The lesser flamingo, Phoeniconaias minor, stands between four and five feet high but is the smallest of the six flamingo species. With the greater flamingo, it is one of two Old World flamingo species. The clearest difference between the two species is that the greater flamingo has a pale pink bill with a contrasting black tip while the lesser flamingo has a dark crimson bill. The lesser flamingo is also shorter and redder in colour.
Marabou storks eat flamingo eggs and young and can cause entire colonies to desert their nests. Attacks by a maximum of 17 Marabou storks caused greater flamingos to desert nests at Lake Elmenteita in south-central Kenya three years running. These storks are common urban scavengers. The soda ash plant would provide them with a permanent food supply.
A study by the East African Lake Natron Consultative Group found that tourists drawn to the region to see lesser flamingos contributed US$12m annually. Tourist to Lake Natron alone is worth US$500,000 per annum excluding associated spending. Visits to the area are likely to increase if the soda ash proposal is rejected.
Lesser flamingos attract tourists to the national parks of Kenya and Ethiopia as well as Tanzania.
In 2001, the Tanzanian government listed Lake Natron as a Ramsar Site under the international Ramsar wetlands treaty. Lake Natron has also been designated an Important Bird Area by BirdLife International.
Up to 30 per cent of the population of chestnut-banded plover is found on the Lake Natron site plus important numbers of Cape teal, marsh sandpiper and little stint. Lesser kudu and gerenuk are mammals likely to be affected together with the endemic fish species, Oreochromis alcalicus.
The species has long pink legs and a long neck. Its large body is rose-pink, the colour coming from pigments in its food, the bacteria Spirulina. The birds eat by holding their bills upside down in the water. Flamingo bills are shaped to filter tiny food items within the bill using a specially adapted tongue.
Lesser flamingos feed on Spirulina which is commonly known as blue-green algae although in fact it is bacteria. Spirulina sometimes gives Lake Natron a pink or red colour. It grows only in salty lakes. Lake Natron is known as a soda lake because of its high concentration of sodium carbonate.
Flamingos live until they are about 40 years old but only breed every five or six years. Non-breeding birds do not return to breeding sites until they are ready to breed again.
The bird lays one chalky white egg on mounds built of mud. Chicks join crèches soon after hatching which can number more than 100,000 birds. The crèches are marshaled by adult birds which lead youngsters by foot to fresh water to drink, a journey that can be longer than 20 miles.
There are thought to be between 2.2 million and 3.25m lesser flamingos in the world of which between 1.5m and 2.5m are found in East Africa. The global population is declining because of habitat loss and contamination. Lack of breeding at Lake Natron will reduce the region’s population.
The lesser flamingo is classified as Near Threatened on the IUCN Red List 2004. It is listed on Appendix II of CITES and on Appendix II of the Convention for the Conservation of Migratory Species.