1,721,010 research outputs found
Population abundance estimates in conservation and biodiversity research
No full textMeasuring and tracking biodiversity from local to global scales is challenging due to its multifaceted nature and the range of metrics used to describe spatial and temporal patterns. Abundance can be used to describe how a population changes across space and time, but it can be measured in different ways, with consequences for the interpretation and communication of spatiotemporal patterns. We differentiate between relative and absolute abundance, and discuss the advantages and disadvantages of each for biodiversity monitoring, conservation, and ecological research. We highlight when absolute abundance can be advantageous and should be prioritized in biodiversity monitoring and research, and conclude by providing avenues for future research directions to better assess the necessity of absolute abundance in biodiversity monitoring
Cacomantis variolosus
No full text<i>Cacomantis variolosus</i> (Vigors & Horsfield, 1827). <p>Brush Cuckoo</p> <p> Uncommon. Heard calling once in lowlands (0–50 m) from scrubby/brushy habitat. <i>Identification</i>: Calls were referenced in the field; the bird was not observed.</p>Published as part of <i>Callaghan, Corey T., Kekeubata, Esau, Waneagea, Jackson, Alabai, Maasafi, Esau, Tommy, MacLaren, David & Major, Richard E., 2019, A collaborative bird survey of East Kwaio, Malaita, Solomon Islands, pp. 1119-1136 in Check List 15 (6)</i> on page 1126, DOI: 10.15560/15.6.111
Fig. 2 in Unveiling global species abundance distributions
No full textFig. 2 | The temporal evolution of the gSAD. From top to bottom:Actinopterygii, Amphibia, Arachnida,Aves,Bivalvia, Cephalopoda, Cycadopsida,Insecta, Liliopsida and Mammalia.For some classes, the apparent unveiling is evident, such as for Aves.Each year represents a rolling 20-year window in which GBIF observations were aggregated.Published as part of Callaghan, Corey T., Borda-de-Água, Luís, van Klink, Roel, Rozzi, Roberto & Pereira, Henrique M., 2023, Unveiling global species abundance distributions, pp. 1-13 in Nature Ecology & Evolution CLXVI (CLXVI) on page 4, DOI: 10.1038/s41559-023-02173-y, http://zenodo.org/record/831979
Aerodramus vanikorensis
No full text<i>Aerodramus vanikorensis</i> (Quoy & Gaimard, 1832). <p>Uniform Swiftlet</p> <p> Common at all elevations. Often seen high above the canopy, and at one point observed an extremely large flock (~200 birds) of presumed Uniform Swiftlets along the coast. Potentially more common in lowland ecosystems than highland ecosystems. <i>Identification</i>: Overall darker and duller in color on dorsum than Glossy Swiftlet, with no apparent sheen observed, ruling out Glossy Swiftlet. Lacked any white rump, ruling out Whiterumped Swiftlet. <i>Voucher registration number(s)</i>: O.78247 (skin).</p>Published as part of <i>Callaghan, Corey T., Kekeubata, Esau, Waneagea, Jackson, Alabai, Maasafi, Esau, Tommy, MacLaren, David & Major, Richard E., 2019, A collaborative bird survey of East Kwaio, Malaita, Solomon Islands, pp. 1119-1136 in Check List 15 (6)</i> on page 1127, DOI: 10.15560/15.6.111
Aplonis metallica
No full text<i>Aplonis metallica</i> (Temminck, 1824). Metallic Starling <p> Common at all elevations, mixing with Singing Starling at times. <i>Identification</i>: Distinct.</p> <p> <i>Aplonis grandis</i> (Salvadori, 1881). Brown-winged Starling</p> <p> Uncommon at all elevations, usually associated with fruiting trees. Subspecies <i>malaitae</i>. <i>Identification</i>: Table 1. <i>Voucher registration number(s)</i>: O.78235 (skin).</p>Published as part of <i>Callaghan, Corey T., Kekeubata, Esau, Waneagea, Jackson, Alabai, Maasafi, Esau, Tommy, MacLaren, David & Major, Richard E., 2019, A collaborative bird survey of East Kwaio, Malaita, Solomon Islands, pp. 1119-1136 in Check List 15 (6)</i> on page 1132, DOI: 10.15560/15.6.111
Fig. 1 in Unveiling global species abundance distributions
