Tundra Plovers

The Eurasian, Pacific and American Golden Plovers and Grey Plover

Des Thompson, Ingvar Byrkjedal

• Publisher: T & AD Poyser
• Year: 2010
• Print ISBN: 9780856611094
• eBook ISBN: 9781408128695
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Zoology
• Index: Biological Sciences

There are four species of tundra plover: the Grey Plover, and the Eurasian, Pacific, and American golden plovers.

They breed only in the northern hemisphere, principally on tundra, and migrate far south to coastal mudflats, saltings and agricultural landscapes. They have attracted avid interest from birdwatchers and researchers worldwide, not least the authors who have studied all four species. The Eurasian Golden Plover has a special claim to fame as questions over its flight speed first prompted the compilation of the world bestseller the Guinness Book of Records!

This ground-breaking book on shorebirds (waders) examines the taxonomy, appearance, behaviour, ecology and conservation of Golden and Grey plovers, and compares and contrasts their natural history and biogeography. There are detailed accounts on all aspects of their lifestyle including feeding, mating, parental care, moults, migration and avoidance of predators. The personal touches in this book add immensely to its value, not least the authors' first hand experiences of the birds and their haunts. Most of their work presented here has not been published before, adding to the significance of this highly original book.

Long-awaited considerations of differences in plumage, vocalisations, habitat use, breeding, movements and food are included. The links between phylogeny, biogeography and behaviour are bound to excite interest. The comparative approach is highly detailed and refreshing, and marks the book as a classic.

Ingvar Byrkjedal has also contributed all of the wonderful colour and line illustrations. Over fifty-five photographs, over one hundred and twenty tables and figures, and many other embellishments complete this definitive book.

CHAPTER 1

The Tundra Plovers:
An Introduction

Eurasian Golden Plover

But to-day I felt more clearly the promise of the tundra — its huge fertility, its immensity, its strange, indefinable magic … On every hillock stood a plover in gold-studded livery, playing on his wild pipe, or malingering piteously to lead one from his hidden nursery.

Maud Haviland describing the tundra at Gol'chikha in A summer on the Yenisei (1915).

THIS is a book about four species, known collectively as the tundra plovers, which belong to the genus Pluvialis. In one way this is a comparative study of the morphology, biogeography and behaviour of the Grey Plover and the three species of golden plovers. In another way it is a journey into the far north, in search of answers to questions about pairing, timing of breeding, habitat use, social behaviour and parental care. Most of all this is a book by and for people who love the birds and their haunts. You may have been on a large coastal mudflat, in the midst of an agricultural landscape, or even wandering across huge tundra plains close to the North Pole. It does not really matter, for so long as you have watched a tundra plover, and thought about its behaviour, ecology and appearance, you are with us.

TUNDRA PLOVERS: THE FOUR SPECIES

The genus Pluvialis belongs to the order Charadriiformes, known as waders in the Old World and shorebirds in the New World (we prefer to use the latter term for this order). The shorebirds consist of nine families, the Charadriidae (Plovers) being one. The Grey Plover (Pluvialis squatarola) is the largest of the four Pluvialis species. It has a circumpolar arctic breeding distribution, though it is absent from the Atlantic part of the Arctic. This striking bird lacks the golden dorsal ‘spangling’, so typical of the golden plovers, and also has a hind toe. The Grey Plover is almost exclusively confined to coastal beaches and mudflats outside the breeding grounds, where it is one of the most widespread of all shorebirds, being found in every continent except Antarctica.

The Eurasian Golden Plover (P. apricaria) breeds across northern Europe from the eastern tip of Greenland right over to the southernmost part of Taimyr Peninsula in Siberia. It is the most southerly of the three golden plovers, characteristic of sub-arctic upland heath and bog, and forest edge tundra.

