by Richard Bland
Herring and Lesser Black-backed Gull populations have been expanding in Bristol since 1970 when the first pair bred in Hotwells, and are increasing in the Clifton area. In July they can be aggressive to people and pets as they seek to protect their very vulnerable young as they learn to fly. The Council is trying to reduce population growth by the use of plastic eggs in nests on accessible roofs, with some success. The Gulls essentially thrive because we leave masses of waste food from fast food outlets on the streets, and cafes still leave food waste out in plastic bags over the weekend.
Clifton has a wealth of mature gardens and the structure of its bird population reflects that. Since 1994 there have been two regular annual British Trust for Ornithology Breeding Bird Surveys that monitor the population change of local species. They have shown some startling changes, including a steep fall in Feral Pigeons, and rise in Wood Pigeons, the rise and then fall of Greenfinches, the collapse of the Starling population, a fall in the Jackdaw colony round the Suspension Bridge, and a fairly stable population of most other common species. These changes are in line with national events.
The cliffs of the Avon Gorge provide an eyrie for Peregrine Falcons. They arrived in the Gorge in 1990, since when over 55 young have been reared from the site. They can often be seen flying over the Village with their young in July. They sometimes use the Wills Tower of the University as a roosting site in winter. Kestrels and Jackdaws also nest on the cliff face. Feral Pigeons nest in some of the rock fissures as their remote ancestors, the Rock Doves, did and they form a ready food source for the Peregrines. Another cliff-nesting species is the Raven, which arrived with the Peregrine, and can also be heard flying over the Village giving its deep-throated call. It usually nests on the Somerset side of the Gorge, but has also used the Downs water tower.
There is a pair of Sparrowhawks in the village. Buzzards nest in Leigh Woods and are often seen on the woodlands of the Downs, though breeding has yet to be proved. The Zoo was one of the very earliest sites for Collared Doves in the 1960s and for a time it supported a substantial winter roost, but since those days they have spread to every area of the city and region. Their local population peaked in 2002. The Zoo pond is one of the few sites of open water in the Village, and Mallard fly into it from the Avon, and breed there. It also supports wild Moorhen.
The mud of the Gorge is much cleaner than it used to be and so less used by Gulls and Crows, but wading birds can still be seen, especially in cold weather in winter. There have been Redshank and Lapwings under the Suspension Bridge, and parties of Black-headed Gulls as well as Mallard can usually be seen. Cormorant fly along the Gorge on their way to feed in the City Docks or the New Cut. As many as eight have been seen together. Herons are often on the mud as well, but also raid garden ponds in the early dawn in March and April.
In September and October during migration, Swallows and House Martins, which are never normally seen in the village, fly over and Meadow Pipits and Skylarks can be seen over the Observatory.
In winter Clifton has a large population of overwintering Blackcaps. This species is now a regular winter visitor to Britain from south Germany, and is an example of micro evolution at work. Individual Blackcaps sometimes become resident in a particular garden between December and March. They especially enjoy fat balls, but will feast on berries first. Pied Wagtails are usually a winter visitor, though they are sometimes seen feeding their young on Clifton Green. Flocks of Chaffinch can be seen on the Promenade when it is a good beech-mast year. Goldfinches are increasingly seen in gardens if Nyger seed is provided. Redwings are common in cold spells, and will first strip Pyracantha, Holly and Hawthorn berries, and then take the Himalayan Cotoneaster. In warm days in March they can be heard in the trees on Clifton Green burbling their strange song. Fieldfare are much less frequent, but are driven in during cold snaps.
Much has changed since 1935 when the delightful booklet was published on the Birds of Clifton Downs by an eighteen-year-old resident, Averil Morley but, surprisingly, much has also remained the same.