title: Temporal changes in kin structure through a population cycle in a territorial bird, the red grouse Lagopus lagopus scoticus.
abstract: Populations of red grouse (Lagopus lagopus scoticus) undergo regular multiannual cycles in abundance. The 'kinship hypothesis' posits that such cycles are caused by changes in kin structure among territorial males producing delayed density-dependent changes in aggressiveness, which in turn influence recruitment and regulate density. The kinship hypothesis makes several specific predictions about the levels of kinship, aggressiveness and recruitment through a population cycle: (i) kin structure will build up during the increase phase of a cycle, but break down prior to peak density; (ii) kin structure influences aggressiveness, such that there will be a negative relationship between kinship and aggressiveness over the years; (iii) as aggressiveness regulates recruitment and density, there will be a negative relationship between aggressiveness in one year and both recruitment and density in the next; (iv) as kin structure influences recruitment via an affect on aggressiveness, there will be a positive relationship between kinship in one year and recruitment the next. Here we test these predictions through the course of an 8-year cycle in a natural population of red grouse in northeast Scotland, using microsatellite DNA markers to resolve changing patterns of kin structure, and supra-orbital comb height of grouse as an index of aggressiveness. Both kin structure and aggressiveness were dynamic through the course of the cycle, and changing patterns were entirely consistent with the expectations of the kinship hypothesis. Results are discussed in relation to potential drivers of population regulation and implications of dynamic kin structure for population genetics.
authors.affiliation: School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK. s.piertney@abdn.ac.uk
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Piertney
authors.forename: Xavier
authors.initials: X
authors.lastname: Lambin
authors.forename: Andrew D C
authors.initials: AD
authors.lastname: Maccoll
authors.forename: Kerry
authors.initials: K
authors.lastname: Lock
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Bacon
authors.forename: John F
authors.initials: JF
authors.lastname: Dallas
authors.forename: Fiona
authors.initials: F
authors.lastname: Leckie
authors.forename: Francois
authors.initials: F
authors.lastname: Mougeot
authors.forename: Paul A
authors.initials: PA
authors.lastname: Racey
authors.forename: Steve
authors.initials: S
authors.lastname: Redpath
authors.forename: Robert
authors.initials: R
authors.lastname: Moss
mesh_terms: D000818:Animals; D046094:Galliformes / Q000502:physiology*; D005838:Genotype; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D011156:Population Density; D012606:Scotland; D012919:Social Behavior