Editing Grouse (section)

=== Mating behavior selection ===
{{Main|Lek mating}}

Male grouse display [[Lek mating|lekking]] behavior, which is when many males come together in one area and put on displays to attract females.<ref name=Fiske>{{cite journal |last1=Fiske |first1=Peder| last2=Rintamaki |first2=Pekka |last3=Karvonen |first3=Eevi|title=Mating success in lekking males: a meta-analysis |journal=Behavioral Ecology |date=1998 |volume=9 |issue=4 |pages=328–338 |doi=10.1093/beheco/9.4.328 |doi-access=free}}</ref> Females selectively choose among the males present for traits they find more appealing.<ref name="Fiske"/> Male grouse exhibit two types: typical lekking and exploded lekking.<ref name=ssd /> In typical lekking, males display in small areas defending a limited territory, and in exploded lekking, displaying males are covered over an expansive land area and share larger territories.<ref name=ssd /> Male grouse can also compete with one another for access to female grouse through territoriality, in which a male defends a territory which has resources that females need, like food and nest sites.<ref name=ssd /> These differences in male behavior in mating systems account for the evolution of body size in grouse.<ref name=ssd /> Males of territorial species were smaller than those of exploded lekking species, and males of typical lekking species were the largest overall.<ref name=ssd /> The male birds that exhibit lekking behavior, and have to compete with other males for females to choose them, have greater sexual dimorphism in size.<ref name=Soulsbury>{{cite journal|last1=Soulsbury|first1=Carl D|last2=Kervinen|first2=Matti|last3=Lebigre|first3=Christophe|title=Sexual size dimorphism and the strength of sexual selection in mammals and birds|journal=Evolutionary Ecology Research|date=2014|volume=16|pages=63–76}}</ref> This suggests the hypothesis of sexual selection affecting male body size and also gives an explanation for why some species of grouse have a more drastic difference between male and female body size than others.{{citation needed|date=October 2020}}