I lived in Arusha for 4 years. We would head out on safari at all times of the year and were never "skunked" of great wildlife sightings.
March is the start of the "off season" as the long rains approach, mostly in April. However, the long rains are not as they sound (they are just longer than the short rains in December) and consist of two or three thunderstorms per day. I clearly remember a day out on the Serengeti when we could count seven thunderstorms in our 360° view - spectacular! It was also on an "off-season" April safari that we saw the "big five" (elephant, Cape buffalo, lion, leopard and the most difficult, rhinoceros) in one day - a rare occurrence at any time of year. With the rains, wildlife becomes more spread out as there is good grazing/browsing everywhere. However a good guide will know where to look.
If you want to email me, I can recommend some outfitters/companies in Arusha if you are booking your own way from Europe or North America. Most people go with companies from the west, but know that they simply subcontract their safaris to local companies as one can often see by the magnetic logos on the trucks!
"Must see" places include:
- Tarangire National Park (Tarangire Safari Lodge is a must in itself - classic Africa without the glizt);
- Lake Manyara National Park;
- Ngorongoro Crater Conservation Area;
- Serengeti National Park.
These are all on the "Northern Circuit" and are the places everyone gets to as they are truly spectacular. Also along the way is Oldupai Gorge where the Leakey's did their early hominid diggings. (BTW, it's spelled with a "p", not a "v" as you will learn from Olle Moita when you are there). Consider also a safari that flies you into the Serengeti then drives you out over the next week or so with Ngorongoro, Lake Manyara and Tarangire along the way (or drive in and fly out). The flight itself is worth the price of admission!
Other places to consider (depending on how long yo have and your budget) are:
- Arusha National Park (we call it Giraffic Park) has great birds, a moist forest ecosystem and just about the best views of Kilimanjaro from Momella Lodge and further up at the look out; also has great guided walking safaris
- the spectacular Rift Valley north of Mto wa Mbu (Mosquito Creek) to Lake Natron with the volcano Oldonyo Lengai (amongst others)
- a trek up Kili - if you do that then give yourself a good 5 to 7 days for the best chance of success (and photos);
- the landscapes around Lake Eyasi (between Ngorongoro and Lake Manyara) may also be worth a day or so with cultural stops to visit the Hadza people.
I could go on an on... if you have any questions, drop me a message or email. Tanzania has the wildlife, the landscapes and wonderful people that could any photographer busy for years!