An example of why exotic crows are bad news

To: Birding Aus <>
Subject: An example of why exotic crows are bad news
From: knightl <>
Date: Sat, 15 Nov 2003 12:56:20 +1000

Tuesday, 11 November, 2003, 15:02 GMT

Crows menace African bird life
 Daniel Dickinson
 BBC News in Tanzania

An "airborne black tide mark" is menacing the native bird life of East Africa, according to ornithologists.

The common crow is using its natural cunning to squeeze indigenous species off the centre stage. It stands accused of killing local birds in Tanzania - such as the paradise flycatcher - causing their numbers to nose-dive.

At last count there were an estimated 300,000 to 500,000 crows in Tanzania's capital, Dar es Salaam, and efforts to control them have been short-lived.

The crow arrived in East Africa in 1891, when the British governor of Zanzibar ordered their import from India. He hoped to harness their scavenging tendencies to combat the litter problem in Zanzibar's streets.

Pandora's Box was opened and the crow population spread, grew and flourished. Now their hunched Hitchcockian figures can be seen in their thousands around East Africa's cities.

Pandora's box

"The crow is not just interested in food scraps," said Fiona Reid, author of Birds of Dar es Salaam. "It also attacks and kills indigenous birds to eat, or to get to, their eggs. They have even been known to attack sick animals like goats or domestic pets."

Crows are amongst the most intelligent birds and their hunting skills are finely tuned, according to Ms Reid. "Crows often work as a team. One will chase a bird away from its nest by swooping aggressively at it, leaving the way open for the second bird to steal the egg," she said.

This entrepreneurial flare is taking its toll on the indigenous bird life of East Africa, driving many species from their natural habitats.

"The effect on indigenous birds has been drastic," Fiona Reid told BBC News Online. "Numerous species, such as the African paradise flycatcher and many sunbirds, have virtually disappeared from Dar es Salaam gardens."

The situation is worsening rapidly. Crows are working their way further inland, feeding off the rubbish that East Africa's growing human population is producing.

Baited traps

Sadly, the history of crow control is not as remarkable as the history of crow expansion. In Tanzania there have been a number of small-scale attempts to cut their numbers, but the initiatives have not been maintained.

The Wildlife Conservation Society of Tanzania (WCST) is orchestrating the anti-crow efforts. At the end of the 1990s, the society mounted a concerted extermination campaign using traps.

The menace terrorises local birds

We had 80 traps across the city at hotels, restaurants, hospitals and social clubs," said Annette Mwyakimi, of the WCST. "We were catching and killing over 1,000 crows a week."

In 1998, the WCST managed to reduce the crow population in Dar es Salaam by over 32,000.

"People from all walks of life told us they could see a big difference, even though the actual crow population had only been cut by about 10%," said Annette Mwyakimi. "They told us they could hear other birds sing for the first time."

Despite its early success, the trapping scheme has been neglected. Many traps have fallen into disrepair and the crow population is beginning to swell dangerously again.

"The crows are encroaching from all corners of Africa," said Ms Reid. "They have been recorded in Cape Town and Durban in South Africa as well as in cities along the north African coast."

Birding-Aus is now on the Web at
To unsubscribe from this mailing list, send the message
"unsubscribe birding-aus" (no quotes, no Subject line)

<Prev in Thread] Current Thread [Next in Thread>
  • An example of why exotic crows are bad news, knightl <=

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU