Game species monitoring using road-based distance sampling in association with thermal imagers: a covariate analysis

Monitorización de especies cinegéticas utilizando el muestreo a distancia con base en una carretera, en combinación con imágenes termográficas: un análisis de covariables La monitorización de las poblaciones de especies cinegéticas es necesaria para evaluar adecuadamente las capturas de los cazadores, en zonas que carecen de los grandes depredadores naturales. Sin embargo, los gestores de la caza deben controlar diversas especies y a menudo carecen de un método de control con un diseño conveniente. Por lo tanto, la monitorización de diversas especies al mismo tiempo en áreas muy grandes podría ser eficaz desde el punto de vista de los costes y del tiempo. Estudiamos la influencia de diversos factores durante la monitorización de tres especies cinegéticas comunes (el jabalí, el corzo y el zorro rojo) utilizando un muestreo a distancia desde la carretera, en asociación con imágenes termográficas. Este examen piloto basado en 20 recuentos nocturnos en cinco lugares contrastantes estudió el efecto de diversas covariables (especie, termografía, observador, tamaño del grupo y tipo de hábitat) sobre las probabilidades de detección (dp). No se hallaron diferencias entre las imágenes termográficas (dpJENOPTIK: 0,186, dpFLIR: 0,193) y el tamaño de los grupos (dp1ind.: 0,243, dp2ind.: 0,259, dp> 2ind.: 0,223), pero sí entre los observadores (dpobs1: 0,207, dpobs2: 0,274, dpobs3: 0,159). También se observaron diferencias esperadas entre las especies (dpwild boar: 0,22, dproe deer: 0,35, dpred fox: 0,32) y entre los tipos de hábitat (dpforest: 0,27, dpedge: 0,74, dpopen: 0,35). Nuestros resultados demuestran que la detectabilidad de los equipos de termografía de bajo coste es similar a la de otros métodos caros, destacando nuevas posibilidades del uso de la termografía para los gestores de la caza. Aunque deberían realizarse ajustes en el diseño del estudio, nuestros hallazgos sugieren que la monitorización de múltiples especies a gran escala podría ser un método eficaz para las especies cinegéticas comunes.Monitorización de especies cinegéticas utilizando el muestreo a distancia con base en una carretera, en combinación con imágenes termográficas: un análisis de covariables La monitorización de las poblaciones de especies cinegéticas es necesaria para evaluar adecuadamente las capturas de los cazadores, en zonas que carecen de los grandes depredadores naturales. Sin embargo, los gestores de la caza deben controlar diversas especies y a menudo carecen de un método de control con un diseño conveniente. Por lo tanto, la monitorización de diversas especies al mismo tiempo en áreas muy grandes podría ser eficaz desde el punto de vista de los costes y del tiempo. Estudiamos la influencia de diversos factores durante la monitorización de tres especies cinegéticas comunes (el jabalí, el corzo y el zorro rojo) utilizando un muestreo a distancia desde la carretera, en asociación con imágenes termográficas. Este examen piloto basado en 20 recuentos nocturnos en cinco lugares contrastantes estudió el efecto de diversas covariables (especie, termografía, observador, tamaño del grupo y tipo de hábitat) sobre las probabilidades de detección (dp). No se hallaron diferencias entre las imágenes termográficas (dpJENOPTIK: 0,186, dpFLIR: 0,193) y el tamaño de los grupos (dp1ind.: 0,243, dp2ind.: 0,259, dp> 2ind.: 0,223), pero sí entre los observadores (dpobs1: 0,207, dpobs2: 0,274, dpobs3: 0,159). También se observaron diferencias esperadas entre las especies (dpwild boar: 0,22, dproe deer: 0,35, dpred fox: 0,32) y entre los tipos de hábitat (dpforest: 0,27, dpedge: 0,74, dpopen: 0,35). Nuestros resultados demuestran que la detectabilidad de los equipos de termografía de bajo coste es similar a la de otros métodos caros, destacando nuevas posibilidades del uso de la termografía para los gestores de la caza. Aunque deberían realizarse ajustes en el diseño del estudio, nuestros hallazgos sugieren que la monitorización de múltiples especies a gran escala podría ser un método eficaz para las especies cinegéticas comunes.Monitoring of game species populations is necessary to adequately assess culling by hunters in areas where natural large predators are absent. However, game managers have to control several species and they often lack of an efficient and convenient survey design method. Monitoring several species at that same time over large areas could thus be cost– and time–effective. We tested the influence of several factors during monitoring of three common game species, (wild boar, roe deer and red fox, using road–based distance sampling in association with thermal imagers. This pilot survey based on 20 night counts in five contrasting sites studied the effect of several covariates (species, thermal imaging, observer, group size, and habitat type) on the detection probabilities (= dp). No differences were observed between thermal imagers (dpJENOPTIK: 0.186, dpFLIR: 0.193) and group sizes (dp1ind.: 0.243, dp2ind.: 0.259, dp> 2ind.: 0.223), but we found differences between observers (dpobs1: 0.207, dpobs2: 0.274, dpobs3: 0.159). Expected differences were also observed between species (dpwild boar: 0.22, dproe deer: 0.35, dpred fox: 0.32) and between habitat type (dpforest: 0.27, dpedge: 0.74, dpopen: 0.35). Our results show that the detectability of low cost thermal imaging equipment is similar to that of more expensive methods, highlighting new possibilities for the use of thermal imagery by game managers. Although adjustments should be made to the study design our findings suggest that large–scale multi–species monitoring could be an efficient method for common game species