The Pacific Golden Plover (P. fulva), formerly known as the Asiatic or Palearctic race of the Lesser Golden Plover, breeds in arctic and sub-arctic tundra from the Yamal Peninsula, across Siberia, into western Alaska. The American Golden Plover (P. dominica) breeds in the New World, from northern Alaska across the sub-arctic into Baffin Island and down the west coast of Hudson Bay. Until recently this was the Lesser Golden Plover, conspecific with what is now the Pacific Golden Plover. But as we shall see later, there is no evidence of inter-breeding where the two birds overlap in Alaska, and they are now regarded as separate species.

Collectively, the four species have many traits in common, and constitute a genus of birds derived, we will argue later, from a single ancestor. Traditionally, there has been no English name in common usage for the genus Pluvialis. Witherby et al. (1940) used the term ‘golden plovers’, appropriate in the 1940s because the genus did not include the Grey Plover. Johnsgard (1981) used ‘great plovers’ for the four species, whilst Cramp & Simmons (1983) referred to them as the ‘tundra plovers’. We regard the tundra plovers as an appropriate term. Being widespread and often highly conspicuous these, more than any other plovers, constitute a distinctive component of the bird life on the arctic and sub-arctic plains and uplands. Even the Eurasian Golden Plover breeds in tundra, or in open moorland, mire and alpine (sometimes referred to as montane or high mountain) expanses which have affinities with the tundra landscapes of Europe. After all, the word ‘tundra’ originates from the Finnish word ‘tunturi’ — a region in northern Finland which is beyond the tree limit. There, in those parts where the surface permafrost layer becomes waterlogged during the summer thaw, the pool-vegetated ridge patterns resemble those of the blanket bog pool-hummock systems of northern and northwestern Britain and Fennoscandia occupied by Eurasian Golden Plovers.

SCOPE

While we concentrate a good deal on the Eurasian Golden Plover we draw equally heavily on published work and recent studies of the four Pluvialis species. Almost every aspect of their biology throws up questions. Even a cursory examination of basic breeding distribution maps prompts questions. Why is the Eurasian Golden Plover such a southern nester, and yet found over such a vast subarctic area? Why does the Pacific Golden Plover not occur on the tundra west of the Urals, and why does it occur so sparingly at the western tip of Alaska? Why does the American Golden Plover not breed in Asia, when its distribution reaches the western extremities of Alaska? Why does the Grey Plover breed across the arctic tundra, in both Siberia and North America, yet remain absent from northern Fennoscandia and Greenland? And why do the American and Pacific golden plovers avoid the blanket bog habitats of the southern coast of Alaska, preferring instead the drier tundra farther north, yet the Eurasian Golden Plover breeds in both water-logged blanket mire, and dry and wet types of tundra?

Chapter 2 introduces the plovers of the world. There are 67 species belonging to 10 genera of which Vanellus, Charadrius and Pluvialis are the most prominent. The chapter summarizes those features which set apart the tundra plovers from the others. Taxonomy, geographical variation, plumage and moults are treated in Chapters 3 and 4. We discuss the problems of taxonomic status. The latest evidence for specific status of the Pacific and American golden plovers is presented. Some researchers maintain that there are two distinct subspecies of P. apricaria, others that it is a monotypic species with polymorphic variation in the form of a cline. In the Grey Plover and Pacific Golden Plover there is an increase in body size towards the Bering Strait, both from the west and from the east. Eurasian Golden Plovers decrease in size eastwards. We present detailed illustrations and descriptions of the birds for different times of the year, and have outlined the field marks to aid identification.

This leads us to phylogeny and biogeography (Chapter 5). Based on external morphological characters of adult birds and downy patterns of chicks, a cladistic analysis (giving a phylogenetic ‘tree’) is presented, with the Common Ringed Plover group as an ‘outgroup’. The phylogenetic results are discussed in relation to hypotheses about a common northern tundra ancestor, and subsequent occurrences of each species. Our findings are contentious and may well generate some debate!

Chapter 6 outlines the distribution, population trends and status of the four Pluvialis species. Here we address matters such as why there is an Atlantic hiatus in the breeding distribution of Grey Plovers, and why the status of Eurasian and American golden plovers has changed in such different ways. For the British Isles, Fennoscandia and the East Baltic states, population changes of Eurasian Golden Plover are examined in relation to variation in upland agricultural reclamation, grazing pressures, deforestation, afforestation and recreation.

