Neotropical Birds Research Articles

Aves explorando flores de Erythrina fusca (Leguminosae, Fabaceae) durante a estação seca no Pantanal de Mato Grosso

Estudos recentes têm evidenciado a importância de flores como recurso alimentar de diversas espécies de aves neotropicais. Este estudo teve o objetivo de listar espécies e descrever o comportamento das aves que se alimentaram de recursos florais de Erythrina fusca (Fabaceae) no Pantanal Mato-Grossense. Para isso, foram acompanhadas aves que se alimentaram em 14 árvores floridas dessa espécie em um total de cerca de 25 horas de observação. Como resultados, 20 espécies de aves pertencentes a sete famílias taxonômicas foram observadas alimentando-se de recursos florais de E. fusca. Apesar de várias espécies de aves terem apresentado comportamentos destrutivos em maior proporção, algumas espécies, sobretudo das famílias Trochilidae e Icteridae, apresentaram estratégias alimentares compatíveis com o transporte de pólen. O cruzamento dos dados obtidos neste estudo com os da literatura indicam que a família Icteridae pode ter relevante papel na polinização dessa espécie vegetal.

Neotropical birds show a humped distribution of within‐population genetic diversity along a latitudinal transect

The latitudinal gradient in species richness is a nearly universal ecological phenomenon. Similarly, conspecific genetic diversity often increases towards the equator - usually explained as the consequence of post-glacial range expansion or due to the shared response of genetic diversity to processes that promote species richness. However, no study has yet examined the relationship between latitude and within-population genetic diversity in exclusively tropical species. We surveyed genetic variation in nine resident bird species co-occurring in tropical lowlands between southern Mexico and western Ecuador, where avian species richness increases with decreasing latitude. Within-population genetic variation was always highest at mid-range latitudes, and not in the most equatorial populations. Differences in demography and gene flow across species' ranges may explain some of our observations; however, much of the pattern may be due simply to geometric constraints. Our findings have implications for conservation planning and for understanding how biodiversity scales from genes to communities.

DNA barcodes provide new evidence of a recent radiation in the genusSporophila(Aves: Passeriformes)

The capuchinos are a group of birds in the genus Sporophila that has apparently radiated recently, as evidenced by their lack of mitochondrial genetic diversity. We obtained cytochrome c oxidase I (COI) sequences (or DNA barcodes) for the 11 species of the group and various outgroups. We compared the patterns of COI variability of the capuchinos with those of the largest barcode data set from neotropical birds currently available (500 species representing 51% of avian richness in Argentina), and subjected COI sequences to neighbour-joining, maximum parsimony and Bayesian phylogenetic analyses as well as statistical parsimony network analysis. A clade within the capuchinos, the southern capuchinos, showed higher intraspecific and lower interspecific divergence than the remaining Argentine species. As most of the southern capuchinos shared COI haplotypes and pairwise distances within species were in many cases higher than distances between them, the phylogenetic affinities within the group remained unresolved. The observed genetic pattern is consistent with both incomplete lineage sorting and gene flow between species. The southern capuchinos constitute the only large group of species among the neotropical birds barcoded so far that are inseparable when using DNA barcodes, and one of few multispecies avian groups known to lack reciprocal monophyly. Extending the analysis to rapidly evolving nuclear and mitochondrial markers will be crucial to understanding this radiation. Apart from giving insights into the evolution of the capuchinos, this study shows how DNA barcoding can rapidly flag species or groups of species worthy of deeper study.

