The grouse season doesn’t officially end until the 10th December however many of the estates in the North York Moors have already finished shooting for the year.
Throughout the season estates test batches of shot grouse to ascertain the strongyle worm population within them.
The Strongyle Worm (Trichostrongylus Tenius) is the biggest killer of grouse, so it’s cycle and density needs careful monitoring. Grouse have a very interesting gut, different to other birds, with 2 extra sections of dead end gut called the caeca that lead back around the larger intestine, this is to drain extra nutrition from their diet. This dead end gut can be taken from the shot birds, sliced up, washed out and then the worms can be counted, this then gives an estimate of the worm volume in the grouse.
Once the worm counts have been completed the gamekeepers and estates make the decision on whether to put out standard or medicated grit for the grouse.
Medicated grit is only available by licence and a vets certificate is required to purchase it. The grouse that are shot on estates enter the food chain so medicated grit cannot be put out onto the moors until shooting has ended as it has an agreed withdrawal period of 28 days.