Kenya Revives Poisoning Campaign to Control Invasive Indian House Crows
NAIROBI – Originally introduced to East Africa in 1891 in Zanzibar to help manage domestic food waste, Indian house crows have become a major ecological threat in Kenya. These invasive birds are responsible for killing native small bird species, potentially spreading disease, damaging food crops, and causing disturbances at tourist hotspots, open-air events, and businesses.
To combat the growing population—especially in coastal areas popular with tourists—Kenya has renewed its effort to poison millions of Indian house crows (Corvus splendens). This marks the first large-scale attempt since a previous initiative was abandoned two decades ago following the ban on importing the poison DRC-1339, commonly known as Starlicide.
Like many invasive species, Indian house crows have multiplied rapidly across Africa, thriving on abundant food waste. Without natural predators, they have become a significant nuisance in several countries, including Djibouti and South Africa. A survey conducted in January 2024 by conservation NGO A Rocha Kenya estimated over 12,000 crows in the town of Watamu, Kilifi County. By March 2024, Malindi, located just 20 kilometers (12 miles) away, recorded a staggering 31,000 crows. These numbers have surged dramatically compared to 2005, when only five crows were counted in Watamu and about 25–30 in Malindi—three years before Starlicide imports were restricted.
In 2022, the private landscaping company Little Kenya Gardens (LKG), which holds exclusive import rights for the poison, acquired 2.5 kilograms (5.5 pounds) of Starlicide for testing, aiming to revive the mass poisoning initiative. This effort is part of the National House Crow Eradication Programme, led by the Kenya Wildlife Service (KWS), which classifies the Indian house crow as an invasive species.
The campaign escalated in 2024, with Kenya setting an ambitious goal of eliminating at least one million crows. Authorities also aim to prevent their spread from coastal areas into inland tourist destinations and the capital, Nairobi.
However, achieving this goal presents significant challenges. According to Erick Kinoti, project coordinator at A Rocha, inadequate disposal of food waste continues to fuel the crows’ rapid breeding, undermining eradication efforts. He noted that LKG imported additional poison in November 2023, though they are still using supplies from 2022 before deploying the new stock.
LKG owner Cecilia Ruto reported that approximately 2,000 crows were eliminated during the 2022 trials to evaluate the poison’s effectiveness. She emphasized that Starlicide is completely metabolized within the crow’s body before death, minimizing risks to scavengers that might feed on the carcasses.
With Kenya intensifying its battle against this invasive species, the success of the poisoning campaign will largely depend on sustained efforts in waste management and population control.
In the U.S., where it was developed more than 50 years ago, Starlicide is registered for the control of birds such as crows, ravens, blackbirds, gulls and magpies that are considered crop pests or that pose a threat to humans or endangered species. The slow-acting poison kills targeted birds within three to 80 hours of consumption, but is said to be nontoxic to nontargeted species.
Since last year, Kinoti, who is leading the current poisoning campaign in partnership with KWS, explains that they organized counts of crow roosts, mapped out bait locations, and gathered data on crow distribution.
It starts with 10-14 days of pre-baiting, in which field officers set out food bait, not poisoned, to accustom the crows to feeding at the bait sites. After this, the actual poisoning begins; Kinoti says the sites are chosen carefully away from human and animal traffic. “It’s an oral poison, so it’s administered by feeding the crows poisoned meat,” he adds. The day after the poisoning, Kinoti explains, a team of collectors is deployed to scout the roosting sites to collect the dead crows.
“Our trained field officers have two main tasks. One is collecting data by counting how many birds feed on the bait, and the second is to chase away any nontarget species that come to the site. So far, we have a visual confirmation that the project is working, [which is an] increase of small bird populations around Watamu and others where poisoning has been carried out. We, however, have a long way to go since we have a huge area to cover regarding the same. We will be conducting roost counts soon to evaluate the number of populations in roosts,” Kinoti tells Mongabay.
“The poisoning program is ecologically friendly because it targets crows, it’s virtually non-toxic to other raptors,” says Shiv Kapila, director of the Naivasha Raptor Centre which is part of the Kenya Bird of Prey Trust. “The benefits of eliminating them outweigh the environmental cost, it is the most humane way of controlling their spread. If the program succeeds, it is a long-term solution to this menace, and we should not be afraid.”
Kapila said Indian house crows have wiped out populations of native birds, especially weavers, in the Diani area, a popular beach just south of the port city of Mombasa. “We have not seen some of these indigenous birds for a decade now. These birds [crows] are a nuisance … the only benefit they have is to eat rubbish … but they snatch food from visitors, they are noisy … yet a lot of people come to the coast of Kenya for tourism,” according to Kapila.
He adds that it’s important to inhibit their spread to the densely populated Nairobi area, where they could become entrenched and explode in numbers. A study published last year found that crows typically build their nests close to human settlements to improve their access to food and chances of survival.
Paul Gacheru, species and sites Manager at the conservation organization Nature Kenya, says that the Indian house crow will have massive negative impacts on native biodiversity and various sectors of the economy, including tourism.
“Countries need to weigh the cost-benefit analysis of having these crows. As for Kenya, these crows are a menace that requires control,” Gacheru tells Mongabay. “The long-term solution needs to take a regional approach to the control of the crows. There is no need for Kenya to spend millions of shillings controlling the crow while Tanzania is not doing the same. This is because Tanzania will eventually become a source population for the species.”
He also called for measures to improve solid waste management in large urban areas, which would minimize food availability for these scavenging birds.
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