The red grouse-shooting season gets under way with the Glorious Twelfth on Monday, with supporters saying it is vital for the economy.
But animal welfare campaigners said their claims were "a joke".
The Moorland Association said the better weather this year than in the past few years means that grouse breeding in England has been more successful.
Its chairman, Robert Benson, said pre-season counts of grouse in England had been delayed by the heatwave, and results were now coming in that showed problems in some areas.
But he said: "Generally, at long last, for the first time in the last few years, we've had a reasonable nesting and hatching period, with good chick survival.
"In odd places, for various reasons, it's not going to be quite as good as they thought."
A good grouse season is "massively important from an economic point of view" to the uplands, Benson said.
The Moorland Association estimates the £67 million English industry helps employ around 1,500 people.
Benson said people came to shoot red grouse from around the world, providing direct employment and knock-on benefits for hotels, restaurants, B&Bs and shops in upland areas where otherwise little would be going on except sheep farming.
But Joe Duckworth, chief executive of animal welfare charity the League Against Cruel Sports, said: "The shooting industry claims that they 'protect' the moorlands, creating a haven for wildlife. What a joke.
"The grouse shooting season does nothing more than annihilate and harm wildlife.
"Countless birds will be killed and injured for pure entertainment, and the precious moorland habitat polluted with toxic lead shot.
The charity described grouse shooting as "notoriously lucrative" and complained that birds were left to die lingering deaths after being shot by inexperienced shooters due to a lack of mandatory firearm training in the UK.