They've come north into the Masai Mara National Reserve from the drier Serengeti in Tanzania.
From the end of October they'll begin their return journey from the Masai Mara to complete a round trip of about 2000km.
The animals are attracted by the flush of oatgrass growth. They also come to give birth to their young. But this is big-cat country, too, and these predators welcome this annual feeding bonanza.
Crocodiles watch the herds crossing the Mara river and grow fat on hapless wildebeest and zebra. Vultures and eagles wait to clean up carcasses.
My day has begun at Governors' Camp, one of a number of safari camps in the 1510sq km reserve, at 5.30am when I'm woken with a cup of another great Kenyan product, coffee.
My three-night home is a luxurious tent, with en suite bathroom, that wants for nothing in comforts - except, perhaps, electricity. But then we are in a remote part of Kenya.
By 6am I'm showered and dressed. It is not yet dawn. A safari truck awaits to take us to the launch site. I'm beginning to feel like an astronaut preparing for a space trip.
Here there is more coffee and a briefing from our pilot, Englishman David, while a ground crew of some 25 help prepare in the soft pre-dawn light three rainbow-coloured balloons for launch. The pilots send up a small balloon to test the wind drift.
"It looks good for today's flight," David announces. "We'll probably be taken over the Mara river."
He selects his 16 passengers and divides us so that our weight is roughly evenly spread around the balloon's basket. We climb in. He gives the gas flame a squirt or two and we gently lift off as the sun starts to make its way over the horizon.
I wondered how my poor head for heights would behave. But maybe it was the excitement of the ride or the fact that we were drifting only just above the trees, but I felt no unease.
The wind carries us at a gentle pace.
In the trees below we spot some giraffe. We fly over a dead tree within metres of a flock of vultures waiting for the first kill of the day. And, sure enough, there is the river.
There's a pod of hippos enjoying the cool water. And now we have left the woodland behind and are over the grasslands. We see countless grazing wildebeest. We see, too, a couple of lions on the prowl. We see elephants, gazelles, impalas - entire zoos-worth of animals.
For the next hour, eyes and cameras are working overtime to take in the stunning panorama of the Masai Mara in early morning. The silence is broken only by the occasional whoosh of the gas burner heating the air in our balloon and regulating our height.
We are seeing wild animals as they are meant to be, wild.
It is totally unscripted, unpredictable. Life goes on here as always: we are simply close-up and privileged onlookers. All too soon the flight is over.
We've covered more than 14km as the crow, or balloon, flies.
David has briefed us on a landing. Nine times out of 10, he says, the basket in which we are suspended will tip over on impact. Fortunately, there are dividers and we won't all fall in a heap.
When the landing does come, we have slowed to a walk. But we do tip the basket. With much laughing we extract ourselves like letters being plucked from a mailbox.
Finally on our return to earth, we are treated to a time-honoured, traditional, hearty champagne breakfast cooked right here on the plains of the Masai Mara.
Oh, and if you want the proof that I had the courage to take a balloon flight, I have the souvenir photograph to show.
CHECKLIST
Getting there: Cathay Pacific has daily flights from Auckland to Hong Kong. In Hong Kong, Cathay Pacific flights connect with Kenya Airways flights to Nairobi.
Safaris: Bench International has a range of safari packages in east Africa. Typical is the eight-day Kenya Highlights safari, which includes the Masai Mara, Lake Nakuru, Amboseli and Tsavo West and Tsavo East National Parks. Prices vary depending on the season but include all transport, accommodation, meals and game-viewing drives and park fees. Safaris can be tailor-made to include any destination in Kenya and neighbouring Tanzania.
Hot air ballooning: See Governors' Balloon Safaris.
David Potts was a guest of Kenya Airways, Cathay Pacific Airlines, Bench International and Governors' Balloon Safaris.
- AAP
