WHY SOME BIRDS DO NOT BREED IN SINGAPORE
Out of over 420 species of birds observed in Singapore, around 140 are considered residents, meaning they are believed to breed in Singapore, with local populations present year-round.
A further 60 or so birds are visitors, breeding regularly in Peninsular Malaysia or the Riau Archipelago, but only occurring in Singapore sporadically for short periods. Why are they unable to maintain a constant presence in Singapore?
When compared with other birds, the peregrine falcon is the exception, not the rule. Its natural breeding areas – crevices in cliffs – vaguely resemble service ledges of skyscrapers.
By contrast, most birds in Singapore have specific habitat preferences. Some are restricted to dense forests, others are only found in wetlands, and many have even stricter requirements within these broad categories. The bridge from these habitats to urban landscapes is one too far to cross for these birds, restricting them to the pockets of these habitats scattered across our small island.
With all these layers, there’s just very little space in Singapore to sustain some kinds of birds. Habitat fragmentation can also be a problem. Even though many birds are able to move between areas of suitable habitat easily, some birds, like babblers, are unable to traverse across modified landscapes and end up confined to small pockets of forest, with unsustainably small populations.
Another challenge, particularly for birds dependent on freshwater wetlands and open grasslands, is the role of invasive fauna species. Invasive predatory fish such as snakeheads in waterways have been recorded preying on the young of locally endangered lesser whistling ducks. Invasive birds like the golden-backed weaver appear to compete with our native baya weavers for food.
