April-September, Okavango Delta Flood
Located at the northern edge of the Kalahari Desert, The Okavango Delta is the largest inland delta in the world. This occurs where the freshwater flood flows inland, rather than out to sea. This year, the flood levels are unusually high, covering around 10,000 square kilometres of land in northern Botswana, an area about the size of East Anglia. The flood allows the delta wildlife to flourish, including fish eagles and kingfishers, which breed during the flood season. Hippos, elephants, warthogs and crocodiles can also be found in the delta area.
The flood creates a number of islands, small and large, which are accessible by boat, and good for wildlife-spotting. An ideal base is the Jao Reserve, west of Mombo, and there are many safari camps in the area. For details, contact Botswana Tourism (01344 298 982; www.botswana.co.za)
AFRICA, ASIA, EUROPE
8 June, Transit of Venus
The transit of Venus is one of the most important dates in this year's astronomical calendar. Half the globe will, with the aid of a sun filter and providing the Sun is not obscured by cloud, be able to watch Venus moving across the Sun. The planet will appear as a black spot crossing the Sun, over a period of about six hours.
The transit will occur as Venus passes in between the Earth and the Sun on 8 June, much like when the Moon eclipses the Sun. This is a rare event, with an average of four Venus transits every 243 years, the last occurring in 1882. The best viewing time will be in the morning, but the transit will take place for much of the day. For more information on viewing the transit: www.transit-of-venus.org.uk
11-12 August, Perseid Meteor Showers
A full moon disappointed astronomers looking out for the Perseid meteor showers last year, but this year things look hopeful. Anybody with access to a clear, dark sky (outside of cities) should witness the event. Perseids are debris shed by the disintegrating comet Swift-Tuttle, usually at a rate of one a minute. Every August, the Earth's orbit takes it through the debris. This year, strong displays are predicted as the Earth passes closer to the centre of the debris. The best places to view the shower will be in the countryside in Europe and Western Asia from 2am until dawn. For details: www.theastronomer.org; or www.space.com/scienceastronomy
September-November, Monarch butterfly migration
The biannual migrations of the Monarch take place in various locations across the US and northern Mexico. From September to November, those in the Rocky Mountains move to eucalyptus trees on the warmer Californian coast, and those east of the Rockies travel south to the mountains of Mexico. As spring approaches, they return. They travel up to 3,000 miles, and it's a spectacular sight, like a moving red cloud. Texas is a good place to witness the migration - butterflies from Canada and the Midwest converge there and move south towards Mexico mid-October. For details: 001 785 864 4441; www.monarchwatch.org
June-July, Serengeti, Wildebeest migration
The Wildebeest migration is a spectacular sight, with more than a million animals moving northwards from the Serengeti plains of Tanzania to the Masai Mara in Kenya, stopping to graze until they have depleted the resources and then moving on. Zebra and antelope often accompany the herds. The cycle begins on the Serengeti plains and works its way north up to the Masai Mara before heading back to Tanzania. Dates are unpredictable as herds are driven by rainfall, but generally the migration moves north from the Serengeti around June and July, and south from the Masai Mara in December and January. June and July is a good time to see it as herds prepare to cross the Grumeti river in the west of Serengeti National Park. Many safari tours are organised with the migration in mind. For details: 00 27 21 481 4900; www.safari.go2africa.com
May, Westmann Islands, Puffin season
In May, Atlantic Puffins return from winter at sea to the 15 Westmann Islands, 30km south of the Icelandic mainland. It is a popular event for nature lovers, as millions of the colourful birds return to the islands to mate and lay their eggs. There are around 10 million puffins in the Westmann Islands, whose tall basalt cliffs provide a breeding ground during the warmer summer months.
A good time to see juvenile puffins is during August, before they learn to swim and take to the water in September, and the best place to view them is the Tjornes peninsula.
Many tour operators organise trips to view the birds from Heimey, the only populated island, while Vik i Myrdal, Iceland's most southerly village, is another good location.
For more information call the Icelandic tourist board on 00 354 535 5500, or visit www.icelandtotal.com