Birds of New Zealand, Hawaii, Central and West Pacific

Mesaj mə
Müəllif:
0
Rəylər
Kitab sizin regionda əlçatan deyil
Oxunmuşu qeyd etmək
Birds of New Zealand, Hawaii, Central and West Pacific
Şrift:Daha az АаDaha çox Аа

BIRDS OF

NEW ZEALAND,

HAWAII

and the

CENTRAL and

WEST PACIFIC

Text and illustrations

by

Ber van Perlo


Contents

Cover

Title Page

Preface

Symbols, Abbreviations and Glossary

Parts of a Bird

Introduction

Species Accounts, Plates and Distribution Maps

1 Podicipedidae (Grebes & Dabchick) & Gaviidae (Loon)

2 Apterygidae (Kiwis) & Spheniscidae (Penguins)

3 Spheniscidae (Penguins)

4 Diomedeidae (Albatrosses)

5 Diomedeidae (Albatrosses)

6 Diomedeidae (Albatrosses)

7 Diomedeidae (Albatrosses) & Procellariidae (Giant Petrels)

8 Procellariidae (Prions, Fulmars & Petrels)

9 Procellariidae (Petrels)

10 Procellariidae (Petrels)

11 Procellariidae (Petrels)

12 Procellariidae (Petrels)

13 Procellariidae (Petrel & Shearwaters)

14 Procellariidae (Shearwaters)

15 Hydrobatidae (Storm-Petrels)

16 Hydrobatidae (Storm-Petrels) & Pelecanoididae (Diving-Petrels)

17 Phaethontidae (Tropicbirds) & Sulidae (Gannets & Boobies)

18 Fregatidae (Frigatebirds), Pelecanidae (Pelican) & Phalacrocoracidae (Cormorants)

19 Phalacrocoracidae (Shags)

20 Ardeidae (Egrets & Herons)

21 Ardeidae (Herons & Bitterns)

22 Ardeidae (Herons) & Threskiornithidae (Ibises)

23 Threskiornithidae (Spoonbills), Dendrocygnidae (Whistling-Duck) & Anatidae (Swans, Shelducks & Goose)

24 Anatidae (Geese)

25 Anatidae (Ducks, Teals & Shovelers)

26 Anatidae (Duck, Wigeons, Teals, Gadwall, Pintail & Garganey)

27 Anatidae (Mallard, Ducks & Teals)

28 Anatidae (Ducks, Scaups, Pochard & Redhead)

29 Anatidae (Goldeneyes, Mergansers, Scoters & Bufflehead)

30 Accipitridae (Eagles) & Pandionidae (Osprey)

31 Accipitridae (Harriers, Sparrowhawk & Goshawk)

32 Accipitridae (Kites, Buzzards & Hawk)

33 Falconidae (Kestrels, Falcons, Merlin & Peregrine)

34 Gruidae (Cranes), Megapodiidae (Scrubfowls) & Phasianidae (Turkey, Guineafowl & Partridges)

35 Phasianidae (Quails, Bobwhite & Francolins)

36 Phasianidae (Pheasants, Junglefowl & Peafowl) & Rallidae (Rails & Weka)

37 Rallidae (Crakes, Rail & Bush-Hen)

38 Rallidae (Watercock, Moorhens, Swamphen, Takahe & Coots)

39 Haematopodidae (Oystercatchers) & Recurvirostridae (Stilts & Avocet)

40 Glareolidae (Pratincole), Charadriidae (Plovers and Lapwing) & Scolopacidae (Sandpiper)

41 Charadriidae (Dotterel, Sandplover & Plovers)

42 Charadriidae (Dotterels, Killdeer & Plovers)

43 Scolopacidae (Godwits, Curlews & Whimbrel)

44 Scolopacidae (Redshanks, Greenshanks, Sandpipers & Yellowlegs)

45 Scolopacidae (Tattlers, Sandpipers, Willet & Turnstone)

