Unwelcome guests: Crows pose big threat to Coast ecosystem

Indian house crows at Kibarani Dumpsite in Mombasa. [File, Standard]

They are everywhere—perched on power lines, rummaging through piles of garbage, loitering at the entrances of roadside eateries, and hovering near fishmongers’ stalls.

Their presence is ubiquitous, and their toneless, dry calls of “Hraaa! Hraaa! Wreee! Wreee!” echo from dawn to dusk.

To locals, these birds are a constant nuisance—unwelcome intruders that they grudgingly endure.

Since their arrival in Kenya nearly 80 years ago, Indian house crows have become the most abundant bird species along the coast. By disrupting ecosystems, harming wildlife, and posing risks to people and businesses, they have earned disdain from ecologists, policymakers, residents, and operators in the tourism sector. These crows are now seen as the coast’s irritants.

If conservation stakeholders have their way, the house crows may soon be gone. In June 2024, the Kenya Wildlife Service (KWS) approved a culling programme targeting one million house crows—the estimated total population—by the end of the year. So, what went so wrong with these birds that the state is now resorting to eradicate?

House crows are native to India. They were first introduced to East Africa in 1891 by a British governor of Zanzibar, who brought them in as a solution to the island’s garbage problem.

“When he arrived, the island was teeming with rubbish,” says Dr Colin Jackson, an ornithologist at A Rocha Kenya, a Christian conservation organisation leading the eradication effort.

“Having seen the crows ‘clean up’ garbage in India, the governor decided to introduce them to Zanzibar to tackle the pollution,” he continues.

However, the plan backfired. By 1917, the crows were declared pests, with bounties offered for dead birds and their eggs. From Zanzibar, the birds either flew or hitched rides on ships to Kenya’s coast, where they were first recorded in Mombasa in 1947. “The problem is that house crows are an invasive species—destructive to the ecosystems they enter,” explains Dr Jackson.

“They destroy nests, eat eggs, prey on small bird species, and terrorise other birds, causing distress. Our local wildlife has suffered greatly because of these birds,” he adds.

Among their victims are the pied crow, the tsongo (a native weaver bird), and nesting seabirds. Unlike in their native India, house crows have no natural predators in Kenya, allowing their population to grow unchecked.

Beyond their ecological impact, house crows are pests in the truest sense, drawing equal scorn from coastal residents. “This bird is a total menace,” says Kazungu ‘Zinlala’ Dzuma, a resident of Jiwe Leupe. “It eats chicks, devastating poultry and leaving farmers with huge losses,” he adds.

He adds, “This bird is cunning and always stalking people for opportunities to steal food. Women who run roadside eateries are constantly on the edge, because the birds can swipe food worth a day’s earnings.”

Dzuma recounts how eating outdoors has become a challenge: “You can’t eat in peace. And you wouldn’t dare leave a small child eating outside—they’ll mob the child aggressively. We all want this bird gone. If we were given poison, we’d do the job ourselves.”

A public health risk

House crows also pose health risks. “They are reservoir hosts for deadly pathogens,” warns Ashimosi Khamadi, a Senior Principal Research Scientist at the Kenya Medical Research Institute.

These pathogens, include bacteria that cause typhoid and avian tuberculosis, and viruses, such as West Nile fever and avian influenza (bird flu). “Avian influenza has caused pandemics before, and these birds could be very effective at spreading the virus,” Khamadi explains.

For poultry farmers, the crows also spread Newcastle disease, a virus capable of wiping out entire flocks.

Research published in September 2024 in Current Biology adds another concern: wild birds that live close to humans, including house crows, are more likely to host antibiotic-resistant bacteria than birds in less urbanised areas.

Such antimicrobial resistance has been labeled deadlier than malaria, tuberculosis, and HIV/Aids combined.

House crows are also a financial burden, particularly in the tourism sector. “The crow is ruining many tourists’ experiences at the coast,” says Florian Biziene, Manager of Ocean Sports, a five-star hotel in Watamu.

Biziene recounts tourists enjoying outdoor meals only to have crows swoop in to steal food. Some hotels now employ guards solely to ward off crows, but this solution adds to operational costs. “The sight of someone walking around with a catapult to scare off birds isn’t the image we want to project to visitors,” Biziene says.

Similarly, Maureen Awuor, General Manager of Ocean Beach Resort in Malindi, highlights how crows harass young guests, particularly children, to snatch food. “They’ve become an additional expense. From hiring guards to cleaning bird droppings, the cost keeps rising,” Awuor laments.

The Kenya Airports Authority (KAA) also views the house crow as a threat. “These birds pose a risk of in-air collisions for planes,” says Harrison Machio, KAA’s General Manager for Operations and Safety.

“A bird weighing just a few kilograms can cause immense damage to aircraft, particularly the engines or other systems,” he adds.

KAA has deployed personnel to chase crows away from airports in Malindi, Lamu, Mombasa, and Diani, but Machio admits that living scarecrows aren’t enough.

The coastal community’s desire to rid itself of house crows is clear. In Part Two, we explore the eradication strategies and their potential impact.

This story was produced with support from the Internews Earth Journalism Network.