The breeding cycle is considered in Chapters 7 to 9. The pre-laying period is covered first. Timing, numbers and sex ratio of birds arriving, pair formation, courtship, nest site selection, aggression and territorial behaviour are all discussed. For the first time, there is full comparative information on display flights of all four species. Relationships within the pair are discussed, and the following are detailed: timing of laying, laying intervals, clutch size, weights and measurements of eggs, incubation behaviour (pattern of nest attendance, sex differences, incubation period and hatching sequence), hatching success, development and care of chicks, and anti-predator behaviour. We provide a particularly detailed assessment of song flights/displays and alarm calls. As in most of the chapters, much of the information has not been published before.

Chapter 10 takes us into post-breeding movements and migration. Spending more than half the year away from its breeding grounds the Eurasian Golden Plover is a partial migrant in the British Isles, but wholly migratory elsewhere. The other three species migrate much farther south. The Pacific Golden Plover ranges from the Pacific Islands, through coastal Australasia and India, to northeast Africa, whereas the American Golden Plover is confined to central South America in winter. The Grey Plover has a world-wide wintering range, mainly in the Subtropics and Tropics though significant numbers are found also in the temperate zone.

On the non-breeding grounds (Chapter 11) we look briefly at the behaviour and ecology of the birds on territories, or in single- and mixed-species flocks. Common associates with Eurasian Golden Plovers in winter, Northern Lapwings and Black-headed Gulls, are introduced. We outline their effects on feeding site usage, time budgeting, energy intake and anti-predator behaviour. The costs and benefits of single-species versus mixed-species flocking are viewed within a highly dynamic association of these species. Although the Eurasian Golden Plover is evidently entirely non-territorial in winter, individuals of the other tundra plovers can be territorial (in some areas predominantly so). We offer some ideas on the extent of territorial behaviour on the non-breeding grounds.

Chapter 12 reviews food and feeding habits. Although worms, insects, and molluscs constitute the basic food of these plovers, consumption of large quantities of berries testifies to the importance of fruit and vegetable matter even for shorebirds. Chapter 13 deals with relationships with other birds. Comparisons across the four species reveal fascinating differences in habitat use, competition and anti-predator behaviour. In areas where American Golden Plovers breed near Grey Plovers the two species show habitat segregation, with the former being the more aggressive of the two. Pacific Golden Plovers in Siberia breed on different habitats depending upon whether or not their close neighbours are Eurasian Golden Plovers or Grey Plovers. One curious feature is the tendency for some shorebirds (notably Dunlin) to form associations with the tundra plovers (and indeed other birds) on the breeding grounds, giving rise to the ‘plover's page’ relationship.

Finally, Chapter 14 considers conservation issues. As with many shorebirds, conservation has to have a global outlook because of the myriad habitats and countries used. The decline, since the mid-19th century, of the Eurasian Golden Plover in western Europe provides us with a key to the changing fortunes of an animal subjected to environmental and human-related pressures. These issues are explored, ending with a short consideration of global warming, which may have a catastrophic impact on tundra plovers especially the Grey Plover. There were drastic declines in populations of American Golden Plovers caused by late 19th century market hunting; their subsequent rapid recovery following protection illustrates the potential impacts of persecution.

We should mention a few conventions used in the book. As mentioned above, we refer to waders as shorebirds. The English names of shorebirds seem to have been modified, so for consistency we have used the list provided by Piersma et al. (1997). Hence the Lapwing, Dotterel and Ringed Plover breeding in Europe are the Northern Lapwing, Eurasian Dotterel and Common Ringed Plover, respectively! Scientific names for birds and mammals are given in Appendix 1, but for other taxa are given in the text. Occasionally we refer to ‘goldies’; this is a popular name for golden plovers, in particular the Eurasian Golden Plover. On the few occasions when we have needed to distinguish between our observations we have used our initials (IB or DBAT). We have tried not to cite other workers' unpublished work (after all, if it is not published it is not in the public domain), but have included reference to written or oral personal communications (pers. comm.).