46 Scolopacidae (Snipes) & Rostratulidae (Painted-Snipe)

47 Scolopacidae (Phalaropes, Dowitchers, Sandpiper & Ruff)

48 Scolopacidae (Sandpipers, Knots & Sanderling)

49 Scolopacidae (Sandpipers, Stints & Dunlin)

50 Stercorariidae (Skuas & Jaegers)

51 Laridae (Gulls)

52 Laridae (Gulls)

53 Laridae (Gull & Kittiwake) & Sternidae (Terns)

54 Sternidae (Terns)

55 Sternidae (Terns & Noddies)

56 Alcidae (Murrelets, Auklet & Puffins), Pteroclidae (Sandgrouse) & Columbidae (Pigeon)

57 Columbidae (Pigeon & Ground-Doves)

58 Columbidae (Pigeons)

59 Columbidae (Fruit-Doves)

60 Columbidae (Fruit-Doves & Doves)

61 Psittacidae (Parakeets, Parrots & Rosellas)

62 Psittacidae (Lory & Lorikeets)

63 Psittacidae (Parakeets), Cacatuidae (Cockatoo & Galah) & Strigopidae (Kea, Kaka & Kakapo)

64 Psittacidae (Parakeets), Coraciidae (Dollarbird), Upupidae (Hoopoe) & Meropidae (Bee-Eater)

65 Cuculidae (Cuckoos)

66 Cuculidae (Cuckoo & Koels), Caprimulgidae (Nightjar & Nighthawk), Cerylidae (Kingfisher) & Halcyonidae (Kookaburra & Kingfishers)

67 Halcyonidae (Kingfishers)

68 Apodidae (Swiftlets, Needletail, Swift & Treeswift)

69 Tytonidae (Barn Owl & Grass-Owl) & Strigidae (Owls)

70 Motacillidae (Wagtails & Pipits) & Alaudidae (Lark)

71 Acanthisittidae (Rifleman & NZ Wren), Prunellidae (Dunnock) & Timaliidae (Laughingthrushes, Hwamei & Leiothrix)

72 Campephagidae (Trillers, Minivet, Cicadabird & Cuckoo-Shrike), Laniidae (Shrike) & Mimidae (Mockingbird)

73 Turdidae (Rubythroat, Rock-Thrush, Thrushes & Shama)

74 Turdidae (Omao, Kamao, Puaiohi & Olomao), Pycnonotidae (Bulbuls), Sylviidae (Warblers) & Megaluridae (Fernbird)

75 Acrocephalidae (Reed-Warblers & Millerbird) & Cettiidae (Bush Warblers)

76 Acrocephalidae (Reed-Warblers)

77 Acanthizidae (Gerygones), Pachycephalidae (Yellowhead, Whitehead & Pipipi), Muscicapidae (Flycatchers & Shrikebills)

78 Monarchidae (Monarchs & Elepaio)

79 Monarchidae (Flycatchers)

80 Rhipiduridae (Fantail, Willie-Wagtail & Silktail)

81 Monarchidae (Monarchs) & Artamidae (Woodswallows)

82 Hirundinidae (Swallows & Martins) & Zosteropidae (White-Eyes)

83 Zosteropidae (White-Eyes & Silvereye)

84 Zosteropidae (White-Eyes), Pachycephalidae (Whistlers) & Paridae (Tit)

85 Petroicidae (Robins), Colluricinclidae (Morningbird), Notiomystidae (Stitchbird) & Meliphagidae (Bellbird & Wattlebird)

86 Meliphagidae (Tui, Myzomelas, Honeyeaters & Mao)

87 Drepanididae (Parrotbill, Akikiki, Creeper, Alauahio, Akepa, Akekee, Iiwi, Akohekohe, Apapane & Poo-Uli)

88 Drepanididae (Ou, Palila, Nukupuu, Akiapolaau, Anianiau, Amakihis)

89 Emberizidae (Yellowhammer, Buntings & Sparrow), Fringillidae (House Finch), Thraupidae (Saffron Finch & Grassquit) & Oriolidae (Oriole)

