The River Thames around Tower Bridge is a typical central London stretch of the river, surrounded by a diverse array of buildings, both modern and historic, and little greenspace nearby. The Thames Path runs along the south bank for most of this section, allowing free access at all times. It has to be said that this is not a patch which anyone would travel to specifically for birdwatching - the range of birds on the river here is far lower than further upstream around Barnes or downstream - but it provides somewhere where there's a chance of a good lunchtime find for those of us who work in the area. There are always gulls to look through - enough Black-headed and Common Gulls between autumn and spring to keep hopes of a Med or Ring-billed alive (though none have yet been found), while the ever-present large gulls include an occasional Yellow-legged (and one Caspian just upstream at Blackfriars). Cormorants are numerous, Coots and Moorhens resident and Great Crested Grebes occasional, but waterfowl are restricted to Mallards, Canada and Greylag Geese and Mute Swans. A very occasional wader, such as Dunlin, Redshank or Oystercatcher, may fly through, but the area is too heavily disturbed for them to stop. Passerines are scarce, particularly since the refurbishment of Potters Field Park, which led to the destruction of a dense shrubbery which still had House Sparrows, as well as breeding Robin, Blackbird, Dunnock, Wren and Song Thrush, and attracted an occasional migrant warbler in spring or autumn. A young Peregrine used to perch regularly on Tower Bridge a couple of years ago, but sightings of any raptor are far from regular recently. Not the world's most inspiring patch, but a Leach's Petrel during the wreck of December 2006 and a couple of Kittiwakes during 2007 show that even the unlikeliest patch can come up trumps now and again!