Lesser flamingoes gather at the lake shores to filter the water through their beaks and obtain their food, the blue-green algae Spirulina platensis, which proliferate in this aquatic alkaline environment. The birds use up annually 250 tons of algae in each lake hectare. Greater flamingoes also visit the lake, in smaller numbers than their shorter relatives. Flamingoes have likely reached two millions at best times, but sadly over the past years these birds suddenly disappear to return on a cyclic basis, always in smaller flocks. Occasionally and due to pollution, cyanobacteria and some toxic species of blue-green algae thrive in the lake waters and poison the lesser flamingoes. This is the price nature and wildlife are bound to pay for the hard coexistence with the human milieu. Albeit efforts targeted to prevent and avoid these deaths, sprouts regularly happen while flamingoes fly around looking for the cleanest habitat. On the other hand, climatic alterations in one or other way strongly impact the birds' populations: excessive rains reduce the water pH and thus slow down the growth of nutritive algae, whereas severe droughts have occasionally dried the lake up. For some strange reason, flamingoes never form breeding colonies at the lake.

Nakuru national park was declared a rhino sanctuary in 1987, when there were only two resident black rhinos. A further 16 were introduced from Solio Ranch, followed by four specimens brought from Nairobi national park in 1990. The first two white rhinos were introduced in the park from Lewa Downs. In 1995, a bigger group of 10 was brought from South Africa. Secure from poachers' attacks thanks to the electric fencing, the rhino population at Nakuru progresses positively and it is easy to find the white rhinos grazing on the clearings by the lake. The browser black rhinos feed on the bush and forest areas, therefore it is unfrequent to sight them in the open field. Both species are not different in colour, in spite of their confusing denomination; both are greyish. Actually, the "white" epithet is a wrong understanding of the afrikaaner term "weit", which does not mean "white" but "wide". The Dutch settlers named this rhino after its wide and flat snout, suitable for grazing, as opposed to the triangular prehensile lip of the black rhino that serves for browsing.

Other species have been introduced in Lake Nakuru's protected environment. In 1974, Rothschild's giraffes from the Soy Plains, in Eldoret, where they had invaded the wheat farms, were released in the park. These animals have thrived here to such an extent that in 1996 some specimens were donated to Uganda and Soysambu Estate at Lake Elmenteita.

Besides rhinos and giraffes, the park hosts a plentiful mammal life which accounts for more than 50 species. Among the large herbivores you can find both common and Defassa waterbucks, which can be distinguished by the white mark on the rump, a hollow circle in the former and a blurry patch in the latter; impalas, Thomson's and Grant's gazelles, buffalos, plains' zebras, elands, warthogs, dik-diks, duikers (bush and black-fronted), klipspringers, bushbucks and reedbucks (Bohor and mountain). A small hippo herd inhabits the northeastern part of the lake (Hippo Point) and at night grazes around. Other small herbivores include hares and rock hyrax.

Primates are represented by baboons, vervet monkeys and black and white colobus. Stare at the latter with your binoculars. Don't they have a human face?

Predators, lions and leopards, introduced from other areas, have successed at the park in such a way that leopards are becoming a quite common sighting. Some 40 lions populate the park; even if you don't get to see them, since the park is small if you prick up your ears you may hear them roaring from the lodge by night. The two species of hyaena (spotted and striped), mongooses (slender and egyptian), African wild cats, civet cats, silver-backed jackals and bat-eared foxes are present as well. Otters swim at the streams that die in the lake. The rare leaf-nosed long-eared bat is a park oddity, though a sighting is unlikely.

Besides the flamingoes, more than 450 bird species populate the park. Fishing birds are present thanks to the abundant fish in the lake. Graham's tilapia, adapted to the saline waters, was imported from Lake Magadi in 1956 and serves as food for great white pelicans, great cormorants and African fish eagles. The best time for bird watching is the rainy season and during the boreal winter, when the lake hosts a wide range of European migratory species. In addition to those already mentioned, among the water birds outstand the little grebe, white winged black tern, avocet, black winged stilt, cattle egret, great white egret, ducks, hammerkop, yellow billed stork, sacred and Hadada ibis, Egyptian goose, blacksmith plover, sandpipers, grey heron, African spoonbill, African snipe, king fishers and African Jacana.

Among terrestrial birds are the ostrich, secretary bird, marabou stork, ground hornbill, Guinea fowls, starlings, ox pecker, bee eaters, fiscal shrike, Kori bustard, martial eagle, European roller, drongo, mourning dove, augur buzzard, yellow necked spurfowl and tawny eagle.