The Nairobi National Park and the neighbouring private wildlife sanctuaries are under a major threat from a weed that is rapidly eating into the grazing area for wildlife, reducing fodder and grasses.
The flowering plant, known as Parthenium hysterophorus or " famine weed" to locals, is spreading fast in the park and its environs.
It usually grows to between 0.5m and 1.5m tall. The weed was declared as noxious in 2010 in Kenya.
Friends of Nairobi National Park have teamed up to uproot the weed capable of producing hundreds thousands seeds, making it to spread fast.
To tame the weed requires uprooting before flowering.
The weed is said to produce substances that do not allow other plants or grasses to germinate or grow once it colonises an area.
When livestock feed on it, it adversely affects meat and milk.
Wildlife conservators are apprehensive the plant is eating up much needed fodder and grass endangering the existence of wildlife within the park and in private sanctuaries.
Enviro Wild Initiative in collaboration with African Sustainability Network (ASNET) has embarked on uprooting the plant in Silole private sanctuary, neighbouring the national park in Ong'ata Rongai,Kajiado County.
The sanctuary has 600 acres hosting different species.
Caroline Kibii, a environment scientist and researcher, said the tedious weed uprooting process is better than chemical and biological control in dealing with the weed.
"The best method to control parthenium is to pull it out while it is still young (before it flowers to suppress the pollen grains). This should involve pulling it out with the roots," said Ms Kibii.
The team of volunteers seeks to reduce the seed load as the weed is dispersed very easily, as a way of complementing routine pullout that is being carried out inside the Nairobi National park.