Biology subjects

Borel, S.

Publications and source records attributed to Borel, S..

3 recordsLinked to original sources

bioRxiv2025

What if wildlife health surveillance was not just for veterinarians? - Opportunistic use of population monitoring by camera traps for syndromic surveillance of the Eurasian lynx (Lynx lynx)

Fifty years after the reintroduction of the Eurasian lynx Lynx lynx to the Vosges and Swiss Jura mountains, the species remains in danger of extinction in France. The main threats it faces are habitat fragmentation, high anthropogenic mortality (mainly vehicle collision but also illegal killing) and low genetic diversity, but little is known about the importance of disease. Camera trapping surveillance provides crucial information for understanding population health status but includes many biases. To be more efficient, surveillance must combine several modalities. This work first presents the development of a protocol for clinical data collection by camera trapping, intended for biologists in charge of the populations monitoring. This method was then applied to the 3574 events, i.e. 270 identified individuals, present between 1997 and 2020 in the lynx photo identification database of the Wolf-Lynx Network (Reseau Loup-Lynx) of the French Biodiversity Agency (Office Francais de la Biodiversite). Seventeen percent of the lynx studied showed at least one change indicative of disease. The most common changes were skin disorders. The others were body condition, ocular or locomotor changes, lack of auriculas and rarely respiratory, behavioral, or digestive troubles. The latter changes were concentrated at the end of the study period, which also corresponded to the period with the most camera traps and therefore the most data. Finally, these observations complemented postmortem surveillance of the French lynx population carried out by the French network of epidemiological surveillance (Reseau SAGIR).

ecology↗

bioRxiv2025

Annotating opportunistic camera-trap images with conditions ofrecording, for the disease surveillance of Eurasian lynx (Lynxlynx)

The French population of the Eurasian lynx (Lynx lynx) is small and fragmented. Any emerging disease would endanger it even further, so health surveillance is crucial. Currently, health monitoring relies on lynx carcass surveillance. In parallel, the Eurasian lynx population is being monitored since 1997 through a large network of observers in different regions and this trove of camera-trap images could allow for the opportunistic detection of clinical signs. Camera traps have been used for a very long time in ecology and, more recently, in epidemiology to study e.g. sarcoptic mange. However, the quality of the images from camera traps varies, the details of the animals body are more or less clearly visible. This work examines how the quality of the images relates to the ability to detect cutaneous changes and abnormal body conditions. Different factors affect image quality and the detection of changes: intrinsic camera parameters like the type and settings of the camera trap, extrinsic factors like the external lighting conditions or the position of the animal in relation to the camera. In our data set, clearly visible cutaneous changes were associated with a different set of factors than visible abnormal body conditions. The camera-trap conditions currently used for ecological monitoring of the lynx are sufficiently diverse to allow for the general surveillance of abnormal health signs. However, for monitoring specific health signs, the camera settings as well as the shooting context should be optimized to ensure the best possible sensitivity and specificity of the detection.

ecology↗

bioRxiv2023

Analysis of a European general wildlife health surveillance program: chances, challenges and recommendations

In the context of a One Health perspective general wildlife health surveillance (GWHS) gains importance worldwide, as pathogen transmission among wildlife, domestic animals and humans raises health, conservation and economic concerns. However, GWHS programs operate in the face of legal, geographical, financial, or administrative conditions. The present study uses a multi-tiered approach to understand the current characteristics, strengths and gaps of a European GWHS that operates in a fragmented legislative and multi-stakeholder environment. The aim is to support the implementation or improvement of other GWHS systems by managers, surveillance experts, and administrations. To assess the current state of wildlife health investigations and trends within the GWHS, we analyzed 20 years of wildlife diagnostic data, conducted an online survey and phone interviews with official field partners (hunting administrators, game wardens and hunters), and performed a time-per-task analysis. Firstly, we found that infectious disease dynamics, the level of public awareness for specific diseases, research activities and increasing population sizes of in depth-monitored protected species, together with biogeographical and political boundaries all impacted case numbers and can present unexpected challenges to a GWHS. Secondly, we found that even a seemingly comprehensive GWHS can feature pronounced information gaps, with underrepresentation of common or easily recognizable diseases, blind spots in non-hunted species and only a fraction of discovered carcasses being submitted. Thirdly, we found that substantial amounts of wildlife health data may be available at local hunting administrations or disease specialist centers, but outside the reach of the GWHS and its processes. In conclusion, we recommend that fragmented and federalist GWHS programs like the one addressed require a central, consistent and accessible collection of wildlife health data. Also, considering the growing role of citizen observers in environmental research, we recommend using online reporting systems to harness decentrally available information and fill wildlife health information gaps.

zoology↗