Oil headed for the first decline in five days as investors assessed the outlook for demand amid a resurgence in Covid-19. Futures in New York dropped toward $71 a barrel after climbing 8.5% over the past four sessions. There are signs that demand for fuels such as gasoline has increased as vaccination programs are rolled out, although the fast-spreading delta variant has raised concerns about the short-term outlook. Tight restrictions have been renewed including curfews in some places.