Red alert on birds facing extinction

THE bird conservation equivalent of a school term report has appeared in Britain.

Each species is given an honours, pass, or fail rating. “Green” listed birds are doing well; “amber” ones “could do better”; but those on the “red” list are in trouble.

Bad boys and girls risk expulsion from school, but birds who don’t measure up face extinction. The new birds-in-danger list makes for gloomy reading. Although six species, including the bullfinch and the quail, have pulled up their socks and moved from red to amber, 18 others have dropped from amber to red.

There are now 52 red-category birds, compared to 40 when the last assessment was made, in 2002. One species in five is in trouble.

A bird is relegated to the red category if its numbers fall below half what they were historically.

Common species, such as the starling and house sparrow, have been on the list for some time. Now, the herring gull has joined them. So, too, has the lapwing, the familiar “pee-wit” of winter wetlands and pasture.

Fieldfares and redwings, thrushes which visit Britain and Ireland in winter, have been demoted, as has our commonest wader, the dunlin.

The casualty that has attracted most attention, however, is the cuckoo. Its case is especially interesting.

It’s one of a several African migrants whose fortunes have declined sharply in recent years, leading to speculation that some common factor is at play.

The group includes the nightingale, that great songster, and the turtle dove of Biblical fame. Although nightingales and turtle doves occasionally turn up in Ireland, they don’t really belong here. Another African visitor in the group, the spotted-flycatcher, is an Irish bird. It used to be fairly common, but not any more.

So, are all of these migrants in trouble for the same reason? Global warming and the ever-expanding human population, which is changing the face of Africa, are bound to impact on bird populations.

We know relatively little about the ecology of birds there, nor are we sure where some of them spend the winter.

The deserts in the north of the continent are increasing in size. Perhaps migrants have difficulty crossing them. The massive collapse in the whitethroat population, in 1969, was due to prolonged drought in the Sahel region, which decimated bird populations.

But Africans are not to blame for global warming.

They, and their birds, are victims of the wasteful ways and insatiable greed of people in the developed world, ourselves included. Ireland ranks fourth in the world for CO2 emissions per capita. Nor is our house in order in other respects. Habitat destruction and pesticide use are rife here.

Wildflowers and so-called “weeds” are being destroyed with chemicals, turning our fields into green deserts where there are few creepy-crawlies that birds can feed to their young.

While environmental vandalism, and the effects of global warming in Africa, are affecting bird populations, other, more mysterious, forces seem also to be at play.

There are still locations in Britain and Ireland that have not been poisoned with chemicals and habitats have remained fairly intact, yet bird numbers in those areas are down.

Within 3km of where I live, for example, there are two large sand-dune systems which are still reasonably intact. Cuckoos used to visit them every summer, but there is no prospect, whatever, of hearing the two-note call any more.

A shortage of “host” species, it has been suggested, may be responsible for the cuckoo’s decline. Meadow pipits and dunnocks are the species in whose nests cuckoos tend to lay their eggs. Although their numbers may have declined, there are still plenty of meadow pipits around.

Dunnocks are common and there are several other species that cuckoos might use as foster parents. A decline in the number of cuckoos is to be expected, but not their total absence from large areas of the country. It’s estimated that the cuckoo population is now only 40% of what it was 50 years ago. Cuckoos are still common elsewhere in Europe. Pilgrims hear them calling as they trudge along the camino to Santiago de Compostela, at the northwestern tip of Spain. Why should cuckoos survive there and not here?

Like that of the corncrake, the decline of the cuckoo is not entirely explained.