May 28, 2009

Cuckoo Joins Growing List Of Threatened UK Bird Species

The "red list" of the UK's most threatened bird species has another entry: the cuckoo, BBC News reported.

The cuckoo, known for its springtime song, has joined a long list of area birds such as the lapwing, yellow wagtail and herring gull, all of which have been deemed to be urgently in need of conservation action.

Since 2002, the number of red-listed birds in the UK has risen by 5 percent to more than one in five.

In the latest assessment of the UK's bird population, the RSPB said the growing number of charismatic, widespread and familiar birds now on the list was "scandalous".

The "most shocking" decline was that of summer-visiting birds, like the cuckoo, which has seen numbers fall by 37 percent in the last 15 years, according to RSPB conservation director Mark Avery.

However, experts are not yet certain why migrant birds are in decline in the UK, but the number of red-listed species has risen to 52 (21 percent) out of 246 birds assessed, which is up from 40 species (16 percent) when the last assessment was done in 2002.

Among the growing number of red-listed bird species, some 21 are summer visitors that spend the winter in sub-Saharan Africa.

However, the bullfinch, quail, reed bunting, Scottish crossbill, stone curlew and woodlark were all downgraded from the red list to "amber" during the last assessment results, to be published in the June edition of British Birds.

"A gap all of us will notice is the lack of the cuckoo's familiar song. Their decline is emblematic of downward trends in many long-distance migrants from Africa," said Andy Clements, director of the British Trust for Ornithology (BTO).

The RSPB's Grahame Madge said that although the cause of the cuckoo's decline is not known, a number of theories have been discussed.

He said researchers will look into whether there are problems with habitat, either in the UK or in Africa, or on their migration route.

Diminishing food supply could be having an impact, as the cuckoo relies heavily on hairy moth caterpillars for food and many species of butterfly and moth are also suffering declines.

There could also be issues with the cuckoo's key hosts, considering the meadow pipit and dunnock are also in decline and cuckoos lay their eggs in other bird's nests.

The rising European temperatures could also be an issue, as migratory birds are losing their ecological advantage over birds which over-winter in Europe.

A shift in range brought on by a changing climate might have resulted in the inclusion of five species to the red list - Temminck's stint, ruff, whimbrel, redwing and fieldfare - which are at the southern edge of their spread in the British Isles.

Additionally, the dunlin and the scaup, two winter visitors, have been added to the red list for the very first time because of declines in their wintering populations.

Their inclusion highlighted an "increasingly widespread phenomenon of climate change-driven shifts in distribution," according to Rich Hearn, the Wildfowl and Wetlands Trust's head of species monitoring.

Others joining the red list include three seabirds: the Balearic shearwater, which is at a higher risk of global extinction than the giant panda; the Arctic skua, the only bird to go straight from the low-concern "green list" straight to red; and the herring gull.


On the Net: