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Return of Caribou to Ungava

Return of Caribou to Ungava

A.T. Bergerud
Stuart N. Luttich
Lodewijk Camps
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  • Book Info
    Return of Caribou to Ungava
    Book Description:

    In an examination of the life history and population biology of the herd, The Return of Caribou to Ungava offers a synthesis of the basic biological traits of the caribou, a new hypothesis about why they migrate, and a comparison to herd populations in North America, Scandinavia, and Russia. The authors conclude that the old maxim, "Nobody knows the way of the caribou," is no longer valid. Based on a study in which the caribou were tracked by satellite across Ungava, they find that caribou are able to navigate, even in unfamiliar habitats, and to return to their calving ground, movement that is central to the caribou's cyclical migration. The Return of Caribou to Ungava also examines whether the herd can adapt to global warming and other changing environmental realities.

    eISBN: 978-0-7735-7678-0
    Subjects: Zoology

Table of Contents

  1. Acknowledgments
    (pp. xv-xviii)
    A.T. Bergerud, Stuart N. Luttich and Lodewijk Camps
  2. Preface
    (pp. xxxv-xxxxviii)
    A.T. Bergerud
  3. CHAPTER ONE Setting and Background
    (pp. 3-30)

    On 12 April 1954, Frank Banfield and John Tener were on an aerial survey flying northeast from Knob Lake over the immense wilderness of Ungava when they located 361 caribou adjacent to the George, Whale, and Wheeler Rivers. They estimated 4,200 animals in the herd. It was the start of research and surveys. Other population estimates followed: 15,000 animals in 1958; a sevenfold increase to 105,000 by 1973; 176,000 by 1976; 271,000 by 1982; a major jump to 472,000 two years later in 1984; and another increase to 700,000 animals by 1988 – all occurring in the herd we named the...

  4. CHAPTER TWO Taxonomy, Ecotypes, Herds, and Morphology
    (pp. 31-53)

    The caribou of Ungava are classified as woodland caribouRangifer tarandus caribou) based on skull measurements (Banfield 1961). Prior to this classification mammalogists recognized a northern form (Rangifer arcticus Caboti) and a southern species (Rangifer caribou caribou) (Seton 1927; Anderson 1938; Harper 1961). The northern form made extensive migrations and lived in the summer largely above tree line; its behaviour was similar to the barren-ground caribou in the Northwest Territories. The southern species made short migrations and lived for the most part below tree line. Our next chapter discusses the postglacial dispersion of the ancestors of the present-day forms into...

  5. CHAPTER THREE The Return of Caribou to Ungava after the Last Ice Age
    (pp. 54-73)

    The earliest records ofRangiferare based on fossils about 1.3 to 1.8 million years old recovered from Fort Selkirk, Yukon, and from the Cape Deceit fauna in Alaska (Guthrie and Matthews 1971; Harington 1999a). The consensus is that caribou evolved in northwestern North America (Eastern Beringia) and then spread to Asia during glaciations when land connections to Asia existed (Ban-field 1961; Harington 1978; Kurtén and Anderson 1980). Hence caribou have persisted through the Nebraskan, Kansan, Illinoian, and Wisconsinan glaciations and the Aftonian, Yarmouthian, and Sangamonian interglacials, when dozens of other mammal species went extinct. Kurtén and Anderson (1980) list...

  6. CHAPTER FOUR The Abundance and Distribution of Sedentary Caribou
    (pp. 74-105)

    In this chapter we discuss the abundance, past and present, and distribution of the caribou in southern Ungava (south of 55°N). The females in these latitudes, in contrast to animals farther north, (the migratory Leaf River and George River herds) do not migrate to common calving grounds but rather disperse at calving (space-out) from other females, seeking birth sites of low predation risk (Bergerud and Page 1987). These animals are called the sedentary ecotype (Bergerud 1988b), and in contrast to the migratory ecotype, they are most aggregated on winter ranges and least aggregated at calving (fig. 2.2).

    These herds live...