90 Fringillidae (Chaffinch, Greenfinch, Goldfinch, Redpoll & Canaries) & Passeridae (Sparrows)

91 Estrildidae (Waxbills & Parrotfinches)

92 Estrildidae (Cordonbleu, Avadavat, Firetail, Silverbill & Munias)

93 Cardinalidae (Cardinal), Thraupidae (Cardinals & Tanager), Icteridae (Meadowlark & Grackle) & Dicruridae (Drongo)

94 Sturnidae (Starlings & Mynas)

95 Sturnidae (Starlings), Artamidae (Magpie), Callaeidae (Kokako & Saddleback) & Corvidae (Rook & Crows)

Acknowledgements

Endnotes

National and International Organisations

Bibliography and Further References

Appendix

Index

Copyright

About the Publisher

Preface

This book should be regarded and treated as a field guide in which the necessary information, needed to identify a bird at the moment you observe it, is given in a condensed form. The low weight and small size thus achieved make it easy to carry the book around and consult in the field. Support of the identification of difficult species can be obtained in more detailed, regional bird books, which could be consulted at home, in vehicles, at your hotel, etc. Sound recordings from commercial CDs and DVDs and transferred to your iPod or other MP3 player can be an important supplementary aid in the field.

It is said that the painting in my books is ‘a bit sketchy, somewhat fast and loose, not finely finished’. However, if you see a bird in the field you see its uniform-coloured plumage parts as a single surface; painting each individual feather will give too much information unless the feathers form a pattern. I also find it difficult to draw straight lines, for example, when depicting the parallel primaries in a folded wing, or perfect circles when forming an eye, but this does not prevent a species from being quickly recognised. To me, it is essential that one can see that my work is hand-painted; I love the magic of small spots and streaks, applied with skill and luck that create a shape of something that looks quite different in reality when seen from nearby.

In the introduction I have paid attention to landscape and habitats, specific to the area, that determine which bird species can be seen; that is also why information is given about plate tectonics, as one of the main landscape-forming factors.

An effort was made to update this book to 2009, but a recent record could not be inserted, namely that of American Avocet Recurvirostris avocetta on Maui, Hawaii. Very similar to 39.9 but with black mantle and white scapulars.

In June 2010, just before finishing writing this book, the fourth edition of the Checklist of the Birds of New Zealand was published by the Checklist Committee Ornithological Society of New Zealand. Only the common names from this publication could be incorporated in this book as explained in the first paragraph of ‘Systematics and Names’.

 

Symbols, Abbreviations and Glossary

Symbols

Habitat: a set of environmental factors that is preferred by a bird

Vocalisation

Notes on range

Abbreviations

1st W – The plumage worn by a bird after moulting from juvenile plumage

2nd W – The plumage worn in the 2nd winter of a bird’s life

– Male

– Males

– Female

– Females

Ad. – Adult

Ads – Adults

Br – Breeding

N-br – Non-Breeding

C – Central

Cf. – Compare to

E – East(ern)

E. – Endemic

Esp. – Especially

Excl. – Excluding

Extr. – Extreme

I – Introduced

I. – Island

Irr – Irregular visitor

Is – Islands

Imm. – Immature

Imms – Immatures

Incl. – Including

Juv. – Juvenile

Juvs – Juveniles

L – Length in cm

N – North(ern), etc.; also in combination with E and W

NI – New Zealand’s North Island

Nom. – Nominate; the subspecies of a species that was the first described

Pl – Plate

R – Rare

S – South(ern)

Sec – Second or seconds

SI – New Zealand’s South Island

Ssp – Subspecies

Ssps – > 1 subspecies

Thr. – Throughout

V – Vagrant

W – Wingspan in cm; can also mean West(ern): depends on context

Countries

A.Sa – American Samoa

Co – Cook Islands

Fi – Fiji

FrPo – French Polynesia

Gu – Guam

Ha – Hawaii

Ki – Kiribati

Ma – Marshall Islands

Mi – Micronesia

Na – Nauru

Ni – Niue

NMa – Northern Marianas

NZ – New Zealand

Pa – Palau

Pi – Pitcairn Islands

Sa – Samoa

Tok – Tokelau

Ton – Tonga

Tu – Tuvalu

WaF – Wallis and Futuna

Glossary

Endemic A species that occurs only in an area with well-defined boundaries such as a continent, a country, an island or a habitat.

Forest A tall, multi-layered habitat in which high trees dominate the canopy, which is continuous and closed.

Gallery forest A riverine belt that is dominated by trees.

Jizz Typical silhouette and stance of a bird species.

