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"Loyola, Rafael"
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Climate change impacts on the distribution of venomous snakes and snakebite risk in Mozambique
2019
This paper aims to understand the impacts of global climate change (GCC) on the distribution of dangerous venomous snakes and snakebite risk in Mozambique, as a contribution to the enhancement of public health policies and snake conservation. We modelled current and future distribution of all 13 dangerous snakes occurring in Mozambique using ecological niche models to assess the likely impacts of climate change estimated as the difference between lost and gained climatic suitable area per species. In addition, we developed a normalized index of snakebite risk based on species diversity and species-specific traits for each time slice. We then superimposed our index to data on human population density to identify areas most prone to this burden. Our findings suggest considerable future reduction in climatically suitable area for nine out of 13 species, with species experiencing a north-south range shift and high rates of species turnover in northern Mozambique. We also found that GCC might alter the spatial patterns of snakebite risk in the country, with considerable increase in the future, affecting most areas in central and southern regions. This finding suggests that GCC will be harmful to venomous snakes in Mozambique with potentially adverse effects on public health. As GCC might induce the approximation of snake climatic suitable areas to highly populated areas, efforts are needed to increase human knowledge of snakebite prevention measures and increase awareness of the relative safety and attacking behaviour associated with some of the snakes studied here ensuring reduction in snakebites and improving species conservation.
Journal Article
Niche conservatism and the invasive potential of the wild boar
by
Hayward, Matt Warrington
,
Paglia, Adriano
,
Loyola, Rafael
in
African swine fever
,
Amazonia
,
Animal Distribution
2017
1. Niche conservatism, i.e. the retention of a species' fundamental niche through evolutionary time, is cornerstone for biological invasion assessments. The fact that species tend to maintain their original climate niche allows predictive maps of invasion risk to anticipate potential invadable areas. Unravelling the mechanisms driving niche shifts can shed light on the management of invasive species. 2. Here, we assessed niche shifts in one of the world's worst invasive species: the wild boar Sus scrofa. We also predicted potential invadable areas based on an ensemble of three ecological niche modelling methods, and evaluated the performance of models calibrated with native vs. pooled (native plus invaded) species records. By disentangling the drivers of change on the exotic wild boar population's niches, we found strong evidence for niche conservatism during biological invasion. 3. Ecological niche models calibrated with both native and pooled range records predicted convergent areas. Also, observed niche shifts are mostly explained by niche unfilling, i.e. there are unoccupied areas in the exotic range where climate is analogous to the native range. 4. Niche unfilling is expected as result of recent colonization and ongoing dispersal, and was potentially stronger for the Neotropics, where a recent wave of introductions for pig-farming and game-hunting has led to high wild boar population growth rates. The invasive potential of wild boar in the Neotropics is probably higher than in other regions, which has profound management implications if we are to prevent their invasion into species-rich areas, such as Amazonia, coupled with expansion of African swine fever and possibly great economic losses. 5. Although the originally Eurasian-wide distribution suggests a pre-adaptation to a wide array of climates, the wild boar world-wide invasion does not exhibit evidence of niche evolution. The invasive potential of the wild boar therefore probably lies on the reproductive, dietary and morphological characteristics of this species, coupled with behavioural thermoregulation.
Journal Article
On the Worrying Fate of Data Deficient Amphibians
2015
The 'Data Deficient' (DD) category of the IUCN Red List assembles species that cannot be placed in another category due to insufficient information. This process generates uncertainty about whether these species are safe or actually in danger. Here, we give a global overview on the current situation of DD amphibian species (almost a quarter of living amphibians) considering land-use change through habitat modification, the degree of protection of each species and the socio-political context of each country harboring DD species. We found that DD amphibians have, on average, 81% of their ranges totally outside protected areas. Worryingly, more than half of DD species have less than 1% of their distribution represented in protected areas. Furthermore, the percentage of overlap between species' range and human-modified landscapes is high, at approximately 58%. Many countries harboring a large number of DD species show a worrying socio-political trend illustrated by substantial, recent incremental increases in the Human Development Index and lower incremental increases in the establishment of protected areas. Most of these are African countries, which are located mainly in the central and southern regions of the continent. Other countries with similar socio-political trends are in southeastern Asia, Central America, and in the northern region of South America. This situation is concerning, but it also creates a huge opportunity for considering DD amphibians in future conservation assessments, planning, and policy at different levels of government administration.
