The Cape Bird Club

Lourens River Estuary– Tern roost at risk   by Jo Hobbs

photograph by Marilyn Scholtz

The evening filled with terns coming in to roost on the beach.

Promerops No 267 (August 2006)

Conservation dilemma – Tern roost at risk

On 29 June 2005, Kalle Hiekkanen had spent the whole morning ringing Common Terns at a nesting site at Äänekoski, central Finland. The day was beginning to warm up, and in this beautiful lake-studded region the mosquitoes can be fierce in summer. He was ringing a young bird just out of the nest and nodded to his companion, "Se on sitten viimeinen tälle päivälle”.* The ring number was AT199363.

Just after sunset on 20 January 2006, Gordon Scholtz was capturing and ringing terns at a roost site on the beach at Lourens River Estuary, Strand (40 km east of Cape Town, on the False Bay coast). It was a warm summer night, and a lucky one for him as he recovered and recorded no fewer than four Common Terns that had previously been ringed in Finland. One of these was AT199363, a tern which had flown over 10 830 km on its first flight. And only a few months previously this beautiful bird was an egg lying on the shore of a lake in Finland! Of the other birds recovered on this day, one was three years old and two others were between 6 and 7 and had already made the same return journey no less than six times.

None of these birds, or the five others recovered by Gordon during the same summer ringing season, had been ringed in the same area in Finland. Others recovered had previously been ringed in Estonia. So what is it that attracts so many of them to converge at the Lourens River Estuary? 

The answer is simple. No people.

The whole beach area extending from the Lourens River Estuary (Strand/Somerset West), westwards for a kilometre through AECI to Denel and Macassar, has been undisturbed since the days of Cecil John Rhodes – in other words, for over a century! This was a restricted area due to the establishment of AECI, an explosives factory (a National Keypoint), which at one time was the largest in the world.

Internationally important bird area

This Estuary is of international importance because between 10 000 and 20 000 Common and Sandwich Terns arrive early in December each year, mostly from Finland, Estonia and other Balkan countries, and use this area as their roost. They remain here for about four months. In addition, several pairs of endangered Black Oystercatchers nest on this beach. As you can see from the photographs, the sight of terns arriving at their evening roost is quite spectacular.

The land adjoining the estuary, owned by AECI, is scheduled for development and is currently undergoing decontamination. The developers, Heartland Properties, (property wing of AECI) are planning to put up some upmarket housing on the land adjacent to the Lourens River Estuary, with access to the beach and estuary. However, we are assured by Alan Penfold, chairman of the Lourens River Conservation Society that there will be no development on either edge of the estuary as the river is gazetted as a Protected Natural Environment. Further low cost housing and some factories are also planned for the remainder of the land, extending almost as far as Macassar.

The actual beach land is known as Farm 790 and is owned by the Government and it will presumably be sold to AECI (Heartland Properties) once the decontamination process has been completed. While the explosives factory was in operation, this was a high security area and constantly patrolled to prevent any access to the beach. The fencing is still there, but it is no longer properly maintained, and if the land is sold it will be difficult to exclude the public from the area and prevent disturbance to the terns, especially as their presence coincides with the summer holiday season.

photograph by Marilyn Scholtz

The wet beach of the Lourens River Estuary is a magnet for migrant terns in summer.

The dilemma facing conservation bodies is how to balance the conservation of this precious area with the recreational expectations of an expanding human population. Is it too much to hope that some compromise can be made, as was done when Simonstown was “invaded” by nesting African Penguins at Boulders Beach? The matter is being followed up by the Western Cape Birding Forum, who will be discussing it with CapeNature officials and BirdLife SA.
(We hope to arrange a viewing of the Splendid Tern Spectacle some time in December, so have your cameras ready.)

Thank you to Gordon Scholtz for his ringing returns, Marilyn Scholz for the superb photos, Jill Mortimer of the Somerset West Bird Club for the background information, and Sini Beckley for the Finnish flavour.

* “Let’s make this the last one for the day”. Of course we can’t be quite sure this is what he said – it might have been “Ja sitten kaljalle!” (Let’s grab a beer!)