Under-threat grouse are helped by cattle, says trust’s research , Teesdale Mercury

Research in Teesdale has revealed that black grouse are breeding three times better in fields where cattle were grazing with sheep than in those grazed by sheep only, because of the greater abundance of insects, which young chicks need to survive.

The Game & Wildlife Conservation Trust identified that fields grazed by cattle had twice as many sawfly larvae, which make up more than two thirds of the diet of newly hatched chicks. Other favoured foods of black grouse chicks such as caterpillars, spiders, harvestmen, plant bugs and flies were also more bountiful in fields with cattle.

The study was conducted in the North Pennines, the stronghold for black grouse in northern England.  

Black grouse breeding productivity has been monitored annually since 1998 across some 40 enclosed fields on nine farms. 

Vegetation and insect abundance information was collected in 2009 from 11 paired fields, one grazed by cattle (cattle only or cattle and sheep) and the other by sheep only.

Dr Phil Warren, a research scientist with the Game and Wildlife Conservation Trust, said: “Low breeding productivity is seriously limiting the recovery of black grouse populations in northern England.

“Poor weather in June, when the chicks hatch, is a major factor, together with predation by stoats and a lack of chick food insects.“

Dr Warren added: “We cannot control the weather, so therefore we need to ensure that breeding habitats are rich in key insects, and that nest predators such as crows, foxes and stoats are controlled to maximise breeding success when weather conditions are good. 

“Reducing sheep grazing does improve breeding success by increasing cover rather than increased sawfly abundance.

“If we can improve the abundance of insects, particularly sawfly larvae then this could dramatically improve the future survival of this enigmatic bird species in the uplands. This early research shows that cattle grazing could hold the key.”