Journal Article
Understanding global patterns of mammalian functional and phylogenetic diversity
by
Armour-Marshall, Katrina
,
Safi, Kamran
,
Diniz-Filho, José Alexandre F.
in
Altitude
,
Animals
,
Biodiversity
2011
Documenting and exploring the patterns of diversity of life on Earth has always been a central theme in biology. Species richness despite being the most commonly used measure of diversity in macroecological studies suffers from not considering the evolutionary and ecological differences among species. Phylogenetic diversity (PD) and functional diversity (FD) have been proposed as alternative measures to overcome this limitation. Although species richness, PD and FD are closely related, their relationships have never been investigated on a global scale. Comparing PD and FD with species richness corroborated the general assumptions of surrogacy of the different diversity measures. However, the analysis of the residual variance suggested that the mismatches between the diversity measures are influenced by environmental conditions. PD increased relative to species richness with increasing mean annual temperature, whereas FD decreased with decreasing seasonality relative to PD. We also show that the tropical areas are characterized by a FD deficit, a phenomenon, that suggests that in tropical areas more species can be packed into the ecological space. We discuss potential mechanisms that could have resulted in the gradient of spatial mismatch observed in the different biodiversity measures and draw parallels to local scale studies. We conclude that the use of multiple diversity measures on a global scale can help to elucidate the relative importance of historical and ecological processes shaping the present gradients in mammalian diversity.
Journal Article
Global priority areas for amphibian research
by
Nori, Javier
,
Loyola, Rafael
,
Villalobos, Fabricio
in
Amphibians
,
complementary‐based assessment
,
Conservation
2018
Aim Lack of biological information is a silent but strong impediment for planning how to rescue amphibians from extinction. Currently, 24% of all amphibian species are assigned to the Data Deficient (DD) category of IUCN. Here, we aim to identify priority areas for amphibian research that could help gather information on these species and overcome such knowledge gap. Location Global. Taxon Amphibians. Methods We mapped the distribution of 1578 DD amphibian species and then defined priority research areas as those areas with high and complementary concentration of amphibian DD species that could be considered important areas for studying (and therefore conserving) such species. To evaluate the performance of the proposed priority research areas, we calculated the percentage of species overlapping these areas, considering all amphibian DD species; recently described species and geographically restricted DD species. We also determined the proportion of priority research areas falling inside each continent and country of the world. Finally, we estimated the level protection of these species and of human pressure on natural ecosystems found within our priority research areas. Results We showed that gathering biological information of species from just 0.4% of the world area could clarify the conservation status of more than 80% of DD amphibians. Most identified priority research areas overlap with regions under high human pressure and only a small percentage of DD amphibian species might cope with those altered conditions. Main conclusions Knowledge shortfalls represent a major issue for amphibian conservation globally, however, the picture could radically change if research efforts and investments are geographically strategically distributed. This study brings the first application of a complementary‐based tool, which has been originally designed and implemented in conservation planning, aimed at generating information that help researchers to fill knowledge gaps as efficiently as possible.
Journal Article
Global priorities for conservation across multiple dimensions of mammalian diversity
by
Costa, Gabriel C.
,
Rondinini, Carlo
,
Loyola, Rafael
in
Biodiversity
,
Biodiversity and Ecology
,
Biological evolution
2017
Conservation priorities that are based on species distribution, endemism, and vulnerability may underrepresent biologically unique species as well as their functional roles and evolutionary histories. To ensure that priorities are biologically comprehensive, multiple dimensions of diversity must be considered. Further, understanding how the different dimensions relate to one another spatially is important for conservation prioritization, but the relationship remains poorly understood. Here, we use spatial conservation planning to (i) identify and compare priority regions for global mammal conservation across three key dimensions of biodiversity—taxonomic, phylogenetic, and traits—and (ii) determine the overlap of these regions with the locations of threatened species and existing protected areas. We show that priority areas for mammal conservation exhibit low overlap across the three dimensions, highlighting the need for an integrative approach for biodiversity conservation. Additionally, currently protected areas poorly represent the three dimensions of mammalian biodiversity. We identify areas of high conservation priority among and across the dimensions that should receive special attention for expanding the global protected area network. These highpriority areas, combined with areas of high priority for other taxonomic groups and with social, economic, and political considerations, provide a biological foundation for future conservation planning efforts.
Journal Article
Climate change threatens protected areas of the Atlantic Forest
by
Melo, Adriano Sanches
,
Loyola, Rafael Dias
,
Lemes, Priscila
in
altitude
,
Amphibia. Reptilia
,
amphibians
2014
Only 7 % of the Atlantic Forest Biodiversity Hotspot is currently protected, though it holds 18 % of all amphibian species in South America. How effective would the Atlantic Forest network of protected areas (PAs) be in a changing climate? Are there some intrinsic features of PAs that drive species loss or gain inside them? We addressed these questions by modeling the ecological niches of 430 amphibian species in the Atlantic Forest and projecting their distributions into three future climate change simulations. We then assessed changes in species richness inside PAs for different time frames and tested their significance via null model. The number of species should decline within Atlantic Forest network of PAs under changing climate conditions. Only altitude was a good predictor of species gains or lost inside PAs. Therefore, we suggest that new PAs established in highlands would be more effective to alleviate the effects of climate change on this imperiled fauna.
