The opening day of the grouse-shooting season is suffering from a fall in bird stocks blamed on mild winters.
The grouse population has been hit by parasitic gut worms
The Game Conservancy Trust (GCT) said not much shooting would take place on the "Glorious Twelfth" in an attempt to boost the grouse population.
The situation is put down to parasitic worms that thrive in mild winters and affect the gut of red grouse.
Also, tick infestations in red grouse chicks have risen in the past two decades - from 4% to 92%.
GCT scientist Dave Newborn said: "After last year's population crash, we have seen a good recovery in England but the fact breeding stock was so low at the start of the year means once again shooting will be very limited this year.
"However, the prospects for a strong recovery next year look positive."
The GCT said the situation in Scotland was "very patchy indeed", with pockets of good numbers but low overall density.
Last year there was hardly any shooting in northern England because of the population crash.
The trust is trying to address the tick problem by treating sheep with insecticide.
Gamekeepers warn that there must be enough birds left over for numbers to recover in future years.
There are about 460 grouse moors in the UK, covering 3.6m acres from Wales and Derbyshire to the Highlands.
The regional director for the British Association for Shooting and Conservation, Philip Pugh, said it was a massive blow for the shooting and tourism industries.
"The red grouse is unique to this country, it is noted as one of the fastest flying and most sporting game birds there is, and they [tourists] will sadly not be coming in the same numbers because there are days being cancelled right across the region," he said.