Birds, Volume 1, Issue 1 (December 2020) – 6 articles

In birds, aggressive behavior can be elicited in the field with a simulated territory intrusion (STI). Here, we compared four different STI methods in nuthatches in the non-breeding season: playback only, playback combined with an inactive wooden model mounted on a robot device, playback and an active model mounted on a robot device, and playback with the robot device only. In the control treatment, birds were not exposed to STI. Experiments were carried out in 12 territories. Behavioral observations included latency to approach, latency to start calling, time spent in the same tree, number of flyovers, minimum distance, number of individuals, number of flights into the tree, and number of calls. There was no significant influence of stimulus presentation. Nuthatches responded equally to all four experimental manipulations, but order of presentation had a strong influence. Full article

Organophosphates are the most widely used insecticide class in agriculture. The effects of organophosphates on insectivorous birds can potentially reduce the capacity of these birds to regulate insect pest populations as well as jeopardizing the survival of vulnerable bird species in matrix habitats. In this study, we investigated the diversity of birds inhabiting commercial macadamia orchards in Australia and assessed community-wide exposure of birds to an organophosphate insecticide (trichlorfon). We also studied the impact of trichlorfon on arthropods, and how this affected bird activity. We used a novel approach, combining bird acoustic surveys, and three different arthropod trapping devices. Birds and arthropods were surveyed immediately before and after a trichlorfon application, in sprayed and unsprayed orchards, at six different sites. Surveys showed that trichlorfon applications produced no changes in bird activity, either at the species or community level. Only one species (Lichmera indistincta) showed a significant increase in acoustic activity after treatment. These results indicate that several (62) bird species, some of which have been noted as undergoing regional decline, are exposed to trichlorfon applications. Additionally, trichlorfon applications also produced rapid, negative impacts on certain arthropod groups, particularly spiders. Because almost (80%) of the bird species recorded in the study include arthropods in their diets, then arthropod contaminated by trichlorfon are likely consumed by these orchard-dwelling birds. We recommend that pest management should incorporate strategies to reduce wildlife exposure to toxic chemicals to meet the joint goals of crop production and wildlife conservation in structurally complex agricultural habitats. Full article

Although birds belonging to order Caprimulgiformes show extensive karyotype variation, data concerning their genomic organization is still scarce, as most studies have presented only results obtained from conventional staining analyses. Nevertheless, some interesting findings have been observed, such as the W chromosome of the Common Potoo, Nyctibius griseus (2n = 86), which has the same morphology and size of the Z chromosome, a rare feature in Neognathae birds. Hence, we aimed to investigate the process by which the W chromosome of this species was enlarged. For that, we analyzed comparatively the chromosome organization of the Common Potoo and the Scissor-tailed Nightjar, Hydropsalis torquata (2n = 74), which presents the regular differentiated sex chromosomes, by applying C-banding, G-banding and mapping of repetitive DNAs (microsatellite repeats and 18S rDNA). Our results showed an accumulation of constitutive heterochromatin in the W chromosome of both species. However, 9 out of 11 microsatellite sequences hybridized in the large W chromosome in the Common Potoo, while none of them hybridized in the W chromosome of the Scissor-tailed Nightjar. Therefore, we can conclude that the accumulation of microsatellite sequences, and consequent increase in constitutive heterochromatin, was responsible for the enlargement of the W chromosome in the Common Potoo. Based on these results, we conclude that even though these two species belong to the same order, their W chromosomes have gone through different evolutionary histories, with an extra step of accumulation of repetitive sequences in the Common Potoo. Full article

Plastic debris makes up the majority of marine debris around the world, and pollution is a serious threat to marine wildlife. Threats represent two types of biological interactions with plastic: entanglement and ingestion. This paper describes interactions of seabirds with plastic in Mirny and draw the attention of researchers to the existing problem. In 2012/2013 and 2015/2016, year-round observations of the author were carried out at Mirny station and Haswell Islands (area of about 12 km²), east Antarctica. One case of entanglement of a molting adult Adélie penguin (Pygoscelis adeliae) in a fishing line was been identified; in addition to one case of an adult emperor penguin (Aptenodytes forsteri) mistakenly ingesting plastic braided rope and subsequently feeding it as part of a food lump to the chick, and two cases of macroplastics found in pellets of south polar skuas (Catharacta maccormicki). Registrations of entanglement and ingestion of macroplastic by seabirds in Mirny are rare. They signal to us about problem that needs to be included in the monitoring for the health of terrestrial biota of the Haswell archipelago. Full article

The Barn Owl Tyto alba is commonly reported as a non-selective predator of small mammals, and its diet has been thoroughly analyzed also to assess the small mammal assembly composition in many study areas. The aim of this work was to analyze the diet of the Barn Owl in the Elba island through the analysis of 161 pellets collected in September 2020. Undigested fragments were isolated and compared with reference collections. We confirmed that the Barn Owl is a typical predator of field mice (62% of relative frequency), with synanthropic murid rodents as the second category of prey. The frequency of consumption of shrews increased by 9% with respect to the previous work, suggesting that the natural environment of Elba island is still in a good health status. Moreover, fragments of two newborn hares were detected, increasing the knowledge on the local trophic spectrum of the Barn Owl. Finally, the skull of a Geoffroy’s Myotis Myotis emarginatus confirmed the presence of this species in Elba island after over 60 years from the first unconfirmed record. Repeated studies conducted in the same study site may provide useful information on prey population trends and local environmental status. Full article