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opennotspecifiedDec 2012View details →

FIGURE 2 in On The Use Of 10-Minute Point Counts And 10-Species Lists For Surveying Birds In Lowland Atlantic Forests In Southeastern Brazil

FIGURE 2: Species accumulation curves and estimation curves using the Chao1 estimator for bird communities in the municipalities of Bertioga and Santos, state of São Paulo, southeastern Brazil, using MacKinnon lists (one sample = one 10-species list) and point counts (one sample = one point count). Each curve represents the average values of 50 randomizations of the sampling order.

opennotspecifiedDec 2011View details →

FIGURE 2 in Birds From Cerradão Woodland, An Overlooked Forest Of The Cerrado Region, Brazil

FIGURE 2: Accumulation curve for number of bird species in relation to sample effort from a cerradão fragment in the municipality of Bauru, São Paulo State, Brazil. Sample accumulation order was randomized 50 times.

opennotspecifiedDec 2011View details →

FIGURE 1 in Birds From Cerradão Woodland, An Overlooked Forest Of The Cerrado Region, Brazil

FIGURE 1: Locations (n = 49) where cerradão bird surveys have been conducted. An arrow indicates the region of Bauru, São Paulo State, southern Brazil. Cerrado is represented by light gray, while Pantanal is represented by dark gray.

opencc-zeroDec 2013View details →

Data from: Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distributions and predict potential future range shifts under a scenario of climate warming. We found well-supported genetic and morphologic clusters corresponding to the mountain ranges where populations were sampled, with 43% of all alleles being restricted to single mountains. Our data suggest that large-scale and long-term geographic isolation on mountain islands caused genetically and morphologically distinct population clusters in Z. poliogaster. However, major genetic and biometric splits were not correlated to the geographic distances among populations. This heterogeneous pattern can be explained by past climatic shifts, as highlighted by our SDM projections. Anthropogenically fragmented populations showed lower genetic diversity and a lower mean body mass, possibly in response to suboptimal habitat conditions. On the basis of these findings and the results from our SDM analysis we predict further loss of genotypic and phenotypic uniqueness in the wake of climate change, due to the contraction of the species' climatic niche and subsequent decline in population size.

opencc-zeroDec 2015View details →

Data from: Rodent-avoidance, topography and forest structure shape territory selection of a forest bird

Background - Understanding the factors underlying habitat selection is important in ecological and evolutionary contexts, and crucial for developing targeted conservation action in threatened species. However, the key factors associated to habitat selection often remain poorly known. We evaluated hypotheses related to abiotic and biotic factors thought to affect territory selection of the wood warbler Phylloscopus sibilatrix, a passerine living in an unpredictable environment owing to irregular rodent outbreaks and showing long-term declines particularly in Western Europe. Results - Comparing breeding territories to unoccupied areas located close-by revealed that territory occupancy in north-western Switzerland was positively related to slope steepness (topographic hypothesis supported) as well as to numbers of tussocks and trees, respectively, while it showed a unimodal relationship to cover of herb layer (forest structure hypothesis supported). Furthermore, a strong negative correlation between breeding territory occupancy and rodent numbers was found, suggesting that wood warblers avoid areas with high rodent densities (rodent-avoidance hypothesis supported). Comparing breeding territories to abandoned territories showed that breeding territories were located on steeper slopes (topography hypothesis supported), at larger distance from the forest edge (anthropogenic disturbance hypothesis supported) and harboured more trees (forest structure hypothesis supported) than abandoned territories. Conclusions - Aside from structural and topographic features of the habitat, wood warblers are affected by rodent numbers when settling, making habitat selection unpredictable from year to year. Forestry practices promoting relatively high tree densities, few bushes and an intermediate low-growing ground vegetation cover would enhance habitat quality for this declining passerine. In contrast, forestry practices aiming at increasing light in forests (selective thinning, group-felling) or keeping forest stands permanently covered with shrubs, bushes and trees of various sizes (continuous cover forestry) do not benefit the wood warbler.

opencc-zeroDec 2014View details →

Data from: Patterns and predictors of β-diversity in the fragmented Brazilian Atlantic forest: a multiscale analysis of forest specialist and generalist birds

