London, England, October 10, 2008--A red deer stag in London's 2,500-acre (1,000-hectare) Richmond Park roars as part of the autumn rutting--or mating--season.

Females are attracted to males with the loudest roars. Males competing for mates also lock horns to establish dominance.

Charles I turned the grounds into a park for red and fallow deer in 1625. The park remains home to more than 600 of the ungulates that graze on grasses and low tree branches.

--John Roach