Herbivores, including wildebeest and zebra, use the Kitengela conservation area and migration corridor to the south of the park to reach the Athi-Kapiti plains. They disperse over the plains in the wet season and return to the park in the dry season. The concentration of wildlife in the park is greatest in the dry season, when areas outside the park have dried up. Small dams built along the Mbagathi River give the park more water resources than these outside areas. They attract water dependent herbivores during the dry season. The park is the northern limit for wildlife migrations in the dry season. The park has a high diversity of bird species, with up to 500 permanent and migratory species in the park. Dams have created a man-made habitat for birds and aquatic species.