1. Biodiversity maintenance in human-altered landscapes (HALs) depends on the species turnover among localities, but the patterns and determinants of β-diversity in HALs are poorly known. In fact, declines, increases, and neutral shifts in β-diversity have all been documented, depending on the landscape, ecological group and spatial scale of analysis. 2. We shed some light on this controversy by assessing the patterns and predictors of bird β-diversity across multiple spatial scales considering forest specialist and habitat generalist bird assemblages. 3. We surveyed birds from 144 point counts in 36 different forest sites across two landscapes with different amount of forest cover in the Brazilian Atlantic forest. We analysed β-diversity among points, among sites, and between landscapes with multiplicative diversity partitioning of Hill numbers. We tested whether β-diversity among points was related to within-site variations in vegetation structure, and if β-diversity among sites was related to site location and/or to differences among sites in vegetation structure and landscape composition (i.e. percent forest and pasture cover surrounding each site). 4. β-diversity between landscapes was lower than among sites and among points in both bird assemblages. In forest specialist birds, the landscape with less forest cover showed the highest β-diversity among sites (bird differentiation among sites), but generalist birds showed the opposite pattern. At the local scale, however, the less forested landscape showed the lowest β-diversity among points (bird homogenisation within sites), independently of the bird assemblage. β-diversity among points was weakly related to vegetation structure, but higher β-diversity values were recorded among sites that were more isolated from each other, and among sites with higher differences in landscape composition, particularly in the less forested landscape. 5. Our findings indicate that patterns of bird β-diversity vary across scales and are strongly related to landscape composition. Bird assemblages are shaped by both environmental filtering and dispersal limitation, particularly in less forested landscapes. Conservation and management strategies should therefore prevent deforestation in this biodiversity hotspot.

Figure 2 in Diet of understorey birds in two Atlantic Forest areas of southeast Brazil

Figure 2. Principal structures observed in the faecal contents of the captured birds: Heads of: Hemiptera Heteroptera (1), Hymenoptera non-Formicidae (2), Hemiptera non-Heteroptera (3), Formicidae (4, 5), Coleoptera Curculionidae (6), Blattariae (7), mandibles of: Blattariae (8), Hymenoptera non-Formicidae (9), Formicidae (10), Mantodea (11), Orthoptera (12), Coleoptera (13), insect larvae (Lepidoptera, 14 and 15), Coleoptera (16), Isoptera (17); others structures: thorax of Hymenoptera non-Formicidae, dorsal vision (18), wing of Hymenoptera non-Formicidae (19), body segment of Diplopoda (20), chelicerae of Araneae (21), fang of Araneae (22), abdominal extremity of Dermaptera (23), cerci (forceps) of Dermaptera (24), elytrum of Coleoptera (25), scutellum of Hemiptera Heteroptera (26), leg of Araneae (27), leg of Hemiptera non-Heteroptera (28), petiole of Hymenoptera non-Formicidae, dorsal and lateral visions (29), bones of amphibian (30), thorax of Formicidae, lateral vision (31), apodeme (internal ridge on an arthropod exoskeleton that forms the attachments for muscles and organs) of Hemiptera non-Heteroptera (32), pedipalp of Pseudoscorpiones (33); seeds of: Zanthoxylum sp. (Rutaceae, 34), Myrtaceae (35), Myrsinaceae (spherical format, 36), Loranthaceae (37), Rudgea recurva (encapsulated by forehead, 38), Psychotria sp. (Rubiaceae, 39), Psychotria suterella (Rubiaceae, 40), Urera baccifera (Urticaceae, 41), Melastomataceae (42), Miconia pusilliflora (Melastomataceae, 43), Cecropia sp. (Cecropiaceae, 44), Lauraceae (45), Alchornea sp. (Euphorbiaceae, 46), Xylopia brasiliensis (Annonaceae, 47), Talauma ovata (Magnoliaceae, 48), Casearia sylvestris (Flacourtiaceae, 49).

Figure 1 in Diet of understorey birds in two Atlantic Forest areas of southeast Brazil

Figure 1. Location of the two sampled areas in the Minas Gerais State, southeast Brazil: (1) Mata Grande, 90 ha; (2) Fazenda Continente forest, 56 ha (showing roads in the edge and interior forest). The internal traces represent the sampling net lines.

Figure 3 in Diet of understorey birds in two Atlantic Forest areas of southeast Brazil

Figure 3. Proportions of faecal samples of birds by area with only fruits, only invertebrates and fruits plus invertebrates.

Figure 4 in Diet of understorey birds in two Atlantic Forest areas of southeast Brazil

Figure 4. Relative frequency (counting of a particular item/counting of all items) and relative occurrence (number of samples in which the taxa occurred/counting of all samples) of each invertebrate group in the samples.

opencc-by-nc-4.0Mar 2019View details →

Figure 1 in An overlooked hotspot for birds in the Atlantic Forest

Figure 1. Location of Serra Bonita NHPR in northeast Brazil.

Figure 6 in Differences in the bird community between a regenerating area and a native forest in Southeastern Brazil

Figure 6. Linear regression between land cover diversity (predictor variable) and bird diversity (response variable). We included an interval of confidence of 95% (grey area). The sampled point counts were pooled according to each site (blue dots – REGEN; orange dots – FOREST).

Figure 3 in Differences in the bird community between a regenerating area and a native forest in Southeastern Brazil

Figure 3. nMDS ordination for the faunal composition (a), the feeding guilds (b) and the foraging strata (c). Each number represents one of the point counts, divided by site (FOREST – points 01–12; REGEN. – points 13–24). The polygons delimit the convex hulls for each group (FOREST and REGEN), showing the absence of superposition of the samples in the multivariate space.

