نتایج جستجو برای: beak
تعداد نتایج: 1228 فیلتر نتایج به سال:
Recent advances have brought new insight into the physiological mechanisms that enable birds and other animals to use magnetic fields for orientation. Many birds seem to have two magnetodetection senses, one based on magnetite near the beak and one based on light-dependent radical-pair processes in the bird's eye(s). Among the most exciting recent results are: first, behavioural responses of bi...
Single unit activity was recorded during a delayed auditory/visual Go/NoGo task from the neostriatum caudolaterale (NCL) of pigeons, a multimodal associative avian forebrain structure comparable to the prefrontal cortex (PFC). The animals were trained to mandibulate (to open their beak) during the Go period after which they received a drop of water as reward. Neuronal activity changes were obse...
Three complete genomes of beak and feather disease virus (BFDV) were recovered from wild twenty-eight parrots (Polytelis anthopeplus monarchoides). The genomes consisted of 1,996 bp with 1,934 identical sites and a typically content stem-loop structure between ORF1 and ORF2. This is the first report of BFDV infection as well as the complete genome sequences for this host species globally.
The present experiments were conducted to test the hypothesis that septal arginine vasotocin (AVT) and vasoactive intestinal polypeptide (VIP) modulate directed song (a courtship behaviour) and aggression in male zebra finches (Taeniopygia guttata). Subjects were surgically fitted with a guide cannula directed at the septum. Following recovery they were tested for aggression and directed song f...
Osteoarthritis of the basal joint of the thumb is common, particularly in postmenopausal females, and can cause considerable pain and disability. Incompetence of the volar beak ligament is thought to be the inciting event that eventually leads to joint degeneration in a predictable pattern. The clinical history and examination can reliably lead to the diagnosis. Radiographs are used to stage th...
The hummingbird beak, specialized for feeding on floral nectars, is also uniquely adapted to eating flying insects. During insect capture the beak often appears to close at a rate that cannot be explained by direct muscular action alone. Here we show that the lower jaw of hummingbirds has a shape and compliance that allows for a controlled elastic snap. Furthermore, hummingbirds have the muscul...
Gryphopsylla maxomydis n. sp. (Pygiopsyllidae), Medwayella rubrisciurae n. sp. (Pygiopsyllidae) and Macrostylophora theresae n. sp. (Ceratophyllidae) are described from endemic rodents in Sulawesi. Gryphopsylla maxomydis was collected from the murids Maxomys musschenbroekii and Paruromys dominator in Central Sulawesi (Sulawesi Tengah). However, M. musschenbroekii appears to be the true host of ...
We have made the first direct interferometric proper motion measurements of the radio pulsar B1757−24, which sits at the tip of the " beak " of the putative " Duck " supernova remnant. The peculiar morphology of this radio complex has been used to argue alternately that the pulsar's space motion was either surprisingly high or surprisingly low. In fact, we show that the pulsar's motion is so sm...
Some birds are just instantly recognisable. From elegant flamingos with graceful necks to toco toucans (Ramphastos toco) their jet-black plumage and distinctive beaks, some stand out from the dowdy crowd. And toucan's outsized beak comes in handy for retrieving fruit cracking nuts. But Glenn Tattersall Brock University, Canada, explains that outrageous bill also doubles as a radiator; he recall...
Psittacine beak and feather disease (PBFD) is a common disease of the psittacine species and is caused by the psittacine beak and feather disease virus (PBFDV). In this study the occurrence of the disease in ring-neck parakeets and budgerigars in South Africa suffering from feathering problems, using polymerase chain reaction as a diagnostic test was investigated. The genetic variation between ...
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