CWAC CWAC
Although this Conservation project has been in operation for almost 33 years , my involvement has been for just over 24 of them.
Over the years I have seen massive changes to the Botrivier Reserve in terms of water conditions, land development (Benquela Cove) which must be a huge contributor to the changes that have occurred as well as more boating activity in the estuary, in respect of bird numbers and species .
On many occasions I have remarked at the dwindling numbers and must be of great concern to S A Birdlife and the conservation Scientist.
The start of the decline was when Cape Nature decided to Blow the Mouth artificially back in ca 2005.
That is when red-knobbed Coot started to disappear from the estuary in large numbers (talking thousands of birds). To-day we are fortunate if we actually count any coot.
Grebes have gone the same way, as well as duck species. We are only really seeing Yellow-billed Duck in small numbers. This can only be attributed to the lack of food source and the water conditions which now prohibit the grasses etc. that these birds feed on and use for nesting material. However, this has still not been scientifically proven. Just my observations.
Back in 2001 the Coot count was in the 10’s of thousands as well as the Grebes which were present in large numbers. Today, these numbers have dwindled to almost ZERO”s.
When do we start worrying that they will disappear from this waterbody for ever????
Kevin Drummond-Hay
Co-ordinated Waterbird Counts
Since July 1993 the Tygerberg Bird Club (TBC) has done Co-ordinated Waterbird Counts
(CWAC) on a regular basis at Botriviervlei. The standard protocol requires counting in
Summer and Winter but, from time to time, counts are done at a higher frequency for specific
purposes. The counting teams comprise mainly TBC members together with some birders
from the vicinity of Kleinmond and Hermanus.
For CWAC purposes Botriviervlei is divided into six sections: A1, A2, B, C, D, and E. Species
counts vary with the seasons and, in particular, breaching of the mouth. Breaching can occur
naturally as a result of high rainwater inflow. However, given the varied interests of
Conservation, birdwatchers, fishermen, Department of Water Affairs and others, CapeNature
implements artificial breaching according to a management plan.
CWAC Data and Purpose
The data is submitted for inclusion in a database that is maintained by the FitzPatrick Institute
of African Ornithology. Anybody wishing to view the data for any CWAC site in the country
may do so by visiting the website http://cwac.birdmap.africa/. Click on “Sites – List”, select
Province, scroll down and select the desired site. This will open a new browser tab displaying
a list of species found and show Min / Avg / Max counts for each.
To view a list of count cards, in the header towards the top of the page, select “View Cards”.
This will show card numbers, dates, season and other information. Clicking on a card number
will open a new tab and display information for that particular count.
CWAC data acts as a long-term waterbird monitoring tool, benefiting conservation efforts,
planning and research purposes. It feeds into the African Waterbird Census Programme and
international agreements such as Ramsar.
BOT RIVER ESTUARY- 30 YEARS of ‘Counting Water Birds’
What is CWAC’ing all about? It is not just the sound ducks make but an extremely important Citizen Science Project which has been on-going for the last 30 years conducted by dedicated members of the Tygerberg Bird Club and stalwart assistance from the Overberg and Helderberg Bird Club members. We salute you!
John Philogene, the late Mariana Delport, who later co-ordinated these CWAC’s (Co-ordinated Water Bird Counts) right up to the time of her early illness in 2018 when she retired to her home town, the late Margaret McCall, who dragged me kicking and screaming to my first CWAC in 2001, injecting me with a birding bug for which there is no antidote but is addictive. You keep having to get a fix, so out you go and find more birds, commune with nature and then the fever passes for a short while until the hunt for new birds, starts again. Earlier, I alluded to the sound ducks make, a sound that has sadly diminished over the years at the Bot River Estuary.
Ducks like many other species of water birds have been disappearing in numbers from this water body. How do we know this? The citizen Scientist of course, far too many to name here individually but who gladly give up their time, family obligations and weekends, taking part in the (CWAC’s), which initially was twice a year , then monthly after the mouth was breached artificially to determine the effects of this and currently now four times annually.
These are people who are committed to this project, providing a data base like no other, our own Rodney Gray and his best half, who not only leads a team at the counts but also meticulously collates all the data from the other teams, and spends hours checking and submitting the data to the ADU (AvifaunalDemography Unit) who then store and provide the collective data for Scientist and graduates writing up scientific papers and theses for their own projects. These Scientists are the people whom we pin our hopes on to solve the ecological problems of the Estuary and hopefully one day we will see water birds in huge numbers return to this wonderful water body as it was in the early days of the late 1990’s and early 2000’s.
Mouth breaching was circa 2004 and we surmise was the root cause of many of our bird species abandoning their traditional breeding and feeding ground.
But, then again, CWAC’ing is not just an information gathering exercise, it is the antidote to the birding bug virus, getting your fix, seeing and counting birds and communing with nature and most of all enjoying the great outdoors.
Kevin Drummond-Hay