Journal Article
consistent metric for nestedness analysis in ecological systems: reconciling concept and measurement
by
Guimarães, Paulo
,
Ulrich, Werner
,
Almeida-Neto, Mário
in
Alternatives
,
Animal and plant ecology
,
Animal, plant and microbial ecology
2008
Nestedness has been widely reported for both metacommunities and networks of interacting species. Even though the concept of this ecological pattern has been well-defined, there are several metrics by which it can be quantified. We noted that current metrics do not correctly quantify two major properties of nestedness: (1) whether marginal totals (i.e. fills) differ among columns and/or among rows, and (2) whether the presences (1's) in less-filled columns and rows coincide, respectively, with those found in the more-filled columns and rows. We propose a new metric directly based on these properties and compare its behavior with that of the most used metrics, using a set of model matrices ranging from highly-nested to alternative structures in which no nestedness should be detected. We also used an empirical dataset to explore possible biases generated by the metrics as well as to evaluate correlations between metrics. We found that nestedness has been quantified by metrics that inappropriately detect this pattern, even for matrices in which there is no nestedness. In addition, the most used metrics are prone to type I statistical errors while our new metric has better statistical properties and consistently rejects a nested pattern for different types of random matrices. The analysis of the empirical data showed that two nestedness metrics, matrix temperature and the discrepancy measure, tend to overestimate the degrees of nestedness in metacommunities. We emphasize and discuss some implications of these biases for the theoretical understanding of the processes shaping species interaction networks and metacommunity structure.
Journal Article
Connectivity of the global network of protected areas
2016
AIM: Millennia of human activity have drastically shaped the Earth's surface confining wildlife in ever more rare and sparse habitat fragments. Within the strategic Plan for Biodiversity 2011–2020, Aichi Target 11 aims at the expansion of the current protected area (PA) system and the maintenance and improvement of its connectivity. This study aims at providing the first overview of the functionality of the PA networks across the six continents at different dispersal distances relevant for terrestrial mammals. LOCATION: Global. METHODS: We used a graph theory approach to assess the connectivity of PA networks of different continents across a wide range of dispersal distances. We assessed the connectivity of country‐level PA networks, the connectivity of continental PA networks and the contribution of country‐level PA networks to continental connectivity. RESULTS: National and continental networks are characterized by very different spatial arrangements that translate into different levels of connectivity, ranging from networks where the reachable area is mostly determined by structural connectivity within PAs (e.g. Africa) to networks where connectivity mostly depends on animal dispersal among PAs (e.g. Europe). PA size correlates positively with connectivity for all species, followed by PA number; dispersal contributes less and positively interacts with number of PAs. MAIN CONCLUSIONS: Continental networks perform worse than national networks. Transboundary connectivity is often weak and should be improved, especially for countries that are important in promoting continental connectivity. Increasing PA coverage and size is a good strategy to improve multispecies connectivity.
Journal Article
Multifaceted diversity–area relationships reveal global hotspots of mammalian species, trait and lineage diversity
by
Renaud, Julien
,
Mazel, Florent
,
Loyola, Rafael
in
Animal and plant ecology
,
Animal, plant and microbial ecology
,
Biodiversity
2014
AIM: To define biome‐scale hotspots of phylogenetic and functional mammalian biodiversity (PD and FD, respectively) and compare them with ‘classical’ hotspots based on species richness (SR) alone. LOCATION: Global. METHODS: SR, PD and FD were computed for 782 terrestrial ecoregions using the distribution ranges of 4616 mammalian species. We used a set of comprehensive diversity indices unified by a recent framework incorporating the relative species coverage in each ecoregion. We built large‐scale multifaceted diversity–area relationships to rank ecoregions according to their levels of biodiversity while accounting for the effect of area on each facet of diversity. Finally we defined hotspots as the top‐ranked ecoregions. RESULTS: While ignoring relative species coverage led to a fairly good congruence between biome‐scale top ranked SR, PD and FD hotspots, ecoregions harbouring a rich and abundantly represented evolutionary history and FD did not match with the top‐ranked ecoregions defined by SR. More importantly PD and FD hotspots showed important spatial mismatches. We also found that FD and PD generally reached their maximum values faster than SR as a function of area. MAIN CONCLUSIONS: The fact that PD/FD reach their maximum value faster than SR could suggest that the two former facets might be less vulnerable to habitat loss than the latter. While this point is expected, it is the first time that it has been quantified at a global scale and should have important consequences for conservation. Incorporating relative species coverage into the delineation of multifaceted hotspots of diversity led to weak congruence between SR, PD and FD hotspots. This means that maximizing species number may fail to preserve those nodes (in the phylogenetic or functional tree) that are relatively abundant in the ecoregion. As a consequence it may be of prime importance to adopt a multifaceted biodiversity perspective to inform conservation strategies at a global scale.
Journal Article