer Review #2 of "Myiarchus flycatchers are the primary seed dispersers of Bursera longipes in a Mexican dry forest (v0.1)"

“…Although the number of frugivorous birds was lower in earlier successional stages (Almazán-Núñez et al, 2015), the presence of migratory dispersers that can tolerate disturbed sites ultimately contributes to the regeneration of these forests (Griscom et al, 2007;Tellería et al, 2014). Despite lower densities, seedlings recruited under nurse plants in the early stage were larger in size than seedlings found at other stages.…”

“…Manuscript to be reviewed insectivorous birds during the dry season (Ortiz-Pulido & Rico-Gray, 2006;Ramos-Ordoñez & Arizmendi, 2011). Furthermore, the distribution of these birds throughout different successional stages of TDF is related to the presence of these trees (Almazán-Núñez et al, 2015).…”

Myiarchusflycatchers are the primary seed dispersers ofBursera longipesin a Mexican dry forest

“…In these forests, the dominant arboreal elements generally belong to the genus Bursera, or Burseraceae ( Rzedowski, Medina Lemos & Calderón de Rzedowski, 2005 ; Almazán-Núñez et al, 2012 ), whose fruits are a food source for resident and migratory frugivorous and insectivorous birds during the dry season ( Ortiz-Pulido & Rico-Gray, 2006 ; Ramos-Ordoñez & Arizmendi, 2011 ). Furthermore, the distribution of these birds throughout different successional stages of TDF is related to the presence of these trees ( Almazán-Núñez et al, 2015 ).…”