Les indicateurs de la pression du cerf élaphe sur la végétation du sous-bois en forêt feuillue tempérée (synthèse bibliographique)

Indicators of red deer pressure on understory vegetation in temperate deciduous forest. A review. During recent decades, populations of large herbivores have increased. Consequently, their pressure on forest vegetation has been exacerbated and, in some forests, has reached levels that have reduced the diversity of forest ecosystem services. Assessing the balance between timber production and hunting remains a crucial question for forest users (foresters, hunters) and requires reliable tools such as ecological indicators. This paper reviews the ecological indicators that characterize the pressure of red deer (Cervus elaphus L.) on understory vegetation in temperate deciduous forest. Such indicators monitor the cover, height, stem density, biomass and species diversity of different indicator plant groups. These plant groups embrace species belonging to the herbaceous stratum, forest regeneration or particular species such as bilberry (Vaccinium myrtillus L.) and bramble (Rubus fruticosus L.). As the choice of indicator plants affects considerably the performance of the ecological indicator of deer pressure on understory vegetation, such decisions must be carried out with caution, taking into account plant abundance and palatability. The reviewed indicators help us to understand the relationship between biodiversity, carrying capacity and deer populations. They are intended for use by forest managers who would like to monitor red deer pressure in relation to forest management goals and forest sustainability

Game species monitoring using road-based distance sampling in association with thermal imagers: a covariate analysis

Monitoring of game species populations is necessary to adequately assess culling by hunters in areas where natural large predators are absent. However, game managers have to control several species and they often lack of an efficient and convenient survey design method. Monitoring several species at that same time over large areas could thus be cost– and time–effective. We tested the influence of several factors during monitoring of three common game species, (wild boar, roe deer and red fox, using road–based distance sampling in association with thermal imagers. This pilot survey based on 20 night counts in five contrasting sites studied the effect of several covariates (species, thermal imaging, observer, group size, and habitat type) on the detection probabilities (= dp). No differences were observed between thermal imagers (dpJENOPTIK: 0.186, dpFLIR: 0.193) and group sizes (dp1ind.: 0.243, dp2ind.: 0.259, dp> 2ind.: 0.223), but we found differences between observers (dpobs1: 0.207, dpobs2: 0.274, dpobs3: 0.159). Expected differences were also observed between species (dpwild boar: 0.22, dproe deer: 0.35, dpred fox: 0.32) and between habitat type (dpforest: 0.27, dpedge: 0.74, dpopen: 0.35). Our results show that the detectability of low cost thermal imaging equipment is similar to that of more expensive methods, highlighting new possibilities for the use of thermal imagery by game managers. Although adjustments should be made to the study design our findings suggest that large–scale multi–species monitoring could be an efficient method for common game species

Transfer Learning for Prostate Cancer Mapping Based on Multicentric MR Imaging Databases

International audienceThis paper addresses the issue of fusing datasets coming from different imaging protocols or scanners to boost the performance of computer aided diagnostic system. We present novel contributions in the field of subspace alignment methods that are part of domain adaptation framework. We first introduce a simple approach based on scaling the features of the different distribution and accounting for the class information. We also extend an unsupervised landmark based approach that has been recently developed to the supervised setting. These methods are evaluated in the context of prostate cancer screening based on two patient MRI databases acquired on different scanners. We demonstrate promising performance of the scaling based method when both databases contain similar number of annotated samples, and stable performance of the landmark based method even with unbalanced datasets

Evaluation of a 3D MR/MR elastic registration method for prostate cancer imaging

International audienceEarly detection and localization of prostate cancer is crucial for appropriate patient management. Recent studies suggest that computer-assisted diagnosis systems combining different imaging modalities (MR/MR, MR/US) can improve prostate cancer detection1 and open the wayto targeted biopsies and focal therapy2. Such fusion processes are limited by prostate motion and deformation, particularly at the prostate-rectum interface. A non-rigid multimodal image registration process based on shape statistics has been developed to coregister T2-weighted MR and 3D transrectal ultrasound acquisitions3. Based on the good precision achieved4, this method was adapted to coregister T2-weighted, diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) images and evaluated on 28 prostate cancer patients