Frequently Asked Questions

Q.Is there a concern about the accuracy of identification of museum specimens?
A. Museum specimens were assumed to have been identified correctly, however; when species, sex or age were in doubt they were not used. Only adult specimens of known sex were used.

Immature Birds:
Q. Do immature birds present a problem?
A. Young birds develop very quickly. For example Red-tailed Hawks fledge in about 45 days. Sharp-shinned Hawks fledge within 23 to 25 days. Great Horned Owls fledge within 31 to 35 days. Therefore, the window of when they are still growing is very small. Often the bones of young birds are identifiable since they are not totally
calcified and notably not fully developed. Immature bones also deteriorate more quickly. However; there does remain a slight possibility of error. Only adult specimens of known sex were measured for this program.


Divergence and Morphometric Differences:
Q. What about the divergence of species? How can you compare measurements between species?
A. Divergence of species is the fundamental principle which makes this program work. Similar species do present some problems; however, the program helps to narrow down the possibilities. Species evolve and their bones alter by twisting, elongating, bulging or compressing making it difficult to take comparative measurements of different species. Comparative "measurement points" should be noted carefully for each species. The program is intended to be used with a comparative faunal collection.


Colour of the Bones:
Q. Can you tell the species apart by the colour of the bones?
A. The colour of the bones are just a result of grease and staining and is not a distinguishing feature which can be used to tell the species apart.

Rollover Images:
Q. Why don't the images of the bones "rollover" on my computer?
A. You must have "Active Content" or "Active Scripting" turned on.


Image Perspective:
Q. Why are all the images the same size?
A. For a given measurement the perspective of the bones are all the same. Photographs are only used to visually discern morphometric differences; therefore, the comparative size of the photographs are irrelevant.

Subspecies and Regional Differences:

Q. What about Subspecies?
A. At this time subspecies have not been dealt with, however; with more time and a larger data set subspecies and regional differences could be considered.


Taxonomic Order:
Q. What taxonomic order was used?
A. The American Ornithological Union http://www.aou.org/checklist/index.php3


Please contact Michael McNall mmcnall@royalbcmuseum.bc.ca if you have any questions.


The Bones Instructions Methods Credits FAQs Royal BC Museum