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Microanatomy of passerine hard-cornified tissues: Beak and claw structure of the black-capped chickadee (Poecile atricapillus)

January 1, 2012

The microanatomy of healthy beaks and claws in passerine birds has not been well described in the literature, despite the importance of these structures in avian life. Histological processing of hard‐cornified tissues is notoriously challenging and only a few reports on effective techniques have been published. An emerging epizootic of beak deformities among wild birds in Alaska and the Pacific Northwest region of North America recently highlighted the need for additional baseline information about avian hard‐cornified structures. In this study, we examine the beak and claw of the Black‐capped Chickadee (Poecile atricapillus), a common North American passerine that is affected by what has been described as “avian keratin disorder.” We use light and scanning electron microscopy and high‐magnification radiography to document the healthy microanatomy of these tissues and identify features of functional importance. We also describe detailed methods for histological processing of avian hard‐cornified structures and discuss the utility of special stains. Results from this study will assist in future research on the functional anatomy and pathology of hard‐cornified structures and will provide a necessary reference for ongoing investigations of avian keratin disorder in Black‐capped Chickadees and other wild passerine species.

Citation Information

Publication Year 2012
Title Microanatomy of passerine hard-cornified tissues: Beak and claw structure of the black-capped chickadee (Poecile atricapillus)
DOI 10.1002/jmor.11023
Authors Caroline R. Van Hemert, Colleen M. Handel, J.E. Blake, R.M. Swor, T. M. O'Hara
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Morphology
Series Number
Index ID 70032319
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Biology MFEB