LANDSCAPE MATRIX AND SPECIES TRAITS MEDIATE RESPONSES OF NEOTROPICAL RESIDENT BIRDS TO FOREST FRAGMENTATION IN JAMAICA

Land cover and land use surrounding fragmented habitat can greatly impact species persistence by altering resource availability, edge effects, or the movement of individuals throughout a landscape. Despite the potential importance of the landscape matrix, ecologists still have limited understanding of the relative effects of different types of land cover and land uses on species patterns and processes in natural systems. Here we investigated whether Neotropical resident bird communities in limestone forest patches differed if they were embedded in three different human-dominated matrix types (agriculture, peri-urban development, and bauxite mining) relative to sites in continuous forest in central Jamaica. We found that species richness, community composition, and abundances were matrix-dependent, with agricultural landscapes supporting greater avian diversity and more intact community assemblages than either peri-urban or bauxite landscapes. Abundance of almost 70% of species differed in forest embedded in the different landscape matrix types. Traits related to resource use best predicted species responses, including diet guild, nest height, habitat association, and foraging strata. Insectivores, frugivores, canopy nesters, understory and canopy foragers, and forest-restricted species rarely observed in matrix habitats had lower abundances in forest fragments embedded in human-dominated matrix types than in continuous forest. In contrast, nectarivores, omnivores, granivores, ground and multi-strata nesters, ground foragers, and species regularly in matrix habitats were least sensitive to forest fragmentation. Results suggest that structure, composition, and land use disturbance regimes in matrix areas impact overall habitat quality in landscapes by potentially mediating resource availability inside as well as outside forest habitat. This study reinforces the importance of differentiating among land cover and land uses in fragmentation research and lends support to the hypothesis that resource availability may be a primary factor driving Neotropical bird responses to fragmentation.

Breeding biology and longevity of Russet-crowned Motmots in central Mexico

Motmots, with their distinctive racketed-tails, represent one of the most easily recognized tropical birds, yet little is known about the basic natural history of most species in the family Momotidae. We report basic breeding biology and longevity of Russet-crowned Motmots (Momotus mexicanus), a medium-sized Neotropical bird that ranges from northwest Mexico to central Guatemala. We monitored nest success of eight pairs from 1 May to 17 July 1998 in tropical deciduous forests in central Mexico. Motmots laid an average of 4.1 eggs and incubated for approximately 20 d. Four of eight nests fledged young. Of these four nests, average hatching success was 69% and average fledgling success was 56%. The mean duration of the nestling period at three nests was 33.7 d. Based on the recapture of one individual bird in April 2008, we provide a longevity estimate that Russet-crowned Motmots can survive at least 11 yr in the wild. These data on nesting success and longevity add to our limited knowledge of the natural history of this understudied species.

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

The feeding habits of understorey birds of two fragments of Atlantic Forest in southeast Brazil were studied, based on faecal content. The 434 samples examined contained 2535 items, principally consisting of invertebrates and fruit, of which 2286 (90.2%) could be identified in detail. Although there was no significant difference between the areas with respect to the occurrence of these two food categories in the diet, there were differences in the relative proportions of some of the invertebrate and plant taxa represented. Some birds that had been considered generalists appeared to have dietary specializations, indicating that existing knowledge of the trophic ecology of neotropical birds is inadequate. To eliminate this critical knowledge gap, it is recommended that studies be undertaken at community level together with examination of faecal samples, the latter being a low-cost, non-invasive, non-lethal technique.

Comparative Genetic Diversity of Wild and Captive Populations of the Bare-Faced Curassow (Crax fasciolata) Based on Cross-Species Microsatellite Markers: Implications for Conservation and Management

The bare-faced curassow (Crax fasciolata) is a large Neotropical bird that suffers anthropogenic pressure across much of its range. A captive population is maintained for conservation management, although there has been no genetic screening of stocks. Based on the six microsatellite markers developed for Crax globulosa, the genetic variability of C. fasciolata and possible differences between a wild and a captive population were investigated. Only three loci were polymorphic, with a total of 27 alleles. More than half of these alleles were private to the wild (n = 8) or captive (n = 7) populations. Significant deviations from Hardy-Weinberg equilibrium were restricted to the captive population. Despite the number of private alleles, genetic drift has probably promoted differentiation between populations. Our results indicate that wild C. fasciolata populations are genetically impoverished and structured, but species-specific microsatellite markers will be necessary for a more reliable assessment of the species' genetic diversity.

