History of Britains Birds
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.
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
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
(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.
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.
Portugal, 22, is a recent marine biology graduate from Aberystwyth.
He lives in Dorset and has been birdwatching around the country
from a very young age. He is currently working with the RSPB
and begins a PhD in Glasgow at the end of the year.