Aimee and I found out recently that this would be our first and last year living and working in Tanzania, so we’ve decided to make the most of it, taking trips to new places as frequently as our schedules and budgets permit. This weekend it was time to head out to Mafia Island, actually a small archipelago of atoll islands offshore from the Rufiji River Delta, one of east Africa’s most important marine ecosystems. We planned to do some diving on Saturday in Chole Bay, in the storied Mafia Island Marine Park, and then search for whale sharks off the mainland side of the island. As always, I hoped to do a bit of birding on the excursion but didn’t expect to see much more than migratory shorebirds, most notably the dapper Crab Plover. 
The coastal area around our hotel had some decent mangrove and coral rag forest habitat, where I had the chance to bird for an hour on Sunday morning. Despite the heat and wind, I found a few decent birds, including the Blue-Cheeked Bee-Eater, Purple-Banded Sunbird, and Pale Batis. Although similar in behavior to flycatchers, the latter is a localized representative of a striking family of birds that includes wattle-eyes and shrike-flycatchers. Very similar in appearance, batises are all small and dimorphic and boldly patterned. I’ve seen a few species before, including this one, but I never hoped to photograph any of them, as they’re extremely active and not very confiding. This time, though, I was able to mimic the male’s clear whistling call, quickly drawing both the female and male in defense of their territory. Note the crown and breast band of both birds, key identification features that distinguish this species from the Black-Headed Batis.
The birding on the beach in front of the hotel was decent too, although I didn't see any Crab Plovers here or around Chole Bay on the other side of the island. Sooty Gull and Greater Crested Tern were common, and I noted the Dimorphic Egret a few times poking through the seaweed that had been washed ashore. Black Kites, Pied Crows, and Indian House Crows contributed further to the general business along the beach. Serious birders looking to explore the island further should consult this excellent article on birding the Mafia Archipelago.
As for the whale sharks, we were lucky to catch up with three spectacular individuals on Sunday morning, heading out after breakfast in a boat from our hotel near Kilindoni (we stayed at Butiama Beach, having purchased a package deal advertised by Coastal Aviation). In less than ten minutes from the shore, we were jumping in the water to swim with these gentle giants as they fed open-mouthed for plankton, filtering rivers of water through their gills. Aimee and I both were able to keep up with the whale sharks for a minute or two, observing the veritable ecosystem that exists around their gaping mouths, including hundreds of remoras, sardines, and other small fish. Despite being over eight meters in length, the only threat they posed was bashing us with their massive tails as they pushed past in the water.Notable birds seen: Notable birds seen: Sooty Gull, Dimorphic Egret, Greater Crested Tern, Blue-Cheeked Bee-Eater, Pin-Tailed Whydah, Pale Batis, Purple-Banded Sunbird, Collared Sunbird, Pied Kingfisher, Grey Plover, Lilac-Breasted Roller, Broad-Billed Roller, Ringed Plover.