Geographic variation in cranial morphology of narwhals from Greenland and the Eastern Canadian Arctic
In cooperation with:
Greenland Institute of Natural Resources, Nuuk, Greenland
Polar Science Center, University of Washington, Seattle, USA
Okapi Wildlife Associates, Quebec, Canada
Narwhals are heavily hunted in Greenland. In this project we investigate the relation between whales hunted in different areas of Greenland and Eastern Canadian Arctic based on skull morphology. We analyzed variation in nine non-metric and eight metric variables in the skulls of 132 narwhals from five localities in Greenland (Qaanaaq, Melville bay, Uummannaq, Qeqertarsuaq, and Scoresbysund,) and one in the Eastern Canadian Arctic (Milne Inlet). Metric variables were used to compare the combined Qeqertarsuaq and Uummannaq sample with the samples from Qaanaaq and Scoresbysund using three different multivariate techniques for each sex. None of the results were significant, however this may be attributed to low sample sizes. Six of the non-metric variables were independent of age and sex and were used in comparing samples from the six localities. No differences were found between the four localities in West Greenland. One of the six variables (NV8) showed differences between the combined West Greenland samples and Milne Inlet. One variable (NV2) showed differences between the combined West Greenland sample and the one from Scoresbysund. Thus, it appears to be possible to detect differences between stocks based on skulls, but with non-metric variables. A major shortcoming of this analysis is the small sample size from several of the areas which made distinguishing differences difficult or impossible. We therefore recommend continued collection of skulls of narwhals to augment samples sizes in future studies.