I had one of the most breathtaking experiences of my life just a few months ago. I was in Kenya’s Amboseli National Park with Lulu, my wife, and we could see the magnificent snow-capped peak of Mount Kilimanjaro.
But it was something closer to us, in the foreground, that was truly astonishing – a vast swarm of hundreds of thousands, even millions, of European swallows flying over the wetland and feasting on a huge hatch of flies.
There were also a few swifts and house martins thrown in for good measure.
I call them European swallows because these wonderful birds spend their summers in Europe, including Britain, where they are an unmistakable sign that the warm weather is on its way.
In recent days, a troubling question has been asked with ever-greater concern from one end of the country to the other: where are all the swallows this year?
They come here after undertaking an incredible, hazardous journey over deserts, mountains and seas so that they can use our long hours of daylight to breed. All they need are plentiful insects to feed on, and copious supplies of mud for nest-building and repairs.
But in recent days, a troubling question has been asked with ever-greater concern from one end of the country to the other: where are all the swallows this year?
There are none on the small farm in Cambridgeshire where I was born, and where I still live and work. There have been swallows on the farm for most of my life and when I was a boy, their nests got well into double figures each summer.
Over recent years we have had just three or four. And today, there is no sign of them in my yard.
Three years ago a neighbour with horses – which mean flies, which equals swallow food – had 14 nests. So far this year, he has none.
Other contacts around the country have the same dismal story – from the Isles of Scilly, Wiltshire, Oxfordshire and Norfolk, to East Yorkshire, the Isle of Man and the Scottish Borders.
They all believe that swallow numbers have plummeted. Worryingly, the RSPB says they should start arriving in March, and now it’s May.
The only promising news is from Dorset and Monmouthshire, which seem to have good numbers.
(House martins are only just arriving so it is too early to judge if they, too, are in trouble, while swifts are due any time now.)
So what has happened and why?
Our migrating birds are being ‘harvested’ in huge numbers as they fly south in the autumn and north in the spring
The simple truth is that our migrating birds are being ‘harvested’ in huge numbers as they fly south in the autumn and north in the spring, and many of our conservation charities have not yet caught up with the horrific consequences.
Trapped in cheap Chinese mist nets slung between tall poles, millions of our summer visitors are being caught, sold and eaten.
Accurate figures are hard to find, but up to 140 million birds a year are being slaughtered as they pass through just one country: Egypt.
A investigation by German TV estimated that mist nests are erected along 700 kilometres of the Egyptian coast and in the Nile Valley, capturing a range of birds from the stunning golden oriole to the tiny but beautiful willow warbler.
There is similar bloodshed in Lebanon, Morocco and in most of the North African countries. Of course, people the world over catch and hunt birds, animals and even insects. Since the time of the pharaohs, migrating birds in north Africa have been caught and eaten using primitive traps and quick-lime – a sticky substance smeared on vegetation and buildings to hold down any birds attempting to perch and rest.
But things today are very different. Bird-catching has gone beyond a sustainable level and is carried out instead on an almost industrial scale, thanks largely to the fine-meshed, readily available and astonishingly cheap plastic netting manufactured in China.
Trapping birds has become like fishing in the air rather than in the sea.
Even if the swallows and swifts do manage to avoid the nets, they are also shot at. Then, if they pause to rest in any oasis they pass, there is the danger of the quick-lime.Shrikes, warblers, cuckoos, flycatchers and wheatears are all vulnerable. Some are not even killed straight away; they have their wings broken and are taken alive to traders, who slit their throats to satisfy halal tradition. Then they are sold for the equivalent of a few pence.
Accurate figures are hard to find, but up to 140 million birds a year are being slaughtered as they pass through just one country: Egypt
And, while these birds might seem tiny in comparison with chickens or turkeys, there is a hungry market.
Quails, for example, can sell for up to £5 a time. The beautiful golden oriel has traditionally been regarded as a natural form of Viagra. Even the smallest birds can be stuffed with exotic herbs and sold to restaurants.
I am particularly concerned for the willow warbler, one of my favourite birds.
For many years its tumbling, liquid call accompanied me in the early morning as I walked out to check our calves and lambs. We still have birdsong – robins, great tits and blackbirds – but there’s been nothing from willow warblers for four years now.
It’s possible that they’ve been disrupted by a natural force, a storm over land or sea, for example. But it is just as likely they were netted and that their traditional journey to our farm has been broken for ever.
The Chinese bear an important share of the blame. Even at the best of times, they are environmentally illiterate.
They should stop selling nets to countries that misuse them.
Before we smugly blame the decline of the swallow and the house martin entirely on the ignorance of rapacious overseas hunters, however, it is important to recognise the part that we in Britain play, too.
Bear in mind the huge loss of insects through the overuse of insecticides in our gardens and on farms. It is a tremendous concern. And people who use nets to prevent birds nesting at their favoured sites are a plain embarrassment.
Sadly, many British farms and homes are now too clean and tidy for nature. Incredible as it might seem, there are still people who illegally smash the mud nests of house martins as they try to build them on house walls and under eaves.
On my farm I go to the other extreme. I have a mud puddle for any swallows or house martins that might want to use it for nesting material.
So we should all strive to make Britain as hospitable as possible for our superb summer visitors. There is a lot of work to do.
But, more than that, the international community should name and shame the countries that are allowing an ecological disaster to unfold.
In many parts of Britain we have already lost the summer sound of the cuckoo and the turtle dove.
It is time the terrible hazards facing the swallow, the house martin and the willow warbler were also tackled head on, before it is too late.