STUDY AREAS AND EARLY STUDIES

Between us, we have spent over 50 years studying tundra plovers. IB has studied Eurasian Golden Plovers in Norway since 1967, American Golden Plovers in Canada in 1986, and Eurasian and Pacific golden plovers and Grey Plovers in Siberia in 1989. DBAT has studied upland/peatland birds, notably shorebirds, in northern Scotland (as part of the Nethersole-Thompson family) since 1964, and with the Nature Conservancy Council (now Scottish Natural Heritage) since 1986. He has researched Eurasian Golden Plovers in winter flocks in the Midlands of England during 1980–1984, making occasional visits to that area thereafter.

Essentially, our studies have encompassed four different habitats: open dwarf shrub-dominated heath and blanket bog (often termed moorland); alpine/ montane (high mountain) plateaux; tundra; and lowland agricultural pastureland. The pictures and short descriptions below convey the diversity of these and other sites where tundra plovers have been studied. As we repeatedly refer to many of these areas...

Table of contents

• Cover
• Title Page
• Copyright Page
• Contents
• List of Plates
• Foreword
• Preface
• Acknowledgements
• Chapter 1 - The Tundra Plovers: An Introduction
• Chapter 2 - Tundra Plovers and their Allies
• Chapter 3 - Taxonomy and Geographical Variation
• Chapter 4 - Plumages and Moults
• Chapter 5 - Phylogeny and Biogeography (with Godtfred Anker Halvorsen)
• Chapter 6 - Breeding Distribution, Population Trends and Status
• Chapter 7 - Breeding Season: Breeding Schedules and Nesting
• Chapter 8 - Breeding Season: Social Behaviour
• Chapter 9 - Breeding Season: Sex Roles and Parental Behaviour
• Chapter 10 - Migration and Non-breeding Distributions
• Chapter 11 - Behaviour and Ecology in the Non-breeding Season
• Chapter 12 - Diet: Food and Feeding
• Chapter 13 - Associations with others Birds
• Chapter 14 - Conservation
• Appendix 1 - Scientific names of birds and mammals mentioned in the book
• Appendix 2 - Plumage variation in Eurasian Golden Plovers in Norway
• Appendix 3 - Descriptions of plumages of the tundra plovers
• Appendix 4 - The phylogeny of the tundra plovers
• Appendix 5 - Breeding densities of tundra plovers in different parts of the world
• Appendix 6a - Nest site habitats of Grey Plovers, as percent of nests in various habitats
• Appendix 6b - Nest site habitats of Eurasian Golden Plovers as percent of nests in various habitats. Percent distribution of random points (RP) within defined study area given in parentheses
• Appendix 6c - Nest site habitat of Pacific Golden Plovers, as percent of nests in various habitats. Percent distribution of random points (RP) within defined study area given in parentheses
• Appendix 6d - Nest habitat of American Golden Plovers, as percent of nests in various habitats. Percent distribution of random points (RP) within defined study area given in parentheses
• Appendix 7 - Duration of incubation
• Appendix 8 - Sequences of tonal element in trills
• Appendix 9 - Breeding season alarm calls
• Appendix 10 - Geographical and temporal distribution of museum specimens used in the construction of Figs 10.1, 10.5, 10.6, 10.9, 10.10, 10.13, 10.14 and 10.17 (migration routes and phenologies of tundra plovers)
• Appendix 11 - Geographical distribution of references (below) used for the migration charts (Figs 10.1, 10.5, 10.6, 10.9, 10.10, 10.13, 10.14 and 10.17) and winter distribution maps (Figs 10.4, 10.8, 10.12, 10.16)
• Appendix 12 - Number of Grey Plovers counted or estimated in various parts of their wintering range
• Appendix 13 - Winter populations of Eurasian Golden Plovers in parts of their range
• Appendix 14 - Number of American Golden Plovers counted in winter on aerial surveys along the coast of South America, 1982–86 (from Morrison & Ross 1989)
• References
• Tables