No full textFig. 1 | Conceptual scheme illustrating the Poisson sampling of a community with species abundances described by a gamma or a log-normal distribution. Two types of gSAD—gamma (left) and log-normal distribution (right) are shown at the top.Each distribution represents the probability f of a species having a given abundance λ, with the gamma distribution having parameters k (shape) and θ (scale) and the log-normal distribution having parameters μ (mean) and σ (standard deviation), and Γ() representing the gamma function.In the middle, sampling of the gSAD with the probability of each species having a given number of individuals sampled described by a Poisson distribution is illustrated. The mean abundance of each species sampled is randomly taken from the SAD.We exemplify two samples of different sizes, where different symbols denote individuals of different species. The bottom graphs show that: if the global abundances have a log-normal distribution, the mixture distribution of abundances in the sample is a Poisson log-normal; if the global abundances follow a gamma distribution the resulting mixture distribution is a negative binomial but in the limit k→0, we obtain the Fisher log-series.Published as part of <i>Callaghan, Corey T., Borda-de-Água, Luís, van Klink, Roel, Rozzi, Roberto & Pereira, Henrique M., 2023, Unveiling global species abundance distributions, pp. 1600-1609 in Nature Ecology & Evolution 7</i> on page 3, DOI: 10.1038/s41559-023-02173-y, <a href="http://zenodo.org/record/8319795">http://zenodo.org/record/8319795</a>
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High-integrity forests are critical for forest specialist birds
Full text linkAim: efforts to retain and restore forest integrity—the degree to which a forest's structure and function are not modified by humans—are increasingly underpinning global biodiversity conservation efforts. However, there is still much uncertainty around how species respond to changes in forest integrity. Geographically variable responses would have consequences for conservation planning assessments and targeted conservation action. Our goal was to quantify the relationship between forest integrity and bird diversity.Location: global; 98 bioregions.Time period: 2017–2020.Major taxa studied: birds.MethodsBy integrating global-scale spatially explicit forest landscape integrity data with a citizen science bird dataset, we provide the first empirical assessment of the relationship between forest integrity and bird diversity.Results: we found that both species richness and abundance of forest specialists had a positive association with integrity. However, the relationship between forest integrity and bird diversity varied across bioregions, with bioregions at low latitudes tending to have more positive relationships between forest integrity and species richness. Of the 74 bioregions assessed, 64% had more than half of their species favouring high integrity forests.Main conclusions: these results support calls for the targeted protection of the world's remaining high-integrity forests but also showcase that consideration must be given to restoring forest integrity where possible
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Improving quantitative synthesis to achieve generality in ecology
Full text linkSynthesis of primary ecological data is often assumed to achieve a notion of ‘generality’, through the quantification of overall effect sizes and consistency among studies, and has become a dominant research approach in ecology. Unfortunately, ecologists rarely define either the generality of their findings, their estimand (the target of estimation) or population of interest. Given that generality is fundamental to science, and the urgent need for scientific understanding to curb global-scale ecological breakdown, loose usage of the term ‘generality’ is problematic. In other disciplines, generality is defined as comprising both generalisability: extending an inference about an estimand from the sample to the population, and transferability: the validity of estimand predictions in a different sampling unit or population. We review current practice in ecological synthesis, and demonstrate that by failing to define the assumptions underpinning generalisations and transfers of effect sizes, generality often misses its target. We provide guidance for communicating nuanced inferences, and maximising the impact of syntheses both within and beyond academia. We propose pathways to generality applicable to ecological syntheses, including the development of quantitative and qualitative criteria with which to license the transfer of estimands from both primary and synthetic studies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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