We know of no tours planned to Mauritania.
There are no birding guides known in Mauritania.
There are regular flights to Nouakchott from Paris and to the African cities of Casablanca, Algiers, Dakar, Bamako, Banjul and Abidjan. Air Mauritanie runs regular internal flights to Nouâdhibou, Atâr, Néma and several other towns. Bush taxis and trucks cover all the major routes but the roads are often bad and the trips slow and long. Hire cars are expensive, but are available in Nouakchott. There is a train which connects Nouâdhibou to Zouérat. There are crossing points over the Senegal River including a ferry at Rosso.
For more information see Lonely Planet.
Driving is possible through some of Mauritania, but it is advisable to take a guide especially when venturing inland or along coastal tracks. Many tar roads have been covered by sand and a knowledge of deserts, winds and even tides is required.
Most safety and health issues are no different from those in many African countries. Guidebooks, travel companies and websites provide much of the advice one needs, but key points warrant repetition here: (1) although not likely to be present in this part of Africa, be aware of the risk of malaria and seek current advice, sleep in a sealed tent or under a net and take prophylaxis as recommended; (2) always ensure you have sufficient water and some method of purification (even if this comprises a pot and a campfire for boiling); (3) do not underestimate the danger of being in the sun for too long, ensure you use sun-block, drink plenty of water and wear a hat; (4) although the prevalence is low in this part of Africa, be aware of the general risk of AIDS; (5) ensure that you take a reasonably-equipped first-aid pack with you including supplies of hypodermic and suturing needles. See the following website or your own embassy website for safety and travel information: US Travel and UK FCO.