50 research outputs found
Edge effects and vertical stratification of aerial insectivorous bats across the interface of primary-secondary Amazonian rainforest
Research ArticleEdge effects, abiotic and biotic changes associated with habitat boundaries, are key drivers
of community change in fragmented landscapes. Their influence is heavily modulated by
matrix composition. With over half of the world’s tropical forests predicted to become forest
edge by the end of the century, it is paramount that conservationists gain a better understanding
of how tropical biota is impacted by edge gradients. Bats comprise a large fraction
of tropical mammalian fauna and are demonstrably sensitive to habitat modification. Yet,
knowledge about how bat assemblages are affected by edge effects remains scarce. Capitalizing
on a whole-ecosystem manipulation in the Central Amazon, the aims of this study
were to i) assess the consequences of edge effects for twelve aerial insectivorous bat species
across the interface of primary and secondary forest, and ii) investigate if the activity
levels of these species differed between the understory and canopy and if they were modulated
by distance from the edge. Acoustic surveys were conducted along four 2-km transects,
each traversing equal parts of primary and ca. 30-year-old secondary forest. Five
models were used to assess the changes in the relative activity of forest specialists (three
species), flexible forest foragers (three species), and edge foragers (six species). Modelling
results revealed limited evidence of edge effects, except for forest specialists in the understory.
No significant differences in activity were found between the secondary or primary forest
but almost all species exhibited pronounced vertical stratification. Previously defined bat
guilds appear to hold here as our study highlights that forest bats are more edge-sensitive
than edge foraging bats. The absence of pronounced edge effects and the comparable
activity levels between primary and old secondary forests indicates that old secondary forest can help ameliorate the consequences of fragmentation on tropical aerial insectivorous
batsinfo:eu-repo/semantics/publishedVersio
Reproductive phenologies of phyllostomid bats in the Central Amazon
Mammals tend to align their most energetically demanding phenological events with periods of peak resource availability. Their reproductive phenology is influenced by local resource availability, potentially leading to geographical variation in their breeding strategy. Although the Amazon is the world’s epicenter of bat diversity, the reproductive phenology of Amazonian bats remains poorly known. Seasonality induces fluctuations in resource availability and most phyllostomid species, crucial agents of seed dispersal, pollination and arthropod suppression in the Neotropics, have been described to exhibit seasonal bimodal polyestry. However, current understanding of phyllostomid reproductive phenology is impaired by the paucity of comparative examinations of the phenologies of sympatric species, using consistent classification schemes based on the number and timing of annual peaks in pregnancy and lactation. Using a multi-year dataset from Central Amazonia, we examined the reproductive phenology of nine bat species (Artibeus concolor, A. obscurus, A. lituratus, Carollia brevicauda, C. perspicillata, Gardnerycteris crenulatum, Lophostoma silvicolum, Rhinophylla pumilio, and Trachops cirrhosus), as well as two feeding ensembles (i.e., frugivores and gleaning animalivores). Only three of the nine species exhibited a bimodal reproductive phenology. Six species and the frugivore ensemble showed unimodal reproductive phenology, while gleaning animalivores displayed an amodal pregnancy pattern. All species except L. silvicolum had their primary pregnancy peak during the mid-dry season. A reproductive peak during the early wet season, or local variation in the duration of the fruiting season may explain the deviation of our observations from the expected bimodal polyestry
Functional recovery of Amazonian bat assemblages following secondary forest succession
Regenerating forests occupy large areas in the tropics, mostly as a result of deforestation for livestock and agriculture, followed by land abandonment. Despite the importance of regenerating secondary forests for tropical biodiversity conservation, studies of temporal effects of matrix regeneration on species responses in fragmented landscapes are scarce. Here, we used an Amazonian whole-ecosystem fragmentation experiment to investigate how changes in matrix quality over time through secondary forest regeneration affect bat assemblages from a functional perspective. We found that forest regeneration in the matrix positively affected functional α diversity, as well as species- and community-level functional uniqueness, reflecting an increase of species that perform different ecological functions in secondary forest over time. According to functional trait composition, animalivorous species showed the clearest signs of recovery associated with matrix regeneration. Consequently, between-period differences in functional β-diversity were highest in secondary forest compared to fragments and continuous forest, determined mainly by trait gains. However, ~ 30 years of secondary forest regeneration were not sufficient for the functional recovery of bat assemblages to levels observed in continuous forest. Restoring degraded habitats while protecting primary forest will be an important strategy for safeguarding high functional diversity of bats and their vital contributions to ecosystem functioning in fragmented tropical landscapes. © 2017 Elsevier Lt
