A gaggle of geese that have gone rogue are dividing opinions in Rosendal and surrounding areas.
In recent months, the birds have been spotted waddling all across the neighbourhood.
Scores of cars have had to stop to let the geese pass and numerous people have guided them back to their home at Rosendal Dam.
For many they’re a harmless sign of nature intermingling with city life.
Others despise the birds, saying they mess all over the place and cause a racket like none.
But many agree on one thing – the geese are walking around more often than before and polluted water from the dam must be the reason for this.
Toxic
Patricia van der Ross, Mayco member for community services and health, admits there is a “toxic” water situation, but the problem is more complicated than that of pollution.
The dam was built in the late 1970s and acts as a sump (a space like a reservoir that collects water) inside an old hollow quarry. It catches run-off water and seepage.
“With each rainfall both nutrients and pollutants are washed into the dam,” she explains.
“Once the warmer months set in and fresh rainwater decreases, the water quality deteriorates drastically.”
The overpopulation of birds in and around the dam has also contributed to the worsening water quality, a problem worsened by residents feeding the birds.
“Feeding of waterfowl attracts larger numbers of bird life, exceeding the population that the dam can sustain. This has a reinforcing effect on deteriorating water quality levels. The combination of decreased oxygen levels and high levels of nutrients and algae is a toxic combination and increases the risk of botulism. The cycle is merely repeated every year with winter rains washing pollutants into the dam, fortifying the cycle.”
It’s caused by a bacterium, which paralyses the birds, essentially stopping them from getting food or water. The birds often die of starvation or dehydration.
Extending foraging ranges
As to why the geese have started taking daily walks into the neighbourhood, Van der Ross says the combination of “toxic algae and high pollutant levels” have decreased the available food for birds at the dam and they’ve extended their foraging range and roosting sites. “This would unfortunately include domestic areas such as residential gardens, etc.”
Domestic geese are generally known to reside close to waterbodies for safety reasons.
She says they first received reports of domestic geese wandering away from the dam in late November 2022. Many residents spoken to dispute this, saying it has been an issue for years.
Over the years numerous birds (of many different feathers) have flocked to Rosendal Dam. Despite the fact that the dam is not a “natural” one, any dam will attract birdlife, she says.
“In a generally dry winter rainfall region like ours, perennial waterbodies are very scarce.”
The dam currently houses 13 bird species, as documented by a student doing research.
They are domestic geese, Egyptian geese, cattle egrets, common moor hens, helmeted guineafowls, sacred ibis, cape weavers, cape sparrows, reed cormorants, red knobbed coots, yellow-billed ducks, white breasted cormorants and blacksmith lapwings.
The domestic geese themselves may be the offspring of farm animals from the region or were kept by early home owners in the area, Van der Ross says.
Three other species at the dam have also started spreading their ranges, in search of food.
The Egyptian geese and helmeted guineafowl, both indigenous species, are two of them. Cattle egrets the other one.
“If (these birds are) not fed, it will fly to different sites, in search of food. They will drastically increase in numbers and become a nuisance, should they be fed, as was observed at Sonstraal Dam.”
What the dam?
The quarry in which the dam was built was in operation until the late 1970’s, when the City of Cape Town started developing the residential area.
Van der Ross says they’ve since requested site development plans to ascertain the rationale for building the dam in the first place.
Are the geese goners?
At the moment, the future of the geese remains unclear.
TygerBurger understands from a source that legislation has been the biggest constraint in removing the birds as soon as possible.
Van der Ross has confirmed they have applied for a permit to capture the geese and relocate them to a farm, where they hope they will be free as proverbial birds.
At the moment the best course of action is to refrain from feeding any of the birds and to treat them as any other wild animal.
“(Feeding) contributes significantly to their behaviour. Additionally, feeding them may also lead to unusual population growth from an unsustainable food source.
