Dirk’s Blog: 13-03-2022

The story I’d like to share today involves a seabird that I think needs a little introduction.  Sulidae are a distinct family of large, streamlined, plunge-diving seabirds. This family divide into gannets and boobies. Gannets are found in cooler climes.  They are common around Cape Town, often seen following the fishing boats as they come into our local harbour in Hout Bay.  Boobies are found in the warmer tropics. We too, can currently be found in the warmer topics. Since first seeing and identifying these birds, we have all become huge fans of boobies (see why I had to introduce them?). In our case we get to see Sula leucogaster, or the Atlantic Brown Booby. They first caught our attention due to their amazing flight.  They are indeed large, larger than common gulls with a spindle shaped body which is much shorter that their wingspan.  Depending on age and moulting stage, their plumage differs in detail. Their beaks hooked at the tip, which is one way to tell they are not gannets. But back to their flight.  That wingspan is large and they hardly move their wings are they dip and dive and glide between rows of rolling swell. They seem to be deliberate in gliding in the trough between two peaks and then glide up along a wave surface where they catch the wind as it skims off the top of the wave. Suddenly they gain lift, shoot into the air only to dive down and repeat this again and again between waves.  One can watch this for hours.  

I believe they dive to catch their prey of small fish and squid. But there is a more spectacular performance from these birds. For every top class contest, one needs at least two participants: enter the flying fish!  These fine fellows have been delighting us with their aqua-aerial acrobatics since we entered the tropics.  About the size of a mackerel or kipper, coloured blue and white, and streamlined as an arrow, these fish have over sized pectoral fins.  These fins give them their capacity of quasi flight.  We have seen them either solo or in small schools as the launch themselves out of the water, glide for what seems like forever, and then splash into the waves like silvery darts.   If you watch them carefully, you can see that they either spread those pectoral fins like a wing to achieve "lift" and remain airborne. But at times these fins seem to be moving at a ferocious pace, seemingly propeller-like. Is this an attempt at flight propulsion?  And linear flight is not their only trick.  As they reach the surface of the water and they need to change direction, they dip their tail fin into the water, flick it and they turn close to right angels. It’s amazing to watch. Likewise, they can extend the length of the flight in a straight line by employing the same trick.  I image they use this ability to escape from aquatic predators.

Now that the scene is set, let's get to the spectacle.  We had had flying fish all around the boat for most of the afternoon. Soon enough a booby appeared on the scene and I started to suspect what it was after. And sure enough, the bird started to eye up the next small flight of flying fish as they shot across the rolling swell. The booby did what they do, flying along the waves and as the next flying fish shot across a wave it was after the little dart in a flash. The flying fish vanished in the wave but the booby must have spotted a school of them just below the surface. The booby skimmed along the water and agitated the water with it’s web feet, which must have frightened some of the flying fish. A moment later, two of them shot out of the water and now the booby was ready. As the fish glided through the air the booby shot after the trailing fish and caught it mid-air in its beak, and swallowed it down. By the time we saw the booby turn, there was nothing to be seen of its fast-food meal.  Not even Snoekies, our local chippy in Hout Bay, can deliver fish that fresh that fast. 

We were all cheering for the sheer brilliance of the performance.  Nature is a spectacle.  One must only be out there to see it.

I must confess, after the less than ideal first week of March, this display and other little wonders have done a lot to improve our mood. As did the much improved rowing conditions, warmer weather and calmer seas. AND, Stef saw a shark. Right next to our boat.

We are now able to cover 1 degree longitude per 24 hour period. Our destination is at 52 degrees west and we are currently at 35 degrees... I will leave the maths for you all to do.

Lots of regards from a happy and healthy Forget-me-Knot Crew!