Riverine belt Any growth along a river or stream that is higher and greener than the more distant surroundings.

Rufescent Tinged with red-rufous colour.

Savanna In this book: any (large) area with a continuous cover of (high) grasses, interrupted by shrub and (5–30%) tree canopy.

Second growth New natural forest developing in places where the original forest has disappeared.

Speculum Patch of colour on the wing contrasting with that of the rest of the wing.

Transient plumage Stage between Br and N-br plumages with traces of Br plumage still visable.

Woodland A habitat in which trees dominate, but the canopy is not closed.

Parts of a Bird


Introduction

Systematics and Names

In order to apply a uniform systematic approach and set of names that are valid in New Zealand, Hawaii, the USA, Asia, Europe and anywhere else, this book follows James F. Clements The Clements Checklist of the Birds of the World, 6th Edition (Helm, 2007) with regard to systematic status (species or subspecies) and names (scientific and English).

However, the best-known or most widely used common names used by New Zealanders and in Hawaii should not be neglected, if only to make it easier to find the birds of this book in regional publications. Therefore, alternative English names for species, advised by the Ornithological Society of New Zealand (OSNZ) for New Zealand and by the American Ornithological Union (AOU) for Hawaii, are indicated as insertions in the ‘Clements name’, preceded by ‘NZ’ or ‘AOU’ in superscript. For example:

the species indicated by number 20.9 (Plate 20, number 9) in this book is named the ‘INTERMEDIATE (or NZPlumed) EGRET’; the ‘Clements name’ is INTERMEDIATE EGRET, while the ‘OSNZ name’ is PLUMED EGRET;

number 28.1 in this book is named the ‘(NZAustralian) WHITE-EYED DUCK’; the ‘Clements name’ is WHITE-EYED DUCK and the ‘OSNZ name’ is AUSTRALIAN WHITE-EYED DUCK.

In a few cases, well-known alternative names are inserted in the ‘Clements names’, such as:

41.5 SNOWY (or Kentish) PLOVER

There are also many local names for subspecies, mentioned by the OSNZ and in use for those that occur in New Zealand; these names are given in numbered notes following the captions. An example is:

38.5 PURPLE SWAMPHEN44 Porphyrio porphyrio

ssp melanotus NZPukeko;

ssp pelewensis [Palau]

ssp samoensis [Samoa and Fiji]

In this example, the subspecies Pukeko occurs solely and exclusively in New Zealand (with the extra complication that it is treated by the OSNZ as Nominate of SOUTH-WEST PACIFIC SWAMPHEN NZPorphyrio melanotus). In the following example there are four subspecies found in New Zealand:

14.8 LITTLE SHEARWATER19 Puffinus assimilis

Nom. NZNorfolk Island Little Shearwater

ssp kermadecensis NZKermadec Little Shearwater

ssp haurakensis NZNorth Island Little Shearwater

ssp elegans NZSubantarctic Little Shearwater

Of these, elegans can also be seen outside the area covered by this book, but only in NZ it is known as Subantarctic Little Shearwater. (Note: The OSNZ has recently risen the Clements subspecies elegans to independent species NZSUBANTARCTIC LITTLE SHEARWATER Puffinus elegans.)

The French names are those of the Commission Internationale des noms français d’oiseaux (CINFO 1993).

The sequence of families in this book is more or less traditional, but strongly adapted in order to include up to a maximum of nine, rarely ten similar-looking species, sometimes from different families, in one plate.

Format of the Species Accounts

Plates

In general, the plumages depicted on the plates are Br. plumages unless otherwise indicated. Normally, the birds on any given plate are painted to the same scale except flight silhouettes, which are normally shown smaller. If and have different visual features, such as colouring or dimensions of body parts (e.g. tail length), both are illustrated, unless the differences are only small (e.g. a slightly duller colour of the ). Juveniles, immatures and/or first winter plumages are shown when they are often seen in these plumages. N-br plumages are given if the birds visit the area in this plumage; migrants such as waders, which are mainly seen in N-br plumage, are illustrated in this plumage on the plates. If several subspecies of a species occur in the area, and they are distinguishable, these are in many but not all cases illustrated, but not for example, those separable mainly on basis of range.