Are the Northern Andes a species pump for Neotropical birds? Phylogenetics and biogeography of a clade of Neotropical tanagers (Aves: Thraupini)

AbstractAim We used mitochondrial DNA sequence data to reconstruct the phylogeny of a large clade of tanagers (Aves: Thraupini). We used the phylogeny of this Neotropical bird group to identify areas of vicariance, reconstruct ancestral zoogeographical areas and elevational distributions, and to investigate the correspondence of geological events to speciation events.Location The species investigated are found in 18 of the 22 zoogeographical regions of South America, Central America and the Caribbean islands; therefore, we were able to use the phylogeny to address the biogeographical history of the entire region.Methods Molecular sequence data were gathered from two mitochondrial markers (cytochrome b and ND2) and analysed using Bayesian and maximum‐likelihood approaches. Dispersal–vicariance analysis (DIVA) was used to reconstruct zoogeographical areas and elevational distributions. A Bayesian framework was also used to address changes in elevation during the evolutionary history of the group.Results Our phylogeny was similar to previous tanager phylogenies constructed using fewer species; however, we identified three genera that are not monophyletic and uncovered high levels of sequence divergence within some species. DIVA identified early diverging nodes as having a Northern Andean distribution, and the most recent common ancestor of the species included in this study occurred at high elevations. Most speciation events occurred either within highland areas or within lowland areas, with few exchanges occurring between the highlands and lowlands. The Northern Andes has been a source for lineages in other regions, with more dispersals out of this area relative to dispersals into this area. Most of the dispersals out of the Northern Andes were dispersals into the Central Andes; however, a few key dispersal events were identified out of the Andes and into other zoogeographical regions.Main conclusions The timing of diversification of these tanagers correlates well with the main uplift of the Northern Andes, with the highest rate of speciation occurring during this timeframe. Central American tanagers included in this study originated from South American lineages, and the timing of their dispersal into Central America coincides with or post‐dates the completion of the Panamanian isthmus.

It's not too Late for the Harpy Eagle (Harpia harpyja): High Levels Of Genetic Diversity and Differentiation Can Fuel Conservation Programs

BackgroundThe harpy eagle (Harpia harpyja) is the largest Neotropical bird of prey and is threatened by human persecution and habitat loss and fragmentation. Current conservation strategies include local education, captive rearing and reintroduction, and protection or creation of trans-national habitat blocks and corridors. Baseline genetic data prior to reintroduction of captive-bred stock is essential for guiding such efforts but has not been gathered previously.Methodology/FindingsWe assessed levels of genetic diversity, population structure and demographic history for harpy eagles using samples collected throughout a large portion of their geographic distribution in Central America (n = 32) and South America (n = 31). Based on 417 bp of mitochondrial control region sequence data, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and South America, although haplotype diversity was significantly higher for South America. Historical restriction of gene flow across the Andes (i.e. between our Central and South American subgroups) is supported by coalescent analyses, the haplotype network and significant F ST values, however reciprocally monophyletic lineages do not correspond to geographical locations in maximum likelihood analyses. A sudden population expansion for South America is indicated by a mismatch distribution analysis, and further supported by significant (p<0.05) negative values of Fu and Li's DF and F, and Fu's F S. This expansion, estimated at approximately 60 000 years BP (99 000–36 000 years BP 95% CI), encompasses a transition from a warm and dry time period prior to 50 000 years BP to an interval of maximum precipitation (50 000–36 000 years BP). Notably, this time period precedes the climatic and habitat changes associated with the last glacial maximum. In contrast, a multimodal distribution of haplotypes was observed for Central America suggesting either population equilibrium or a recent decline.SignificanceHigh levels of mitochondrial genetic diversity in combination with genetic differentiation among subgroups within regions and between regions highlight the importance of local population conservation in order to preserve maximal levels of genetic diversity in this species. Evidence of historically restricted female-mediated gene flow is an important consideration for captive-breeding programs.

