Photographic Guide to the Birds of Malaysia & Singapore. Morten Strange
Читать онлайн книгу.
tropical rainforest at various altitudes
A simple colour-code has been applied to the maps:
Where breeding populations are augmented by migratory birds during the winter, this is explained in the text. Winter here refers to the northern hemisphere winter months December, January and February, the actual migratory season for most birds lasts from September to April. A few migrants can in fact be met with in winter quarters almost all months of the year.
Most migratory birds in Southeast Asia arrive on the so-called East Asian Flyway, following either the Malay Peninsula or the Philippine archipelago south, as illustrated in Figure 7 (page 40), which has been modified after Sonobe and Usui (1993).
We are aware that other authors, such as Lekagul and Round (1991) use a more elaborate system of four colour codes to distinguish between migratory and sedentary residents, and between passage migrants and winter visitors. This was deemed impractical in our case as it would only lead to a false sense of accuracy if applied here.
Figure 6: Vertical levels of the rainforest
Since the maps are quite small it is not possible to accurately pick out Singapore, Hong Kong and Brunei. These areas are therefore mentioned specially in the text where appropriate, except for montane species which by definition will not occur in these lowlands.
Although not a country, Hong Kong has been singled out because of a long tradition of birdwatching in and around this territory. Otherwise the southern provinces of China are collectively referred to as south China except for Yunnan province, which is the only location in China for some Oriental region birds. The islands of Taiwan and Hainan can be identified on the map. Please see de Schauensee (1984) for a more detailed account of Chinese avifauna.
In Southeast Asia, there is a prolific trade in captive birds, and some individuals inevitably escape from their cages. Others are deliberately released during religious festivals, Lim and Gardner (1997) lists 58 species spotted in the wild in Singapore which are totally alien to that nation. In general these so-called escapees are not included in ornithological literature and are also not covered here. A few species, however, establish viable breeding populations in this way outside their natural range. These are referred to here as introduced species.
Abundance code
We have tried to provide the reader with some idea of how common the bird is and how likely it is to be found in the field. It must be said that this is a highly subjective exercise and any label attached can only serve as a rough guideline.
The usual reference books are not very reliable for this purpose. Note that MacKinnon & Phillipps (1993) describe the Bushy-crested Hornbill as an 'Abundant hornbill... in Borneo', Legagul & Round (1991) has it as a 'Fairly common resident' in Thailand. Contrary to that, Poonswad and Kemp (1993) list this species as rare in Indonesia and endangered with local extinction in Thailand.
For this purpose I have relied as much on published trip reports and personal comments by fellow birdwatchers as my own experiences. Since I have never seen a Bushy-crested Hornbill, despite travelling through prime habitat in both Thailand and East Malaysia for days and weeks, I simply labelled it as 'generally scarce', although it must be said that it appears to be locally fairly numerous in parts of Peninsular Malaysia. Lekagul and Round (1991) describe the Plain-backed Sparrow as Very common resident' in Thailand, yet birdwatchers have commented to me that they have travelled for weeks through that country working hard to find one or two individuals. Therefore it is listed here as 'uncommon'.
It could be that field guides are either written by very capable ornithologists who easily locate scarce birds, or that they tend to copy from other outdated references. Newer publications like Sun et al, (1998) tend to provide a more realistic picture on status. At any rate, it has been my experience that resident rainforest birds especially are few in number and are usually infrequently encountered, therefore many of those have been 'down-graded' to uncommon status here, which I hope will give the reader a more realistic expectation of birdwatching conditions in the region. In montane forest habitat, the diversity is lower, but the density tends to be higher, and more montane residents thus have been labelled fairly common or even common.
Where there appears to be a great discrepancy in status within range, this has been differentiated between the countries. Please note that references to status do not apply to Myanmar, where very little current information is available.
Some terms used:
Widespread means that the bird occurs over a wide geographical area and in a variety of habitat types.
Local is the antonym for widespread and is used where a species is restricted to a special habitat within a small geographical area.
The term scarce indicates that a bird occurs in low numbers (while an uncommon bird although uncommonly encountered could be locally and seasonally numerous or might be numerous elsewhere in extralimital range).
Numerous is the antonym of scarce, a species occurring in large numbers.
Abundant is very numerous, occurring in very large numbers, sometimes dense flocks.
Figure 7: Southeast Asia migration routes
Modified from Viney, Phillipps and Lam (1994) and Lim and Gardner (1997) we have used the following colour codes to indicate abundance of birds.
Globally threatened status
We have included a code for globally threatened status. It follows the important BirdLife International study, which was published in Collar et al. (1994), please consult this book for more detailed information. Briefly, this survey operates with four main categories, which have been adopted unchanged here:
The author in freshwater wetlands.
LITTLE GREBE (Red-throated Little Grebe)
Tachybaptus ruficollis 25 cm