Another Life: A long wait for the badgers’ chocolate bars

A friend with an outlier badger sett just the other side of the hedge was reminded of his intermittent neighbours on a brilliant morning last week when two football-sized bundles of dry grass appeared on his garden path. The spring-cleaning of the sett and the gathering of fresh bedding has been a reassurance that all is well next door, welcomed even in the year when the animals wrenched a sheaf from his best daffodils, just nicely in flower.

Since each neat, strawy bundle is about as much as a badger’s short arms could embrace, it’s a puzzle to find two so readily abandoned, seemingly for good. But much of the badger world is still mysterious, despite the immense amounts of research devoted to them.

It’s getting on for half a century since the first one, dead of bovine TB, was found in Gloucestershire, an English hot-spot of the cattle disease. Then this paper’s environment correspondent, I predicted a grim future for the animal in Ireland, despite nominal protection under the Wildlife Act.

According to research by the Irish Wildlife Trust (IWT), the Government's culling programme in areas of TB outbreak has so far killed about 100,000 badgers. Scientific estimates of their total national population have fallen successively: 148,000 in 1995, 84,000 in 2009, to 60,000 in 2012 – a trend that could suggest extinction by 2020. The IWT complained of this decline to the Council of Europe and, in 2012, the Government responded, in a lengthy dossier of evidence (T-PVS/Files (2012) 33).

Some of the great span of the figures, it suggested, had come from different bases of calculation, including assumptions of average badger numbers in a social group. The report accepted estimates of up to 120,000 badgers in the Republic before 2000, down to about 70,000 badgers in 2012.

But, it said, the annual amount of new land “being brought under treatment” is now falling, and: “As the badger vaccination programme is gradually rolled out, the level of culling will be further reduced.”

The mammal “red list” for Ireland, published by the National Parks and Wildlife Service in 2009, suggested that, despite the culling, badger baiting and sett interference, the badger population was not threatened and of “least concern” to the International Union for Conservation of Nature (IUCN).

However, charting the progress of the vaccination programme can be like tracing the tunnels in a big badger sett. Given the years it can take between a laboratory “breakthrough” in human disease intervention and bringing a new pill into use, it is, perhaps, not surprising that administering an effective dose to a large, wild, free-roaming animal has presented many time-consuming problems. After nearly 20 years, it seems we may be getting there.

The 15-year work programme launched by the Department of Agriculture in 1998 had first to adapt and develop the BCG vaccine that controls the disease in humans.

Tests on the best ways to administer it were trialled on captive badgers, but the wild environment has different conditions. Vaccination of wild badgers on a wide enough scale has also to reckon with the cost.

European success in halting the spread of rabies in foxes by scattering the countryside with medicated baits seemed to offer a ready line of research. But what is the flavour most appealing to Meles meles? Aniseed, apple, curry, fish, garlic, peanut and strawberry were all tested in the field. Carob and cocoa powder were the most eagerly gobbled up, as chocolate-covered peanut bars. But how do you stop a group's dominant badger from scoffing the lot?

While such logistics are under study, a key three-year field trial has been completed in 755sq km of Co Kilkenny. Some 300 badgers were living there, around one third of them, probably, with TB as judged from previous culling.

In an elaborate double-blind trial, some badgers received an oral vaccine, others a placebo, with sweeps of recapture to test individual immune responses. At the end of the trial, all were “depopulated” and the badgers lined up for post mortems. Analysis is as yet unreported.

In Northern Ireland in 2012 the Minister for Agriculture Michelle O’Neill asked her officials to design and cost a new approach, namely catching and testing live badgers, culling those with TB and hand-vaccinating the others for release. This has been welcomed by the Irish Wildlife Trust, especially for apparent approval by both farmers and conservationists.

Meanwhile, the exact means by which cattle and badgers are exchanging TB remains an intransigent mystery. A long-term study by TCD zoologists, led by Dr Nicola Marples, has used satellite tracking collars to follow the movements of 40 badgers in Co Wicklow.

It has found that, while the animals make long journeys at night, they clearly avoid fields where cattle were present, as well as most kinds of farmyard. Knowing just where to offer badgers free chocolates will not be easy.