The History of Britains Birds

by Steve Portugal

The last 3,000 years have seen dramatic changes in Britain's landscape, some brought about by a subtle warming of the climate, others by mans continuing activities. Throughout the ages, man has continuously put pressure on the environment as he has altered the landscape to make way for agriculture and urban development. When the Romans arrived they set about deforesting the land to build housing and boats, whilst in the seventeenth century the Dutch brought technology with them that enabled mass widespread drainage off all the major wetland areas, particularly in Cambridge and East Anglia.

Climate change has also played its part in shaping our Avifauna of today. During the Medieval time especially there was an ever so slight increase in the average temperature, particularly during the summer months. These slight variations in temperature effect species on the northern or southern extremes of their range, and can result in a return to Britain of many species that favour a warmer climate, whilst loosing those more characteristic of an Arctic tundra ecosystem. This has been the case in the last century, with a warming northward trend in the first half, and a colder southward tendency in the second half. With such regular changes in the environment, both natural and man induced, it's not surprising that Britain's birds have changed in variety and abundance considerably over the last 3,000 years.

By the late Iron Age, we'd already lost some our larger bird species from a combination of climate change, deforestation and disturbance. Dalmatian Pelicans (Pelecanus crispus) were driven to extinction by disturbance and hunting, whilst Cory's Shearwater (Calonectris dioedea) and Barnacle Goose (Branta leucopsis) were long lost breeders due to a change in the climate. The disappearance of the Eagle Owl (Bubo bubo) is a bit more of a mystery, but likely to be a result of deforestation.

The onset of agriculture benefited species such as Grey Partridge (Perdix perdix), Quail (Coturnix coturnix) and Corncrake (Crex Crex), and despite the fact they were heavily hunted, they prospered. The wetlands that were drained to make way for farmland during the 1600's perhaps had the most dynamic effect on bird diversity and abundance. The early parts of the 1600's saw the disappearance of two large species, the Common Crane (Grus grus) and the Eurasian Spoonbill (Platalea leucorodia). Both species need large areas of fens and wetlands and are highly intolerant of human disturbance at nest sites. The loss of wetlands also resulted in a dramatic decline of other species. With most this downward spiral continued until they too were extinct as regular breeding birds; Black Tailed godwits (Limosa limosa) ceased to breed in 1885, Ruff (Philomachus pugax) in 1871 and Black Tern (Chlidonias niger) in 1885. With good habitat management, some of these have been regained in the last 50 years, but Black Terns and Little Gulls (Larus minutus) are still sporadic and erratic breeders.

Great Bustard (Otis tarda) was another species lost. It was vulnerable because of its size and edibility, need of large open spaces, and intolerance of disturbance at nest sites. Surprisingly it managed to hold on to the 19th century before dying out. The Great Auk (Alca impennis) was a regular breeder on the northern isles of St. Kilda, Orkney and Shetland. Martin Martins first described it in 1698 and by the eighteenth century it was referred to as scarce. The last Great Auk in Britain was a male shot in Papa Westray in 1813, and the last of its kind in Iceland in 1844.

It's a little less obvious why the Kentish Plover (Charadrius alexandrinus) no longer breed in the United Kingdom. Before the 1920's they were still up to twenty pairs breeding regularly along the south coast, by 1940 there were only sporadic breeding attempts and it is now only a rare vagrant mainly to Sussex, Kent and Dorset. Probable reasons for this disappearance are a change in climate and more importantly, an increase in human disturbance on their breeding haunts of shingle beaches.
Mans main influence has been in his tendency to introduce foreign species, either for commercial, shooting or ornamental purposes, and it's easy to forget which species are native and those which are not. The first species to be introduced into the wild is thought to be the Mute Swan (Cygnus olor) before 1886. From the thirteenth to the eighteenth century they were the property of the crown, assigned to others by license and marked with distinguishing features but not confined. The Canada and Egyptian Geese were introduced around the same time, thought to be 1678. It's not clear whether they were introduced as a food source or for ornamental purposes, but introductions were successful and the species are still present today.

Pheasants and Partridges are a group of birds that have had a wide range of species introduced both for ornamental purposes and sport. The Common Pheasant (Phasianus colchicus) was brought over by the Norman's in the eleventh century and soon dispersed around the country, being introduced to parts of Wales, Scotland and Ireland in the late sixteenth century. By the early nineteenth century they had become the most important game bird. In 1673 Charles the second released a number of Red-legged Partridges (Alectoris rufa) at Windsor, brought over from France with the purpose of increasing the targets for guns. However, whilst the introduction was a success, the bird did not live up to its sporting expectations, as it has a tendency to run for long distances as opposed to taking flight! The Golden Pheasant (Chrysolophus pictus) introduced in the 1830's and the Lady Amherst Pheasant (Chrysolophus amherstiae) around 1930, were released purely for ornamental purposes. Both species have small but stable populations, their sedentary nature preventing any further spread. Other species introduced include Little Owl (Athene noctua) in 1870, Gadwall (Anas strepera) in 1850 and Ruddy Duck (Oxyura jamaicensis) in 1950.

It's not always the case that man either removes or introduces a species, many birds have naturally colonised the United Kingdom. The Fulmar (Fulmarus glacialis) had undergone a massive expansion, particularly in the last two hundred years, increasing from a few pairs on St. Kilda in 1878 to a current population estimate of around 300,000 pairs. The Collared Dove (Streptopelia decaocto) has a similar story. Nesting was first proven in Lincolnshire in 1952 and by the 1960's had colonised most of the British Isles, and has a present population of over 50,000 pairs. The Cetti's Warbler (Cettia cetti) and Firecrest (Regulus ignicapillus) have a matching history also. Before the 1950's they were nothing but rare vagrants to the south coast but by the end of the 1960's, both had established themselves as regular breeding birds in the southern counties. Perhaps two of the most recent colonisers have been the Little Egret (Egretta garzetta) and the Mediterranean Gull (Larus melanocephalus). They too had been just occasional visitors in spring and autumn to the south coast but in 1976 the first pair of Mediterranean Gulls were discovered breeding in Hampshire and by 1983 were breeding at six sites in southern England. The story of the Little Egret is even more recent, with the bird still classified as a vagrant at the start of the 1990's. By the end of the decade it was a familiar sight at most coastal marshes in the south, and it continues today to spread both north and inland, with breeding first taking place a couple of years ago in Dorset.

One thing a look at the history of our birds can tell us is that it is very difficult to predict what will happen in the future. Some species will naturally fluctuate, appear and disappear as breeding birds whilst others will permanently establish themselves within the British fauna. It's unlikely that anyone predicted having breeding pairs of Bee-Eater (Merops apiaster) and Icterine Warbler (Hippolais icterina) this year, but it is also hard to understand why the Wryneck (Jynx torquilla) and Red-Backed Shrike (Lanius collurio) have disappeared.

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