Enteritis as a Cause of Mortality in the Western Bluebird (Sialia mexicana)

2001 ◽  
Vol 45 (3) ◽  
pp. 760 ◽  
Author(s):  
R. J. Bildfell ◽  
E. K. Eltzroth ◽  
J. G. Songer
Keyword(s):  
2008 ◽  
Author(s):  
Judith A. Guinan ◽  
Patricia A. Gowaty ◽  
Elsie K. Eltzroth
Keyword(s):  

The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 118 ◽  
Author(s):  
Amber J. Keyser ◽  
Marilynne T. Keyser ◽  
Daniel E. L. Promislow

2006 ◽  
Vol 3 (9) ◽  
pp. 527-532 ◽  
Author(s):  
Matthew D Shawkey ◽  
Susan L Balenger ◽  
Geoffrey E Hill ◽  
L. Scott Johnson ◽  
Amber J Keyser ◽  
...  

Combinations of microstructural and pigmentary components of barbs create the colour displays of feathers. It follows that evolutionary changes in colour displays must reflect changes in the underlying production mechanisms, but rarely have the mechanisms of feather colour evolution been studied. Among bluebirds in the genus Sialia , male rump colour varies among species from dark blue to light blue while breast colour varies from blue to rusty. We use spectrometry, transmission electron microscopy and Fourier analysis to identify the morphology responsible for these divergent colour displays. The morphology of blue rump barbs is similar among the three species, with an outer keratin cortex layer surrounding a medullary ‘spongy layer’ and a basal row of melanin granules. A spongy layer is also present in blue breast barbs of mountain bluebirds Sialia currucoides and in rusty breast barbs of western Sialia mexicana and eastern bluebirds Sialia sialis . In blue barbs melanin is basal to the spongy layer, but is not present in the outer cortex or spongy layer, while in rusty barbs, melanin is present only in the cortex. The placement of melanin in the cortex masks expression of structural blue, creating a rusty display. Such shifts in microstructures and pigments may be widespread mechanisms for the evolutionary changes in the colours of feathers and other reflective structures across colourful organisms.


2009 ◽  
Vol 54 (1) ◽  
Author(s):  
Maciej Skoracki ◽  
Maureen Flannery ◽  
Greg Spicer

AbstractSix species of the syringophilid mites belonging to the genus Syringophiloidus Kethley, 1970 (Acari, Prostigmata) are recorded from eight avian hosts from USA. Four new species are described and illustrated: S. molothrus sp. nov. from the Brown-headed Cowbird Molothrus ater (Boddaert) (Passeriformes, Icteridae), S. carolae sp. nov. from the Acorn Woodpecker Melanerpes formicivorus (Swainson) (Piciformes, Picidae) and from the Northern Cardinal Cardinalis cardinalis (Linnaeus) (Passeriformes, Cardinalidae), S. sialius sp. nov. from the Western Bluebird Sialia mexicana Swainson (Passeriformes, Turdidae), and S. thryothorus sp. nov. from the Carolina Wren Thryothorus ludovicianus (Latham) (Passeriformes, Troglodytidae). The previously described species S. motacillae Bochkov et Mironov, 1998 is new for USA. Two host species, the American Robin Turdus migratorius Linnaeus (Turdidae) and the Steller’s Jay Cyanocitta stelleri (Gmelin) (Passeriformes, Corvidae), are new for S. presentalis Chirov et Kravtsova, 1995.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2457
Author(s):  
Elisa J. Abeyta ◽  
Andrew W. Bartlow ◽  
Charles D. Hathcock ◽  
Jeanne M. Fair

Geographic ranges of plants and animals are shifting due to environmental change. While some species are shifting towards the poles and upslope in elevation, the processes leading to these patterns are not well known. We analyzed 22 years of western bluebird (Sialia mexicana) data from a large nest box network in northern New Mexico at elevations between 1860 m and 2750 m. This population has shifted to higher elevations over time, but whether this is due to changes in nesting behavior and preference for higher elevation within the population or driven by immigration is unclear. We banded adults and nestlings from nest boxes and examined nesting location and elevation for individual birds captured two or more times. Most recaptured birds nested at the same nest boxes in subsequent years, and the number of birds that moved upslope did not significantly differ from the number that moved downslope. Fledglings moved greater distances and elevations than adults, but these movements were not upslope specific. Female fledglings showed greater changes in elevation and distance compared to male fledglings, but again, movements were not consistently upslope. The upslope shift in this population may be due to birds immigrating into the population and not from changes in individual nesting behavior.


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