[5th July was getting a bit long so here’s an addendum covering a couple of days.]
I’m used to seeing birds following moving items. Seagulls often follow tractors ploughing fields and Francine and I have watched a gang of Black Kites similarly following a tractor in France. Seagulls are frequently seen flying along behind or beside a cross channel ferry, too.
So, watching Swallows zooming about over the Cubango River beside our houseboat, the Okavango Spirit, as she was moved slowly downstream to quieter moorings away from some Shakawe music, was no particular cause for comment.
[Incidentally, the Cubango River IS the Okavango River – Cubango is the Portuguese name given to it in Angola to the north where it rises. To keep the unforgettable and potentially unpronounceable information coming, the Okavango Delta, famously without an outflow into any other water body, is known as an endorheic basin, disappearing into the Kalahari Desert.]
In the UK we are used to Barn Swallows (Hirundo rustica) migrating from southern Africa to breed in our country and other parts of northern Europe. Their journey takes about 6 weeks and the little darlings have been doing this since before the Sahara was a desert. About 10,000 years ago what we know as the Sahara Desert was lush and green with plants and water bodies. Now our Swallows are forced to run the gauntlet and cross one of the more inhospitable places on the planet.
There are, though, many more types of swallow in southern Africa that do not make the perilous journey. Those zooming about our houseboat were clearly different. Whereas ours have a deep red “face”, these were Wire-tailed Swallows (Hirundo smithii) with a russet skull cap. Just as a seagull sometimes settles on a ship, these occasionally alighted on our houseboat which, having singularly failed to track their fast flight, was the only time I could get a picture of them. I saw them first sitting on the rear platform of the boat. When I went downstairs for a shower, one was sitting just feet away on a rail outside our cabin.
As Capt. Sam moved his Okavago Spirit back up stream in two stages, our seemingly constant companions remained with us. I still failed to get one flying but I did notice that they were zooming up to the “eaves” of the lounge/dining area on the upper deck of the boat. (Cabins were below.) I slid open one of the “patio” doors and realized that the birds were actually nesting on the boat. No wonder they were following it everywhere it went.
I did see birds disappearing below the rear platform of the boat, where my first suspect had been sitting, so I’m sure they were also nesting there, just inches above the water level.