Black grouse and parasites

Parasites are extremely important in grouse populations.

Parasites and sexual signals

Parasites and predation risk

In a number of species, indiduals that are more parasitized are more vulnerbale to predation (Moller 2007, 2012). An analysis of hunted black grouse found that birds hunted with a dog were more heavily parasitized than those hunted without (Isomursu et al. 2008). Experiements on red grouse showed that birds treated with anti-helmintic drugs were less detectable by dogs (Hudson et al. 1992), presumably because parasitism makes birds more visible olfactorily.

Reference

Hudson P.J, Dobson A.P, Newborn D. (1992) Do parasites make prey vulnerable to predation? Red grouse and parasites. J. Anim. Ecol. 61, 681692. Isomursu M. et al. 2008. Parasitized grouse are more vulnerable to predation as revealed by a dog-assisted hunting study. Ann. Zool. Fenn. 45: 496502.