Figure 5 in Differences in the bird community between a regenerating area and a native forest in Southeastern Brazil

Figure 5. Fisher's alpha diversity index for each site (FOREST and REGEN). Boxes represent 25–75% percentiles, while the horizontal black lines represent the median, and whiskers represent 10–90% percentiles.

Figure 4 in Differences in the bird community between a regenerating area and a native forest in Southeastern Brazil

Figure 4. Rarefaction curves of FOREST and REGEN sites. The polygons (circle and triangle) represents the exact number of individuals obtained for a respective site. The unbroken line represents the interpolation curve, while the dotted line represents the extrapolation one. The shaded area refers to the interval of confidence.

Figure 2 in Differences in the bird community between a regenerating area and a native forest in Southeastern Brazil

Figure 2. Relative richness of species pooled for each foraging strata (left) and feeding guilds (right). For the foraging strata, we considered ground (GRO), understory (UND), midstory (MID), canopy (CAN), forest generalist (FOR), mixed (MIX), aerial (AER), and aquatic (AQU) species. For the feeding guilds, we considered invertebrate predator (INV), vertebrate predator (VER), generalist predator (PRE), scavenger (SCA), frugivore (FRU), granivore (GRA), nectarivore (NEC), generalist herbivore (HER), and omnivore (OMN).

Figure 1 in Differences in the bird community between a regenerating area and a native forest in Southeastern Brazil

Figure 1. Map of the Jardim Botânico Municipal de Bauru (JBMB). We highlighted the FOREST (green) and the REGEN (yellow) sites. We also delimited the point counts used to assess the bird community.

opencc-zeroOct 2021View details →

Timing is everything: Acoustic niche partitioning in two tropical wet forest bird communities

When acoustic signals sent from individuals overlap in frequency and time, acoustic interference and signal masking may occur. Under the acoustic niche hypothesis (ANH), signaling behavior has evolved to partition acoustic space and minimize overlap with other calling individuals through selection on signal structure and/or the sender's ability to adjust the timing of signals. Alternately, under the acoustic clustering hypothesis, there is potential benefit to convergence and synchronization of the structural or temporal characteristics of signals in the avian community, and organisms produce signals that overlap more than would be expected by chance. Interactive communication networks may also occur, where species living together are more likely to have songs with convergent spectral and or temporal characteristics. In this study, we examine the fine-scale use of acoustic space in montane tropical wet forest bird communities in Costa Rica and Hawai'i. At multiple recording stations in each community, we identified the species associated with each recorded signal, measured observed signal overlap, and used null models to generate random distributions of expected signal overlap. We then compared observed vs. expected signal overlap to test predictions of the acoustic niche and acoustic clustering hypotheses. We found a high degree of overlap in the signal characteristics (frequency range) of species in both Costa Rica and Hawai'i, however, as predicted under ANH, species significantly reduced observed overlap relative to the random distribution through temporal partitioning. There was little support for acoustic clustering or the prediction of the network hypothesis that species segregate across the landscape based on the frequency range of their vocalizations. These findings constitute strong support that there is competition for acoustic space in these signaling communities, and this has resulted primarily in temporal partitioning of the soundscape.

opencc-zeroDec 2022View details →

Data from: Titmice are a better indicator of bird density in Northern European than in Western European forests

Population sizes of many birds are declining alarmingly and methods for estimating fluctuations in species' abundances at a large spatial scale are needed. The possibility to derive indicators from the tendency of specific species to co-occur with others has been overlooked. Here we tested whether the abundance of resident titmice can act as a general ecological indicator of forest bird density in European forests. Titmice species are easily identifiable and have a wide distribution, which makes them potentially useful ecological indicators. Migratory birds often use information on the density of resident birds, such as titmice, as a cue for habitat selection. Thus, the density of residents may potentially affect community dynamics. We examined spatio-temporal variation in titmouse abundance and total bird abundance, each measured as biomass, by using long-term citizen science data on breeding forest birds in Finland and France. We analyzed the variation in observed forest bird density (excluding titmice) in relation to titmouse abundance. In Finland, forest bird density linearly increased with titmouse abundance. In France, forest bird density non-linearly increased with titmouse abundance, the association weakening towards high titmouse abundance. We then analyzed whether the abundance (measured as biomass) of random species sets could predict forest bird density better than titmouse abundance. Random species sets outperformed titmice as an indicator of forest bird density only in 4.4% and 24.2% of the random draws, in Finland and France, respectively. Overall, the results suggest that titmice could act as an indicator of bird density in Northern European forest bird communities, encouraging the use of titmice observations by even less-experienced observers in citizen science monitoring of general forest bird density.