Kristine Kirkby wrote:
A hatch-year Red-tailed hawk trapped in Richmond, B.C. in late 2017, demonstrated symptoms of Long-billed Syndrome. The individual had a broken lower-mandible, and so was admitted to a rehabilitation centre, where it remained until the lower mandible grew to a length where the bird could eat natural prey without difficulty. Upon initial examination by the researcher who trapped the hawk, as well as the rehabilitation staff, the cause of the break was thought to be trauma. When I observed the bill of the hawk, on April 13, 2018, prior to its release, I noticed the beak was demonstrating the sickle-shaped characteristic of Long-billed Syndrome.
A recent trend of beak abnormalities have been discovered across orders of birds in North America, and are often debilitating Handel et al. (2010); Zylberberg et al. (2016). A particular type of deformity, characterized by overgrowth of keratin in the beak, has been described by researchers and rehabilitation experts (C. Anderson, personal communication, 2014; Zylberberg (2016).
Raptors (including hawks, eagles, falcons, owls), particularly in the Pacific Northwest of North America, have been demonstrating such beak deformities (Anderson, C., personal communication, 2014). Clifford (Bud) Anderson, a raptor researcher, described the deformities in hawks, first noticed in 1998, as Long-billed Syndrome.
LEO says: This observations was shared with avian bill deformity researcher Dr. Caroline Van Hemert with the USGS Alaska Science Center.
Caroline Van Hemert wrote:
Overall, this report is accurate and provides an interesting observation, especially in a juvenile bird. It’s important to note that the disease described among Alaskan birds is known as “avian keratin disorder” (AKD). We are currently investigating a potential link between the beak deformities observed in raptors and those in passerines. As a side note, I would suggest citing Handel et al. (2010) and Van Hemert and Handel (2010) in the statements included here that describe AKD in chickadees, crows, and other birds. It would be appropriate to also include the Zylberberg et al. (2016) citation in reference to our recent finding that a novel picornavirus (Poecivirus) is associated with AKD in Black-capped Chickadees and other affected species and is being evaluated as a possible cause. See also Zylberberg et al. (2018). Observers of beak deformities in Alaska can post their report to the USGS Alaska Science Beak Deformity website
Online resources
Long-billed Hawk Syndrome
Long-billed Hawk Syndrome - Audubon Syndrome of Portland
Alaska Science Center- Beak Deformities
Presentations
Long-billed Hawk Syndrome
Literature cited
Handel, C.M., Pajot, L.M., Matsuoka, S.M., Van Hemert, C., Terenzi, J., Talbot, S.L., Mulcahy, D.M., Meteyer, C.U. & Trust, K.A. (2010) Epizootic of beak deformities among wild birds in Alaska: An emerging disease in North America?. The Auk 127(4): 882-898.
Van Hemert, C.V. and Handel, C.M., 2010. Beak deformities in Northwestern Crows: Evidence of a multispecies epizootic. The Auk, 127(4), pp.746-751.
Zylberberg, M., Van Hemert, C., Dumbacher, J.P., Handel, C.M., Tihan, T. & DeRisi, J.L. 2016 Novel picornavirus associated with Avian Keratin Disorder in Alaskan birds. mBio 7(4).
Zylberberg, M., Van Hemert, C., Handel, C.M. and DeRisi, J.L., 2018. Avian keratin disorder of Alaska black-capped chickadees is associated with Poecivirus infection. Virology journal, 15(1), p.100.
.