An effort has been made to show the birds in their typical ‘jizz’; what birders call jizz is a difficult to define combination of size, relative proportions and body carriage of a bird. Part of a bird’s jizz can be, for example, its stance (the angle of its body axis to the horizontal).

Captions

The information for each species is given in this order:

• the English name in bold capitals (with alternative names in standard lower case);

• the French name between square brackets;

• the scientific name in italics;

• length in cm, measured from tip of bill to tip of tail (L) or between the tips of spread wings (W);

• identification notes with emphasis on the main features, or those that are not visible in the plates (e.g. the colour pattern that appears when a bird opens its wings) or those that are most important for separation from similar species. Notes on behaviour are often added when important for identification;

• habitat (the set of environmental factors, preferred by a bird species) preceded by the symbol ; only simple terms are used such as forest, woodland, marsh, plantations, savanna;

• voice, preceded by the symbol where possible a distinction has been made between ‘call’ and ‘song’ as being the basic vocalisations of birds, ‘call’ being any short, probably unrestrainable sound, given by a bird to indicate its presence to himself or other animals, ‘song’ being the modus in which a (sometimes also the ) advertises its possession of a territory or its mood (anger, nervousness, contentment, togetherness).

In the voice, attention is paid to:

• pitch, using a subjective scale ‘very low, low, mid-high, high, very high, very/extremely high, extremely high’, wherein ‘very low’ and ‘extremely high’ indicate vocalisations that are just not quite too high or too low to be audible and ‘mid-high’ for the normal pitch of an average person’s voice, if trying to imitate the vocalisation;

• speed, for which terms are used as ‘very slow, slow, calm, rapid, hurried, fast’;

• tempo, as defined by the ‘length’ between notes, indicated by the use or absence of hyphens between notes, so beep beep beep is slower than beep-beep-beep, while beepbeepbeep is the fastest. Also terms such as rattle and trill are used to describe tempo; an apostrophe as in t’sreee is used to indicate a short, yet noticeable separation between two consonants;

• loudness, described as soft, weak, loud, ringing, etc.;

• structure, indicated by terms such as accelerated, lowered, gliding, crescendo, staccato, etc.;

• length of song or call given in seconds;

• quality in terms such as harsh, shrieking, mewing, etc.;

• transcriptions – this is the most difficult way to describe ‘voice’ for several reasons: different people will transcribe bird vocalisations using different vowels and consonants (for example, compare the way in which in several bird guides the chirping of a house sparrow is transcribed) and the differences that exist between written and spoken text in different languages (French people will transcribe a sound in a different way to a Dutch or English speaker).

To keep transcriptions short, use is made of the punctuation mark ‘-’ to indicate repetition of one or more foregoing notes. In ‘preep -’ the note(s) are repeated 1–3 times, in ‘preep - -’ the repetition is more than three times and in ‘preep—’ the repetition is given very fast.

The use of an acute accent on a vowel, for example in weétjer, means that part is accentuated; the diacritic grave, as in rèh-rèh rèh, is used to indicate that the ‘e’ sounds as the ‘e’ in ‘red’; similarly, ò sounds as the ‘o’ in ‘pot’; parts of transcriptions written in capitals are uttered louder.

 

The vocalisations in this book might support an identification or may make it easier to remember a bird sound when it is heard again. However, it should be kept in mind that though the vocalisations of many seabirds, herons and other large waders are described, they vocalise only or mainly in, above or near their breeding colonies.

The description of voice in this book is based on tapes, CDs and DVDs (see Bibliography).


Distribution Maps

Information about range, seasonality and occurrence can be an important aid in supporting or weakening an identification. In the distribution maps, attention is paid to these factors, expressed in the key on page 14.

