Higdon Wildlife Consulting

Winnipeg, Canada

Higdon Wildlife Consulting

Winnipeg, Canada
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Smith A.J.,Ramboll | Higdon J.W.,Higdon Wildlife Consulting | Richard P.,Canadian Department of Fisheries and Oceans | Orr J.,Canadian Department of Fisheries and Oceans | And 2 more authors.
PLoS ONE | Year: 2017

To understand beluga whale (Delphinapterus leucas) estuarine use in the Nelson River estuary, southwest Hudson Bay, we recorded and examined beluga movements and habitat associations for the July through August period in 2002–2005. We compared locations of belugas fitted with satellite transmitters (“tags”) (2002–2005) and aerial-surveyed (2003 and 2005) belugas for years of differing freshwater flow from the Nelson River which is influenced by hydroelectric activity. Using the beluga telemetry location data, we estimated an early August behavioral shift in beluga distribution patterns from local estuarine use to a progressively more migratory behavior away from the estuary. The timing of this shift in behavior was also apparent in results of beluga aerial surveys from the 1940s–1960s, despite environmental changes including later freeze-up and warming ocean temperatures. Overall, during the higher than average discharge (“wet”) year of 2005, the three tagged belugas ranged farther from the Nelson River but not farther from the nearest shore along southwestern Hudson Bay, compared to the 10 tagged belugas tracked during the “dry” years of 2002–2004 with below average discharges. Aerial survey data for 2003 and 2005 display a similar dry vs. wet year shift in spatial patterns, with no significant change in overall density of belugas within the study area. In the Nelson estuary, proximity to the fresh-salt water mixing area may be more important than the shallow waters of the upper estuary. Killer whales (Orcinus orca) were observed in the Churchill area (200 km northwest) during each year of study, 2002–05, and belugas may benefit from the proximity to shallow estuary waters that provide protection from the larger-bodied predator. Study results contribute to an understanding of the influence of environmental variation on how and why belugas use estuaries although considerable uncertainties exist and additional research is required. © 2017 Smith et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Reinhart N.R.,Royal Veterinary College | Reinhart N.R.,UK Institute of Zoology | Ferguson S.H.,University of Winnipeg | Ferguson S.H.,University of Manitoba | And 5 more authors.
Polar Biology | Year: 2013

Killer whales (Orcinus orca) are increasing in occurrence and residence time in the eastern Canadian Arctic (ECA) in part due to a decrease in sea ice associated with global climate change. Killer whales prey on bowhead whales (Balaena mysticetus) of the Eastern Canada-West Greenland (EC-WG) population, but their patterns of predation pressure and effect on the EC-WG population's ability to recover from historical whaling remain unknown. We analyzed photographs of individual bowhead whale flukes from five regions within the EC-WG population's geographic range (Cumberland Sound, Foxe Basin, Isabella Bay, Repulse Bay and Disko Bay), taken during 1986 and from 2007 to 2012, to estimate the occurrence of rake marks (parallel scars caused by killer whale teeth). Of 598 identified whales, 10.2 % bore rake marks from killer whales. A higher occurrence of rake marks was found in Repulse and Disko Bays, where primarily adult bowhead whales occur seasonally, than in Foxe Basin, where juveniles and females with calves occur. Older bowheads, which have had greater exposure time to killer whales due to their age, had higher occurrences of rake marks than juveniles and calves, which may indicate that younger whales do not survive killer whale attacks. A high proportion of adult females also had rake marks, perhaps due to protecting their calves from killer whale predation. In order to quantify the effect of killer whales on EC-WG population recovery, further research is needed on the relationship between the occurrence of rake marks and bowhead adult, calf, and juvenile mortality in the ECA, as well as more information about Arctic killer whale ecology. © 2013 Springer-Verlag Berlin Heidelberg.

Galicia M.P.,York University | Thiemann G.W.,York University | Dyck M.G.,Environment Canada | Ferguson S.H.,University of Winnipeg | Higdon J.W.,Higdon Wildlife Consulting
Ecology and Evolution | Year: 2016

Polar bear (Ursus maritimus) subpopulations in several areas with seasonal sea ice regimes have shown declines in body condition, reproductive rates, or abundance as a result of declining sea ice habitat. In the Foxe Basin region of Nunavut, Canada, the size of the polar bear subpopulation has remained largely stable over the past 20 years, despite concurrent declines in sea ice habitat. We used fatty acid analysis to examine polar bear feeding habits in Foxe Basin and thus potentially identify ecological factors contributing to population stability. Adipose tissue samples were collected from 103 polar bears harvested during 2010–2012. Polar bear diet composition varied spatially within the region with ringed seal (Pusa hispida) comprising the primary prey in northern and southern Foxe Basin, whereas polar bears in Hudson Strait consumed equal proportions of ringed seal and harp seal (Pagophilus groenlandicus). Walrus (Odobenus rosmarus) consumption was highest in northern Foxe Basin, a trend driven by the ability of adult male bears to capture large-bodied prey. Importantly, bowhead whale (Balaena mysticetus) contributed to polar bear diets in all areas and all age and sex classes. Bowhead carcasses resulting from killer whale (Orcinus orca) predation and subsistence harvest potentially provide an important supplementary food source for polar bears during the ice-free period. Our results suggest that the increasing abundance of killer whales and bowhead whales in the region could be indirectly contributing to improved polar bear foraging success despite declining sea ice habitat. However, this indirect interaction between top predators may be temporary if continued sea ice declines eventually severely limit on-ice feeding opportunities for polar bears. © 2016 The Authors. Ecology and Evolution published by John Wiley & Sons 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.

