Species characteristics associated with extinction vulnerability and nestedness rankings of birds in tropical forest fragments

Abstract

Following habitat fragmentation, species are predicted to go locally extinct from remnant patches in a predictable order due to differential extinction vulnerabilities. This selective species loss will result in nested distributions of species such that species found in depauperate patches will also tend to be found in larger, more speciose patches. Therefore, it should be possible to determine the relationship between species-specific characteristics and extinction vulnerability by comparing the order in which species are nested [i.e. nestedness ranking (NR)] with various natural history characteristics available from the literature and/or collected in the field. In this study, we investigate the relationship between the NRs of 41 resident forest-interior bird species inhabiting recently isolated landbridge islands in Lago Guri, Venezuela, with a large number of natural history characteristics collected from the literature (regional abundance, body length, habitat specificity, trophic guild, sensitivity to disturbance, range size) and from the field (local population density). In a comparison of the best regression models generated using just variables available through the literature (i.e. no local population density) with the best model generated using all possible variables, we found that the inclusion of field-based data significantly improved the amount of variation explained. The best overall model (r 2 = 0.40, Po0.001) included body size, habitat specificity, zoogeographic distribution (a measure of range size) and local population density as predictors of NR. Understanding the factors that influence extinction vulnerability has important implications for conservation and could be used to help direct management efforts.

Structure of bird communities in eucalyptus plantations: nestedness as a pattern of species distribution

“…According to Mendonça-Lima (2012) the loss or replacement of species in silviculture areas seem to determine nestedness. Feeley et al (2007) explained the occurrence of nestedness by selective loss of species, i.e., only species with fewer habitat requirements are able to "transpose" the conditions imposed by silviculture. Furthermore, other processes such as local immigration and species extinction may result in nestedness (Ulrich et al, 2009).…”

Ecological Traits of Phyllostomid Bats Associated with Sensitivity to Tropical Forest Fragmentation in Los Chimalapas, Mexico

“…The identification of these traits is critical for designing species-specific conservation strategies [12,14,15]. However, the relative importance of each attribute is unclear [4,16,17] and varies among taxa [12,13,[18][19][20]. Furthermore, methodological approaches do not consider the high degree of multicolinearity or synergistic interactions among these traits [16,17].…”

Ecological impacts of tropical forest fragmentation: how consistent are patterns in species richness and nestedness?

“…There is an extensive literature on avian responses to fragmentation, as well as data on ecological traits (e.g. [14,52,53]), which we use to examine whether there is a consensus in SARs and patterns of nestedness among a wide range of tropical bird studies and among different feeding guilds. Most studies to date have focused on single taxa, but it is unclear the degree to which species and taxon responses are idiosyncratic or predictable [54,55].…”

“…[10][11][12][13][14]) and insects [15 -20]. Many previous studies have focused on describing changes in species richness following fragmentation, and have typically assessed the conservation value of forest remnants through the use of species -area relationships (SARs), which measure the rate at which species richness is lost as fragment size declines [21].…”