  7. CHAPTER FIVE Past Population Fluctuations
    (pp. 106-122)

    The late Wisconsinan ice sheet began to decay in Ungava prior to 9,000 BP, and the northern coastal sections were free of ice by 9,000 BP (fig 1.8; Ritchie 1987; Faunmap 1994). The upper George River deglaciated 8,500 years ago and created Lake Naskaupi, which collapsed about 7,000 BP (Clark and Fitzhugh 1990). However, there were still some ice remnants and large glacial lakes 5,000 BP that would have impeded the movement of caribou (Jordan 1975; Samson 1978; Lauriol and Gray 1987).

    Even tough temperatures were warmer than at present, it took hundreds of years for primary plant succession to...

  8. At Home in the Wilderness: The Mushuau Innu and Caribou
    (pp. 123-134)

    Nitassinan – our land” – the vast interior of the Quebec-Labrador peninsula, is the traditional homeland of those Innu whose lives and destiny have been irrevocably linked to the coming and going of caribou. More than 7,000 years ago, while the last vestiges of the glacial ice sheet that once covered much of northern North America still lingered in the George River valley, and much of Nitassinan was covered by huge pro-glacial lakes, small intrepid bands of Innu ancestors waited at crossing places to ambush the animals on which their lives depended. Archaeological research, much of it conducted by the Innu themselves,...

  9. CHAPTER SIX Causal Factors in Historical Fluctuations
    (pp. 135-149)

    We will base our discussion of possible causal factors in population fluctuations on our analysis of the past fluctuations of the George River herd as indexed by root-scar data presented by Morneau and Payette (2000). They developed an original technique to measure past abundance by quantifying the scars on living conifer roots that bisect caribou trails. This scar index was conducted over a 144-year period from 1848–92 (fig. 6.1) in the vicinity of Indian House Lake, the very centre of the historical range of the George River herd. Their index was highly correlated with population estimates derived from census...

  10. CHAPTER SEVEN Forage and Range
    (pp. 150-180)

    In the 1940s–1950s the terrestrial lichen ranges in the central interior of Ungava were the most extensive in North America and possibly the world (fig. 1.1; Hustich 1951). The range extended from the closed canopy line of the Eastman River (52°N) north to Kuujjuaq (58°N) in central Ungava. This lichen woodland of scattered black spruce and larch was protected by some of the greatest snow depths for an extensive region in North America: Lichen heights in climaxCladonia rangiferina, C.alpestris(nowCladina stellaris) stands were often 10–15 cm deep with a biomass estimated at 2,500 Kg/ha (Hustich...

  11. CHAPTER EIGHT Body and Antler Growth
    (pp. 181-221)

    The George River caribou herd has the smallest ratio of summer range above tree line to winter range below tree line of any of the seven largest migratory herds in North America. The winter range of the George River caribou herd exceeds the summer landscape by a factor of nine. We have documented (chapter 7), as have Crête et al. (1990a); Crête and Huot (1993); and Manseau et al. (1996), that by at least 1988 vascular plants on the summer range were seriously overgrazed. Nonetheless, large lichen supplies remained on the winter range. This sequence is the reverse of that...

  12. CHAPTER 9 Physical Condition
    (pp. 222-266)

    Circumpolar caribou reside in a pulsating environment where seasons of plenty alternate with seasons of scarcity, and they have evolved an annual cycle of sharply fluctuating body mass and tissue deposition related to life-history consequences. For females, fat reserves and body weights peak in October–November at the end of the season of nutrient rich forage; males also reach peak condition at the time of the rut, but unlike females, males utilize nearly all their fat reserves during the short breeding interval. Females may decline in protein/fat reserves from November to April (Tyler 1987), but the loss is extremely rapid...

  13. CHAPTER TEN Recruitment, Mortality, and Population Growth
    (pp. 267-291)

    Each mammal species has a characteristic, maximum rate of increase (rm) which is a product of litter size, age of puberty, the adult sex ratio, and longevity (Cole 1954). The rmfor caribou has been estimated to be r = 0.32 (λ = 1.37) and has been empirically documented where animals have been introduced to new habitats (especially islands) where there were no predators and summer forage had not been utilized previously (Bergerud 1980; Heard 1990). However, rmrates do not occur for caribou on established ranges coexisting with their natural predators. The common rates of increase recorded for herds...