The Area Covered

The area encompasses the following 20 political entities, given in random sequence:

• Hawaii (US State)

• Fiji (Republic)

• Tonga (Kingdom)

• Nauru (Republic)

• Samoa (Republic)

• American Samoas (US unincorporated Territory)

• Kiribati (Republic)

• Marshall Islands (Republic)

• Federated States of Micronesia (free association with the USA)

• Tuvalu (British Commonwealth)

• Tokelau (New Zealand Territory)

• Niue (free association with New Zealand)

• Cook Islands (free association with New Zealand)

• Guam (US unincorporated Territory)

• Wallis and Futuna (French Overseas Collectivity)

• Pitcairn Islands (UK Overseas Territory)

• Northern Marianas (Commonwealth in union with USA)

• Palau (Republic)

• French Polynesia (French Overseas Territory)

• New Zealand (British Commonwealth)



The Environment

Some Basics for Oceania

The following paragraphs give a short introduction to the factors that determine the presence and distribution of bird species in the area. The main factor that dominates all others is that the area is composed of islands, varying between very large and very small, lying either far apart from or close to each other. All these islands have been uplifted from the ocean bottom by tectonic activity; those in the tropics are modified by reef building. Almost all islands, except the most southern ones, were once covered by forest. The final stage in the formation of habitats was the way in which people transformed and used the environment.

TECTONICS The outer mantle of the earth is formed by solid rock (the lithosphere), covered by an accumulation of sediments, volcanic products and changed basic rock (the crust). The lithosphere overlays the asthenosphere, a mantle of plastic flowing rock.

The lithosphere is horizontally subdivided into seven or eight major plates and many minor plates, which ride on the asthenosphere. Some of these plates and parts of them are denser and heavier, lay lower and form the floor of the oceans. The plates move in relation to each other:

• at spreading (divergent) boundaries (A1);

• at collision (convergent) boundaries (A2); and

• at transform boundaries (A6), where two plates move in opposite directions.

The area covered by this book is dominated by a convergent border between the oceanic Pacific Plate and the continental Australian and Filipino Plates (see map ‘PLATE TECTONICS’).

Tectonic plates separate (or diverge) from each other along a 80,000km long, mainly mid-ocean network (A1) that encompasses the earth. Nearest to the area is a network segment along the west coasts of North and South America. A typical spreading (or divergent) zone (C) can be described as a pair of parallel ridges on both sides of a rift. The rift bottom fills itself with upwelling, red-hot magma, which drives the plates apart and forms new ocean floor.

Collision boundaries are zones of subduction, where heavier oceanic plates dive under lighter continental plates as shown in A2 and D. These zones are marked by a deep trench (D3). When the crust, together with lithospheric material, sinks into the asthenosphere it is heated to such a high temperature that magma chambers (D4) are formed, which float to the surface forming rows of volcanoes (D5) arranged in island arcs (the Kermadecs and Northern Marianas are typical island arcs). These arcs form a sort of perforation, along which the edge of the overlaying plate is often torn off and dragged under itself on the back of the submerging plate.

Other types of conflicting boundaries are also possible (A6), for example, where plates or plate fragments rub along each other under a sharp corner.


The speed of spreading is unevenly dispersed along the mid-ocean ridge system. Tensions are solved by many fissures (A7) perpendicular to the rift. The rift segments (B8) shift in relation to each other; the parts of fissures between rift segments are called transform faults. The movement at their sides is in opposite directions, which may cause volcanic activity. The outer parts of the fissures are called fracture zones; these separate areas moving in the same direction, which causes no or only low volcanic activity.

Here and there, far from the edges, magma penetrates through the ocean plate. These places are known as hotspots (E); hot magma wells up via these holes giving birth to volcanic islands at the surface. Because the ocean plate moves in a north-westerly direction the hot spots keep drilling holes, forming chains of islands, the youngest being the most eastern one. The Hawaiian islands are a good example.

The map ‘PLATE TECTONICS’ also shows a transform fault (green line on map), running from the Nazca Plate (near South America) via the Pitcairns to the Line Islands, which could have produced the many islands of the Pitcairn, Tuamotu and Line Islands. However, their origin could also have been a hot spot near Easter Island.


REEF BUILDING There are many species of coral organisms. The group that can build a reef is only found:

• in clear salt waters;

• at depths shallower than 50m (beneath this depths the coral skeletons change to coral limestone, darker yellow-green in figures);

• with an optimum temperature of 26–27°C; and

• strong currents and/or heavy agitation (otherwise food particles are unable to reach the tentacles of the polyps).


Most if not all tropical Pacific islands have a volcanic origin. Reef building starts as soon as a new volcano has emerged (A) and coral larvae have been carried in by ocean currents.


