Biology subjects

Said, S.

Publications and source records attributed to Said, S..

3 recordsLinked to original sources

bioRxiv2025

Spatial covariation between wild boars and other mammals in peri-urban landscapes: insights for management from southern France

Global urbanization is rapidly increasing, transforming ecosystems and favoring generalist species that adapt to human-modified environments. The wild boar, a highly adaptable species, is expanding its range and increasingly observed in urban and peri-urban areas, where it can cause accidents, damage, and health concerns. To mitigate their presence, non-lethal control strategies such as vegetation clearing in peri-urban parks and wastelands are being implemented to reduce the number of suitable resting sites. However, the ecological consequences of such habitat modifications on other wildlife species remain poorly understood. This knowledge gap limits the development of effective urban wildlife management strategies that seeks to balance ecological, social and economic considerations without harming wild boar populations and urban ecosystems. In this context, we used camera trapping to study the covariation between wild boars and other mammal species in a peri-urban area, with the aim of guiding targeted and effective management strategies. Here, we show a widespread presence of wild boars but no spatial or temporal covariation between the wild boars and the other species. In contrast, we found strong spatial structuring in mammal communities, primarily driven by small carnivores (mustelids, genets, cats, foxes) and a minimal influence of temporal variation, confirming that spatial factors, rather than seasonal changes, largely shaped species distributions. The study of the temporal variation across months indicated minimal seasonal structuring but revealed substantial within-site variability in month-to-month species abundance, with a general abundance gradient driven by common species like wild boar, cat, and fox. In conclusion, our results show that the lack of spatial covariation between wild boar and other species prevents reliable predictions, supporting a targeted rather than general approach to vegetation management.

ecology↗

bioRxiv2020

How to use random walks for modeling the movement of wild animals

Animal movement has been identified as a key feature in understanding animal behavior, distribution and habitat use and foraging strategies among others. At the same time, technological improvements now allow for generating large datasets of high sampled GPS data over a long period of time. However, such datasets often remain unused or used only in part due to the lack of practical models that can directly infer the desired features from raw GPS locations and the complexity of existing approaches. Some of them being disputed for their lack of rational or biological justifications in their design. We propose a simple model of individual movement with explicit parameters based on essential features of animal behavior. The main thrust was to stick to empirical observations, rather than using black-box models that could possibly perform very well while providing little insight from an ecological perspective. We used a simple model, based on a two-dimensional biased and correlated random walk with three forces related to advection, attraction and immobility of the animal. These forces can be directly estimated using individual raw GPS data. The performance of the model is assessed through 5 statistics that describe the spatial features of animal movement. We demonstrate the approach by using GPS data of 5 roe deer with high frequency sampling. We show that combining the three forces significantly improves the model performance. We also found that the models parameters are not affected by the sampling rate of the GPS, suggesting that our model could also be used with low frequency sampling GPS devices. Additionally, the practical design of the model was verified for detecting spatial feature abnormalities (such as voids) and for providing estimates of density and abundance of wild animals. Our results show that a simple and practicable random walk template can account for the spatial complexity of wild animals. Integrating even more additional features of animal movement, such as individuals interactions or environmental repellents, could help to better understand the spatial behavior of wild animals.

animal behavior and cognition↗

bioRxiv2020

A novel drug-combination screen in zebrafish identifies epigenetic small molecule candidates for Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a severe neuromuscular disorder and is one of the most common muscular dystrophies. There are currently few effective therapies to treat the disease, although many small-molecule approaches are being pursued. Specific histone deacetylase inhibitors (HDACi) can ameliorate DMD phenotypes in mouse and zebrafish animal models and have also shown promise for DMD in clinical trials. However, beyond these HDACi, other classes of epigenetic small molecules have not been broadly and systematically studied for their benefits for DMD. Here, we performed a novel chemical screen of a library of epigenetic compounds using the zebrafish dmd model. We identified candidate pools of epigenetic compounds that improve skeletal muscle structure in dmd zebrafish. We then identified a specific combination of two drugs, oxamflatin and salermide, that significantly rescued dmd zebrafish skeletal muscle degeneration. Furthermore, we validated the effects of oxamflatin and salermide in an independent laboratory. Our results provide novel, effective methods for performing a combination small-molecule screen in zebrafish. Our results also add to the growing evidence that epigenetic small molecules may be promising candidates for treating DMD.

pharmacology and toxicology↗