African swine fever (ASF) is an infectious and highly fatal disease affecting wild and domestic swine, which is unstoppably spreading worldwide. In Europe, wild boars are one of the main drivers of ...spread, transmission, and maintenance of the disease. Landscape connectivity studies are the main discipline to analyze wild-species dispersal networks, and it can be an essential tool to predict dispersal-wild boar movement routes and probabilities and therefore the associated potential ASF spread through the suitable habitat. We aimed to integrate wild boar habitat connectivity predictions with their occurrence, population abundance, and ASF notifications to calculate the impact (i.e., the capacity of a landscape feature to favor ASF spread) and the risk (i.e., the likelihood of a habitat patch becoming infected) of wild boar infection across Europe. Furthermore, we tested the accuracy of the risk of infection by comparing the results with the temporal distribution of ASF cases. Our findings identified the areas with the highest impact and risk factors within Europe's central and Eastern regions where ASF is currently distributed. Additionally, the impact factor was 31 times higher on habitat patches that were infected vs non-infected, proving the utility of the proposed approach and the key role of wild boar movements in ASF-spread. All data and resulting maps are openly accessible and usable.
Land conversion is causing habitat loss and fragmentation worldwide, particularly in Africa, where the proliferation of agricultural development corridors may threaten vital areas for ecological ...connectivity and wildlife survival. To conserve connectivity, careful landscape planning is necessary, which strongly relies on remotely sensed land cover maps. Here, we present a remote sensing‐based framework that efficiently identifies priority locations for connectivity conservation. We applied the framework in the Kilombero catchment and development cluster of the Southern Agricultural Growth Corridor (SAGCOT) in Tanzania, where new agricultural development projects could act as barriers for connectivity. Using satellite imagery from Sentinel‐1 and 2, we mapped the mixture of mountain and lowland land covers and habitats with an overall accuracy of 75%. Then, we assessed ecological connectivity to predict African elephant corridors and prioritize them in two ways. First, we identified elephant corridors that contribute the most to current landscape connectivity, and second, we identified those whose restoration would significantly enhance landscape functionality and improve the current connectivity level. We mapped 214 potential elephant corridors, identified 43 of them as priority for conservation, and 43 as target for restoration. Our model predicted four already known corridor areas in and around the Kilombero valley floodplain, and other important corridors not yet identified by previous studies in the south of the basin. Priority elephant corridors inside the floodplain showed narrow widths and low permeability, indicating low functionality in the connectivity network. Nevertheless, the abundance of priority corridors for restoration suggests that connectivity could be recovered if the recommended measures are applied during SAGCOT planning and implementation process. Our findings demonstrate the possibilities of combining multispectral and radar data for guiding biodiversity management in development corridors and for assessing ecological connectivity worldwide.
We present a broadly applicable approach that combines Sentinel‐1 and 2 imagery to identify priority locations to protect and restore ecological connectivity. Our approach involves the production of land cover and habitat maps with enough spatial and thematic resolution to predict wildlife corridors and prioritize them based on their current and potential importance for connectivity. We tested the approach with the African elephant in the Kilombero catchment (Tanzania), where a development corridor will bring new agricultural and infrastructure projects that could act as barriers for elephant dispersal. We found multiple elephant corridors with an unprecedented level of detail in the region. Moreover, we prioritized those that should be protected and restored to secure the functionality of the connectivity network during the development corridor implementation process. These findings demonstrate the capabilities of our approach and support the potential of combining Sentinel‐1 and 2 imagery for mapping and assessing connectivity.
Ecological modeling requires sufficient spatial resolution and a careful selection of environmental variables to achieve good predictive performance. Although national and international ...administrations offer fine-scale environmental data, they usually have limited spatial coverage (country or continent). Alternatively, optical and radar satellite imagery is available with high resolutions, global coverage and frequent revisit intervals. Here, we compared the performance of ecological models trained with free satellite data with models fitted using regionally restricted spatial datasets. We developed brown bear habitat suitability and connectivity models from three datasets with different spatial coverage and accessibility. These datasets comprised (1) a Sentinel-1 and 2 land cover map (global coverage); (2) pan-European vegetation and land cover layers (continental coverage); and (3) LiDAR data and the Forest Map of Spain (national coverage). Results show that Sentinel imagery and pan-European datasets are powerful sources to estimate vegetation variables for habitat and connectivity modeling. However, Sentinel data could be limited for understanding precise habitat–species associations if the derived discrete variables do not distinguish a wide range of vegetation types. Therefore, more effort should be taken to improving the thematic resolution of satellite-derived vegetation variables. Our findings support the application of ecological modeling worldwide and can help select spatial datasets according to their coverage and resolution for habitat suitability and connectivity modeling.
