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Winnipeg, Canada

Ferguson S.H.,University of Winnipeg | Ferguson S.H.,University of Manitoba | Higdon J.W.,Higdon Wildlife Consulting | Westdal K.H.,Oceans North Canada
Aquatic Biosystems | Year: 2012

Background: Killer whales (Orcinus orca) are the most widely distributed cetacean, occurring in all oceans worldwide, and within ocean regions different ecotypes are defined based on prey preferences. Prey items are largely unknown in the eastern Canadian Arctic and therefore we conducted a survey of Inuit Traditional Ecological Knowledge (TEK) to provide information on the feeding ecology of killer whales. We compiled Inuit observations on killer whales and their prey items via 105 semi-directed interviews conducted in 11 eastern Nunavut communities (Kivalliq and Qikiqtaaluk regions) from 2007-2010.Results: Results detail local knowledge of killer whale prey items, hunting behaviour, prey responses, distribution of predation events, and prey capture techniques. Inuit TEK and published literature agree that killer whales at times eat only certain parts of prey, particularly of large whales, that attacks on large whales entail relatively small groups of killer whales, and that they hunt cooperatively. Inuit observations suggest that there is little prey specialization beyond marine mammals and there are no definitive observations of fish in the diet. Inuit hunters and elders also documented the use of sea ice and shallow water as prey refugia.Conclusions: By combining TEK and scientific approaches we provide a more holistic view of killer whale predation in the eastern Canadian Arctic relevant to management and policy. Continuing the long-term relationship between scientists and hunters will provide for successful knowledge integration and has resulted in considerable improvement in understanding of killer whale ecology relevant to management of prey species. Combining scientists and Inuit knowledge will assist in northerners adapting to the restructuring of the Arctic marine ecosystem associated with warming and loss of sea ice. © 2012 Ferguson et al; licensee BioMed Central Ltd.

Pomerleau C.,University of Quebec at Rimouski | Pomerleau C.,Canadian Department of Fisheries and Oceans | Lesage V.,Maurice Lamontagne Institute | Ferguson S.H.,Canadian Department of Fisheries and Oceans | And 3 more authors.
Marine Ecology Progress Series | Year: 2012

The eastern Canada-West Greenland (EC-WG) bowhead whale Balaena mysticetus population is slowly recovering from the intensive commercial whaling of the 18th and 20th centuries. However, climate change, through effects on ice conditions and prey availability, is one of several threats that might affect bowhead whale recovery. In this study, we exploited the variability observed in isotopic signatures of prey assemblages across the eastern Arctic to examine variability in diet among bowhead whales (n = 202) and identify their potential foraging areas. We compared δ13C and δ15N isotope ratios of biopsied skin samples with those of potential zooplankton prey species collected across the Canadian eastern Arctic, and calculated the proportional contributions of various sources (zooplankton) to the diet of bowhead whales using a Bayesian stable isotope mixing model. A cluster analysis indicated some variability in isotopic composition among groups of individuals, but not between males and females or age classes. The isotopic model discounted Davis Strait and Disko Bay as potential foraging areas for bowhead whales, at least in spring and summer. Lancaster Sound, Baffin Bay and the Gulf of Boothia were the 3 main areas likely used for summer feeding, where bowhead whales fed primarily on large Arctic calanoid copepods (Calanus hyperboreus, C. glacialis, Metridia longa, and Paraeuchaeta spp.), mysids and euphausiids. While some inter-individual variability in diet was observed, the strong dependence of this endemic Arctic species on Arctic zooplankton may make them vulnerable to the predicted latitudinal shift in prey species composition caused by ongoing warming. © Inter-Research and Fisheries and Oceans Canada 2012.