  14. CHAPTER ELEVEN Limiting Factors
    (pp. 292-317)

    Wildlife management in North America has a history of searching for the most limiting factor (Leopold 1933), i.e., the mortality loss that holds down the potential rate of increase more than any factor. Once it is found, steps are taken to reduce or manage this loss. Limiting factors do not have to be density-dependent in action. They can reduce numbers whether populations are low or high. The most frequently mentioned limiting factors for caribou are starvation, accidents, hunting mortality, weather-related deaths and natality, disease and parasites, and predation (Banfield 1954; Kelsall 1968; and Skoog 1968; Bergerud 1971b; Valkenburg et al....

  15. CHAPTER TWELVE The Use of Space
    (pp. 318-352)

    Most species of vertebrates have a means of spacing themselves across the habitat. Bergerud’s model (Bergerud 1974b) for caribou proposes that these ungulates evolved in recent times in a largely open habitat in the presence of wolves (Canis lupus), resulting in a gregarious lifestyle. This gregarious social structure in the presence of sparse and ephemeral arctic flora, variable snow cover, and insect harassment gave rise to contingencies that required annual cycles in aggregation and movement behaviours. We would like to further document the cycle in mobility and the use of space by the George River caribou herd in Ungava and...

  16. CHAPTER THIRTEEN Environmental Factors in Distribution and Movement
    (pp. 353-403)

    Caribou are continually on the move (figs. 13.1–13.3; table 13.1). Their gregarious herd structure entails shifting, if for no other reason than the impacts of grazing and trampling on the vegetation. Nonetheless, one recognizes a basic annual cycle of acceleration and deceleration in these movements, or, as Skoog (1968) described it, “a cycle of shifts and pauses,” certainly a sequence we found relevant to the annual travels of caribou in Newfoundland (Bergerud 1974b). We’d like to quantify this cycle and understand the environmental influences that affect distribution, mobility rates and changes in azimuths, taking into consideration insects, forage, wind,...

  17. CHAPTER FOURTEEN Optimal Foraging and Predation Risk in the Winter and Growing Season
    (pp. 404-431)

    There is a growing concern among caribou biologists about the impact of global warming on caribou. But the concerns voiced (Russell 1993; Griffith et al. 1998; Gunn 2000b; Weladji et al. 2002; Heggberget et al. 2002) relate solely to optimal foraging considerations and exclude how predation risk will alter as temperatures increase in the Arctic. Certainly the latter will be affected by climate change, and we feel that predation impacts will be the primary means by which survival rates will alter in North America.

    Belovsky (1991) held that insect and predator avoidance will “constrain” optimal foraging. Lima and Dill (1990),...

  18. CHAPTER FIFTEEN Spacing Theory of Calving and Migration
    (pp. 432-478)

    The spectacular spring migrations of caribou/reindeer in the Arctic and the return of females to particular calving areas (fig. 15.1) have long intrigued laymen and scientists alike, but they have not been adequately explained from a theoretical perspective (Baker 1978). The only movement that the George River herd undertakes that qualifies as a true migration is the spring return of preparturient females to the calving ground on the Labrador tundra (fig. 13.28). Dingle (1996) defines true migration as undistracted movement, not directly responsive to resources, where cessation is primed by the movement itself. Based on Naskapi lore and the ages...

  19. CHAPTER SIXTEEN Population Regulation
    (pp. 479-510)

    The interaction between natural mortality and population density constitutes the central element of any population model of ungulates (Caughley 1977). A limiting factor may operate independently of density, but the impact of a regulating factor varies with density. The idea that population growth would be limited is credited to Malthus (1803); that this can operate through factors that vary with density we credit to Howard and Fiske (1911) , and these density-dependent factors can influence either reproductive rates or mortality (Lack 1954). In our analysis of demography as it relates to densities, we have divided the growth of the herd...

  20. Appendix: Summer Energy Budgets for Lactating Females
    (pp. 513-538)