Ratios of stable isotopes in feathers have great potential for identifying the connectivity of bird migrations and the origin of harvested individuals of game species. In particular, the relationship between the hydrogen ratio due to latitudinal variation in precipitation (δDp) and that in feathers (δDf) is often used to determine unknown individuals' latitude of origin. We assessed this relationship between Canada Geese nesting in the temperate zone (Branta canadensis maxima) and the subarctic (B. c. interior). For this game species, the origin of harvested birds is important for developing management that maintains a desirable level of harvest while ensuring continued viability of all subspecies and breeding populations. We collected freshly grown primaries from three populations of interior and five of maxima and analyzed them for δD, δ13C, and δ15N. Multivariate analysis suggested no overall differences in isotopic composition between subspecies. A univariate assessment indicated a significant difference in δ15Nf, despite substantial overlap between subspecies, and no difference in δDf or δ13Cf. Of particular interest is the lack of difference in δDf, despite the large latitudinal differences in δDp and between the subspecies' breeding ranges. Values of δDf averaged -131.85‰ ± 1.36 for interior, -131.63‰ ± 0.71 for maxima, and we found no overall relationship between δDf and δDp. Overall, our results suggest that δD, δ13C, and δ15N alone have limited ability to discriminate between subspecies interior and maxima and hence have limited applicability for estimating the origin of harvested birds and/or identifying molt migrants of maxima.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 114 • No. 3