The first stage is a fringing reef (B) at a short distance from land and normally en-compassing a shallow lagoon. It takes about 10,000 years from stage A to reach stage B.


In the course of time the volcano erodes or the local ocean bottom subsides. If coral growth can keep up with the speed of this process, a barrier reef (C) is formed on the base of coral limestone; note the wider, locally deeper lagoon.


Ultimately, all land will be eroded, and the barrier reef will become an atoll (D) en-closing an open lagoon. The process from A to D can take 30 million years.


It is possible that an atoll can be uplifted by movements in the earth’s crust, by which an uplifted coral island is formed. A limestone rock emerges (E) and becomes encircled by a fringing reef.

LAND USE AND VEGETATION TYPES Once most islands were mainly covered by forest. The arrival of man brought about many changes in this environment and the following are the main present-day habitats.


Ocean

Open Tropical Ocean: warm water contains less prey (fish, squid, etc.) than cold water, therefore most seabirds in the tropical ocean are more numerous at places where deep cold currents from higher latitudes well up above (under) sea mounts (submerged volcanoes) and at the western edges of the Pacific.

Temperate Ocean: water temperatures between 10 and 18°C, found between the tropics and 48°S and N. Rich in oxygen and nutrients, very rich in fish (less species than in tropical seas, but often in large shoals) and in other life forms.

Coastal habitats

Lagoon: shallow, clear water rich in food for terns, gulls, noddies, tropicbirds and frigatebirds.

Seashore: especially important for migrating shorebirds.

Mangrove: mangrove stands support many bird species and form a habitat where heronries are often found.

Littoral Forest: the forests and thickets bordering the beach.


Lowland forest types

Lowland Dry Forest: found at the dry north-western side of high mountain chains, where the rain, brought in by the eastern trade winds, is released on the eastern slopes. All forms of dry forest are almost completely transformed to agricultural use. In the mixed exotic/native remains a few of the original endemic bird species may be found, plus many alien species.

Lowland Rainforest: as highland rainforest but with a more diverse range of tree species, denser undergrowth and many tree ferns.

Agricultural habitats

Coconut/Breadfruit Forest: found in the coastal areas of many Pacific islands. Mixed with species such as guavas, mango and Ficus. This is an ancient man-made habitat.


Farmland: food crops, fruit orchards, floriculture, vanilla, etc.

Savanna: low production grassland with some tree cover, many breadfruit shrubs and dominated by exotic grasses. Often replaces (dry) forest after repeated burning.

Grassland: areas dominated by grasses with little tree and shrub cover, also replacing former forest. Savanna and grassland in Pacific islands are normally the result of human activity.


Wetlands

Wetlands: rare freshwater habitat in the Pacific; most original wetland is drained and changed to crop- and grassland. Wetland bird species are now dependent on man-made ponds, reservoirs, sewage fields, etc.

Upland forest types

Production Forest: mainly Caribbean Pine or Eucalyptus plantations.

Upland Dry Forest: once covered about one-third of the lar-ger Fijian islands and also was common at the leeside of the Hawaiian islands; now greatly altered to savanna with sparse vegetation.

Montane Rainforest: various forest types united by high humidity and limited temperature variations. Exact timing of dry season varies. Characterised by epiphytes and mosses. This habitat has often disappeared from the smaller islands and the remains on larger islands are threatened.

Cloud Forest: the highest parts of rainforest, which are characterised by a high incidence of fog.

Secondary Forest: new natural forest where the original forest has disappeared. As a habitat it is highly variable, from low woodland to tall forest with more open canopy than virgin forests and lacking old emergent trees.


Other habitat types

Lava Plains and other bare ground at high altitudes: for some bird species this forms an important habitat (Hawaii Goose, Omao, Tahiti Petrel, White-tailed Tropicbird).


Some Basics for New Zealand

GEOLOGY The core of New Zealand was pushed, compressed and folded up against the Australian area some 370 million years ago. About 300 million years later (or 70 million years ago) New Zealand and Australia were separated along a rift that created the Tasman Sea. The rift ‘healed’ and 25 million years ago the eroded and flattened remains started to be uplifted again.