Parasitofauna survey of song thrushes (Turdus philomelos) from the eastern part of Spain.

Thrushes (Turdus spp.) are migratory passerine birds found in northern Europe during the summer months and in southern Europe and north of Africa during the winter. They constitute an important small game bird group very appreciated by Spanish hunters. Between October 2013 and February 2014, 90 adult song thrushes were collected for their exam. After necropsies, three species of helminths were macroscopically recovered from 15 birds (16.7%): Morishitium sp. (16.7%), Splendidofilaria mavis (6.7%) and Dilepis undula (7.8%). One of them showed an adult cestode in the lung. Moreover, 12 of the positive thrushes (80%) harboured microfilaria in pulmonary blood vessels and three of them (20%) were infected by Sarcocystis sp. on skeletal musculature. All parasitized birds showed lesions, ranging from mild to moderate airsacculitis, bronchitis and coelomitis associated to Morishitium sp. infection. To the authors' knowledge, this is the first description of Sarcocystis spp. in song thrushes from Spain. Our results reveal the need for further studies to evaluate the epidemiological role of song thrushes as spreaders of parasites during their annual migration.

Cardiopulmonary nematode infections in wild canids: Does the key lie on host-prey-parasite evolution?

Cardiopulmonary nematodes are among the most pathogenic parasites of domestic and wild canids. The aim of this study was to describe the species diversity, prevalence and infection intensity of these parasites in the Iberian wolf (Canis lupus signatus) and the red fox (Vulpes vulpes) in the northwest of the Iberian Peninsula. 257 foxes and 74 wolves were necropsied between 2008 and 2014. Four nematode species were identified: Angiostrongylus vasorum, Eucoleus aerophilus, Crenosoma vulpis and Filaroides hirthi. This last species was only found in wolves, being the first time that is cited worldwide in this wild canid. The overall parasite prevalence was significantly higher in foxes (70%) than in wolves (28%). Specifically, prevalences in foxes and wolves were, respectively, 43% and 22% for A. vasorum, 33% and 5% for E. aerophilus, and 30% and 9% for C. vulpis. The prevalence of F. hirthi was 16%. The A. vasorum intensity was significantly higher in foxes than in wolves. Differences between host species in the risk of infection would be associated to diverging feeding behavior, and possibly reflects a parasite-host adaptation related to host's hunting strategies and cardiorespiratory requirements. This study revealed an association between infection and environmental factors, and highlighted a wide variation in the spatial distribution of A. vasorum. Our results indicate that cardiopulmonary parasites are widespread in wild canids in northwest Spain, and further agrees with other studies indicating the expansion of A. vasorum in Europe and, therefore, the urgent need to investigate infection in dogs in sympatric areas.

The physiological cost of male-biased parasitism in a nearly monomorphic mammal.

BACKGROUND: Even though male-biased parasitism is common in mammals, little effort has been made to evaluate whether higher parasitic burden in males results in an extra biological cost, and thus a decrease in fitness. Body condition impairment and the augmentation of oxidative stress can be used as indicators of the cost of parasite infections. Here, we examined relationships between gastrointestinal and respiratory helminths, body condition and oxidative stress markers (glutathione peroxidase, paraoxonase-1) in 28 Pyrenean chamois (Rupicapra p. pyrenaica) sampled in autumn. RESULTS: Only male chamois showed a reduction in body condition and higher oxidative stress due to parasite infection, likely because of the extremely high parasite burdens observed in males. CONCLUSIONS: This study made evident a disparity in the physiological cost of multiple parasitism between sexes in a wild mammal, mainly due to parasitic richness. Because of the similar life expectancy in male and female chamois, we suggest that males may have developed natural mechanisms to compensate for higher parasite loads during the rut.