Contexte : The increase of trace metal elements (TME) concentrations can be problematic because some TME are clearly toxic and are in the substance priority list of the Agency of Toxic Substances and Disease Registry (ATSDR) (ATSDR 2019). For example, arsenic (As) and lead (Pb) are ranked 1st and 2nd on the 2019 list (ATSDR 2019). Yet, few studies address the effects of TME on the fauna. Such studies are required to tackle the consequences of urbanization. It is true that different studies in highly polluted industrial sites have shown negative effects of TME on wildlife. For example, reproductive success of great tits (Parus major), blue tits (Cyanistes caeruleus) and pied flycatchers (Ficedula hypoleuca) is lower in environment with high TME concentration (As, Cadmium (Cd), Copper (Cu), Nickel (Ni) and Pb) (Eeva and Lehikoinen 2004, Eeva et al. 2009). Such studies are not directly transposable to the urban environment because these concentrations are not representative of the diffuse pollution of the urban environment. Moreover, a correlation in a study area is not a demonstration of a causal relationship between specific environmental stressors and animal health because of putative cofounding factors. In the previous examples, the effect of food availability may be important to explain the differences between the sites (Eeva et al. 2005). This is why we will perform controlled laboratory experiments in this project. We will test how cocktails of TME at ecologically relevant concentrations for an urban area directly affects different components of oxidative stress in a bird species. We will also investigate the consequences on stress hormone, coloration and immune response to integrate different aspects of bird physiology. Moreover, we will also manipulate food quantity, for two main reasons: (i) to mimic natural conditions where food is limited, (ii) to highlight putative trade-offs that may be apparent only in some conditions such as food limitation.

Objectif : The aim is to study the physiological effects of a cocktail of TME at ecologically relevant concentrations for an urban environment. This study in controlled conditions will show whether there is a causal relationship between TME exposition and oxidative stress and on which specific marker.

Méthodologie : We will use three doses of a TME cocktail and a control situation (no TME) for a total of 80 adult male birds (see our previous study, Saulnier et al. 2020). The birds will be exposed to the cocktail during 3 months. The TME will be given in drinking water as done in previous studies (Saulnier et al. 2020). Moreover, half of the birds will have access to food ad libitum and half of the birds will have access to a limited amount of food. All the birds will be supplemented with Ca, with cuttlefish bones, as recommended for captive zebra finches. The feeding behaviour of the birds will be monitored using RFID feeders and by equipping the birds with rings with PIT-tags. In each cage, we will have 2 feeders: one with the normal seed mix and one with pieces of cuttlefish bone for the Ca supplementation. In the group with limited food intake the amount of seeds put in the feeder will be limited. Thanks to the RFID, we will monitor the number of visits to each feeder and the time spent feeding for each bird.
We will have 8 groups (4 concentrations of TME and 2 food quantity) with 10 birds per group. We will have 16 cages with 5 birds per cage.

Références bibliographiques :
ATSDR. 2019. The ATSDR 2019 substance priority list. U.S.A.: Agency for Toxic Substances and Disease Registry, U.S. Public Health Service.
Eeva, T., M. Ahola, and E. Lehikoinen. 2009. Breeding performance of blue tits (Cyanistes caeruleus) and great tits (Parus major) in a heavy metal polluted area. Environmental Pollution 157:3126–3131.
Eeva, T., and E. Lehikoinen. 2004. Rich calcium availability diminishes heavy metal toxicity in Pied Flycatcher. Functional ecology 18:548–553.
Eeva, T., M. Ryömä, and J. Riihimäki. 2005. Pollution-related changes in diets of two insectivorous passerines. Oecologia 145:629–639.
Saulnier, A., J. Bleu, A. Boos, I. El Masoudi, P. Ronot, S. Zahn, M. Del Nero, and S. Massemin. 2020. Consequences of trace metal cocktail exposure in zebra finch (Taeniopygia guttata) and effect of calcium supplementation. Ecotoxicology and Environmental Safety 193:110357.

Compétences requises :
* Connaissances et fort intérêt en écophysiologie et écologie comportemental ;
* Analyse statistique des données avec R ;
* Mise en place d’un design expérimental
* Suivi des oiseaux pendant l’expérimentation
* Rigueur, capacités de rédaction (français et anglais).

Compétences développées pendant le stage :
* Possibilité de formation à la manipulation des oiseaux
* Dosages en laboratoire (biochimie, biologie moléculaire)

Possibilité de poursuite en thèse : oui (financement ANR)

Structure d’appartenance et lieu du stage : Institut Pluridisciplinaire Hubert Curien (IPHC), Strasbourg

Identités et coordonnées des encadrantes :
Josefa Bleu, enseignante-chercheure, IPHC, DEPE, équipe ADAGE
Sylvie Massemin, enseignante-chercheure, IPHC, DEPE, équipe ADAGE

Contacts : [email protected] et [email protected]

Candidature : merci d’envoyer votre CV, lettre de motivation, relevés de notes de M1, rapport de stage de M1 à nos deux adresses email. Toutes les candidatures reçues avant le 24/09 seront étudiées. Après cette date, si le stage n’a pas été pourvu, les candidatures seront étudiées au fur et à mesure.

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