|
Steering
Committee formed in the Western Cape November 2002.
A Steering Committee was formed to address the seriously escalating House Crow (Corvus splendens) population on the Cape Flats and South Peninsula. The Committee consists of City of Cape Town Nature Conservation, Western Cape Nature Conservation Board, the SPCA, the Fitzpatrick Institute and the Cape Bird Club Conservation
Committee representatives.
History
of House Crows in the Western Cape.
-
In
1977 there were about 300 House Crows in the Western Cape.
-
A
student under Tony Williams (Cape Nature Conservation) made a study of the House Crows in
Khayelitsha and at the Cape Town International Airport Industrial site in 1997.
-
The Cape Bird Club funded part of
this project.then.
-
It is estimated
the present population has grown to about 5000. Recently observed as
far south as Fish Hoek in the South Peninsula.
Description
and habits.
-
They
originate from India, Pakistan and Iran and have arrived in South
Africa
via ships.
-
Length
about 43cm, weight 310 – 360g, Iris brown, bill, legs and feet
black. Smaller than the Black Crow. Slender build mainly shiny black
with a sooty grey breast, nape and mantle. Voice, a shrill kwaa,
kwaa.
-
They
forage on the ground, walk with a perky gait sometimes hopping. Flys
straight, wingbeats slow and shallow, performs aerial manoeuvres.
-
They
are omnivoorous; grain, fruit, nectar, birds fledglings and eggs,
small mammals, lizards, fish, insects, crabs, carrion, scraps,
offal.
-
They
compete with local bird species by attacking the adults and destroying their nests and eating their eggs.
-
The
nest consists of a large bowl of sticks with pieces of wire lined
with plant material and animal fibres. Nests are often constructed
in trees, on telephone poles and powerline poles.
-
They roost in huge flocks
in trees outside of the breeding season.
Health
risk.
-
House
Crows are a good indicator, their presence means more uncovered edible rubbish lying around,
therefore a social decline in health standards in the vacinity.
-
They spread
human diseases such as salmonella, entramoeba and giardia by eating
discarded food matter and then washing themselves and defecating in water used by humans.
-
They
often congregate at open air abattoirs and food markets and areas
where human rubbish is dumped.
-
The risk is even greater in informal settlements where sanitation facilitiess are non existant.
-
Like other birds introduced from overseas, the
House Crow is also a potential carrier of infectious diseases which could decimate domestic and native bird populations.
-
It is
regarded as an intelligent and active scavenger that stores food,
sometimes in house roofs.
They
can dominate the food chain to exclude all other indigenous species.
Protecting the biodiversity of our indigenous species is very important
to make sure our unique Cape Flats Fynbos remains for the future
generations.
|