Intoxication secondaire

secondary-intoxication

Deux articles pour mieux comprendre l’intoxication secondaire: la possible intoxication de prédateurs après avoir mangé plusieurs proies intoxiquées.

Sage, M., Fourel, I., Cœurdassier, M., Barrat, J., Berny, P. & Giraudoux, P. (2010). Determination of bromadiolone residues in fox faeces by LC/ESI-MS in relationship with toxicological data and clinical signs after repeated exposure. Environ. Res. 110, 664–674.

GROLLEAU, G., LORGUE, G. & NAHAS, K. (1989). Toxicité secondaire, en laboratoire, ďun rodenticide anticoagulant (bromadiolone) pour des prédateurs de rongeurs champêtres: buse variable (Buteo buteo) et hermine (Mustela erminea). EPPO Bull. 19, 633–648.

Les deux articles sont dans notre contexte : bromadiolone (rodenticide anticoagulant de seconde génération), campagnols, renards et hermines.

Sur ce sujet, nous avons collecté des campagnols dans chaque site d’étude en collaboration avec la FREDON Franche-Comté. Les résidus de bromadiolone dans le foie des campagnols vont être analysés en collaboration avec Vetagro Sup. Ainsi, nous aurons à notre disposition des informations sur la présence de bromadiolone dans les campagnols, proies importantes des prédateurs en conditions naturelles.

The experience from New Zealand

We continue collecting data and samples for our project but there are already relevant studies that help us to understand the effect of anticoagulant rodenticides on predators and rodent populations. For instance, this one from New Zealand:

Murphy, E.C., Clapperton, B.K., Bradfield, P.M.F. & Speed, H.J. (1998). Effects of rat‐poisoning operations on abundance and diet of mustelids in New Zealand podocarp forests. New Zeal. J. Zool. 25, 315–328.

In this country stoats, weasels and ferrets were introduced to control the populations of rabbits.  Unfortunately, small mustelids and other alien predators have contributed to the rarefaction of many native species in New Zealand. One of the main management tools to control these alien predators and rodents is the use of anticoagulant rodenticides and other poisoned baits to protect New Zealand’s biodiversity.

In the proposed study there were reductions of number of trapped stoats and thus assumed declines of population densities during the early use of anticoagulant rodenticides to kill rats. However there is a recovery in the number of trapped stoats soon after.

In our project we are also studying this population changes of small mustelids, not well known at our geographic context and system.

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Here it’s me helping in the monitoring of alien predators during a stay that conducted at Landcare Research during my PhD.

Des murs traditionnels pour la biodiversité

La Fédération Départementale des Chasseurs du Doubs a organisé le samedi dernier l’activité suivant:

restauration-mur-traditionnel

 

Malheureusement je n’ai pu participer mais je voulais le diffuser pour l’importance qu’a pour la biodiversité et spécialement pour les populations de petit mustélidés, l’hermine et la belette. Beaucoup des traces que je trouve sur mes tubes de suivi des empreintes sont placées sur murs traditionnels.

Le problème des campagnols et autres pestes agricoles est un problème aussi d’homogénéisation paysagère comme vous pouvez constater dans cette article:

Bianchi, F. J. J. A., Booij, C. J. H., & Tscharntke, T. (2006). Sustainable pest regulation in agricultural landscapes: a review on landscape composition, biodiversity and natural pest control. Proceedings of the Royal Society of London B: Biological Sciences, 273(1595), 1715-1727.

La présence de ces murs aide aux populations des petits mustélidés et autres prédateurs, que mangent des campagnols et potentiellement aident à diminuer les dégâts des campagnols.

20161126-mur-gonsans-b-vuillemin-et-g-pourchet-11

Merci a Marie Salomon pour ces photos et flyer.

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Biomathematics models to answer our research question

campagnol-maths

We have been working on this and we have submitted an abstract for the SETAC Europe Congress 2017. For me, Javier, it will be very enriching because I never attended to a congress of the Society of Environmental Toxicology and Chemistry

setac-2017

We add here the submitted abstract in case it interests you 🙂

Is rodenticide use disrupting the natural regulation of vole populations? A biomathematics modelling approach

Javier Fernandez-de-Simon1, Virgile Baudrot1, Michael Coeurdassier1, Xavier Lambin2, Patrick Giraudoux1,3

1Laboratoire Chrono-environnement UMR 6249 UBFC-CNRS, 16 Route de Gray, 25000, Besançon, France

2School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, Scotland, UK

3Institut Universitaire de France, Paris, France
E-mail contact: javier.fernandez_de_simon_romero@univ-fcomte.fr

