Valeria Ojeda’s scientific contributions

En Argentina, el riesgo que los rodenticidas anticoagulantes podrían presentar para las aves rapaces locales fue reconocido inicialmente en la década de 1980. Lamentablemente, 40 años después de esta primera señal de alarma, los rodenticidas anticoagulantes siguen siendo ampliamente utilizados en el país y en toda Sudamérica, sin haberse estudiado el problema medioambiental que estos pueden suponer. Aquí presentamos una revisión práctica e integral sobre los rodenticidas anticoagulantes y la intoxicación por estos en aves rapaces. Discutimos su impacto, tanto sobre individuos como en sus poblaciones, como también los aspectos relacionados al manejo de animales intoxicados y a la necesidad de contar con capacidad diagnóstica en la región. La información aquí recopilada permitirá contar con contenidos relevantes, actualizados y accesibles necesarios para abordar el estudio de esta amenaza para la conservación de las aves rapaces de Argentina y de otros países de Sudamérica. Al mismo tiempo, esperamos que promueva investigaciones sobre el tema que permitan dar los pasos necesarios para evaluar y mitigar el riesgo que el uso de los rodenticidas anticoagulantes puede tener sobre las aves rapaces y otra fauna silvestre

We describe pathological aspects of an infection caused by parasitic nematodes in skeletal muscles of a Magellanic woodpecker (Campephilus magellanicus), providing the first description of any disease findings in this species. A weakened female with locomotory dysfunction was rescued near Bariloche city (Argentine Patagonia), which soon died. At the necropsy, unexpected masses of tissue were located at three joints (legs and tail). A dissection of these masses exposed numerous nematodes in the musculature surrounding the joints that were identified as Hamatospiculum flagellispiculosum (Nematoda: Diplotriaenidae), a species that was not previously found in Piciformes (woodpeckers, toucans, and allies) of the Neotropical Region. In this report, we complement the original parasite description from 1952 with SEM images, and extend the species range about 2000 km southwards. Histopathological analysis (tissues sectioned 4–6 microns, stained with hematoxylin and eosin) of the affected tissues revealed parasitic myositis with muscle fibrosis. Severe muscle degeneration and necrosis, fibrous tissue replacing muscle tissue, chronic inflammation with widespread diffuse mononuclear infiltration, and parasitic content (adult roundworms, eggs, and eggs with first-stage larvae) were present in all samples. The multifocal nature of these lesions was consistent with the locomotory dysfunction exhibited by the bird. Both the immune response (mononuclear infiltration without eosinophils, which normally fight helminth colonization) and the clinical severity of this case (a lethal, multifocal macroparasite infection) are noteworthy. The expected immune response may have been suppressed through immunomodulation by the parasite, as observed for filarial parasites. Based on their demography and life history traits (i.e., long-lived picids that produce a single nestling every 1–2 years, and live in sparse populations), Magellanic Woodpeckers do not seem to be obvious hosts of an obligately killing parasite, and other (more regular) hosts should be expected to occur in the same region.