The Greenland White-fronted Goose Anser albifrons flavirostris

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not yet been sufficient to halt the linear annual increase in numbers since protection. The Greenland White-fronted Goose was a population that was declining due to habitat loss and hunting, but where protection from hunting has increased survival in proportion to the former size of the hunting bag, enabling the population to enter a phase of increase. Apparently confined to 72 traditional areas by behavioural site loyalty throughout its range, the population has shown signs of slowing its expansion in numbers in very recent years due to declining reproductive success.
9 Synthesis 9.1 Anticipatory acquisition of nutrients, density dependence and constraints upon fitness In spring, every female Greenland White-fronted Goose of breeding age must clear three nutritional hurdles in order to breed successfully. The annual cycle involves completion of two spring migration episodes. Both require the bird to make the necessary physiological and anatomical modifications and lay down fuel reserves to sustain two flights of 1,500 km, one over the sea to Iceland, and the second crossing the sea and the Greenland Ice Cap. The ease with which an individual can clear these hurdles has various fitness consequences. Failure to construct large enough flight muscles or energy stores to sustain the flight will result in death en route – this much natural selection will ensure. However, the ability to accumulate the necessary resources to only just complete the two flights leaves no stores for investment in reproduction. Slow accumulation of adequate stores will delay departure from staging areas and Lipid costs of egg laying and incubation Costs � body mass (kg) BMR (kJ) Lipid equivalent of 1xBMR (g/day) DEE (xBMR) time of arrival to the nesting grounds, so condition mediated timing of breeding may also affect reproductive output in this way. To complete the journey to the breeding grounds early enough with some extra stores remaining is likely to contribute to the investment in reproduction, and this, together with efficiency in finding food during the pre-nesting period, is likely to determine, to a major extent, the reproductive success of that individual. On the other hand, there must be some upper limit on the amount of energy or other nutrient stores, set by the cost of carrying such excess body mass (e.g. predation risk and enhanced energy use induced by heavier flying weight, see review in Witter & Cuthill 1993). Nevertheless, the ability to acquire specific nutrients to store for use at key points in the winter and spring has consequences for the ability of a bird to reproduce, or, in the extreme, to survive each migration. The efficiency (and therefore the rate) of accumulation of such 'capital' through a series of acquisi- Table 9.1. Protein and lipid energy requirements for a laying Greenland White-fronted Goose, her clutch of 3 or 6 eggs and subsequent incubation. Analysis follows methods of Meijer & Drent (1999), using Basal Metabolic Rate estimated from the relationships for non-passerines derived by Aschoff & Pohl (1970), i.e. BMR = 330.W 0.722 (where W = body weight in kg.) and based on the assumption that daily energy expenditure (DEE) during laying is equivalent to 1.7 x BMR. Protein costs were calculated using the modified formula of Robbins (1981) related to body weight according to the formula 2.68.W 0.75 g protein day -1 (see Meijer & Drent 1999 for full explanation). Laying/ incubation period (days) Lipid used in laying/ incubation period (g) Lipid used in clutch (g) Total minimum and minimum lipid investment (g) Laying 2.78 690 18.2 1.7 4-8 123.5-247.1 49-98 172.5-345.1 Incubation 2.78 690 18.2 1.1 26 519.6 519,6 Protein costs of egg-laying and incubation Costs � body Maintenance Laying/ Protein used in Protein used in Total mass (kg) protein incubation period laying/incubation clutch minimum (g/day) (days) period (g) (g) and minimum protein investment (g) Laying 2.78 5.7 4-8 23.1-46.2 56-112 79.1-158.2 Incubation 2.78 5.7 26 165.0 165.0 73
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Contents Summary ..................
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Summary The Greenland White-fronted
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Greenland White-fronted Geese are u
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Dansk resumé Den grønlandske blis
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1 Introduction 1.1 Why Greenland Wh
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The Greenland White-fronted Goose i
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more direct measures of 'body condi
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2Limits to population size in recen
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Despite the morphological similarit
Page 23 and 24: Scotland, the wettest peat soils we
Page 25 and 26: of this goose population. At the sa
Page 27 and 28: Spring count 16000 12000 8000 4000
Page 29 and 30: 3 Accumulation of body stores and t
Page 31 and 32: Body mass (g) 3500 3000 2500 adult
Page 33 and 34: h -1 and none showed any sign of re
Page 35 and 36: labelled water), the precise extent
Page 37 and 38: 4 Spring staging in Iceland and the
Page 39 and 40: Body mass (g) Body mass (g) 4000 35
Page 41 and 42: Goose droppings/m 2 6 5 4 3 2 1 0 P
Page 43 and 44: er 3KJ was a behaviourally dominant
Page 45 and 46: 5 Pre-nesting feeding 5.1 Introduct
Page 47 and 48: imagery and searches in helicopters
Page 49 and 50: 6 Reproduction 6.1 Breeding distrib
Page 51 and 52: predicted that at the end of this p
Page 53 and 54: Percentage of juveniles Figure 6.1.
Page 55 and 56: Mean age of first breeding 8 7 6 5
Page 57 and 58: periods in each winter as the exten
Page 59 and 60: Geese, it might be expected that in
Page 61 and 62: 7 Moult of flight feathers 7.1 Intr
Page 63 and 64: mass at different stages of regrowt
Page 65 and 66: of available fresh green growth of
Page 67 and 68: 8 Survival 8.1 Introduction Almost
Page 69 and 70: the hunting mortality rate K t for
Page 71 and 72: during the period when the populati
Page 73: lands. This process was certainly u
Page 77 and 78: Mass based on API scores 3600 3200
Page 79 and 80: social system has traditionally reg
Page 81 and 82: ers (J. Madsen unpubl. data). In th
Page 83 and 84: limitation which operates during an
Page 85 and 86: NUTRIENT & ENERGY ACCUMULATION RATE
Page 87 and 88: eeding geographical locations respe
Page 89 and 90: 10 Acknowledgements A thesis is sup
Page 91 and 92: mark and to Ebbe Bøgebjerg for the
Page 93 and 94: L. Kramer, J.N. Kristiansen, T. Lai
Page 95 and 96: Marked Individuals in the Study of
Page 97 and 98: mussels, Mytilus edulis. Journal of
Page 99 and 100: Nichols, J.D. (1991) Extensive moni
Page 101 and 102: Thompson, S.C. & Raveling, D.G. (19
Page 103 and 104: 12Appended manuscripts 1: Fox, A.D.
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The Greenland White-fronted Goose Anser albifrons flavirostris

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