Instances of avian osteoarthritis from the Unalaska Sea Ice Project, Unalaska Island, Alaska.

OBJECTIVE: This project is designed to examine the prevalence of skeletal pathology in two archaeological avian bone assemblages. MATERIALS: Archaeological avian bone assemblages with Number of Identified Specimens of 14,909 (UNL-055) and 36,866 (UNL-048). METHODS: Visual examination of humeri, coracoids, tarsometatarsi, and cranial elements for pathology during taxonomic identification. RESULTS: 83 instances of skeletal pathology were observed in these assemblages and were most prevalent in the UNL-048 assemblage. Marginal osteophytes around the articular surfaces of the coracoid were the primary bone pathology in the UNL-048 avian assemblage. CONCLUSIONS: The prevalence of osteoarthritis in surface diving birds at the UNL-048 site could be due to changing climate. SIGNIFICANCE: Considering the environmental factors that contribute to instances of animal pathology allows for a more contextual interpretation of the cultural processes that occurred at archaeological sites. LIMITATIONS: Time and budgetary constraints did not allow for examination of the entire avian assemblage. SUGGESTIONS FOR FUTURE RESEARCH: Further intensive review of archaeological avian assemblages alongside consideration of environmental and cultural processes occurring during the site occupation is advised.

Computed Tomography of the Mandibles of a Stranded Offshore Killer Whale (Orcinus orca).

A mature, adult female, offshore killer whale (Orcinus orca) was stranded deceased in Portage Bay, Alaska, in October 2015. Full necropsy examination with histopathology was performed. Consistent with previous studies of offshore killer whales, and thought to be a result of their unique elasmobranch diet, all the teeth were significantly abraded and almost flush with the gingival margin. Age was estimated at 30-35 years based on annuli and growth arrest lines in a remaining tooth. The dentate portion of the mandibles were excised en bloc and frozen until imaging could be completed. Radiography and computed tomography revealed lesions consistent with severe abrasion, pulp exposure and evidence of endodontic and/or periodontal disease in nine of the 15 mandibular teeth present (60.0%). Only five (33.3%) teeth were suspected to have been vital at the time of death based on imaging. Lesions were more severe rostrally, with the caudal teeth less affected. Autolysis precluded gingival histopathology and no teeth were analyzed histologically. Necropsy examination revealed a likely multifactorial cause of death, with most significant lesions including the severe chronic periodontal/endodontic disease with abrasion, inanition and emaciation with possible cardiovascular disease. This case highlights the importance of imaging in evaluating periodontal and endodontic status, especially post mortem when other tissues are no longer available, and demonstrates that periodontal and endodontic disease occur naturally in this species and can be a significant cause of morbidity in mature free-ranging killer whales of the offshore ecotype.