The dark-rumped swift (Apus acuticauda) belongs to the family of swifts, spinetails and swiftlets, Apodidae.
The dark-rumped swift species are distributed in India, Bhutan and Thailand. There are less than 700 mature living swifts in the world. The IUCN has listed these swift species as "Vulnerable" to extinction.
Dark-rumped swift - Overview
- Scientific name: Apus acuticauda
- Species author: (Jerdon, 1864)
- Synonyms/Protonym: C.[ypselus] acuticanda [sic] Jerdon, 1864
- Family: Apodidae › Apodiformes › Aves › Chordata › Animalia
- Vernacular names: English: Dark-rumped swift, Chinese: 暗背雨燕, French: Martinet d'Assam, German: Glanzrückensegler, Spanish: Vencejo de los Khasi, Russian: Блестящий стриж, Japanese: セグロアマツバメ
- Other names: Khasi Hills Swift
- Distribution: India, Bhutan, Thailand
- Diet and feeding habits: insects
- IUCN status listing: Vulnerable (VU)
Appearance, physical description and identification
The dark-rumped swift (Apus acuticauda) is a large swift, measuring 16 to 17 cm in length.The upperparts of the dark-rumped swift are blackish and glossy. The back has slaty blue hue. The underparts are blackish brown. The throat region is grayish white. There are darker scaly marks on the upper breast, as the feathers have darker edges. The lower belly is blackish. The underwings are brownish.
The dark-rumped swift has deeply forked tail and but for the rump it is very much like Pacific swift. The Pacific swift has white rump. Their call is an extremely high-pitched " tsiririri" sound.
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Origin, geographical range and distribution
The dark-rumped swift species are distributed in India, Bhutan and Thailand. Vagrants have been recorded in Sri Lanka and Nepal. There are records of their presence in China (Yunnan) and unconfirmed reports of their presence from Myanmar and Cambodia.In India, these dark-rumped swift species are distributed in the states of Assam, Meghalaya, Nagaland and Mizoram.
Ecosystem and habitat
These dark-rumped swift species have moderate forest dependence. These species occur in altitudes from 500 to 2470 meters.The natural ecosystems of these dark-rumped species include tropical and subtropical moist lowland forests, deep gullies, rocky areas, inland cliffs and mountain peaks.
Diet and feeding behavior
The diet of these dark-rumped swift species is not clearly known. However they have been observed to forage along with Pacific swifts whose diet is mainly bees, wasps, termites, moths and flies.Reproduction and breeding habits
The breeding season of these dark-rumped swift species in India is believed to be from February to June, with a peak period in March to May.The dark-rumped swift breed colonially in the crevices and caves of rocky cliffs and deep gorges, at an elevation of 200 to 1,350 meters. The breeding sites are usually located close to forests. Breeding colonies of up to 250 birds had been recorded.
Migration and movement patterns
The dark-rumped swift species are fully migratory birds.Breeding colonies of dark-rumped swift are found in the Himalayan foothills in Bhutan and north-eastern India. The birds normally disappear after breeding and reappear the following year. There are records of the presence of these species throughout the year from India.
Their migratory movements and wintering areas are not clearly known. There are records of their presence in the non-breeding season in Thailand as well as China (Yunnan). Vagrant dark-rumped swifts have been recorded in Sri Lanka and Nepal.
Conservation and survival
The global population size of the dark-rumped swift (Apus acuticauda) is estimated to be around 150 to 700 mature individual birds. The overall population trend of these dark-rumped swift species is considered to be stable. Throughout its range it is reported to be rare. The generation length is 12.5 years. Their distribution size is about 158,000 sq.km.The dark-rumped swift (Apus acuticauda) has approached the thresholds for being Vulnerable, under the range size criterion, under the population trend criterion and also under the population size criterion. The habitat destruction is the main threat that has endangered the survival of these species.
IUCN and CITES status
The IUCN (International Union for Conservation of Nature) has categorized and evaluated the swift species and has listed it as "VULNERABLE". The CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) status is ‘Not Evaluated’ for the dark-rumped swift (Apus acuticauda).| Taxonomy and scientific classification of Apus acuticauda | |
|---|---|
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Apodiformes |
| Family: | Apodidae |
| Subfamily: | - |
| Genus: | Apus |
| Species: | A. acuticauda |
| Binomial name: | Apus acuticauda |
| IUCN status listing: |
 Vulnerable |
Current topic in Birds of India: Dark-rumped swift - Apus acuticauda.