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String-pulling is among the most widespread cognitive tasks used to test problem-solving skills in mammals and birds. The task requires animals to comprehend that pulling on a non-valuable string moves an otherwise inaccessible food reward to within their reach. Although at least 90 avian species have been administered the string-pull test, all but five of them were perching birds (passeriformes) or parrots (psittaciformes). Waterbirds (Aequorlitornithes) are poorly represented in the cognitive literature, yet are known to engage in complex foraging behaviours. In this study, we tested whether free-living ring-billed gulls (Larus delawarensis), a species known for their behavioural flexibility and foraging innovativeness, could solve a horizontal string-pull test. Here, we show that 25% (26/104) of the ring-billed gulls that attempted to solve the test at least once over a maximum of three trials were successful, and that 21% of them (22/104) succeeded during their first attempt. Ring-billed gulls are thus the first waterbird known to solve a horizontal single-string-rewarded string-pull test. Since innovation rate and problem-solving are associated with species' ability to endure environmental alterations, we suggest that testing the problem-solving skills of other species facing environmental challenges will inform us of their vulnerability in a rapidly changing world.

Species of Hystrichis are parasite nematodes of the digestive tract of aquatic birds in South America, Europe and Asia. In Brazil, Hystrichis acanthocephalicus has been reported in Phimosus infuscatus. There are few data on the morphometry of this species and there are no reports on pathological conditions that it causes. Therefore, the purpose of this study was to report morphometric data from H. acanthocephalicus and describe the pathological effects of this parasite on the Phimosus infuscatus proventriculus. Thirty gastrointestinal tracts of P. infuscatus were examined to search for nematodes and H. acanthocephalicus occurred in 83% of hosts. Were measured the total length and body width of males and females, and of their respective cuticular spines, esophagus, spicules and eggs, and the internal and external diameter of copulatory bursa. Histopathological examination revealed parasitic structures in the proventriculus from the lumen (anterior end) to the outer layers of the organ (intermediate and posterior parts), in which we observed inflammatory reaction with infiltration of heterophils, hemorrhage and hemosiderin. The results of this study of histopathology, morphometry and parasitological indices are the first ones reported to H. acanthocephalicus and should contribute to the identification and recognition in cases of outbreaks in the Neotropical region. Resumo Espécie de Hystrichis são nematoides parasitos do trato digestório de aves aquáticas, na América do Sul, Europa e Ásia. No Brasil, foi registrado Hystrichis acanthocephalicus, em Phimosus infuscatus. Existem poucos dados sobre a morfometria e não há registros relativos à patologia desta espécie. Portanto, o objetivo deste estudo foi relatar dados morfométricos de H. acanthocephalicus e descrever os efeitos patológicos deste parasito no proventrículo de Phimosus infuscatus. Foram examinados trinta tratos gastrintestinais de P. infuscatus para a pesquisa de nematoides e H. acanthocephalicus ocorreu em 83% dos hospedeiros. Mediu-se o comprimento total e largura do corpo de machos e fêmeas, dos espinhos cuticulares, do esôfago, dos espículos, dos ovos, respectivamente, e a largura interna e externa da bolsa copuladora. Nos exames histopatológicos foram encontradas estruturas parasitárias no proventrículo, desde o lúmen (porção anterior) até as camadas mais externas do órgão (porções intermediária e posterior), nas quais se observou reação inflamatória com infiltrado de heterófilos, presença de hemorragia e deposição de hemossiderina. Os resultados desse estudo sobre histopatologia, morfometria e índices parasitológicos são os primeiros relatados para H. acanthocephalicus e deverão contribuir para a identificação e reconhecimento em casos de surtos na região Neotropical.

International audience; In environment, birds often fast in connection with breeding, migration or drastic climatic conditions and need to mobilize lipid reserves during these periods. The impairment of lipid metabolism by cadmium (Cd; 1 mg kg(-1) added in diet) was investigated on palmiped Cairina moschata. Expression levels of genes involved in lipid metabolism, mitochondrial metabolism and detoxification were investigated in liver and muscle of ducks. Lipid content in muscle and liver were analysed and plasma triglycerides were quantified. After 20 days, ducks exposed to Cd displayed a lower body weight and lower lipid content in liver than controls. In muscle, the increase of lipid content was only significant for control ducks but not for exposed ducks. Exposed ducks appeared unable to sufficiently transport and store lipids into peripheral tissues. Cd impairs lipid metabolism by several ways. First, Cd triggered the down-regulation of fatty acids synthesis in liver even if the NADPH production and the mitochondrial metabolism are enhanced, suggesting a stronger energy needs. Secondly, the associated decrease of plasma triglycerides and lipoprotein lipase activity with Cd are consistent with impairment of lipids storage in peripheral tissues.

Objective: To determine the helminth parasites of Anas crecca (A. crecca) in one of proper refuges of Iran, Fereydunkenar. Methods: A total number of one hundred thirty-six gastrointestinal tracts of green-winged teal (A. crecca) were collected from Fereydunkenar, Mazandaran province during September and October 2011. The gastrointestinal tracts were examined for helminth infection. Results: The total infection rate was 70.50% (96) that 68.96% (40) of males and 71.79% (56) of females shown helminthes infection. The examined A. crecca harbored one species of Nematoda, Cestoda and two species of Digenea which were as following: Contracaecum larvae (from stomach wall), Diorchis stefanskii (D. stefanskii) (from small intestine), Hypoderaeum conoideum (from small intestine) and Notocotylus attenuatus (N. attenuatus) (from caecum), respectively. There was no significant difference in the prevalence of infection between examined males and females ducks in Hypoderaeum conoideum, D. stefanskii and N. attenuatus (P>0.05) whereas a significant relationship was observed between males and females in Contracaecum larvae (P

International audience; This study aimed to assess the effect of two dietary cadmium (Cd) levels (C1: 1 mg kg−1; C10: 10 mg kg−1) on bird Anas platyrhynchos exposed for 10, 20 and 40 days (5 animals per experimental condition). Ducks were able to accumulate high amounts of Cd, especially in kidneys (after 40 days: C1 8.1±1 mg kg−1, C10 37.7±4.3 mg kg−1). After 40 days, the lowest Cd level triggered oxidative stress and stimulated mitochondrial metabolism. At the same time, highest amounts of Cd (C10 group) only triggered repression of genes encoding for catalase and acetyl-CoA carboxylase, with repression factors of 1/50 and 1/5, respectively. High dose exposures were then associated with the repression of genes encoding for antioxidant, whereas low dose exposure triggered their induction. In contrast, the onset of MT gene expression appeared quickly for the C10 group even if a time delay was observed between gene expression and protein accumulation. Through the comparison of A. platyrhynchos and Cairina moschata, the response to Cd toxicity appeared species-dependent. Discrepancies between species could be explained by differential utilization of MT. This pathway of detoxification seemed sufficient to counter Cd toxicity.