Rocha et al - Secondary forest regeneration benefits old-growth specialist bats in a fragmented tropical landscape_data.xlsx
<p>Abundance data of bat species sampled at the
Biological Dynamics of Forest Fragments Project, Central Amazon, Brazil, ~15
years (1996-2002) and ~30 years (2011-2013) after forest clearing. Data is
organized as used for the joint species distribution model of the publication “Rocha, R., Ovaskainen,
O., Lopez-Baucells, A., Farneda, F., Sampaio, E., Bobrowiec, P., Cabeza, M.,
Palmeirim, J. and Meyer, C.F.J., 2018. Secondary forest regeneration benefits
old-growth specialist bats in a fragmented tropical landscape. <i>Scientific Reports</i>. DOI:
10.1038/s41598-018-21999-2”. Data includes:</p>
<p><br></p><p>Matrix Y: Abundance
data of bat species captured during a given mist-netting session.</p>
<p><br></p><p>Matrix X: Covariates used for the
joint species distribution model. These variables were: i) habitat type (coded
as continuous_forest, fragment_interior or secondary_forest); ii) survey period
(1996-2002 (coded as 1) or 2011-13 (coded as 2); iii) percentage of secondary
forest cover within a radius of 500 m from each site; and iv) survey effort
given as mist-net hours [1 mist-net hour (mnh) equals one 12-m net open for 1
h].</p>
<p><br></p><p>Matrix T: Habitat
affinity classification of the species present in the matrix Y.</p>
<p><br></p><p>Matrix C: Phylogenetic
correlation matrix of the species present in the matrix Y.</p
CESTES - A global database for metaCommunity Ecology: Species, Traits, Environment and Space
CESTES is a global database for metaCommunity Ecology: Species, Traits, Environment and Space. It compiles 80 datasets from trait-based studies. Each dataset includes four matrices: species community abundances or presences/absences across multiple sites, species trait information, environmental variables and spatial coordinates of the sampling sites. CESTES presents a harmonized structure and covers a diversity of ecosystem types (marine, terrestrial, freshwater), taxonomic groups (plants, vertebrates, invertebrates...), geographical regions, and spatial scales. The CESTES database is a live database: it will be maintained and expanded in the future as new datasets become available (https://icestes.github.io/sharedata). A zipped folder called “CESTES.zip” includes two alternative formats for the CESTES database: - a “xCESTES” folder that includes 80 Excel files (one file per dataset), each named according to the following structure: “AuthorPublicationYear.xlsx” - a “rCESTES” folder that includes the CESTES core processed database (comm, traits, envir, coord matrices) as an R list object “CESTES.RData” plus two R scripts, and two metadata tables for data processing and exploration. This “CESTES.zip” folder also includes: - an extended metadata table, “CESTES_metadata.xlsx”, that provides the general metadata information of all the datasets, - a tutorial document, “HOW_TO_SHARE_MY_DATA_FOR_CESTES.pdf”, that explains how to share data for integrating future datasets in the database. A second zipped folder, called "ceste.zip", corresponds to the non-spatial ancillary to CESTES. We provide access to 10 additional datasets that were not completely suitable for the CESTES database, due to the absence of spatial information or insufficient metadata but that were potentially valuable for their three other data matrices (comm, traits, envir). They follow the same structure as CESTES, except that they do not present the “coord” sheet and sometimes include only partial metadata. The “ceste.zip” zipped folder includes the 10 data files + 1 metadata file called "ceste_metadata.xlsx"
A measurement of
Using a dataset corresponding to 9 fb of integrated luminosity collected with the LHCb detector between 2011 and 2018 in proton-proton collisions, the decay-time distributions of the decay modes and are studied. The decay-width difference between the light and heavy mass eigenstates of the meson is measured to be ∆Γ = 0.087 ± 0.012 ± 0.009 ps, where the first uncertainty is statistical and the second systematic.[graphic not available: see fulltext]Using a dataset corresponding to of integrated luminosity collected with the LHCb detector between 2011 and 2018 in proton-proton collisions, the decay-time distributions of the decay modes and are studied. The decay-width difference between the light and heavy mass eigenstates of the meson is measured to be , where the first uncertainty is statistical and the second systematic
Observation of and decays
International audienceThe and decays are observed for the first time using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of , corresponding to an integrated luminosity of . The relative branching fractions times the beauty-baryon production cross-sections are measured to be \begin{align*} \mathcal{R}\left(\frac{\Xi_b^0}{\Lambda_b^0}\right) \equiv \frac{\sigma\left(\Xi_b^0\right)}{\sigma\left(\Lambda_b^0\right)} \times \frac{\mathcal{B}\left(\Xi_b^0 \rightarrow \Xi_c^+ D_s^-\right)}{\mathcal{B}\left(\Lambda_b^0 \rightarrow \Lambda_c^0 D_s^-\right)} =(15.8\pm1.1\pm0.6\pm7.7)\%, \mathcal{R}\left(\frac{\Xi_b^-}{\Lambda_b^0}\right) \equiv \frac{\sigma\left(\Xi_b^-\right)}{\sigma\left(\Lambda_b^0\right)} \times \frac{\mathcal{B}\left(\Xi_b^- \rightarrow \Xi_c^0 D_s^-\right)}{\mathcal{B}\left(\Lambda_b^0 \rightarrow \Lambda_c^0 D_s^-\right)} =(16.9\pm1.3\pm0.9\pm4.3)\%, \end{align*} where the first uncertainties are statistical, the second systematic, and the third due to the uncertainties on the branching fractions of relevant charm-baryon decays. The masses of and baryons are measured to be and , where the uncertainties are statistical, systematic, and those due to charm-hadron masses, respectively