Ecology Predicts Levels of Genetic Differentiation in Neotropical Birds

Despite the theoretical link between the ecology and the population genetics of species, little empirical evidence is available that corroborates the association. Here, we examined genetic variation in 40 codistributed species of lowland Neotropical rain forest birds that have populations isolated on either side of the Andes, the Amazon River, and the Madeira River. We found widely varying levels of genetic divergence among these taxa across the same biogeographic barriers. Our investigation of the extent to which ecological traits predicted the amount of cross-barrier divergence revealed a strongly significant relationship between the forest stratum at which a species forages and the level of cross-barrier genetic differentiation. Canopy species had statistically lower genetic divergence values across the Andes and the two Amazonian rivers than did understory birds. We hypothesize that the association reflects an effect of dispersal propensity, which is greater in canopy birds, on the movement of alleles among demes (i.e., migration) and, consequently, on the interdemic proportion of the genetic variance. Differences in dispersal propensity may also explain the observation that understory species contain a significantly greater number of subspecies than do canopy species. This result indicates that higher rates of diversification may occur in lineages with lower dispersal propensity.

Low and variable reproductive success of a neotropical tyrant-flycatcher, Chapada Flycatcher (Suiriri islerorum)

The decline of several bird populations has been related to reduced reproductive success. Here we used the logistic-exposure method to model the temporal (age, daily, annual) variation in reproductive success of a neotropical tyrant-flycatcher, the Chapada Flycatcher (Suiriri islerorum), which has been described only recently (2001). We monitored 56 nests, in a reserve in central Brazil, over four seasons from 2003 to 2006. Predation affected 66% of the monitored nests, but varied greatly across years. The probability of daily survival decreased 7% day−1 with the age of the nest and the reproductive success varied greatly between years (16.8, 75.4, 6.7 and 21.4%, 2003–06 respectively). Mean reproductive success (using three analytical methods) ranged from 21 to 25%, but from only 13 to 16% when results from 2004 were excluded. Such low and variable reproductive success is atypical for a neotropical bird. In combination with the small population size and known decline of this population, our findings raise conservation concerns for this isolated population.

Ecological and life-history factors influencing the evolution of maternal antibody allocation: a phylogenetic comparison

Maternally derived yolk antibodies provide neonates with immune protection in early life at negligible cost to mothers. However, developmental effects on the neonate's future immunity are potentially costly and thus could limit yolk antibody deposition. The benefits to neonatal immunity must be balanced against costs, which may depend on neonate vulnerability to pathogens, developmental trajectories and the immunological strategies best suited to a species' pace of life. We measured yolk antibodies and life-history features of 23 species of small Neotropical birds and assessed the evidence for each of several hypotheses for life history and ecological effects on the evolution of yolk antibody levels. Developmental period and yolk antibodies are negatively related, which possibly reflect the importance of humoral immune priming through antigen exposure, and selection to avoid autoimmunity, in species with a slower pace of life. There is also a strong relationship between body size and yolk antibody concentration, suggesting that larger species are architecturally equipped to produce and transfer higher concentrations of antibodies. These results suggest that developmental effects of maternally derived antibodies, such as imprinting effects on B-cell diversity or autoimmune effects, are important and deserve more consideration in future research.

Dos nuevos registros de alimentación de Quiscalus mexicanus Y Cyanocorax sanblasianus en la costa de Chamela, Jalisco, México

Information over the feeding habits of neotropical birds have been relatively few documented, this is the first report in México over the depredation of the mole crabs (Emerita spp.) by the Great-tailed Grackle (Quiscalus mexicanus) and for Ruddy-ground Dove (Columbina talpacoti) by San Blas Jay (Cyanocorax sanblasianus), in the coast of Chamela, Jalisco, México.

