Avian keratin disorder: Difference between revisions
→Prevalence: Two documented instances of beak overgrowth before 1990s |
→Prevalence: Incidence in corvids |
||
| Line 14: | Line 14: | ||
== Prevalence == |
== Prevalence == |
||
Prior to the study by Handel et al., overgrown rhamphotheca had only been reported in two species of Alaskan bird, these being the [[American tree sparrow|tree sparrow]] and a single specimen of the [[Two-barred crossbill|white-winged crossbill]].<ref name="West1959a">{{cite journal|last1=West|first1=George C.|title=Effects of High Air Temperature on the Bill and Claw Keratin Structures of the Tree Sparrow|journal=The Auk|date=October 1959|volume=76|issue=4|doi=10.2307/4082330|url=http://www.jstor.org/stable/4082330|accessdate=3 April 2017}}</ref><ref name="West1974a">{{cite journal|last1=West|first1=George C.|title=Abnormal Bill of a White-Winged Crossbill|journal=The Auk|date=July 1974|volume=91|issue=3|doi=10.2307/4084484|url=http://www.jstor.org/stable/4084484|accessdate=3 April 2017}}</ref> |
Prior to the study by Handel et al., overgrown rhamphotheca had only been reported in two species of Alaskan bird, these being the [[American tree sparrow|tree sparrow]] and a single specimen of the [[Two-barred crossbill|white-winged crossbill]].<ref name="West1959a">{{cite journal|last1=West|first1=George C.|title=Effects of High Air Temperature on the Bill and Claw Keratin Structures of the Tree Sparrow|journal=The Auk|date=October 1959|volume=76|issue=4|doi=10.2307/4082330|url=http://www.jstor.org/stable/4082330|accessdate=3 April 2017}}</ref><ref name="West1974a">{{cite journal|last1=West|first1=George C.|title=Abnormal Bill of a White-Winged Crossbill|journal=The Auk|date=July 1974|volume=91|issue=3|doi=10.2307/4084484|url=http://www.jstor.org/stable/4084484|accessdate=3 April 2017}}</ref> |
||
While overgrown and crossed beaks have been identified in upwards of 30 species within Alaska alone, many of those have had only a handful of individuals affected. Other than black-capped chickadees, the species most affected are various [[Corvidae|corvids]], nuthatches, and woodpeckers. In addition, surveys of Northwestern and American crow populations has indicated the possibility of regional clusters of AKD.<ref>{{cite journal|last1=Van Hemert|first1=Caroline|last2=Handel|first2=Colleen M.|title=Beak deformities in Northwestern Crows: evidence of a multispecies epizootic.|journal=The Auk|date=October 2010|volume=127|issue=4|doi=10.1525/auk.2010.10132|url=http://www.jstor.org/stable/10.1525/auk.2010.10132|accessdate=3 April 2017}}</ref> |
|||
== References == |
== References == |
||
Revision as of 19:16, 3 April 2017
Avian keratin disorder (AKD) is an emerging disease among wild birds in North America characterized by overgrowth and deformities of beaks. Cases were first observed among black-capped chickadees in Alaska in the late 1990s, and has spread rapidly since then.[1] The pathology of AKD is still not understood, but one candidate is Poecivirus, a prospective new species of virus within the family Picornaviridae.
Symptoms
AKD is specifically accelerated growth of the rhamphotheca, the keratinized outer layer of birds’ beaks.[2] The effects of this are much longer or crossed beaks, a condition which is debilitating and often deadly. It obstructs birds' ability to feed and preen themselves, with the resulting dirty and matted plumage unable to play its role in thermoregulation.[3]
One potential secondary symptom is the formation of lesions on various other keratinized tissues. Areas affected include the skin, legs, feet, claws, and feathers. Since AKD is not yet well-understood, it has not been determined whether these lesions are strictly a secondary symptom or part of a systemic disorder.[3]
Prevalence
Prior to the study by Handel et al., overgrown rhamphotheca had only been reported in two species of Alaskan bird, these being the tree sparrow and a single specimen of the white-winged crossbill.[4][5] While overgrown and crossed beaks have been identified in upwards of 30 species within Alaska alone, many of those have had only a handful of individuals affected. Other than black-capped chickadees, the species most affected are various corvids, nuthatches, and woodpeckers. In addition, surveys of Northwestern and American crow populations has indicated the possibility of regional clusters of AKD.[6]
References
- ^ Zylberberg, Maxine; Van Hemert, Caroline; Dumbacher, John P.; Handel, Colleen M.; Tihan, Tarik; DeRisi, Joseph L. (26 July 2016). "Novel Picornavirus Associated with Avian Keratin Disorder in Alaskan Birds". mBio. 7 (4). doi:10.1128/mBio.00874-16.
{{cite journal}}:|access-date=requires|url=(help) - ^ Van Hemert, Caroline; Handel, Colleen M.; O’Hara, Todd M. (July 2012). "Evidence of accelerated beak growth associated with avian keratin disorder in black-capped chickadees (Poecile atricapillus)". Journal of Wildlife Disease. 48 (3). doi:10.7589/0090-3558-48.3.686.
{{cite journal}}:|access-date=requires|url=(help) - ^ a b Handel, Colleen M.; Pajot, Lisa M.; Matsuoka, Steven M.; Van Hemert, Caroline; Terenzi, John; Talbot, Sandra L.; Mulcahy, Daniel M.; Meteyer, Carol U.; Trust, Kimberly A. (October 2010). "Epizootic of Beak Deformities Among Wild Birds in Alaska: An Emerging Disease in North America?". The Auk. 127 (4). doi:10.1525/auk.2010.10111.
{{cite journal}}:|access-date=requires|url=(help) - ^ West, George C. (October 1959). "Effects of High Air Temperature on the Bill and Claw Keratin Structures of the Tree Sparrow". The Auk. 76 (4). doi:10.2307/4082330. Retrieved 3 April 2017.
- ^ West, George C. (July 1974). "Abnormal Bill of a White-Winged Crossbill". The Auk. 91 (3). doi:10.2307/4084484. Retrieved 3 April 2017.
- ^ Van Hemert, Caroline; Handel, Colleen M. (October 2010). "Beak deformities in Northwestern Crows: evidence of a multispecies epizootic". The Auk. 127 (4). doi:10.1525/auk.2010.10132. Retrieved 3 April 2017.
 | This bird-related article is a stub. You can help Wikipedia by expanding it. |
 | This veterinary medicine–related article is a stub. You can help Wikipedia by expanding it. |