Search results for "Flight feather"
showing 4 items of 4 documents
The flight feather moult pattern of the bearded vulture (Gypaetus barbatus)
2015
Moult is an extremely time-consuming and energy-demanding task for large birds. In addition, there is a trade-off between the time devoted to moulting and that invested in other activities such as breeding and/or territory exploration. Moreover, it takes a long time to grow a long feather in large birds, and large birds that need to fly while moulting cannot tolerate large gaps in the wing, but only one or two simultaneously growing feathers. As a consequence, large birds take several years to complete a full moult cycle, and they resume the moult process during suboptimal conditions. A clear example of this pattern is the Bearded Vulture (Gypaetus barbatus), which needs 2-3 years for chang…
Wing feather moult and age determination of Snowy Owls Bubo scandiacus.
2012
Moult of primary and secondary flight feathers of Snowy Owls Bubo scandiacus was studied from 53 museum specimens retaining some juvenile feathers. There were no ringed Snowy Owls of known age in the skin material, and the moult pattern has thus been interpreted using the moult of Eagle Owls Bubo bubo as a model. The difference between juvenile and adult primaries is described. Greater coverts may facilitate age determination of single flight feathers. Snowy Owls start their first flight feather moult M1 by shedding the innermost 2-6 secondaries during their second summer (as 2C birds). A majority of the owls also shed primary P7 during this first moult, occasionally also P8. This moult pro…
Different Scales of Spatial Segregation of Two Species of Feather Mites on the Wings of a Passerine Bird
2011
The "condition-specific competition hypothesis" proposes that coexistence of 2 species is possible when spatial or temporal variations in environmental conditions exist and each species responds differently to those conditions. The distribution of different species of feather mites on their hosts is known to be affected by intrinsic host factors such as structure of feathers and friction among feathers during flight, but there is also evidence that external factors such as humidity and temperature can affect mite distribution. Some feather mites have the capacity to move through the plumage rather rapidly, and within-host variation in intensity of sunlight could be one of the cues involved …
Quill mites (Acari: Syringophilidae) from Aegithalos caudatus (Passeriformes: Aegithalidae)
2004
Three species of syringophilid mites (Acari: Syringophilidae) were collected from quills of Aegithalos caudatus (Passeriformes: Aegithalidae) in Poland, Picobia caudati sp. n. from body feathers, Dissonus scirpaceus Skoracki, 1999 from rectrices, and Syringophilopsis aegithali Bochkov et al., 2001 from secondaries.