Insects found in birds’ nests from the Neotropical Region (except Argentina) and immigrant species of Neotropical origin in the Nearctic Region

Neotropical birds’ nests have received a great deal of attention because sylvatic species of Triatominae (Hemiptera: Reduviidae) and parasitic flies of the genus Philornis (Diptera: Muscidae) were discovered inside them. Those insects known in birds’ nests from Argentina, the chacoan region of Bolivia, and the southern portion of Brazil and Uruguay were extensively but not completely summarized by Turienzo &amp; Di Iorio (2007). The present contribution summarizes all insects known to occur in birds’ nests from the Neotropical Region (except for Argentina and the Antarctic Region of adjacent countries), updating Hicks’ catalogues for this part of the world. Regarding birds, the list comprises 172 taxa identified to species (in 38 families), 8 to genus (in 6 families), 6 to family (in 4 families), and 27 birds´nests not identified. Regarding insects of the Neotropical region, 123 were identified to species (13 Blattaria; 5 Coleoptera; 26 Diptera; 34 Hemiptera; 15 Hymenoptera; 23 Psocoptera; 6 Siphonaptera; 1 Thysanura), 96 to genus (5 Blattaria; 8 Coleoptera; 48 Diptera; 4 Hemiptera; 6 Hymenoptera; 25 Psocoptera), 63 to superfamily, family or subfamily (1 Blattaria; 21 Coleoptera; 10 Diptera; 7 Hemiptera; 14 Hymenoptera; 1 Isoptera; 3 Orthoptera; 5 Psocoptera; 1 Thysanoptera), and 34 to order (6 Blattaria [including 1 Mantodea]; 6 Coleoptera; 3 Diptera; 3 Embioptera; 2 Hemiptera; 3 Hymenoptera; 1 Thysanoptera; 2 Isoptera; 4 Lepidoptera; 1 Orthoptera; 1 Phthiraptera; 2 Psocoptera). Associations of Neotropical insects with birds´nests were extracted from 392 references including original and posterior citations. Some North American species of insects that are neotropical immigrants are discussed, while a few other had been accidentally introduced in both directions. Synonymies, old combinations, misidentifications, original localities, amounts of insects, and repositories when they were stated, are provided.

Probing Evolutionary Patterns in Neotropical Birds through DNA Barcodes

BackgroundThe Neotropical avifauna is more diverse than that of any other biogeographic region, but our understanding of patterns of regional divergence is limited. Critical examination of this issue is currently constrained by the limited genetic information available. This study begins to address this gap by assembling a library of mitochondrial COI sequences, or DNA barcodes, for Argentinian birds and comparing their patterns of genetic diversity to those of North American birds.Methodology and Principal FindingsFive hundred Argentinian species were examined, making this the first major examination of DNA barcodes for South American birds. Our results indicate that most southern Neotropical bird species show deep sequence divergence from their nearest-neighbour, corroborating that the high diversity of this fauna is not based on an elevated incidence of young species radiations. Although species ages appear similar in temperate North and South American avifaunas, patterns of regional divergence are more complex in the Neotropics, suggesting that the high diversity of the Neotropical avifauna has been fueled by greater opportunities for regional divergence. Deep genetic splits were observed in at least 21 species, though distribution patterns of these lineages were variable. The lack of shared polymorphisms in species, even in species with less than 0.5M years of reproductive isolation, further suggests that selective sweeps could regularly excise ancestral mitochondrial polymorphisms.ConclusionsThese findings confirm the efficacy of species delimitation in birds via DNA barcodes, even when tested on a global scale. Further, they demonstrate how large libraries of a standardized gene region provide insight into evolutionary processes.