Higdon J.W.,Higdon Wildlife Consulting | Ferguson S.H.,Crescent University
Aquatic Mammals | Year: 2014

In the early 1950s, probably 1955, a group of killer whales (Orcinus orca) became entrapped in developing landfast sea ice in northeast Foxe Basin in the eastern Canadian Arctic (Nunavut). Reports of killer whale ice entrapments are rare, and this is, to our knowledge, the only fatal entrapment reported for the Canadian Arctic. The entrapment was previously reported and briefly discussed by Blackadar (1964), but significant additional information became available from local Inuit elders, some of whom experienced the event first-hand. We summarize Inuit knowledge of this ice entrapment, using (1) semi-directed interviews with 12 hunters and elders conducted in 2008 and 2010 as part of a study on Inuit knowledge on Arctic killer whales, (2) a first-hand account of the event provided by a local elder in 2006 and 2011, and (3) transcripts from the Igloolik Oral History Database (extracted in 2008). Previous authors have noted that hunters harvested two killer whales, a female and a calf, but local knowledge summarized here indicates that more killer whales, at least five and probably 11 to 12, were entrapped and at least two harvested, while the rest likely died. Local knowledge also provided new information that the killer whales were entrapped in a different location than previously reported and that they survived in the breathing hole for several months before harvest. Inuit are reliable observers with excellent recall abilities, particularly for observations of rare events related to the natural environment that encompasses their way of life. The observations reported here are significant in understanding the physiology of killer whale starvation in cold waters, for managers monitoring frequency of episodic events, and in developing appropriate responses to rare entrapment events.

Higdon J.W.,Higdon Wildlife Consulting | Byers T.,Byers Environmental Studies | Brown L.,University of Winnipeg | Ferguson S.H.,University of Winnipeg
Polar Record | Year: 2013

Sightings of killer whales (Orcinus orca) are increasing in the eastern Canadian Arctic, but trends in the western Arctic have not been thoroughly examined. We summarise killer whale observations from the Canadian Beaufort Sea, primarily from traditional ecological knowledge interviews and group workshops conducted in 1993 and 2006-2007. After correcting for duplicative reports, we documented 31 observations occurring from the 1940s to 2000s (18 of the 31 observations could be attributed to a particular decade whereas others could not). Killer whales are rare in the Canadian Beaufort Sea, with only 1-5 reported sightings per decade since the 1940s (median = 3). In 1993 only 15% of Inuvialuit hunters in three communities had observed them, including some sightings in Alaska. Recent mapping workshops (2006-2007) collected only eight sightings from 128 participants in all six regional communities. Local observations indicate no apparent increase in killer whale presence in the western Canadian Arctic. Sightings were widely distributed across the region, although concentrated in the Mackenzie Delta area with few to the east. Killer whales are annually observed as far north as Barrow, Alaska, but do not appear to make regular eastward movements and are rare in Canadian waters. © 2013 Cambridge University Press.

Higdon J.W.,Higdon Wildlife Consulting | Higdon J.W.,University of Winnipeg | Westdal K.H.,University of Winnipeg | Ferguson S.H.,University of Winnipeg
Journal of the Marine Biological Association of the United Kingdom | Year: 2014

Traditional ecological knowledge is being increasingly used in wildlife management in northern regions, and Inuit harvesters in Nunavut, Canada, have extensive knowledge about local wildlife species. We collected Inuit knowledge on killer whales (Orcinus orca) through 105 semi-directed interviews in 11 Nunavut communities from 2007 to 2010. Interviewees provided extensive information on killer whale movements, seasonal presence, distribution and abundance in the eastern Canadian Arctic. Observations from different communities were often complementary, and there was consistency in interview comments both within and among regions. Nearly all participants had seen killer whales at least once, and the whales were present every summer (July-September) in all regions, although movements depended on ice conditions. Relative abundance of killer whales varied by region, and they were reported more often in North Baffin communities than in other regions. Killer whales migrated through Hudson Strait and Lancaster Sound following their marine mammal prey. Estimates of local population sizes were variable, with suggested numbers that varied from tens to the low hundreds. Most interviewees in the Foxe Basin, Hudson Bay and north Baffin regions thought that killer whale presence was increasing. In contrast, half the South Baffin interviewees noted declines in past abundance due to the 1977 harvest of 14 whales that became trapped in a saltwater lake. Interviews provided information at a long temporal and wide spatial record. Inuit are reliable observers and continued killer whale research will be most effective if it integrates modern science approaches with the traditional skills, knowledge and experience of Inuit harvesters. © 2013 Marine Biological Association of the United Kingdom .

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