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La paloma torcaza (Zenaida auriculata) es una de las especies de aves más co-munes y abundantes de Argentina, con gran capacidad de adaptación a los am-bientes modificados por el hombre. Un aspecto clave del éxito de esta especiees su capacidad para anidar de manera colonial en remanentes de bosque enpaisajes agrícolas. Este factor ha contribuido significativamente al crecimientopoblacional experimentado por la especie en las últimas décadas. Se presentael hallazgo de una nidada colonial en rastrojos de sorgo. En octubre de 2013 selocalizó una colonia de anidamiento de paloma torcaza en un lote con rastrojosde sorgo. En dicho lote, se realizaron 5 transectas de faja. Se obtuvo un promediode 0,89 nidos (±0,19) por m 2 y 1,79 (±0,17), huevos por nido. La mayoría (93,4 %)de los huevos estaba sano y el resto (6,6 %) mostraba signos de depredación.Éste sería el primer registro publicado de anidamiento colonial de torcaza enrastrojos de cultivo de sorgo. Establecer la frecuencia de este comportamientode anidamiento a escala regional y estimar el impacto que podría tener sobre elcrecimiento poblacional de esta especie sería importante para comprender, demanera más cabal, los aumentos poblacionales experimentados por esta palomaen los últimos años.

It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp.), shiny cowbirds (Molothrus bonariensis), and eared doves (Zenaida auriculata). Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD50) and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be substantially more sensitive to formulated beta-cyfluthrin (LD50 = (170 ± 41) mg/kg) than the other two species tested (LD50 = (2234 ± 544) mg/kg and LD50 = (2271 ± 433) mg/kg, resp.). The LD50 obtained for canaries was also considerably lower than typical toxicity values available in the literature for pyrethroids. This study emphasizes the need for testing a broader range of species with potentially toxic insecticides, using modern up and down test designs with minimal numbers of birds.

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Treated seeds and their cotyledons can present a toxicological risk to seed-eating birds. To assess whether avoidance behavior limits exposure and consequently the risk to birds, three fields were sown with soybeans. Half of the surface of each field was sown with seeds treated with 42 g/100 kg seed of insecticide imidacloprid (T plot, treated) and the other half with seeds without imidacloprid (C plot, control). Unburied seeds were surveyed in C and T plots at 12 and 48 h post-sowing. Damaged seedlings were surveyed in C and T plots at 12 days post-sowing. The abundance and richness of birds was surveyed at the field level (without distinguishing between C and T plots) before, during, and after sowing, and 12 days post-sowing. Unburied seed density was higher in the headlands of the T plots than in the C plots, but did not differ between 12 and 48 h. The damage to cotyledons of seedlings was 15.4% higher in C plots than in T plots. The abundance and richness/ha of birds that eat seeds and cotyledons were lower after sowing, indicating a deterrent effect on birds by sowing imidacloprid-treated seeds. Although the variation in seed density over time does not allow solid conclusions to be drawn about the avoidance of seeds treated by birds, the seedling results suggest an aversive effect of imidacloprid-treated soybeans on birds. The dominant species was the eared dove (Zenaida auriculata), whose risk of acute poisoning by imidacloprid in soybean seeds and cotyledons was low, according to its toxicity exposure ratio, foraged area of concern, and foraged time of concern.

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Eared doves (Zenaida auriculata) cause significant economic damage to mature sunflower in Argentina. Empirical evidences indicate that some sunflower hybrids (e.g. confectionary and stripped oilseed) might be less susceptible to bird damage than others (e.g. black oilseed). However, these less susceptible hybrids could imply a trade-off between damage reduction and oil content on the seeds. In this work, we investigated the potential of a new oil-con hybrid types (OC: oilseed × confectionary cross) as a tool to prevent eared dove damage to sunflower crops. We compared the performance (damage values), morphological characteristics and nutritive quality of this hybrid compared to other three standard sunflower hybrids (BO: black oilseed, SO: striped oilseed, and CON: confectionary), both in the field and in cages. In both tests, doves significantly selected BO and SO hybrids over CON and OC hybrids. The OC hybrid was not selected, despite its high nutritional value. Results suggest that achene size could be an important morphological trait influenced eared dove selection of hybrids, independently of other seed characteristics. Based on these results, the OC hybrid tested in this study seems to be a promising tool for preventing eared dove damage to sunflower in Argentina.