Relationship between the presence of House Sparrows (Passer domesticus) and Neotropical bird community structure and diversity

Invasive exotic species pose an important threat to biodiversity worldwide. However, there is little information on the effects that specific exotic bird species have on native biota. The House Sparrow is an excellent ecological model to evaluate the effect that an invasive exotic species has on native bird communities. Our study describes the relationship of the presence and abundance of House Sparrows with the structure, diversity, and composition of native bird communities in West Mexico. We used two approaches to compare House Sparrow invaded and non-invaded bird communities: (1) at a small geographic-scale that allowed us to evaluate shifts in avian communities with presence of the House Sparrow under similar environmental conditions; and (2) at the landscape-level to evaluate the effect of this species under a scenario of greater environmental heterogeneity. Results from both approaches show that areas invaded by House Sparrows have heavily-dominated avian communities with low species richness, while non-invaded areas exhibit highly-even and species-rich bird communities. Species turnover analysis indicates that the decrease in the number of bird species in House Sparrow invaded areas is caused by species loss, rather than a shift in species composition. Our results indicate that the invasion of an area by the House Sparrow, through synergistic interactions with human activities, determines the composition, structure, and diversity of native bird communities.

Ecology Predicts Levels of Genetic Differentiation in Neotropical Birds

Ecology Predicts Levels of Genetic Differentiation in Neotropical Birds

MATING SYSTEM AND SEXUAL CONFLICT IN THE BLUE-BLACK GRASSQUIT (Volatinia jacarina, AVES: EMBERIZIDAE): EXTRA-PAIR MATING BEHAVIOR SETS THE SCENE

Here we review several field and laboratory studies with the blue-black grassquit ( Volatinia jacarina ) to show how different aspects of its mating system are inter-related. We discuss previous studies on the negative effects of parasitism upon secondary sexual characters of grassquits and the lack of female choice for healthier males. We also review what is known about the mating patterns of this species and discuss the elevated rates of extra-pair paternity obtained in laboratory experiments with the reactions of males and females towards extra-pair males. From basic breeding biology to complex social and genetic interactions, the present review illustrates how the study of a single species allows for a broader interpretation of many hypotheses and assumptions that are seldom considered with Neotropical birds.

The historical biogeography of Pteroglossus aracaris (Aves, Piciformes, Ramphastidae) based on Bayesian analysis of mitochondrial DNA sequences

Most Neotropical birds, including Pteroglossus aracaris, do not have an adequate fossil record to be used as time constraints in molecular dating. Hence, the evolutionary timeframe of the avian biota can only be inferred using alternative time constraints. We applied a Bayesian relaxed clock approach to propose an alternative interpretation for the historical biogeography of Pteroglossus based on mitochondrial DNA sequences, using different combinations of outgroups and time constraints obtained from outgroup fossils, vicariant barriers and molecular time estimates. The results indicated that outgroup choice has little effect on the Bayesian posterior distribution of divergence times within Pteroglossus, that geological and molecular time constraints seem equally suitable to estimate the Bayesian posterior distribution of divergence times for Pteroglossus, and that the fossil record alone overestimates divergence times within the fossil-lacking ingroup. The Bayesian estimates of divergence times suggest that the radiation of Pteroglossus occurred from the Late Miocene to the Pliocene (three times older than estimated by the “standard” mitochondrial rate of 2% sequence divergence per million years), likely triggered by Andean uplift, multiple episodes of marine transgressions in South America, and formation of present-day river basins. The time estimates are in agreement with other Neotropical taxa with similar geographic distributions.

The structure of the parasite–host interactions between Philornis (Diptera: Muscidae) and neotropical birds

Philornisis a neotropical, monophyletic genus of Muscidae (Diptera) (Couriet al. 2007) that includes many bird parasites (Skidmore 1985). The interaction system ofPhilornisand birds is very peculiar: fly adults are free-living and only larvae interact with birds (Couri 1985, 1999; Dodge 1963). Larval trophic habits are known for 22 of the 49 species (de Carvalhoet al. 2005) and are divided into three groups: coprophagous (P. aitkeniandP. rufoscutellaris), free-living haematophagous (P. falsificus) and subcutaneous (18 spp.).Philornis downsiis unusual because the first and the early second instars display a subcutaneous phase, whereas the late second and third phases show a nest-dwelling haematophagous phase (Fesslet al. 2006).