SWIFT101: It’s a bird, it’s a plane, it’s… Swifts?

Having trouble identifying the small aerodynamic specks in the sky? This article will guide you through the identification of the 11 swift species in Singapore and how you can differentiate them from the similar-looking treeswifts and swallows.

Can you tell which species of swift this is? Introduction Have you ever looked up at the sky and wondered what those little aerodynamic birds swooping around are? These are likely swifts, one of the more commonly sighted groups of birds in Singapore. These birds are known to spend most of their lives in flight. This means that whether you are in or outdoors, if you stare at the sky, there is a good chance you will see these amazing birds. But you might be puzzled, is that a swift, treeswift or swallow? Are they the same? How do you differentiate them? Fret not, for this article will answer these questions. Differentiating Swifts from Swallows As you might have already guessed, swifts and swallows are not the same. In fact, they belong to two very different groups of birds and are distantly related from one another. Swifts (Family: Apodidae) and treeswifts (Family: Hemiprocnidae) belong to the same order (Apodiformes) and are closely related to hummingbirds (which are not found in Asia) and nightjars. On the other hand, swallows (Family: Hirundinidae) belong to the order of perching birds (Order: Passeriformes), which includes more than half of all bird species, like the commonly seen mynas, bulbuls and sparrows. But how do we tell them apart? Firstly, you would never find swifts perching, and the only time you will find one not in flight is likely when it is in its nest (or if it’s grounded for some reason). This means that when you spot a perched bird which you are unsure whether it is a swift or a swallow, it is unlikely to be a swift. However, it is possible to find treeswifts perching, and we will go through the identification of treeswifts in the next section. Secondly, the shape of swallows in flight is quite different from that of swifts. Swallows generally have broader wings, while swifts have narrower wings that give them either a sickle-shaped or paddle-shaped look. Pacific Swallow in flight Eastern Red-rumped Swallow in flight Thirdly, the two groups can be differentiated by their flight pattern. Swallows typically fly with their wings swept down and back. swifts on the other hand do not sweep their wings back in such an exaggerated motion and tend to glide or soar more than swallows. Identifying Treeswifts While treeswifts belong to their own family (Hemiprocnidae), they are closely related to swifts and appear more similar in flight to swifts as compared to swallows. However, as mentioned above, treeswifts perch, while swifts do not. Treeswifts also appear more elongated with proportionally longer bodies and tails compared to swifts. Grey-rumped Treeswift (Hemiprocne longipennis) The Grey-rumped Treeswift superficially looks like a swift in flight, but they are larger. The body is elongated compared to swifts and possesses a relatively long tail with a deep fork. The underparts are whitish with a greyish throat. The head, nape and mantle are a dark glossy green, contrasted by a grey back and rump. This species has blackish lores, and the males have chestnut-coloured ear-coverts, while females have black ear-coverts—one of the key features to look out for, because no swifts in Singapore have such an elaborate-looking face. Immatures have some whitish spots on the head instead of a clean glossy green head, and whitish underparts peppered with blackish scales. Male Grey-rumped Treeswift in flight Female Grey-rumped Treeswift in flight Whiskered Treeswift (He. comata) The Whiskered Treeswift resembles the Grey-rumped Treeswift in flight but can be distinguished by their smaller size and differences in plumage colours. The back and underparts of the Whiskered Treeswift are mostly olive-bronze, with a whitish vent. The head, upper throat, nape and wings are a dark glossy blue, and the most distinguishing feature from the Grey-rumped Treeswift is the clean, white supercilium and malar streak running across the face of this species. Like the Grey-rumped Treeswift, male Whiskered Treeswifts have chestnut ear-coverts while females have black ear-coverts. This species is a very rare visitor to Singapore and was last recorded in 2011. Male Whiskered Treeswift in flight Female Whiskered Treeswift perched The Swifts of Singapore With the confusing non-swift taxa out of the way, we can now proceed with the identification of swifts (Family: Apodidae). Currently, we recognise 11 species on the Singapore checklist, of which five are resident species that can be seen year-round, five are either migratory or rare visitors, and one vagrant. Swifts are powerful fliers, often darting and dancing around high in the sky against the glare of the sun, making their identification especially challenging. Here are the diagnostic characteristics and their flight behaviours which could help you identify these birds with confidence. The following species are introduced in order of rarity of occurrence, and both good- and record-quality photographs are presented to help you identify each species even if you only managed to...