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Wednesday, 12 September 2012

The darling buds of Spring

A bird in the hand is a certainty, but a bird in the bush may sing. 
- Bret Harte 


South Africa is famous for its sunshine. A subtropical location, moderated by ocean on three sides of the country and the altitude of the interior plateau, account for the warm temperate conditions so typical of South Africa – and so popular with its foreign visitors.

It's a relatively dry country, with an average annual rainfall of about 464mm (compared to a world average of about 860mm). While the Western Cape gets most of its rainfall in winter, the rest of the country is generally a summer-rainfall region. At the same time, temperatures in South Africa tend to be lower than in other countries at similar latitudes – such as Australia – due mainly to greater elevation above sea level.

September is the beginning of spring in South Africa. There’s excitement in the air as nature starts turning green, blossoms appear on trees, insects come alive and days get warmer. There's plenty to see and do when you visit South Africa in September and October. Babies are born in the game reserves, northern hemisphere birds start arriving.


One such arrival is the Red-chested Cuckoo (Cuculus solitarius - Piet-My-Vrou) whose beautiful call can start as early as 4am in the morning and actually, I've even heard him 12 o'clock at night - calling, calling - trying to find his mate perhaps, who also made the long journey from the Republic of the Congo or Sierra Leone, Somalia? 

As we move into the summer months more and more species will arrive here to take advantage of the prolific food supply. Already the Wahlberg Eagles are back in early August. As an Intra African migrant they don’t have to travel far and are not away for long. 

Most birds, especially those that attempt non-stop or very long flights, have to build up fat reserves before hand. These fat deposits are a response to hormonal changes that in turn, are a response to environmental changes. Some birds may even double their body weight such is the demand of this hazardous journey. Journeys of 10 000km are not unusual while the longest round trip is undertaken every year when the Arctic Tern flies a staggering 50 000 km. The larger birds like raptors and storks migrate short distances between stop off points and do not need to fatten up before leaving. The Steppe Eagles that come all the way from the Russian Steppes (Palaeartic-African Migrants) arrive here in November/December. These birds tend to fly over land; they need the warm air of the thermals to fuel their flight as well as the food available only from land. Many of these birds, including the Lesser Spotted Eagles, Booted eagles, Storks and Pelicans fly in huge concentrations over Israel and Gibraltar between their nesting grounds in Eurasia and their non breeding sites in Africa twice a year. Their flight plan is longer than a sea route and man-made factors add extra risk. 

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2 comments:

  1. This is a fascinating post on bird migration, Maree. Thank you.

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  2. Glad you like it Kathryn, September is the time when I watch the return of many birds I know, can't wait for my Swallows to return!

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