نتایج جستجو برای: bird
تعداد نتایج: 24284 فیلتر نتایج به سال:
there are 61 species in 14 families of fish-eating birds in iran. the fish-eating birds of the north of iran belong to 41 species in 10 families which include 67.2 percent of total fish eating bird species and 71% of fish-eating bird’s family of iran. resident birds constitute 13% of the fisheating birds of the caspian sea coasts and the rest are migratory in autumn and winter. there exist 3 ...
Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US) and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 116 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to ...
Collisions between birds (and other wildlife) and aircraft are known to cause substantial losses to the aviation industry in terms of damage and delays every year. Techniques exist to control bird numbers on airfields and hence to reduce the number of wildlife strikes, but they are applied at widely different levels from airport to airport. Some of this variation may be due to differing levels ...
Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems...
The study of the mechanisms which govern bird orientation and navigation is severely hindered by the difficulty of reconstructing the route taken by the bird. Several methods have been used to study bird flights: direct observation using binoculars; following the bird by aeroplane or helicopter (Griffin, 1943; Hitchcock, 1952; Fiaschi, Baldaccini, Ioale & Papi, 1981); using a transmitter carrie...
| We describe our initial progress in developing gesture-based tools for real{time animation choreography. We outline the important characteristics of our aerodynamic bird ight model, used as the basis for a bird character, our single-sensor gesture recognition system, and the techniques used to couple the two systems to put the bird under interactive gestural control. The gesture system recogn...
Evaluating bird population trends requires baseline data. In North America the earliest population data available are those from the late 1960s. Forest conditions in the northern Great Lake states (U.S.A.), however, have undergone succession since the region was originally cut over around the turn of the twentieth century, and it is expected that bird populations have undergone concomitant chan...
BACKGROUND In chronic hypersensitivity pneumonitis (chronic HP), antigen avoidance is critical for disease management; however, complete avoidance is difficult because of unrecognized exposure to antigens. Recently, we revealed that the amount of avian antigen (AAA) in household dust at the time of diagnosis predicted the progression of chronic bird-related HP. The purpose of this study is to e...
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