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.

Westdal K.H.,Oceans North Canada | Higdon J.W.,Higdon Wildlife Consulting | Ferguson S.H.,University of Winnipeg
Polar Biology | Year: 2016

In January 2013, a group of killer whales (Orcinus orca) was discovered in an ice entrapment in eastern Hudson Bay, Canada. The whales escaped the entrapment after several days, which ended the discussion on response options. The event did, however, highlight the need for a better understanding of killer whale entrapments to guide future responses. We conducted a literature review of ice entrapment and ice-induced stranding mortality events for killer whales in the Northern Hemisphere and identified 17 events dating from 1840 to 2013, ranging from a single whale to more than 20. Ice entrapments occurred in both pack ice (mobile ice) and fast ice (ice which forms and remains fast along the coast), with most records (70 %) coming from midlatitude regions with seasonal ice cover (e.g., Sea of Okhotsk and eastern Canada). Most events resulted in mortality, and time to mortality depended on ice conditions with whales surviving longer in fast-ice entrapments, where ice is more stable than in mobile ice. © 2016 Springer-Verlag Berlin Heidelberg

Kelley T.C.,University of Manitoba | Higdon J.W.,Higdon Wildlife Consulting | Ferguson S.H.,University of Winnipeg
Canadian Journal of Zoology | Year: 2014

Little is known about their mating systems, but odontocetes may utilize the same types of mating systems as terrestrial mammals. Species with relatively large testes are likely to be polygynandrous, while species with smaller testes and greater sexual size dimorphism (SSD) are predicted to be polygynous. The "Machiavellian intelligence or sexual conflict" hypothesis predicts that polygynadrous species also evolved larger brains both to coerce conspecifics to mate and to resist mating attempts by undesirable mates. The "costly tissue" hypothesis predicts that species investing heavily in testes invest less in brain tissue and vice versa to conserve energy. Residual testes and brain mass measurements were used to test the sexual conflict and costly tissue hypotheses in 40 species of odontocetes. Correlations were performed on both raw data and independent contrasts to control for phylogeny. There was a significant positive correlation between residual testes mass and SSD in both data sets, and between residual testes mass and residual brain mass in the non-phylogenetically controlled data set. Results indicate a negative relationship between increased testes masses and SSD in odontocetes. There was no support for the costly tissue hypothesis. Support for Machiavellian intelligence or sexual conflict hypothesis was found only when phylogenetic effects were not considered.

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 .

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.

Westdal K.H.,Oceans North Canada | Higdon J.W.,Higdon Wildlife Consulting | Ferguson S.H.,Oceans North Canada
Arctic | Year: 2013

Killer whale (Orcinus orca) sightings are increasing throughout the eastern Canadian Arctic, and residents of Nunavut are concerned about the possible impact of killer whale predation on other marine mammals that are of socio-economic and cultural importance to Inuit. We analyzed the attitudes of Inuit towards killer whales, drawing on 105 semi-directed interviews conducted in 11 eastern Nunavut communities (Kivalliq and Qikiqtaaluk regions) between 2007 and 2010. Information gathered included interviewees' firsthand knowledge, as well as knowledge they had gained through oral history. Interviews provided data on interactions between Inuit and killer whales, physical descriptions and nature of killer whales in this region, overall opinion of interviewees with respect to killer whales, historical use of the animal, opinions regarding research on killer whales and effects of killer whales on other species, particularly the whales and seals harvested for Inuit subsistence. Interviewees described killer whales as their helpers more often than as their competitors, but also as feared and dangerous. Overall, negative opinions were more common than positive opinions, and some interviewees also had a conflicted attitude towards killer whales. More participants viewed killer whales as smart and fast than as beautiful and playful. Inuit attitudes toward killer whales did not vary significantly with sex, age, hunter status, or experience with killer whales, but did vary somewhat across regions. Inuit knowledge and perspectives play a critical role in wildlife management, especially in a changing Arctic. Conservation and management of species that are important to the Inuit subsistence harvest in Nunavut must take into consideration killer whale predation, Inuit knowledge, and Inuit views and attitudes towards killer whales.

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