Silver-backed Needletail

The silver-backed needletail is a species of swift in the family Apodidae. The account opened places it in Southeast Asia, Sumatra, Java and Taiwan, as a vagrant to Christmas Island, with natural habitat of subtropical or tropical moist lowland forest (Wikipedia, general species account).

That is all the source opened says about it. It does not name Nepal, and gives no size, plumage, diet or breeding detail, so none are stated. Its inclusion in Nepal's guide is flagged for checking, and the entry is kept very short rather than borrowing from other needletails.