Can parasites synchronise the population fluctuations of sympatrictetraonids?
/ examining some minimum conditions

Sympatric populations of tetraonid birds tend to fluctuate in synchrony, at least onlocal scales. If shared parasites among sympatric populations of different tetraonidspecies are to operate as a local, synchronizing factor for population fluctuations atleast two conditions should be met

Per R. Holmstad, Peter J. Hudson, Vigdis Vandvik and Arne Skorping, OIKOS 109: 429-434, 2005