Alan,
I would echo Mike's advice.
Car hire is a non-starter & whilst taxis are cheap & would seem a good option you will get the daylights hounded out of you if you go out birding alone. It is better to pay for a recognised birding guide to take you out.
If staying in a Kololi hotel (Kairaba, Senegambia) then the hotel gardens will provide excellent birding most mornings.
If staying at Kotu then walk to the Kotu bridge & hire a birding guide there for one of your days.
Spending a day at Kotu (the creek & the cycle track) which includes a visit to the golf course & Kotu ponds (the sewage works) will give a very good range of birds.
Hiring Modou Colley for a day trip to Pirang (Shrimp farm) & the Faraba Bush track would be an excellent move. This area has the potential for some excellent birding if accompanied by a good guide. Pirang holds an elusive pair of Black Crowned Cranes which are not always reliable but the site holds a wealth of other waterbirds, raptors & small passerines. If you go try to ensure you enter the shrimp farm (which is currently not operational) -the gate is locked but can be easily negotiated. You may have to walk for 20 mins in baking heat to reach the back pools but it will be worth it -expect 2 species of Pelican, Gt Flamingoes, Yellow-billed Stork, African Spoonbills, Great/Intermediate/Little/Black Egrets, Western Reef Heron, Striated Heron, White-faced Whistling Ducks, Pied & Malachite Kingfishers, various waders, Quailfinch, Bishops, etc.
Faraba Bush Track is excellent for raptors including Brown, Beaudouin's & occasionally Western Banded Snake Eagles as well as Long Crested, Wahlberg's & occasionally Martial Eagle. Other birds should include 3 Roller species, lots of passerines and possibly Sandgrouse at dusk.
To give an idea of what to expect all the following images were taken at Pirang or Faraba.
Please let me know if you need any other info or want to contact Modou (his website is:
http://www.gambianbirds.com/ )
