many raptors in the Accipitridae family, the females are considerably larger than the males, but for brevity, an average size has been given for comparison. Only within the Phasianidae, where the male pheasant can sometimes be more than double the size of the female, have both sizes been included. Where extremely elongated tail feathers distort measurements, this has also been mentioned.
Photographs
Each species is illustrated with a photograph, sometimes two. If the sex of the bird is not mentioned, the photograph shows an adult bird that cannot be identified with regard to sex. Where sexes differ, this is mentioned in the first paragraph of each entry (Description). The term 'sexes similar' is only used on occasions where most other species within the family are sexually dimorphic—for instance some flowerpeckers.
Unless otherwise mentioned, resident birds are shown in breeding plumage and migrants are shown in non-breeding or winter plumage. An additional photograph might show the other sex of the species or a bird in flight.
Most photographs are taken on location in Southeast Asia and show wild individuals. Where no authentic photograph was available, one showing a captive bird might be used, in which case it is mentioned in the description. We have done this consistently as we felt it was important for the reader to know that habitat, perch and surroundings might not appear as they would in the field. Only one species is shown held in the hand—the Coral-billed Ground-cuckoo.
Description: bird topography
The description has been kept to a minimum. We have preferred to let the pictures do the talking and have only described what is not obvious, such as parts of the bird not visible in that particular pose or the appearance of the opposite sex. Efforts have been made, however, to point out so-called diagnostic features where appropriate. In the field there is often one single feature that distinguishes one species from all others. The Common Kingfisher has a tiny rufous dot behind the ear— once you spot that one all your worries are over! This technique enables trained birdwatchers to quickly put a name to most of the birds they see, leaving them more time to concentrate on the really tough groups with no (or very faint) diagnostic features.
Some species have no relatives that resemble them closely. These are easy to identify on all occasions, so have simply been labelled 'unmistakable'. Please bear in mind that this term and the diagnostic label only apply within the region covered. While the short bill of the Little Curlew is diagnostic in Southeast Asia, it is not enough as a single identification feature when compared with the Slender-billed Curlew of Eurasia or the Eskimo Curlew of the Americas, which both have fairly small bills. Parts of the bird are mentioned using the standard norm in bird books, but slightly modified for this specific purpose.
The upper surface of the entire body including the mantle, wings, back and rump are often referred to collectively as upperparts, and likewise the entire under surface of the bird including the throat, breast, belly, flanks and vent is labelled collectively as underparts. Taxonomic variations and similar species not illustrated are also covered in this section.
Figure 4: The different parts of a bird
Voice
Calls follow our main references, especially Lekagul and Round (1991) and Lim and Gardner (1997), authors who have vast personal experiences studying bird vocalisation. Only in a few instances are descriptions modified slightly in accordance with our experiences.
Even using these authoritative sources for reference, verbalisation of bird calls is a tricky business. The frequently heard call by a common and noisy species like the Wood Sandpiper is variously described: King, Woodcock and Dickinson (1975): fi-fi-fi or ziss, iss-iss
Lekagul and Round (1991): chiff-chiff-chiff
Lim and Gardner (1997): si-si-si
MacKinnon and Phillipps: chee-chee-chee
From our own experience we chose wee-wee-wee as the best verbalisation.
The less often heard Changeable Hawk-eagle is thus described:
King, Woodcock and Dickinson (1975): yeep-yip-yip-yip
Lekagul and Round (1991): kri-kri-kri-kri-kree-ah
Lim and Gardner (1997): hwee-hwee-hwee
MacKinnon and Phillipps: kwip-kwip-kwip-kwee-ah
Here we chose to follow Lim and Gardner (1997), partly from personal experience, partly from certainty that the author is very familiar with the call.
Despite these discrepancies in verbalisation, we felt it was important to include a voice description. Combining the call with observations can sometimes be crucial for identification. And while many families have similar calls within members—most bulbuls produce a similar soft chatter—other families are very diverse. The Bushy-crested Hornbill screams, the Rhinoceros Hornbill honks and the White-crowned Hornbill hoots. At least knowing that much is a help for the beginner
However, in our experience, calls cannot be learned from a book. Audio tapes may help, but the best method is to go out there off the trails and find the bird making the call—often time and time again until the connection stays with you.
Habits
This section includes an account of where the bird can be found and how it is likely to behave. Terms describing habitat are mainly self-explanatory except for forest birds. Since the exact distribution of different forest types in this region is a very complex subject, we have made a simple distinction between wet evergreen tropical rainforest and deciduous forests. Rainforest comprising mainly tall dipterocarp trees is the predominant vegetation type in the Philippines and in the Sunda subregion, including the Malay Peninsula and Borneo. It also grows with a slightly different tree composition in wet tropical parts of continental Thailand, Myanmar and Indochina where the term evergreen forest is often applied—please see Lekagul and Round (1991) for a more detailed explanation. In deciduous forest a majority of the trees shed their leaves during the dry winter months; this habitat type prevails in the northern drier and more seasonal subtropical areas. Although some species occur in both habitats there are also great differences in the respective avifaunas.
The terms primary and secondary forest have been used as defined in the Glossary. Secondary forest varies from low regrowth with few large trees remaining, to areas selectively logged decades back with many large trees remaining, or regrown forest, labelled mature secondary growth in this volume. Where canopies meet and form a continuous cover, even though some disturbance may have taken place, the term closed forest is sometimes applied. At the other end of the scale, where no large trees are left standing, the habitat is labelled scrub.
Forest changes composition with elevation, likewise does the associated avifauna. In the tropics this change is both profound and amazing. In the East Malaysian state of Sabah on Borneo it is possible to travel from the lowlands at Poring Hot Springs to the summit of Mount Kinabalu at 4,101 metres within a couple of days—a journey that has been compared to travelling overland from the Equator to the Arctic.
Very few birds occur across the whole altitudinal range. In fact most birds occur only in the lowland forest. A few are restricted to the extreme lowlands below 300 metres but many also move into the foothills or submontane elevations. At 900 metres elevation the composition of birds changes significantly as many different species can only be found in the lower and upper montane elevations. A few occur only in alpine habitats near the tree limit, which in the tropics is around 3,600 metres.
Therefore the altitudinal
