Search Results (6)

The independent origins of middle ears in testudinates, lepidosaurs, and archosaurs in the Triassic led to lineage-specific developments in their auditory epithelia. In comparison to the inferred ancestral state, little changed in testudinates, but archosaurs and most lepidosaurs evolved longer, differentiated auditory papillae. In archosaurs, sensory hair cells specialized across and along the papillae, resulting in mainly sensory tall hair cells and mainly mechanically active short hair cells. Crocodilians have 5 mm-long papillae, but relatively low upper frequency limits at around 4 kHz. Avian papillae are mostly 3 to 5 mm in length, being shorter in small species; in owls they exceptionally reach almost 12 mm and have an upper limit of above 10 kHz. Lepidosaurs retained the ancestral papilla as a low-frequency responsive area with one type of hair cell, but most added newly evolved areas (of max. 2 mm length) consisting of oppositely oriented hair cells responding to frequencies above 1 kHz. Initially, these areas flanked both ends of the ancestral area and were redundant in their responses to sound. The evolution of specific configurations in most families eliminated this redundancy, but the paths taken resulted in diverse anatomies that show high degrees of family specificity. Despite these differences, the high-frequency hearing limit of lepidosaurs rarely exceeds 5 kHz. Full article

The long-eared owl (Asio otus) is a medium-sized owl species that is well-distributed in almost all of the territories in Portugal. Nematodes were found in the oral cavity of a long-eared owl (A. otus) admitted to CRASSA (Wildlife Rehabilitation Centre of Santo André). During a physical exam and stabilization of the bird, five nematodes were collected. The worms were examined and measured under light microscopy, and photos were taken. After a morphological analysis was conducted, all the nematodes (five females) were identified as Synhimantus (Synhimantus) laticeps. Two specimens were subjected to molecular analysis, which confirmed the result. This study provides a combined morphological and genetic approach to S. laticeps. To the authors’ best knowledge, this is the first report including genetic sequencing of S. laticeps in a long-eared owl (A. otus) from Portugal. Full article

Voles from the Genus Microtus are rodents with a subterranean lifestyle. Central Italy is populated by two species of the Genus, the North-Western Microtus savii and the South-Eastern endemic Microtus brachycercus. Although morphometric features able to help distinguish M. savii from M. brachycercus are lacking, a peculiar morphology of the anterior end of the first lower molar is typical, but not exclusive, of M. brachycercus. Since some skulls with a compatible dental morphology were collected from Long-eared owl pellets in Umbria (Central Italy), a genetic assessment was deemed necessary to verify the possible presence of M. brachycercus outside of its known distribution range. Hemimandibles were isolated and used for both genetic and morphometric dental analyses. Despite the fact that this could suggest the presence of a M. brachycercus population, genetic analyses confirmed the species attribution to the M. savii complex, showing peculiar genetic polymorphisms that can either be due to the wide sampling area, represented by the owls’ hunting grounds, or to the recent evolutive history of the analysed population. This study, once again, underlines the importance of integrative taxonomy, suggesting the key role of predators as field-assistants to minimize the impact of sampling campaign on natural populations. Full article

In this study, we improved the energy acquisition efficiency of tidal turbines with bionic airfoils by optimizing the seagull, long-eared owl, sparrowhawk, and two-dimensional airfoils, thereby obtaining a better lift–drag ratio. We used Isight software to integrate the Integrated Computer Engineering and Manufacturing (ICEM) software and used Fluent simulation software, batch operation file, and multi-island genetic algorithm to maximize the lift–drag ratio as the objective function for optimizing the original airfoil. The optimized upper airfoil profile was distributed upward from the starter wing, and the thickness of the upper wing was the greatest. Meanwhile, the lower airfoil profile was thinner and more curved. The thickness of the three airfoils was distributed backward from the front of the wing, with the maximum thickness at the front, and the maximum camber was distributed backward from the front. The three optimized wings exhibited a maximum lift–drag ratio at an angle of attack of approximately 5°, with the sparrowhawk wing having a maximum lift–drag ratio of 80.87 at an angle of attack of 6°, the seagull wing having a maximum lift–drag ratio of 76.82 at an angle of attack of 4°, and the long-eared owl wing having a maximum lift–drag ratio of 68.43 at an angle of attack of 5°. Full article

Climate change, excessive exploitation of agricultural land which reduces natural habitats, wildlife shooting, and the use of pesticides all cause difficulties for wildlife, with considerable numbers of animals being brought to wildlife rescue centres. Although the efforts of staff involved in wildlife management at these centres usually focus on therapeutic treatments to reintroduce them into the wild, the monitoring of pathogens that may be transmitted to humans is of relevance. Campylobacter (C.) jejuni and C. coli are frequently carried by animals without inducing clinical signs and are responsible for enteric disorders and more rarely extra-intestinal disease in humans. Farm species and poultry, in particular, are the main reservoirs of C. jejuni and C. coli, but wild animals may also be carriers. The aim of this paper was to investigate the presence of C. jejuni and C. coli in wild birds housed at a wildlife rescue centre and to evaluate the sensitivity of the detected strains to antibiotics. Campylobacter was found in 52 out of 209 (24.88%) birds from 33 different species. C. jejuni was more prevalent, while C. coli was only detected in three Long-eared Owls (Asio otus). The incidence of the infection was particularly high (72.22%) among omnivorous species. Infection rates were higher in birds housed indoors (57.14%) than outdoors (31.74%). Moreover, Campylobacter was not detected in species whose mean temperature body is below 40 °C or higher than 42.2 °C. The most common antibiotic resistance in the tested strains was against trimethoprim/sulfamethoxazole, ciprofloxacin and enrofloxacin. In addition, multi-drug resistance was also found. The results highlight the need to increase biosecurity measures at rescue centres so as to reduce health-related risks to workers involved in wildlife management. Full article

The winter roost of the long-eared owl Asio otus in Crimea (South of Ukraine), located in Simferopol, is described. In 2015–2017, the number of long-eared owls varied on a convex curve, with the maximum reached at the end of November and in December. The birds exhibited a strong preference for roosting in conifers, where we recorded 89% of the owls. There was an inverse relationship between the mean of the maximum daily temperature (°C) and the number of owls in both seasons. The owls were not sensitive to abrupt but short-term temperature changes, but the temperature decrease curve caused practically synchronous changes in the dynamics of bird numbers. It was found that the number of owls significantly differed based on weather conditions in 16 trees. The proportion of owls sitting on coniferous trees increased with unfavourable weather, and the converse pattern was observed for deciduous trees. Full article