Abstract
Background
When assessing connectivity, it is crucial to rely on accurate modeling frameworks that consider species movement preferences and patterns. One important aspect is the level of ...randomness or unpredictability in the route selection. In this respect, traditional approaches (based on least-cost path or circuit theory) consider species movements unrealistically as totally deterministic or as totally random. A recent approach (randomized shortest path) advocates for choosing intermediate levels of randomness through a single parameter. This parameter may be optimized by validating connectivity surfaces developed from different levels of randomness against observed movement data. However, connectivity models are seldom validated, and it is still unclear how to approach this task. To address this knowledge gap, this paper aims at comparing different validation methods to infer the optimal randomness level in connectivity studies. Additionally, we aimed to disentangle the practical consequences of applying traditional connectivity approaches versus using an optimized level of movement randomness when delineating corridors.
Methods
These objectives were accomplished through the study case of the Iberian lynx, an endangered species whose maintenance and recovery depend on the current connectivity among its population nuclei. We firstly determined a conductance surface based on point selection functions accounting for the behavioral state (territorial or exploratory) of individuals. Secondly, we identified the level of randomness that better fits lynxes’ movements with independent GPS locations and different validation techniques. Lastly, we delineated corridors between lynx population nuclei through a) the randomized shortest path approach and the extreme and optimal levels of randomness of each validation method, and b) the traditional connectivity approaches.
Results
According to all used validation methodologies, models with intermediate levels of randomness outperformed those with extreme randomness levels representing totally deterministic or random movements. We found differences in the optimal randomness level among validation methods but similar results in the delineation of corridors. Our results also revealed that models with extreme randomness levels (deterministic and random walk) of the randomized path approach provided equivalent corridor networks to those from traditional approaches. Moreover, these corridor networks calculated with traditional approaches showed notable differences in patterns from the corridor network calculated with an optimized randomness level.
Conclusions
Here we presented a connectivity model with a solid biological basis that calibrates the level of movement randomness and is supported by comprehensive validation methods. It is thus a step forward in the search and evaluation of connectivity approaches that lead to improved, efficient, and successful management actions.
An ambitious conservation programme to save the Iberian lynx from extinction conducted several reintroductions aiming to restore its historical range. The urgency due to the delicate conservation ...status prompted translocating captive-born and wild individuals, while preventing an early assessment of how both groups combined their space-use and differed in post-release movements. To address this issue, we conducted a comprehensive movement ecology analysis using GPS data of 161 Iberian lynxes from 9 populations. First, we classified five movement phases within individuals' trajectories: residence areas (stable and transient), excursions, post-release dispersals, and transitions between residences. Second, we used continuous-time movement models to estimate range size and daily speeds and measured the distance travelled during extra-territorial movements. Finally, we conducted comparative analyses to evaluate differences between captive-born, wild translocated, and wild non-translocated individuals across phases, sex, age-class and populations. Most individuals in all groups established home ranges, supporting the reintroduction main goal. Yet, contrary to the species' natural pattern, captive-born subadults did not show intersexual home range size differences, which emerged after experiencing free-ranging, when becoming adults. More differences emerged for non-residential behaviours. Captive-born lynxes were more prone to post-release dispersal, to slower post-release movements and to having smaller transient residences, indicating cautious behaviour. Our study supports using captive-born individuals for reintroductions, while prioritizing wild individuals for reinforcements in highly competitive populations. Further, we suggest relevant metrics for planning translocations and connectivity management, and we demonstrate how an integrated ex-situ and reintroduction initiative can substantially contribute to restoring an endangered species' distribution range.
Display omitted
•Individual space-use behaviours shape population distributions.•As aimed, translocated wild and captive-born lynxes mostly established home ranges.•Captive subadults showed wild-like resident behaviour after free-range experience.•Captive-born lynxes showed post-release movements indicative of cautious behaviour.•Ex-situ conservation and translocations are effective to restore species ranges.
Objective: To evaluate the usefulness of the serum concentration of nine matrix metalloproteinases (MMPs) as biomarkers of spontaneous abortion.
Methods: A retrospective nested cohort case-control ...study was carried out in Zacatecas, Mexico. MMP-1-3, MMP-7-10, and MMP-12-13 were analyzed in serum from women who had spontaneous abortion of unknown causes (n = 7), who suffered abortions attributed to urinary tract infection (n = 7) and from those with healthy pregnancies without complications (controls; n = 20). Protein profiles were determined between 11 and 13 weeks of gestation (GW) using the Bio-Plex Pro Human MMP Panel. Differences in serum MMP concentrations between the study groups and their correlation with clinical findings were evaluated statistically.
Results: There were differences in serum concentrations of MMP-9 between groups of spontaneous abortion of unknown cause (13.2 ± 7.5 ng/µL), abortion attributed to urinary tract infection (11.6 ± 5.8 ng/µL) and the controls (11.8 ± 16.5 ng/µL) (p = .022). Compared with controls, higher serum concentrations of MMP-8, MMP-9, and MMP-10 were observed in the group of spontaneous abortions of unknown causes (p value < .05). A negative correlation between MMP-8 and MMP-9 and urine density was also identified (r = −0.949, p value = .0167; and r = −0.947, p = .0167).
Conclusions: Elevated serum concentrations of MMP-8, MMP-9, and MMP-10 were associated and preceded by the appearance of spontaneous interruption of pregnancy of unknown causes. Our results support the hypothesis that altered MMP modulation may be related with the pathogenesis of spontaneous abortion.
PDF
