They are the bad boys of the Kenyan skies: swooping down to steal food from tourists’ plates, pushing out local bird species from their habitats and raiding crops. After decades of trying to control its population of crows – also known as the Indian house crows – the Kenyan government has declared a war on them. It plans to eliminate one million house crows by December 31.
In a post on X on June 7, the Kenya Wildlife Service said, “House crows are invasive alien birds that have been a nuisance to the public for decades…These birds also pose a major inconvenience to the hotel industry along the coast. Today, the Kenya Wildlife Service led a consortium of stakeholders in developing an action plan to eliminate one million house crows from Kenya’s coast by 31st December 2024.”
The plan: poison the birds using starlicide, an avicide that the Kenyan government will import from New Zealand.
Dr Colin Jackson, ornithologist, conservationist and CEO of A Rocha Kenya, a conservation organisation that has been involved in the culling of crows, told The Indian Express that they would require around 5-10 kilograms of the poison, at $6,000 per kg, to kill one million house crows in the country. The poison, he said, will be mixed with offcuts of meat supplied by the hotel industry and offered to the house crows.
The proliferation of the Indian house crow (Corvus splendens) has severely impacted local ecosystems and communities in East African countries, including Kenya.
A species that’s native to India, house crows often attack indigenous birds, kill them and feed on their eggs. Crows usually work as a team — for instance, if one attacks a bird and chases it away from its nest, the other swoops in to steal the eggs. Experts say this aggressive behaviour of the crows has forced several native birds to leave their natural habitat. In Kenya, birds such as scaly babblers, pied crows, sunbirds, weaver birds, and waxbills have been displaced by house crows.
It is not just native birds; crows are known to torment and kill newborn or sick calves and goats and eat a range of small reptiles, amphibians, mammals, and insects.
Local communities have suffered too — crows damage fruit trees such as mango and guava, and raid crops, including wheat, maize, millet, rice, and sunflowers, leading to losses for local farmers.
Even the hospitality industry has been hit. “Crows land up on lawns and in hotels looking for food. Hotels with air conditioners — an ideal spot for nesting — artificial water bodies and swimming pools have a lot of crows. They dirty the area and their cawing disturbs tourists,” said K S Gopi Sundar, co-chair of the IUCN Stork, Ibis and Spoonbill Specialist Group.
There are multiple accounts of how a species that’s native to India and the subcontinent, besides other parts of Asia and the Middle East, began to be spotted in East Africa sometime in the 1890s.
According to one account, they were brought from India to the island of Zanzibar (then a protectorate of the British and currently a part of Tanzania) on the orders of its then governor, who had previously served in India, to help deal with piling garbage. The island had a serious litter problem, leading to frequent breakouts of epidemics.
Another account suggests that these crows reached the region through ships that arrived from the Indian subcontinent. Sundar of IUCN’s Stork, Ibis and Spoonbill Specialist Group said, “Crows were very common pets among sailors as they are extremely intelligent. We know for sure that this is how crows reached Australia and we are fairly certain that’s how they got to some parts of Africa.”
Regardless of how these crows reached East Africa, their arrival brought a new set of problems. Within a few years, their population skyrocketed, and by 1917, Zanzibar had declared them pests and put a bounty on their heads — anyone who brought in a dead crow or even a crow’s egg could walk home with a prize money. These efforts did not amount to much and house crows proliferated across the region.
By 1947, the crows had reached Kenya and currently, their population in the country is estimated to be between 750,000 and 1 million.
Studies show that crows have a remarkable ability to remember faces, use tools (they can, for instance, take a twig and turn it into a hook), and communicate in sophisticated ways. They are also known to solve higher-order and relational-matching tasks and are credited with advanced rational thinking, much like humans and apes.
However, in Africa, they are best known for being a ruthless and efficient coloniser.
“House crows adapt to new environments relatively fast as long as the temperature regime and rainfall are suitable. They are also extremely flexible in terms of what they can eat. They are predators of eggs of smaller birds, and can also feed on human food. For instance, in India, they eat all kinds of cooked food such as churmuri and pani puri. As a result, they are able to survive not only in the wild but also in urban areas,” said Sundar.
Moreover, there are only a few predators of crows — a handful of hawks, eagles, and owls are known to hunt crows but not in large numbers. That’s because crows can easily figure out how to avoid their attackers.
“So, when there is plenty of food and less predation, the population of crows explodes. And that is exactly what has happened in East Africa,” Sundar said.
However, in India, he said, crows are not as common as they were a decade or two ago. “Over the last 20 years, I have not seen too many crows in our parks and houses. Interestingly, they stream out very early in the morning – you can see huge flocks of crows flying out. We do not know where they are going, what they are doing. That is because there is not enough research done on them in our country,” Sundar said.
This is not the first time that an attempt will be made to eliminate house crows in Kenya. “From the 1980s till 2005, there was a low-level control happening in the country by poisoning the house crows,” said Dr Colin Jackson of A Rocha Kenya.
The initiative, however, was stopped by Kenya’s government in 2005 as the poison had not been imported through official channels and procedures. Also, the drive did not produce the desired results due to a lack of government involvement, among other reasons.
Jackson is hopeful that the latest attempt to eliminate house crows will be successful. “The difference is that this time the government has issued the permit to import starlicide, and has accepted a protocol that allows us to use the poison (for culling crows),” he added.
Poisoning seems to be the most effective way to eliminate the house crows. Shooting or trapping them does not work as these birds are intelligent enough to avoid areas where they witness other crows dying or being trapped.
“There are two advantages of using starlicide. Once the crow has consumed the poison, it will not die until about 10 to 12 hours later. This means that we will feed the crows early in the morning and they will die when they get to their roost site in the evening. The surviving crows will see their mates dying around them, but will not associate the death with the place where they had fed in the morning. The following morning, the survivors are back at the feeding site without any concern,” Jackson said.
The other benefit is that starlicide is entirely metabolised by the crow before it dies — which means, there is little risk of secondary poisoning to any other species that feeds on the dead crow.
As Kenya works on its culling plan, other countries, including Yemen, Singapore and some of the European nations, where the house crows have become invasive pets, will be watching closely.