Abstract Anthropogenic activities modify ecosystems and as a result some ecological relationships are altered. For instance, many agricultural areas have followed a process of intensification. In these areas, voles frequently achieve pest levels through cyclic outbreaks reducing the food available for livestock and crop yields. Subsequently, some farmers respond using anticoagulant rodenticides to control voles. Thus, predators may be indirectly controlled by secondary exposure to rodenticides or by a reduction of food sources. Therefore, anticoagulant rodenticides might be acting analogously as a superpredator, interfering in the natural regulation of vole populations. Under what circumstances this may arise is not known. The objective of this study is to understand the interactions between an anticoagulant rodenticide (bromadiolone) to control vole populations and its indirect effects over vole specialist predators (stoats Mustela erminea and weasels Mustela nivalis) and a generalist predator of voles (the red fox Vulpes vulpes). We use a biomathematics modelling approach based on differential equations to explore several scenarios of this system. To study this we developed a model with two coupled dynamics: (i) the three studied animal populations, and (ii) their bromadiolone concentration. The four scenarios used are: Scenario 1, no bromadiolone use and no foxes; Scenario 2, bromadiolone use but no foxes; Scenario 3, no bromadiolone use but foxes; and Scenario 4, bromadiolone use and foxes. We observed the behaviour of the parts of the system until dynamics stabilisation. Our findings in Scenario 1 show a population decline of voles up to an equilibrium in relation to a mustelid numerical response. In Scenario 2, we found a quick decline of voles and mustelids, followed by their recovery. In Scenario 3, there were stable vole dynamics and small effect of predation over voles. In Scenario 4, we found a decline and delayed recovery of all species. The highest final vole densities appear in Scenario 3 and 4, with red foxes, which are affected by bromadiolone use but also behave as generalist predators with wider food spectrum and thus less exposure. They also feed on small mustelids, specialist predators of voles. The next steps of this study will be to model additional scenarios, using new parameters and sensitivity analyses. The future modelling results will be compared with field results in areas where bromadiolone showed red fox population decreases.

As you can see Virgile Baudrot, recently awarded with a PhD by the Université Bourgogne Franche-Comté, is providing a great input in this study. I am definitively learning a lot with him about biomathematics models and I strongly recommend reading this brilliant paper on functional responses that has been recently published:

 

Baudrot, V., Perasso, A., Fritsch, C., Giraudoux, P. & Raoul, F. (2016). The adaptation of generalist predators’ diet in a multi-prey context: insights from new functional responses. Ecology 97, 1832–1841.

If you are more interested on his research, you can also find him for instance in several internet sites:

https://chrono-environnement.univ-fcomte.fr/spip.php?article1682

https://www.researchgate.net/profile/Virgile_Baudrot

https://fr.linkedin.com/in/virgile-baudrot-03a08195

 

 

 

Invasive mustelids show use of anticoagulant rodenticides

A nice article recently published with Prof. Xavier Lambin as coauthor.

Ruiz-Suárez, Norberto, et al. “Rate of exposure of a sentinel species, invasive American mink (Neovison vison) in Scotland, to anticoagulant rodenticides.” Science of the Total Environment 569 (2016): 1013-1021.

http://www.sciencedirect.com/science/article/pii/S0048969716312839

Congratulations to the authors, for these new findings.I am sure they will allow mapping rodenticide risks and consequently  help biodiversity conservation and management.

ruiz-suarez2016-science-of-the-total-environment

Nuit Européen des Chercheurs 2016

 

nuit-europeenne-des-chercheurs-2016

Comme chaque année, l’Université de Bourgogne Franche Comte a organisé la Nuit Européenne des chercheurs, où nous avons eu la possibilité d’exposer nos travaux en collaboration avec d’autres membres du Laboratoire Chrono-environnement. Entre 19h et 23h, nous avons accueillis sur notre stand entre 50-100 personnes qui ont été sensibilisées à l’utilisation de la bromadiolone comme outil de lutte contre les pullulations et les dégâts causés par les campagnols. Aussi, nous avons abordés la problématique de l’empoisonnement et ses conséquences sur la faune sauvage. Nous avons également fait le point sur l’état d’avancement de notre étude qui concerne les relations bromadiolone-prédateurs-campagnols et plus précisément le suivi des populations des petits mustélidés, des renards et des campagnols. De plus, nous avons proposé un petit jeu de reconnaissance des traces des animaux permettant d’identifier des petits mammifères dans les tubes de suivi des empreintes. Enfin, nous avons distribué un flyer résumant notre projet.

Ici, un lien du Est Republicain sur la Nuit Européen des Chercheurs 2016:

http://www.estrepublicain.fr/edition-de-besancon/2016/10/01/besancon-la-nuit-europeennes-des-chercheurs

nuit-des-chercheurs-une-nuit-d-echanges

Merci à Jeremy Querenet et l’UBFC pour son implication et support pour diffuser notre projet.

https://www.facebook.com/jeremy.querenet/videos/1069311316457424/

France Bleu et la Cellule Europe ont connu notre projet

Voilà les liens. Merci bien pour l’intérêt.

Comme ça, on va faire un peu de communication en langue française aussi. Bonne écoute et bonne lecture ! 🙂

https://www.francebleu.fr/emissions/c-est-bon-savoir/besancon/c-est-bon-savoir-18

http://valorisation.univ-fcomte.fr/pages/fr/menu4199/financements-de-projets/programmes-europeens/lettres-de-liaison-18546.html